_:b291653168 "9"^^ . _:b291653169 "9"^^ . _:b291653182 "7"^^ . _:b291653183 "7"^^ . . . _:b291653180 "7"^^ . _:b291653667 . _:b780347 . _:b291653181 "7"^^ . . _:b291653413 . _:b291653178 "8"^^ . _:b291653590 . _:b291653206 . _:b291653501 . _:b291653479 . _:b291653179 "7"^^ . _:b780354 "the cytoplasmic domain of E-cadherin (cyt-E-cadherin), which has been reported to sequester signaling-competent \u03B2-catenin, thus abrogating the \u03B2-catenin\u2013TCF4 transcriptional activity (Gottardi et al., 2001; Simcha et al., >>2001<<). As expected, overexpression of a GFP\u2013cyt-E-cadherin construct in LS174T cells resulted in a strong decrease of nuclear \u03B2-catenin staining, which then colocalized with the GFP\u2013cyt-E-cadherin fusion in a perinuclear pattern (Fig." . . _:b291653176 "8"^^ . . _:b291653177 "8"^^ . _:b291653190 "6"^^ . _:b780340 . _:b291653332 . . _:b291653191 "6"^^ . . . _:b291653252 . _:b291653188 "6"^^ . _:b291653189 "6"^^ . . . _:b291653360 . _:b291653186 "6"^^ . _:b291653187 "6"^^ . . _:b291653546 . _:b291653184 "7"^^ . _:b291653219 . _:b291653185 "7"^^ . _:b291653197 "5"^^ . _:b291653196 "5"^^ . _:b291653521 . . _:b291653199 "5"^^ . _:b291653522 . _:b291653604 . _:b291653198 "5"^^ . _:b291653194 "6"^^ . _:b291653442 . . _:b291653195 "6"^^ . _:b291653214 . _:b291653533 . _:b291653679 . _:b291653192 "6"^^ . . _:b291653193 "6"^^ . . _:b291653612 . _:b291653596 . _:b291653597 . _:b291653598 . _:b291653205 "5"^^ . _:b291653599 . _:b291653592 . . _:b291653593 . _:b291653594 . _:b291653204 "5"^^ . _:b291653595 . _:b291653588 . _:b291653685 . _:b291653589 . . _:b291653590 . _:b291653207 "5"^^ . . _:b291653591 . . _:b291653584 . _:b291653585 . _:b291653586 . _:b291653206 "5"^^ . _:b291653587 . _:b291653580 . _:b291653581 . _:b291653582 . _:b291653186 . . _:b291653583 . _:b291653201 "5"^^ . _:b291653597 . _:b291653576 . _:b291653459 . _:b291653577 . _:b291653578 . _:b291653200 "5"^^ . _:b291653579 . . _:b291653572 . _:b291653382 . _:b291653573 . _:b291653574 . _:b291653203 "5"^^ . _:b291653575 . _:b291653568 . _:b291653569 . _:b291653570 . _:b291653707 . _:b291653202 "5"^^ . _:b291653571 . . _:b291653628 . _:b291653629 . _:b291653630 . _:b291653213 "5"^^ . _:b291653631 . _:b291653624 . _:b291653625 . _:b291653626 . _:b780318 "SOX9 function is best known for its essential roles in chondrogenesis (Foster et al., 1994; Wagner et al., >>1994<<; Wright et al., 1995; Bi et al., 1999, 2001) and the development of the male gonad (Foster et al., 1994; Wagner et al., 1994; Kent et al., 1996; S\u00FCdbeck et al., 1996)." . _:b291653212 "5"^^ . . _:b291653627 . _:b291653620 . _:b291653621 . _:b291653622 . _:b780396 "cells (Silberg et al., 2000; Rings et al., 2001) and to promote cell differentiation by activating transcription of genes encoding typical differentiation markers, including MUC2, sucrase-isomaltase, and lactase (Lorentz et al., >>1997<<; Yamamoto et al., 2003)." . _:b291653215 "5"^^ . _:b291653623 . _:b291653616 . _:b291653617 . _:b291653618 . _:b291653214 "5"^^ . _:b780386 . _:b291653619 . _:b291653612 . _:b291653515 . _:b291653613 . _:b291653614 . _:b291653209 "5"^^ . _:b291653615 . _:b291653608 . _:b291653609 . _:b291653610 . _:b291653208 "5"^^ . _:b291653611 . _:b291653604 . _:b291653605 . _:b291653606 . _:b291653211 "5"^^ . _:b291653607 . _:b291653576 . _:b291653600 . _:b291653601 . _:b291653602 . . _:b291653603 . _:b291653210 "5"^^ . _:b291653532 . _:b291653533 . _:b291653221 "4"^^ . _:b291653534 . _:b291653535 . _:b291653180 . _:b780371 "SOX9 was first described as the gene responsible, when heterozygously mutated, for the skeletal malformation syndrome, CD, which is sometimes associated with XY sex reversal (Foster et al., >>1994<<; Wagner et al., 1994). Of note, no intestinal epithelium defect has been reported to date in CD patients, indicating that SOX9 haploinsufficiency may not be critical in this tissue." . _:b291653528 . _:b291653529 . _:b291653220 "4"^^ . _:b291653530 . _:b291653531 . . _:b291653524 . _:b291653525 . _:b291653223 "4"^^ . _:b291653526 . _:b291653527 . _:b291653520 . _:b291653521 . _:b291653522 . _:b291653222 "4"^^ . _:b291653523 . _:b291653516 . . _:b291653517 . _:b291653518 . _:b291653217 "4"^^ . _:b291653519 . _:b291653512 . _:b291653513 . . _:b291653514 . _:b291653515 . _:b291653216 "5"^^ . _:b291653508 . . _:b291653509 . _:b291653510 . _:b291653219 "4"^^ . _:b291653511 . . _:b291653504 . _:b291653505 . _:b291653506 . _:b291653218 "4"^^ . _:b291653507 . _:b291653564 . _:b291653565 . _:b780332 . _:b291653566 . _:b291653229 "4"^^ . _:b291653567 . _:b291653560 . _:b291653561 . _:b291653562 . _:b291653228 "4"^^ . _:b291653563 . . _:b291653556 . _:b780387 . _:b291653557 . _:b291653558 . _:b291653231 "4"^^ . _:b291653559 . _:b291653552 . _:b291653553 . _:b291653554 . _:b291653230 "4"^^ . _:b291653555 . _:b780324 . _:b291653548 . _:b291653549 . _:b291653550 . _:b291653225 "4"^^ . _:b291653551 . _:b291653544 . _:b291653545 . _:b291653546 . _:b780367 "We conclude that SOX9 is involved in the regulation of CDX2 but not CDX1, which is consistent with previous reports showing that CDX1 is a direct transcriptional target of the \u03B2-catenin\u2013TCF4 complex (Lickert et al., >>2000<<). c-Myc has also been described as a direct \u03B2-catenin\u2013TCF4 target (He et al., 1998), but its expression level is not altered neither by SOX9 gain/loss of function (Fig. 5). Several SOX9-dependent genes are down-regulated in cells" . _:b291653224 "4"^^ . _:b291653547 . _:b291653540 . _:b291653541 . _:b291653542 . _:b291653227 "4"^^ . _:b291653543 . _:b291653536 . . _:b291653537 . _:b291653538 . _:b291653226 "4"^^ . _:b291653539 . _:b291653468 . _:b291653469 . _:b291653355 . _:b291653470 . _:b291653237 "4"^^ . _:b291653471 . _:b291653464 . _:b291653465 . _:b291653466 . _:b291653236 "4"^^ . . _:b291653467 . _:b780414 . . _:b291653460 . _:b291653461 . _:b291653462 . _:b291653239 "4"^^ . _:b291653463 . _:b291653456 . _:b291653662 . _:b291653457 . _:b780329 . _:b291653458 . _:b291653238 "4"^^ . _:b291653459 . _:b291653452 . _:b291653453 . _:b291653454 . _:b291653233 "4"^^ . _:b291653455 . _:b291653448 . _:b291653449 . _:b291653450 . _:b291653232 "4"^^ . _:b291653451 . _:b291653444 . _:b291653445 . _:b291653446 . _:b291653235 "4"^^ . _:b291653447 . _:b291653440 . _:b291653441 . _:b291653442 . _:b291653234 "4"^^ . . _:b291653443 . . _:b291653500 . _:b291653501 . _:b291653614 . _:b291653502 . _:b291653245 "4"^^ . _:b291653503 . _:b291653496 . _:b291653497 . _:b291653498 . _:b291653244 "4"^^ . _:b291653499 . _:b291653227 . _:b291653492 . _:b291653493 . _:b291653494 . _:b780328 "Strikingly, SOX9 controls the transcription of target genes which are specific for each process: in chondrogenesis, it regulates the cartilage specific genes Col2a1 (Bell et al., >>1997<<; Lefebvre et al., 1997; Bi et al., 1999), Col11a2 (Bridgewater et al., 1998), Aggrecan (Sekiya et al., 2000), and campomelic dysplasia (CD)\u2013RAP (Xie et al., 1999)." . _:b291653247 "4"^^ . . _:b291653495 . _:b291653488 . _:b291653389 . _:b291653489 . . _:b291653490 . _:b291653246 "4"^^ . . . _:b291653491 . _:b780391 . _:b291653484 . . _:b291653485 . _:b291653486 . _:b780308 . _:b291653241 "4"^^ . _:b291653608 . _:b291653487 . _:b291653594 . _:b291653480 . _:b291653481 . _:b291653482 . _:b291653240 "4"^^ . _:b291653483 . _:b291653476 . _:b291653477 . _:b291653322 . _:b291653478 . _:b291653243 "4"^^ . _:b291653479 . _:b291653472 . . _:b291653473 . _:b291653223 . _:b291653474 . _:b291653242 "4"^^ . _:b291653475 . _:b291653404 . _:b291653405 . _:b291653406 . _:b291653253 "4"^^ . _:b291653407 . _:b291653400 . _:b291653401 . _:b291653198 . _:b291653402 . _:b291653252 "4"^^ . _:b291653403 . . _:b291653396 . _:b291653397 . . _:b291653398 . _:b291653255 "4"^^ . _:b291653399 . _:b291653392 . _:b291653393 . _:b291653394 . _:b291653254 "4"^^ . _:b291653476 . _:b291653395 . _:b291653388 . _:b291653389 . _:b780325 "roles in chondrogenesis (Foster et al., 1994; Wagner et al., 1994; Wright et al., 1995; Bi et al., 1999, 2001) and the development of the male gonad (Foster et al., 1994; Wagner et al., 1994; Kent et al., 1996; S\u00FCdbeck et al., >>1996<<). SOX9 is also involved in the development of the neural crest (Spokony et al., 2002) and of the spinal cord glial cells (Stolt et al., 2003)." . _:b291653390 . _:b291653249 "4"^^ . . _:b291653391 . _:b291653384 . _:b291653385 . _:b291653386 . _:b291653248 "4"^^ . _:b291653387 . _:b291653380 . _:b291653381 . _:b291653382 . _:b291653251 "4"^^ . _:b291653383 . _:b291653628 . _:b291653376 . . _:b291653377 . _:b291653378 . _:b291653250 "4"^^ . . _:b291653379 . _:b291653436 . . _:b291653437 . _:b291653261 "3"^^ . _:b291653438 . _:b291653439 . _:b291653432 . _:b291653433 . _:b291653260 "3"^^ . _:b291653434 . _:b291653435 . _:b291653428 . _:b291653429 . _:b780337 "NH2-terminally flagged wild-type and COOH-terminally truncated SOX9-pcDNA expression constructs have been described previously (S\u00FCdbeck et al., >>1996<<; de Santa Barbara et al., 1998). The antisense SOX9 expression construct was generated by cloning the BamHI\u2013EcoRI fragment containing the SOX9 ORF from SOX9-pcDNA into the same restriction sites of pIRESneo (CLONTECH Laboratories, Inc." . _:b291653263 "3"^^ . . _:b291653430 . _:b291653431 . _:b291653424 . _:b291653425 . _:b291653262 "3"^^ . _:b291653426 . _:b291653427 . _:b291653420 . _:b291653421 . _:b291653470 . _:b291653422 . _:b291653257 "4"^^ . _:b291653423 . _:b291653436 . _:b291653416 . _:b291653417 . _:b291653418 . _:b291653256 "4"^^ . _:b291653419 . _:b291653348 . _:b291653412 . _:b291653413 . . _:b291653259 "4"^^ . _:b291653414 . _:b291653415 . _:b291653408 . _:b291653408 . _:b291653409 . _:b291653410 . _:b291653258 "4"^^ . _:b291653411 . _:b291653340 . . _:b291653341 . _:b291653269 "3"^^ . _:b291653342 . _:b291653343 . _:b291653336 . _:b291653337 . _:b291653268 "3"^^ . _:b291653426 . _:b291653338 . . _:b291653339 . _:b291653332 . _:b291653333 . _:b291653271 "3"^^ . _:b291653334 . _:b291653335 . . _:b291653328 . _:b291653329 . _:b291653270 "3"^^ . _:b291653256 . _:b291653330 . _:b291653331 . _:b291653324 . _:b291653325 . _:b291653265 "3"^^ . _:b291653540 . _:b291653326 . _:b291653327 . _:b291653339 . _:b291653320 . . _:b291653321 . _:b291653693 . _:b291653264 "3"^^ . _:b291653322 . _:b291653323 . _:b291653316 . _:b291653317 . _:b291653267 "3"^^ . _:b291653318 . _:b291653319 . _:b291653582 . _:b291653312 . _:b291653313 . _:b291653266 "3"^^ . . _:b291653314 . _:b291653315 . _:b291653372 . _:b291653373 . _:b291653277 "3"^^ . _:b291653374 . _:b291653233 . _:b291653375 . _:b291653504 . _:b291653368 . _:b291653369 . _:b291653276 "3"^^ . _:b291653343 . _:b291653370 . _:b780362 "In the intestinal epithelium, the CDX1 transcription factor is mostly expressed in the crypts whereas CDX2 is mostly active on the villi (Subramanian et al., 1998; Silberg et al., >>2000<<). Both genes are thought to be important for the antero-posterior patterning of the intestinal epithelium and in defining patterns of proliferation and differentiation along the crypt-villus axis (Silberg et al., 2000). CDX1/-2 are," . _:b291653371 . _:b780401 "To date, SOX9 has generally been described as a transcriptional activator (S\u00FCdbeck et al., 1996; Bell et al., 1997; Lefebvre et al., 1997; Ng et al., >>1997<<; de Santa Barbara et al., 1998; Liu et al., 2000; Sekiya et al., 2000; Liu et al., 2001; Panda et al., 2001), although it was recently found to mediate a dual transcriptional effect on the COL2A1 gene, depending on the promoter elements" . _:b291653364 . _:b291653365 . _:b780400 . _:b291653279 "3"^^ . _:b291653366 . _:b291653367 . _:b291653360 . _:b291653361 . _:b291653278 "3"^^ . _:b291653362 . _:b291653363 . _:b291653333 . _:b291653356 . _:b291653357 . _:b291653273 "3"^^ . _:b291653358 . _:b291653359 . _:b291653352 . _:b291653353 . _:b291653272 "3"^^ . _:b291653354 . _:b291653355 . _:b291653348 . _:b291653349 . _:b291653275 "3"^^ . _:b291653350 . _:b291653351 . . _:b291653437 . _:b291653344 . _:b291653345 . _:b291653274 "3"^^ . _:b291653346 . . _:b291653347 . _:b291653276 . _:b291653277 . _:b291653285 "3"^^ . _:b291653278 . _:b291653279 . _:b291653272 . . . _:b291653273 . _:b291653284 "3"^^ . _:b291653274 . _:b291653275 . _:b291653268 . _:b291653269 . _:b291653287 "3"^^ . _:b291653270 . _:b291653371 . _:b291653271 . _:b291653264 . _:b780378 "to a location, the bottom of the crypt, which is also considered to be the cellular \u201Cniche\u201D of the epithelium, where cells contain nuclear \u03B2-catenin in response to Wnt signaling (Batlle et al., 2002; van de Wetering et al., >>2002<<)." . _:b291653265 . _:b291653286 "3"^^ . _:b291653266 . _:b291653267 . _:b291653260 . _:b291653345 . _:b291653261 . _:b291653281 "3"^^ . _:b291653262 . _:b291653263 . _:b291653256 . _:b291653373 . _:b291653257 . _:b780353 "proteins, we overexpressed the cytoplasmic domain of E-cadherin (cyt-E-cadherin), which has been reported to sequester signaling-competent \u03B2-catenin, thus abrogating the \u03B2-catenin\u2013TCF4 transcriptional activity (Gottardi et al., >>2001<<; Simcha et al., 2001)." . _:b291653280 "3"^^ . _:b291653347 . _:b291653258 . _:b291653259 . _:b291653252 . _:b291653253 . _:b291653283 "3"^^ . _:b291653254 . _:b291653255 . _:b291653248 . _:b780320 . _:b291653588 . _:b291653249 . _:b291653282 "3"^^ . _:b291653250 . _:b291653251 . _:b291653308 . _:b291653309 . _:b291653293 "3"^^ . _:b291653310 . _:b291653311 . _:b291653304 . _:b291653305 . _:b291653292 "3"^^ . _:b291653306 . _:b291653307 . . _:b291653300 . _:b291653301 . _:b291653295 "3"^^ . _:b291653302 . _:b291653668 . _:b291653303 . _:b291653296 . _:b291653297 . _:b291653294 "3"^^ . _:b291653298 . . _:b291653299 . . _:b291653292 . _:b291653293 . _:b291653289 "3"^^ . _:b291653247 . _:b291653294 . _:b291653295 . _:b780374 . _:b291653288 . . _:b291653289 . _:b291653288 "3"^^ . . _:b291653290 . _:b291653291 . _:b291653284 . _:b291653285 . _:b291653291 "3"^^ . . _:b291653286 . _:b291653303 . _:b291653287 . _:b291653280 . _:b291653281 . _:b291653290 "3"^^ . _:b291653282 . . _:b291653283 . _:b291653212 . _:b291653213 . _:b291653301 "3"^^ . _:b291653214 . _:b291653215 . _:b291653208 . _:b780330 . _:b291653447 . _:b291653209 . _:b291653300 "3"^^ . _:b291653210 . _:b291653211 . _:b291653204 . _:b291653205 . _:b291653303 "3"^^ . _:b291653206 . _:b291653207 . _:b291653200 . _:b780409 . _:b291653201 . _:b291653302 "3"^^ . _:b291653202 . _:b291653203 . _:b780335 . _:b291653176 . _:b291653196 . _:b291653335 . _:b291653197 . _:b291653297 "3"^^ . . _:b291653198 . _:b291653199 . _:b291653192 . _:b291653481 . _:b291653193 . _:b291653296 "3"^^ . _:b291653194 . _:b291653246 . . . _:b291653195 . _:b291653188 . _:b291653189 . _:b291653299 "3"^^ . _:b291653349 . _:b291653190 . _:b291653191 . _:b291653184 . _:b291653185 . _:b291653298 "3"^^ . _:b291653186 . _:b291653493 . _:b291653187 . . _:b291653244 . . _:b291653309 "3"^^ . _:b291653245 . _:b291653246 . . . . _:b291653247 . _:b291653240 . _:b291653241 . _:b291653308 "3"^^ . _:b291653242 . _:b291653243 . _:b291653236 . _:b291653237 . _:b291653311 "3"^^ . _:b291653358 . _:b291653238 . _:b291653239 . _:b291653232 . _:b291653233 . _:b291653310 "3"^^ . _:b291653234 . _:b291653235 . . . _:b291653228 . . _:b291653229 . _:b291653305 "3"^^ . _:b291653648 . _:b291653230 . . _:b291653231 . _:b780326 . _:b291653224 . _:b291653225 . _:b291653304 "3"^^ . _:b291653226 . _:b291653227 . . . _:b291653220 . _:b291653221 . _:b291653307 "3"^^ . _:b291653222 . _:b291653223 . . _:b291653216 . _:b291653217 . _:b291653306 "3"^^ . _:b291653218 . _:b291653537 . _:b291653219 . _:b291653317 "3"^^ . _:b780404 . _:b291653316 "3"^^ . . _:b291653319 "3"^^ . . _:b291653318 "3"^^ . . _:b291653313 "3"^^ . _:b291653312 "3"^^ . . _:b291653315 "3"^^ . _:b291653482 . _:b291653314 "3"^^ . _:b291653180 . _:b780358 . _:b291653181 . _:b291653325 "3"^^ . _:b291653182 . _:b291653183 . _:b291653699 . _:b291653176 . . _:b291653177 . _:b291653324 "3"^^ . _:b291653178 . _:b291653220 . _:b291653179 . _:b291653172 . _:b780352 . _:b291653401 . _:b291653173 . _:b291653327 "3"^^ . _:b291653174 . _:b291653558 . _:b291653175 . _:b291653168 . _:b780356 . _:b291653169 . _:b291653326 "3"^^ . _:b291653170 . . _:b291653171 . _:b291653164 . _:b291653165 . _:b291653321 "3"^^ . . _:b291653166 . _:b291653167 . . _:b780355 . _:b291653160 . _:b291653393 . _:b291653320 "3"^^ . _:b291653248 . _:b291653639 . . _:b291653161 . _:b291653162 . _:b291653163 . _:b291653156 . _:b780398 "To date, SOX9 has generally been described as a transcriptional activator (S\u00FCdbeck et al., >>1996<<; Bell et al., 1997; Lefebvre et al., 1997; Ng et al., 1997; de Santa Barbara et al., 1998; Liu et al., 2000; Sekiya et al., 2000; Liu et al., 2001; Panda et al., 2001), although it was recently found to mediate a dual transcriptional" . _:b291653157 . _:b291653323 "3"^^ . _:b291653158 . _:b291653159 . _:b291653152 . _:b291653153 . _:b291653322 "3"^^ . _:b291653154 . _:b291653155 . _:b291653528 . _:b291653333 "3"^^ . _:b291653332 "3"^^ . _:b291653335 "3"^^ . _:b291653697 . _:b291653334 "3"^^ . _:b780377 . _:b780378 . _:b291653329 "3"^^ . _:b291653328 "3"^^ . _:b291653331 "3"^^ . _:b291653330 "3"^^ . _:b780407 "Liu et al., 2000; Sekiya et al., 2000; Liu et al., 2001; Panda et al., 2001), although it was recently found to mediate a dual transcriptional effect on the COL2A1 gene, depending on the promoter elements involved (Kypriotou et al., >>2003<<). Interestingly, recent studies in the central nervous system showed that SOX1, SOX2, and SOX3 act as repressors of postmitotic neuronal markers." . _:b291653341 "3"^^ . _:b291653519 . _:b291653340 "3"^^ . . . _:b291653343 "3"^^ . _:b780379 . _:b291653202 . _:b291653342 "3"^^ . _:b291653289 . _:b291653337 "3"^^ . _:b291653336 "3"^^ . . . _:b291653339 "3"^^ . . _:b291653338 "3"^^ . _:b291653383 . _:b291653349 "3"^^ . _:b291653348 "3"^^ . _:b291653253 . _:b291653272 . _:b291653351 "3"^^ . . . _:b291653456 . _:b291653350 "3"^^ . _:b291653356 . _:b291653345 "3"^^ . . _:b291653344 "3"^^ . _:b291653258 . . _:b291653724 . _:b291653347 "3"^^ . . _:b291653346 "3"^^ . _:b291653357 "2"^^ . _:b780357 "As a consequence, TCF4 null mice die perinatally (Korinek et al., >>1998<<). As the Wnt signaling pathway is essential for SOX9 expression in cultured cells, we expected that SOX9 expression would be disrupted in the intestinal epithelium of TCF4 null mice." . _:b291653356 "2"^^ . . _:b291653336 . _:b291653359 "2"^^ . . _:b291653560 . _:b291653491 . _:b291653358 "2"^^ . . _:b291653353 "2"^^ . . _:b291653451 . _:b291653297 . . _:b291653352 "2"^^ . _:b291653352 . _:b291653355 "2"^^ . . _:b291653354 "2"^^ . _:b780349 . . . _:b291653677 . _:b291653365 "2"^^ . _:b291653196 . . _:b291653364 "2"^^ . . _:b291653367 "2"^^ . _:b291653366 "2"^^ . _:b291653361 "2"^^ . . _:b291653360 "2"^^ . _:b291653615 . _:b780359 . _:b291653363 "2"^^ . _:b780305 . . _:b291653299 . _:b291653362 "2"^^ . . _:b291653649 . . _:b291653373 "2"^^ . . _:b291653203 . _:b291653372 "2"^^ . _:b780343 . _:b291653375 "2"^^ . _:b291653374 "2"^^ . _:b291653369 "2"^^ . . . _:b291653368 "2"^^ . _:b780339 . _:b291653209 . . _:b291653371 "2"^^ . _:b780300 "In the small intestine, a fourth cell type, the Paneth cells, migrates downward and settles at the bottom of the crypts as terminally differentiated cells (Potten and Moeffler, 1990; Stappenbeck et al., >>1998<<)." . _:b291653701 . _:b291653370 "2"^^ . . . _:b291653381 "2"^^ . _:b780302 . . _:b291653251 . . _:b291653460 . _:b291653192 . _:b291653475 . _:b291653380 "2"^^ . _:b291653463 . _:b291653383 "2"^^ . _:b291653673 . _:b291653709 . _:b291653382 "2"^^ . _:b291653377 "2"^^ . _:b291653376 "2"^^ . . . _:b780308 "Moreover, targeted mutations of APC or \u03B2-catenin are sufficient to initiate tumorigenesis in the mouse (Fodde et al., >>1994<<; Shibata et al., 1997; Harada et al., 1999), highlighting the importance of the Wnt pathway in the development of cancer." . _:b291653379 "2"^^ . _:b291653378 "2"^^ . . . . _:b291653389 "2"^^ . _:b291653388 "2"^^ . _:b291653264 . . _:b291653391 "2"^^ . _:b291653390 "2"^^ . _:b291653385 "2"^^ . _:b780407 . . _:b780348 . _:b291653234 . _:b780307 "Such mutations result in stabilization of \u03B2-catenin, which then continuously interacts with TCF4, leading to constitutive activation of target genes (Korinek et al., >>1997<<). Moreover, targeted mutations of APC or \u03B2-catenin are sufficient to initiate tumorigenesis in the mouse (Fodde et al., 1994; Shibata et al., 1997; Harada et al., 1999), highlighting the importance of the Wnt pathway in the development of" . _:b291653384 "2"^^ . _:b291653509 . . _:b291653387 "2"^^ . _:b291653516 . _:b291653386 "2"^^ . _:b291653346 . _:b780354 . _:b291653397 "2"^^ . _:b291653177 . _:b291653396 "2"^^ . _:b291653547 . _:b291653399 "2"^^ . _:b291653398 "2"^^ . . _:b291653393 "2"^^ . _:b291653266 . _:b291653551 . _:b291653392 "2"^^ . . . _:b291653395 "2"^^ . _:b291653394 "2"^^ . _:b291653526 . . _:b291653405 "2"^^ . _:b291653454 . _:b291653404 "2"^^ . _:b291653407 "2"^^ . . _:b780304 . _:b291653406 "2"^^ . _:b780387 "For instance, in chondrogenesis, Wnt-4 signals through the \u03B2-catenin\u2013TCF-LEF pathway to accelerate chondrogenesis (Hartmann and Tabin, 2000), a process in which SOX9 function is essential (Bi et al., >>1999<<; Akiyama et al., 2002)." . _:b291653401 "2"^^ . _:b291653400 "2"^^ . . _:b291653403 "2"^^ . _:b291653153 . _:b291653402 "2"^^ . _:b291653413 "2"^^ . . _:b291653412 "2"^^ . _:b291653415 "2"^^ . _:b291653398 . _:b291653414 "2"^^ . _:b291653712 . _:b291653714 . _:b291653409 "2"^^ . _:b291653408 "2"^^ . . . _:b291653411 "2"^^ . . _:b291653410 "2"^^ . _:b780314 "Similarly to TCFs, SOX proteins have been widely implicated in the establishment of cell multipotency (Avilion et al., 2003; Kim et al., 2003), cell commitment (Mori-Akiyama et al., 2003; Stolt et al., >>2003<<), and differentiation (Kamachi et al., 2000; Stolt et al., 2002)." . . _:b291653421 "2"^^ . . _:b291653420 "2"^^ . . _:b291653423 "2"^^ . _:b780393 "Wnt signals are also involved in the development of the neural crests (Yanfeng et al., 2003), where SOX9 has also recently been found to be required (Spokony et al., 2002; Cheung and Briscoe, 2003; Mori-Akiyama et al., >>2003<<). It will be interesting to determine whether Wnt signals are involved in the regulation of SOX9 in such structures." . . . _:b291653422 "2"^^ . _:b291653417 "2"^^ . _:b291653411 . _:b291653416 "2"^^ . _:b291653328 . _:b291653419 "2"^^ . _:b780360 . _:b291653418 "2"^^ . _:b291653429 "2"^^ . _:b291653708 . _:b291653428 "2"^^ . _:b780402 "To date, SOX9 has generally been described as a transcriptional activator (S\u00FCdbeck et al., 1996; Bell et al., 1997; Lefebvre et al., 1997; Ng et al., 1997; de Santa Barbara et al., >>1998<<; Liu et al., 2000; Sekiya et al., 2000; Liu et al., 2001; Panda et al., 2001), although it was recently found to mediate a dual transcriptional effect on the COL2A1 gene, depending on the promoter elements involved (Kypriotou et al.," . _:b291653431 "2"^^ . _:b291653430 "2"^^ . _:b291653274 . _:b291653425 "2"^^ . . _:b291653287 . _:b291653424 "2"^^ . _:b780327 "SOX9 is also involved in the development of the neural crest (Spokony et al., 2002) and of the spinal cord glial cells (Stolt et al., >>2003<<). Strikingly, SOX9 controls the transcription of target genes which are specific for each process: in chondrogenesis, it regulates the cartilage specific genes Col2a1 (Bell et al., 1997; Lefebvre et al., 1997; Bi et al., 1999), Col11a2" . _:b291653427 "2"^^ . . _:b291653426 "2"^^ . _:b291653637 . _:b291653437 "2"^^ . . _:b291653436 "2"^^ . . _:b291653439 "2"^^ . _:b291653574 . _:b291653438 "2"^^ . _:b291653433 "2"^^ . _:b291653432 "2"^^ . _:b291653435 "2"^^ . _:b291653400 . _:b291653434 "2"^^ . _:b291653445 "2"^^ . . _:b291653444 "2"^^ . _:b291653447 "2"^^ . . . . _:b291653446 "2"^^ . _:b291653441 "2"^^ . _:b291653440 "2"^^ . . _:b291653443 "2"^^ . _:b291653488 . _:b291653442 "2"^^ . . _:b291653453 "2"^^ . _:b291653319 . _:b291653452 "2"^^ . _:b291653394 . . _:b291653455 "2"^^ . _:b291653441 . _:b780410 "Furthermore, SOX10, closely related to SOX9, is involved in the maintenance of neural crest stem cells multipotency and inhibition of neural differentiation (Kim et al., >>2003<<), SOX2 maintains precursor cells of the mouse blastocyst in a multipotent state (Avilion et al., 2003), and SOX1\u20133 counteract the activity of proneural proteins to keep neural cells undifferentiated (Bylund et al., 2003)." . _:b291653454 "2"^^ . _:b291653595 . _:b291653449 "2"^^ . _:b291653448 "2"^^ . _:b780357 . _:b291653451 "2"^^ . _:b291653450 "2"^^ . _:b291653450 . _:b291653461 "2"^^ . _:b780416 . _:b291653460 "2"^^ . . _:b291653179 . . _:b291653463 "2"^^ . _:b291653599 . _:b291653530 . _:b291653462 "2"^^ . _:b291653457 "2"^^ . _:b291653414 . _:b780406 "been described as a transcriptional activator (S\u00FCdbeck et al., 1996; Bell et al., 1997; Lefebvre et al., 1997; Ng et al., 1997; de Santa Barbara et al., 1998; Liu et al., 2000; Sekiya et al., 2000; Liu et al., 2001; Panda et al., >>2001<<), although it was recently found to mediate a dual transcriptional effect on the COL2A1 gene, depending on the promoter elements involved (Kypriotou et al., 2003)." . _:b291653456 "2"^^ . . _:b291653459 "2"^^ . . _:b780342 . . _:b291653458 "2"^^ . _:b291653157 . _:b291653469 "2"^^ . _:b291653158 . _:b291653364 . _:b291653468 "2"^^ . _:b291653379 . _:b291653471 "2"^^ . _:b780370 "discussion" . _:b780379 "This fragment did not contain a canonical TCF binding sequence (ATCAAAGG), but contained several noncanonical TCF binding sites, such as described, for instance, in the Siamois (Brannon et al., >>1997<<) and Cyclin D1 (Tetsu and McCormick, 1999) promoters." . _:b291653470 "2"^^ . _:b780307 . _:b291653465 "2"^^ . . _:b780306 . _:b291653290 . _:b291653464 "2"^^ . . . . _:b291653531 . _:b291653467 "2"^^ . _:b291653466 "2"^^ . . . _:b291653477 "2"^^ . . _:b291653476 "2"^^ . _:b780347 "RT-PCR was performed with mouse neonate intestine, using degenerate oligonucleotide primers (Cremazy et al., >>1998<<). The amplified products were cloned and sequenced, leading to the identification of SOX3, SOX4, SOX5, SOX7, SOX9, and SOX18." . _:b291653479 "2"^^ . _:b291653237 . _:b291653478 "2"^^ . _:b780417 "Mice heterozygous for the CDX2 gene are hypersensitive to sporadic, chemically induced, colon carcinogenesis (Bonhomme et al., 2003), and this was confirmed in a mouse model of familial adenomatous polyposis (Aoki et al., >>2003<<). MUC2 deficiency also leads to spontaneous intestinal tumors (Velcich et al., 2002). Conversely, restoration of CDX2 expression in human colon carcinoma cells suppressed proliferation and soft agar growth (Hinoi et al., 2003). Here, we" . _:b291653606 . _:b291653647 . _:b291653438 . _:b291653473 "2"^^ . _:b291653286 . . . _:b291653472 "2"^^ . _:b291653330 . _:b780400 "To date, SOX9 has generally been described as a transcriptional activator (S\u00FCdbeck et al., 1996; Bell et al., 1997; Lefebvre et al., >>1997<<; Ng et al., 1997; de Santa Barbara et al., 1998; Liu et al., 2000; Sekiya et al., 2000; Liu et al., 2001; Panda et al., 2001), although it was recently found to mediate a dual transcriptional effect on the COL2A1 gene, depending on the" . _:b291653475 "2"^^ . . _:b291653474 "2"^^ . _:b291653485 "2"^^ . . _:b291653484 "2"^^ . _:b780389 "Moreover, in the developing mouse limb buds, the expression patterns of SOX9 and of the Wnt-antagonist Dickkopf are mutually exclusive (Grotewold and Ruther, >>2002<<). Wnt signals are also involved in the development of the neural crests (Yanfeng et al., 2003), where SOX9 has also recently been found to be required (Spokony et al., 2002; Cheung and Briscoe, 2003; Mori-Akiyama et al., 2003). It will be" . _:b291653487 "2"^^ . . _:b291653486 "2"^^ . _:b291653163 . . _:b780342 "The CDX-2 promoter reporter constructs were published previously (Lorentz et al., >>1999<<)." . _:b291653481 "2"^^ . _:b291653529 . _:b291653480 "2"^^ . _:b291653483 "2"^^ . _:b291653378 . _:b291653482 "2"^^ . . _:b291653493 "2"^^ . _:b291653257 . _:b291653291 . _:b291653492 "2"^^ . _:b291653495 "2"^^ . _:b291653500 . _:b291653494 "2"^^ . . _:b291653489 "2"^^ . . . _:b291653488 "2"^^ . _:b291653491 "2"^^ . _:b291653717 . . _:b291653490 "2"^^ . _:b780351 . . _:b291653501 "2"^^ . . _:b291653629 . . _:b780350 . _:b291653500 "2"^^ . _:b291653503 "2"^^ . _:b291653502 "2"^^ . _:b291653686 . _:b291653497 "2"^^ . . _:b291653496 "2"^^ . . _:b291653499 "2"^^ . . . _:b291653498 "2"^^ . _:b780346 "results" . _:b291653509 "2"^^ . _:b780319 . . _:b291653508 "2"^^ . _:b291653511 "2"^^ . _:b291653424 . _:b291653510 "2"^^ . . _:b780363 "Both genes are thought to be important for the antero-posterior patterning of the intestinal epithelium and in defining patterns of proliferation and differentiation along the crypt-villus axis (Silberg et al., >>2000<<). CDX1/-2 are, respectively, positively and negatively regulated by the Wnt pathway. Indeed, coculture experiments, as well as loss of CDX1 expression in the gut of TCF4-deficient mice, led to the conclusion that CDX1 is a target of the" . _:b291653505 "2"^^ . _:b291653674 . _:b291653504 "2"^^ . _:b291653507 "2"^^ . . . _:b291653492 . . _:b291653506 "2"^^ . . _:b291653218 . _:b291653534 . _:b291653309 . _:b291653517 "2"^^ . _:b291653516 "2"^^ . _:b291653354 . _:b291653593 . _:b291653519 "2"^^ . _:b291653518 "2"^^ . . _:b291653513 "2"^^ . . _:b291653698 . _:b291653512 "2"^^ . _:b291653620 . _:b291653515 "2"^^ . _:b291653623 . _:b291653577 . _:b291653598 . _:b291653514 "2"^^ . _:b291653525 "2"^^ . _:b291653524 "2"^^ . _:b291653527 "2"^^ . . _:b291653526 "2"^^ . _:b291653521 "2"^^ . _:b291653520 "2"^^ . _:b291653570 . . _:b291653680 . _:b291653523 "2"^^ . . _:b291653240 . _:b291653522 "2"^^ . _:b780303 . _:b291653533 "2"^^ . _:b291653532 "2"^^ . . . _:b291653418 . _:b291653535 "2"^^ . . . _:b291653534 "2"^^ . . . _:b291653529 "2"^^ . _:b291653528 "2"^^ . . _:b291653531 "2"^^ . _:b291653530 "2"^^ . . . . _:b291653541 "2"^^ . . _:b291653540 "2"^^ . _:b291653543 "2"^^ . _:b291653652 . . _:b780344 . _:b291653542 "2"^^ . _:b291653537 "2"^^ . _:b291653536 "2"^^ . _:b291653539 "2"^^ . . _:b780312 . . . _:b291653538 "2"^^ . . _:b291653318 . _:b291653549 "2"^^ . _:b291653381 . . _:b291653548 "2"^^ . . _:b291653380 . . _:b291653551 "2"^^ . _:b291653383 . _:b291653550 "2"^^ . _:b291653382 . _:b780358 "We then screened by RT-PCR a panel of previously reported Wnt\u2013\u03B2-catenin\u2013TCF4-regulated genes (van de Wetering et al., >>2002<<). This led to the identification of both SOX9-dependent and SOX9-independent Wnt target genes (Fig. 5), indicating branching of the Wnt response, which might explain how the Wnt pathway can exert a wide spectrum of cellular effects." . _:b291653545 "2"^^ . _:b291653377 . . _:b291653544 "2"^^ . _:b291653710 . _:b291653376 . _:b291653547 "2"^^ . _:b291653379 . _:b291653561 . _:b291653546 "2"^^ . _:b291653378 . . _:b291653557 "2"^^ . _:b291653389 . . _:b291653556 "2"^^ . _:b291653388 . _:b291653559 "2"^^ . _:b291653391 . . _:b291653399 . _:b291653306 . _:b291653558 "2"^^ . _:b291653390 . _:b291653713 . _:b291653553 "2"^^ . _:b291653363 . _:b291653385 . _:b291653552 "2"^^ . _:b291653384 . _:b291653555 "2"^^ . _:b291653387 . _:b291653554 "2"^^ . _:b291653386 . _:b291653565 "2"^^ . _:b291653397 . _:b291653564 "2"^^ . . _:b291653396 . _:b291653567 "2"^^ . _:b291653399 . . _:b291653566 "2"^^ . _:b780367 . _:b291653168 . _:b291653398 . _:b291653561 "2"^^ . . _:b291653393 . _:b291653691 . _:b291653560 "2"^^ . . _:b291653392 . _:b291653563 "2"^^ . _:b780364 . _:b291653395 . _:b291653562 "2"^^ . _:b291653394 . _:b291653573 "2"^^ . . _:b291653405 . _:b291653572 "2"^^ . _:b291653404 . _:b291653388 . _:b291653658 . _:b291653575 "2"^^ . . _:b780386 "For instance, in chondrogenesis, Wnt-4 signals through the \u03B2-catenin\u2013TCF-LEF pathway to accelerate chondrogenesis (Hartmann and Tabin, >>2000<<), a process in which SOX9 function is essential (Bi et al., 1999; Akiyama et al., 2002)." . _:b291653407 . . _:b291653578 . _:b291653574 "2"^^ . _:b291653591 . . _:b291653406 . _:b780344 "The TCF4 K.O. mouse has been described previously (Korinek et al., >>1998<<). For immunofluorescence experiments, nuclei were stained with Hoechst (H33258; Sigma-Aldrich)." . _:b291653569 "2"^^ . _:b291653401 . _:b291653689 . _:b291653568 "2"^^ . _:b291653400 . _:b291653571 "2"^^ . _:b291653296 . _:b291653217 . _:b291653403 . _:b291653384 . _:b291653570 "2"^^ . _:b291653402 . _:b780310 . _:b291653581 "2"^^ . _:b291653413 . _:b780334 "During male gonad development, it controls the expression of the anti-M\u00FCllerrian hormone gene (de Santa Barbara et al., >>1998<<). In the neural crest, the expression of the transcription factor Slug depends on SOX9 (Spokony et al., 2002), whereas SOX9 target genes remain to be identified in the spinal cord." . _:b291653580 "2"^^ . . _:b291653412 . _:b291653361 . _:b780373 . _:b291653583 "2"^^ . . _:b291653415 . _:b291653191 . . _:b291653582 "2"^^ . _:b291653414 . _:b291653577 "2"^^ . _:b780394 "For instance, SOX9 represses the expression of the CDX2 transcription factor, known to be mostly active in villus cells (Silberg et al., >>2000<<; Rings et al., 2001) and to promote cell differentiation by activating transcription of genes encoding typical differentiation markers, including MUC2, sucrase-isomaltase, and lactase (Lorentz et al., 1997; Yamamoto et al., 2003)." . . . _:b291653409 . . _:b291653576 "2"^^ . _:b291653408 . _:b291653579 "2"^^ . _:b291653411 . _:b291653578 "2"^^ . _:b291653410 . _:b291653589 "2"^^ . _:b291653421 . . _:b291653588 "2"^^ . _:b291653224 . . _:b291653420 . . _:b291653591 "2"^^ . _:b780384 . _:b291653423 . _:b291653590 "2"^^ . _:b291653422 . . _:b291653585 "2"^^ . _:b291653417 . _:b291653584 "2"^^ . _:b291653416 . _:b291653478 . . _:b291653587 "2"^^ . _:b291653419 . _:b291653385 . . _:b291653517 . _:b291653586 "2"^^ . . _:b291653418 . _:b291653597 "2"^^ . . _:b291653268 . _:b291653429 . _:b291653596 "2"^^ . _:b291653270 . _:b291653428 . _:b291653599 "2"^^ . . _:b291653431 . _:b291653583 . _:b291653598 "2"^^ . _:b291653430 . . _:b291653593 "2"^^ . _:b291653425 . _:b291653592 "2"^^ . . _:b291653424 . . _:b291653595 "2"^^ . _:b291653427 . _:b291653536 . _:b291653601 . _:b291653594 "2"^^ . _:b291653426 . _:b291653605 "2"^^ . _:b291653437 . _:b291653604 "2"^^ . _:b291653436 . _:b291653607 "2"^^ . _:b780353 . _:b291653439 . _:b291653556 . _:b291653183 . _:b291653606 "2"^^ . . _:b291653438 . _:b291653601 "2"^^ . _:b780388 "For instance, in chondrogenesis, Wnt-4 signals through the \u03B2-catenin\u2013TCF-LEF pathway to accelerate chondrogenesis (Hartmann and Tabin, 2000), a process in which SOX9 function is essential (Bi et al., 1999; Akiyama et al., >>2002<<). Moreover, in the developing mouse limb buds, the expression patterns of SOX9 and of the Wnt-antagonist Dickkopf are mutually exclusive (Grotewold and Ruther, 2002). Wnt signals are also involved in the development of the neural crests" . _:b780381 . _:b291653433 . . . _:b291653600 "2"^^ . _:b291653432 . . . _:b291653603 "2"^^ . _:b291653435 . _:b291653602 "2"^^ . _:b780365 . _:b291653434 . _:b291653613 "2"^^ . _:b291653445 . _:b291653612 "2"^^ . _:b291653444 . _:b291653615 "2"^^ . _:b291653447 . _:b291653281 . _:b291653614 "2"^^ . _:b291653446 . _:b291653587 . _:b291653609 "2"^^ . _:b291653441 . . _:b291653608 "2"^^ . _:b291653503 . _:b291653440 . _:b291653611 "2"^^ . _:b291653443 . _:b291653169 . _:b291653610 "2"^^ . . _:b291653442 . . _:b291653621 "2"^^ . _:b291653453 . _:b291653620 "2"^^ . . _:b291653452 . _:b291653623 "2"^^ . _:b291653455 . _:b780389 . _:b291653471 . _:b291653622 "2"^^ . . . _:b291653454 . _:b291653617 "2"^^ . _:b291653449 . _:b291653483 . _:b291653616 "2"^^ . _:b291653448 . _:b291653619 "2"^^ . _:b291653451 . _:b291653618 "2"^^ . _:b780372 "SOX9 was first described as the gene responsible, when heterozygously mutated, for the skeletal malformation syndrome, CD, which is sometimes associated with XY sex reversal (Foster et al., 1994; Wagner et al., >>1994<<). Of note, no intestinal epithelium defect has been reported to date in CD patients, indicating that SOX9 haploinsufficiency may not be critical in this tissue." . _:b291653262 . _:b291653450 . . _:b291653629 "2"^^ . _:b291653461 . _:b291653628 "2"^^ . _:b780413 . _:b291653460 . _:b291653631 "2"^^ . _:b291653508 . _:b291653700 . _:b291653463 . _:b291653630 "2"^^ . _:b291653301 . _:b291653462 . _:b291653625 "2"^^ . _:b291653457 . _:b291653624 "2"^^ . _:b291653456 . _:b291653627 "2"^^ . _:b291653459 . . . _:b291653626 "2"^^ . _:b291653458 . . _:b291653469 . _:b291653302 . . _:b291653468 . _:b291653471 . . _:b291653470 . . _:b291653465 . _:b291653464 . . _:b291653719 . _:b291653467 . . _:b291653625 . _:b291653532 . _:b291653466 . _:b291653477 . _:b780410 . . _:b291653476 . _:b291653479 . . _:b291653478 . . _:b291653448 . _:b291653473 . _:b780300 . . _:b291653472 . _:b291653159 . _:b291653368 . _:b291653294 . _:b291653475 . _:b291653474 . _:b291653602 . _:b291653160 . . _:b291653485 . . _:b291653484 . _:b780335 "In the neural crest, the expression of the transcription factor Slug depends on SOX9 (Spokony et al., >>2002<<), whereas SOX9 target genes remain to be identified in the spinal cord." . . . _:b291653487 . _:b291653213 . _:b291653486 . _:b780415 . . . . _:b291653481 . . . _:b291653480 . . _:b291653626 . . _:b291653483 . _:b291653637 . _:b291653482 . _:b291653636 . . _:b291653493 . _:b291653639 . _:b291653492 . _:b291653638 . _:b291653495 . _:b291653633 . _:b780419 . _:b291653675 . _:b780334 . . _:b291653396 . _:b291653494 . _:b291653632 . . _:b291653175 . _:b291653695 . . _:b291653489 . _:b291653635 . _:b780416 "Mice heterozygous for the CDX2 gene are hypersensitive to sporadic, chemically induced, colon carcinogenesis (Bonhomme et al., >>2003<<), and this was confirmed in a mouse model of familial adenomatous polyposis (Aoki et al., 2003)." . _:b780322 "SOX9 function is best known for its essential roles in chondrogenesis (Foster et al., 1994; Wagner et al., 1994; Wright et al., 1995; Bi et al., 1999, 2001) and the development of the male gonad (Foster et al., >>1994<<; Wagner et al., 1994; Kent et al., 1996; S\u00FCdbeck et al., 1996). SOX9 is also involved in the development of the neural crest (Spokony et al., 2002) and of the spinal cord glial cells (Stolt et al., 2003)." . _:b291653488 . . _:b291653634 . . . _:b291653544 . _:b291653491 . _:b291653645 . _:b291653300 . _:b291653490 . . _:b291653644 . . . _:b291653501 . _:b291653647 . _:b291653500 . _:b291653646 . _:b291653314 . _:b780341 "Kondoh (Institute for Molecular and Cellular Biology, Osaka University, Osaka, Japan), and the MUC-2-luciferase reporter (Yamamoto et al., >>2003<<) was a gift from Y." . _:b291653503 . _:b291653641 . . _:b291653245 . _:b291653502 . _:b291653640 . _:b291653715 . _:b291653676 . _:b780345 . _:b291653497 . _:b780381 "Indeed, although this promoter has been poorly characterized, scattered regulatory enhancer elements have been detected up to 1 megabase upstream of the human SOX9 transcriptional unit (Wunderle et al., >>1998<<; Bishop et al., 2000)." . _:b291653643 . _:b291653703 . _:b291653718 . . _:b780408 "In this case, SOX1\u20133 inhibit neurogenesis by activating transcription and, conversely, repression of their as yet unknown target genes facilitates neuronal differentiation (Bylund et al., >>2003<<). Here, we show that a forced activator version of SOX9 (SOX9-VP16) mimics the properties of wild-type SOX9, which suggests an analogous situation, where the intermediate activation of a repressor transcription factor mediates the" . _:b291653496 . _:b291653642 . _:b291653499 . _:b291653653 . _:b291653603 . _:b291653498 . _:b291653572 . _:b291653652 . . _:b291653509 . . _:b291653655 . _:b780359 "CDX1/-2 genes, both homologues of the Drosophila homeobox Caudal gene (Duprey et al., >>1988<<; Suh et al., 1994), exemplified such branching." . _:b291653508 . _:b291653702 . _:b291653541 . _:b291653654 . . _:b291653511 . . _:b291653649 . _:b291653510 . _:b291653648 . _:b291653505 . _:b291653651 . _:b291653504 . _:b291653650 . _:b291653507 . _:b291653661 . _:b780349 "The SOX9 expression pattern strikingly matches the domain of the epithelial cells stimulated by Wnt molecules, where nuclear \u03B2-catenin can interact with TCF4 to activate transcription (van de Wetering et al., >>2002<<). Although the Wnt pathway controls multiple aspects of intestine epithelium physiology, little is known about downstream transcription factors." . _:b780338 . _:b291653506 . _:b291653660 . _:b291653517 . _:b291653663 . _:b291653516 . _:b291653662 . _:b780333 . _:b291653519 . _:b291653428 . _:b291653657 . _:b291653518 . _:b780316 "have been widely implicated in the establishment of cell multipotency (Avilion et al., 2003; Kim et al., 2003), cell commitment (Mori-Akiyama et al., 2003; Stolt et al., 2003), and differentiation (Kamachi et al., 2000; Stolt et al., >>2002<<). Here, we screened the intestine epithelium for expressed SOX genes to investigate the possibility of a functional link with the related Tcf factors." . . _:b291653656 . . _:b291653513 . _:b291653659 . . _:b291653512 . _:b291653658 . . _:b291653515 . _:b291653380 . _:b291653669 . . _:b291653514 . _:b291653512 . _:b291653668 . _:b291653543 . _:b291653525 . _:b291653671 . _:b291653524 . _:b291653670 . _:b291653527 . . _:b291653665 . _:b291653526 . . . _:b291653664 . _:b291653521 . _:b291653667 . _:b291653520 . _:b291653238 . _:b291653666 . . _:b291653553 . _:b291653523 . _:b291653677 . _:b291653522 . _:b291653676 . _:b291653533 . _:b291653679 . _:b291653532 . _:b291653678 . _:b291653535 . _:b291653194 . _:b291653673 . _:b291653534 . _:b291653672 . _:b291653529 . _:b780341 . . _:b291653675 . _:b291653528 . _:b291653365 . _:b291653674 . _:b291653692 . _:b291653490 . _:b291653531 . _:b291653685 . _:b291653530 . _:b291653684 . _:b291653635 . _:b291653541 . _:b291653687 . . _:b780395 . _:b291653540 . _:b291653686 . _:b291653427 . . _:b291653351 . _:b291653543 . _:b291653681 . . . . _:b291653542 . _:b291653680 . _:b291653537 . _:b291653683 . . _:b291653536 . _:b291653682 . _:b291653539 . _:b291653693 . _:b291653538 . _:b291653499 . _:b291653692 . _:b780304 "The Wnt pathway also regulates the expression of the Eph/Ephrin surface molecules, responsible for the ordered positioning of epithelial cells along the crypt-villus axis (Batlle et al., >>2002<<). In addition, Wnt signals control the differentiation of the secretory cell lineage of the epithelium, because overexpression of the Wnt-pathway inhibitor Dickkopf1 blocks differentiation of the Paneth, goblet, and enteroendocrine cell" . _:b291653549 . _:b291653484 . _:b291653695 . . _:b291653548 . _:b291653562 . _:b291653694 . _:b291653551 . _:b291653689 . _:b291653550 . . _:b291653688 . _:b291653182 . _:b291653545 . _:b291653691 . _:b291653278 . . _:b291653544 . _:b291653690 . _:b780366 . _:b291653547 . _:b291653701 . _:b291653546 . . _:b291653700 . . _:b291653557 . . _:b291653703 . _:b291653556 . _:b291653702 . _:b291653559 . _:b291653697 . _:b291653558 . _:b291653696 . . _:b291653553 . . _:b291653699 . _:b291653552 . _:b291653698 . _:b291653555 . _:b291653709 . _:b291653550 . _:b291653554 . _:b291653708 . . _:b291653565 . _:b291653269 . _:b291653711 . _:b780348 "As the subcellular localization of SOX9 is regulated in some structures, such as the gonad (Smith and Koopman, >>2004<<), we tested whether the intestinal epithelium cytoplasmic staining was specific, using Western blot analysis of nuclear and cytoplasmic subcellular fractions of mouse intestine epithelial cells and of human cultured HT29-16E cells." . _:b291653564 . _:b291653350 . _:b291653710 . _:b291653567 . _:b291653705 . _:b291653566 . _:b291653704 . _:b291653311 . _:b291653561 . _:b291653707 . _:b291653520 . _:b291653560 . _:b291653706 . _:b291653630 . _:b291653645 . _:b291653563 . _:b291653717 . _:b291653562 . _:b291653716 . _:b291653397 . _:b291653573 . _:b291653719 . _:b291653572 . _:b291653718 . _:b291653575 . _:b291653713 . _:b291653574 . _:b291653712 . _:b291653569 . _:b780397 . _:b291653165 . _:b291653715 . _:b291653518 . _:b291653568 . _:b291653714 . _:b291653571 . _:b780402 . . _:b291653570 . _:b291653724 . _:b291653581 . _:b291653236 . _:b291653580 . . . _:b291653583 . _:b291653721 . _:b780298 "introduction" . . _:b291653582 . _:b291653720 . _:b291653228 . _:b291653577 . _:b291653723 . _:b780319 "SOX9 function is best known for its essential roles in chondrogenesis (Foster et al., 1994; Wagner et al., 1994; Wright et al., >>1995<<; Bi et al., 1999, 2001) and the development of the male gonad (Foster et al., 1994; Wagner et al., 1994; Kent et al., 1996; S\u00FCdbeck et al., 1996)." . _:b291653576 . _:b291653622 . _:b291653722 . _:b291653579 . _:b780412 "(Kim et al., 2003), SOX2 maintains precursor cells of the mouse blastocyst in a multipotent state (Avilion et al., 2003), and SOX1\u20133 counteract the activity of proneural proteins to keep neural cells undifferentiated (Bylund et al., >>2003<<). Thus, contribution to the maintenance of cells in an undifferentiated state might be a property shared by several SOX transcription factors, and our finding that SOX9 is regulated by the Wnt pathway, which is also known to inhibit" . _:b291653431 . _:b291653578 . _:b291653467 . . _:b291653589 . . . _:b291653588 . . _:b291653591 . . _:b291653590 . _:b291653341 . _:b780383 "In an alternative model, the Wnt regulation of SOX9 might involve one or several intermediate transcription factors, such as CDX-1 or c-MYC, which have already been described as direct Wnt targets (He et al., >>1998<<; Lickert et al., 2000) and are not regulated by SOX9 in our RT-PCR experiment." . _:b291653585 . _:b291653584 . _:b291653298 . _:b291653581 . _:b291653587 . . _:b780323 "SOX9 function is best known for its essential roles in chondrogenesis (Foster et al., 1994; Wagner et al., 1994; Wright et al., 1995; Bi et al., 1999, 2001) and the development of the male gonad (Foster et al., 1994; Wagner et al., >>1994<<; Kent et al., 1996; S\u00FCdbeck et al., 1996). SOX9 is also involved in the development of the neural crest (Spokony et al., 2002) and of the spinal cord glial cells (Stolt et al., 2003)." . _:b291653586 . _:b291653597 . . _:b780324 "best known for its essential roles in chondrogenesis (Foster et al., 1994; Wagner et al., 1994; Wright et al., 1995; Bi et al., 1999, 2001) and the development of the male gonad (Foster et al., 1994; Wagner et al., 1994; Kent et al., >>1996<<; S\u00FCdbeck et al., 1996). SOX9 is also involved in the development of the neural crest (Spokony et al., 2002) and of the spinal cord glial cells (Stolt et al., 2003)." . . _:b291653205 . _:b291653596 . _:b291653599 . . . _:b291653571 . _:b291653598 . . . _:b291653377 . _:b291653593 . _:b291653641 . _:b291653592 . _:b780369 "In addition to CDX2 and its target gene MUC2 (Yamamoto et al., >>2003<<; Figs. 5 and 6 a), there was slight but reproducible SOX9-dependent down-regulation of genes encoding the differentiation markers Fabp-i and Galectin-4 (not depicted)." . _:b291653595 . . . _:b291653594 . _:b291653605 . _:b291653604 . _:b780405 . _:b291653607 . _:b291653606 . _:b291653601 . _:b291653600 . _:b291653603 . _:b291653259 . . _:b291653602 . _:b291653226 . _:b291653613 . _:b291653249 . _:b291653612 . . _:b780332 "genes which are specific for each process: in chondrogenesis, it regulates the cartilage specific genes Col2a1 (Bell et al., 1997; Lefebvre et al., 1997; Bi et al., 1999), Col11a2 (Bridgewater et al., 1998), Aggrecan (Sekiya et al., >>2000<<), and campomelic dysplasia (CD)\u2013RAP (Xie et al., 1999). During male gonad development, it controls the expression of the anti-M\u00FCllerrian hormone gene (de Santa Barbara et al., 1998)." . _:b291653615 . _:b780362 . _:b291653614 . _:b780363 . _:b291653609 . _:b291653655 . _:b291653608 . _:b291653276 . . _:b291653611 . . _:b291653610 . _:b291653596 . _:b780305 "control the differentiation of the secretory cell lineage of the epithelium, because overexpression of the Wnt-pathway inhibitor Dickkopf1 blocks differentiation of the Paneth, goblet, and enteroendocrine cell types (Pinto et al., >>2003<<). Finally, mutations in components of the Wnt pathway, including the tumor suppressor APC and the multifunctional \u03B2-catenin protein, are found in the vast majority of colon cancers (Morin et al., 1997)." . _:b291653621 . _:b291653620 . _:b291653623 . _:b291653622 . _:b291653617 . _:b291653605 . _:b291653723 . _:b291653616 . _:b291653619 . _:b780388 . _:b291653618 . _:b291653232 . _:b291653629 . _:b291653628 . _:b291653631 . _:b291653630 . . _:b291653625 . _:b291653624 . _:b291653627 . _:b291653626 . _:b291653279 . _:b780369 . . . _:b291653495 . . . . _:b291653284 . . _:b291653573 . _:b291653523 . . _:b780394 . _:b780376 "Paneth cells, which occupy the bottom of the small intestine crypts, beneath the cells constituting the proliferative compartment, are postmitotic, fully differentiated cells (Cheng, >>1974<<). Thus, SOX9 is expressed in proliferative cells, which probably include the stem cells, as well as in the terminally differentiated Paneth cells. This suggests that SOX9 expression is not restricted either to a single cell type or to the" . _:b291653704 . _:b291653455 . _:b291653640 . . _:b291653412 . . . . _:b780325 . . . _:b291653230 . _:b780401 . _:b291653265 . _:b291653404 . . . . . _:b291653157 . . _:b291653575 . . . _:b291653156 . . . _:b291653159 . _:b291653158 . . _:b780330 "Strikingly, SOX9 controls the transcription of target genes which are specific for each process: in chondrogenesis, it regulates the cartilage specific genes Col2a1 (Bell et al., 1997; Lefebvre et al., 1997; Bi et al., >>1999<<), Col11a2 (Bridgewater et al., 1998), Aggrecan (Sekiya et al., 2000), and campomelic dysplasia (CD)\u2013RAP (Xie et al., 1999)." . . _:b291653153 . . _:b291653152 . _:b291653155 . _:b780337 . _:b291653241 . . _:b780392 . _:b291653154 . _:b291653165 . _:b291653164 . _:b291653331 . _:b291653164 . . _:b291653167 . _:b291653416 . _:b291653166 . _:b780374 "More recently, SOX9 was found to be essential for the development of the neural crests and the central nervous system (Xie et al., 1999; Spokony et al., >>2002<<; Mori-Akiyama et al., 2003)." . . _:b291653161 . . _:b291653160 . . _:b291653197 . _:b291653163 . _:b291653162 . . _:b291653173 . . _:b780385 "A study of the transcriptional response of NCCIT human embryonal carcinoma cells to the Wnt-3a signal identified SOX9 as one of the genes which was up-regulated upon Wnt-3a signaling (Willert et al., >>2002<<). Such Wnt-regulation of SOX9 thus might also exist in additional structures where SOX9 expression has been reported." . _:b291653405 . _:b291653172 . . _:b291653175 . _:b780391 "Wnt signals are also involved in the development of the neural crests (Yanfeng et al., 2003), where SOX9 has also recently been found to be required (Spokony et al., >>2002<<; Cheung and Briscoe, 2003; Mori-Akiyama et al., 2003)." . _:b291653204 . _:b291653174 . _:b291653169 . _:b291653168 . _:b291653261 . . _:b291653171 . _:b291653624 . _:b291653170 . . _:b291653181 . _:b291653155 . _:b291653180 . _:b291653183 . _:b291653182 . . _:b291653324 . _:b291653177 . . _:b291653176 . _:b291653179 . . _:b291653423 . . _:b291653178 . _:b291653659 . _:b291653189 . . _:b291653566 . _:b780361 . _:b291653188 . _:b291653191 . _:b291653190 . _:b291653185 . _:b291653403 . _:b780312 "Similarly to TCFs, SOX proteins have been widely implicated in the establishment of cell multipotency (Avilion et al., 2003; Kim et al., >>2003<<), cell commitment (Mori-Akiyama et al., 2003; Stolt et al., 2003), and differentiation (Kamachi et al., 2000; Stolt et al., 2002)." . . _:b291653184 . _:b780331 . _:b291653181 . _:b291653187 . _:b291653524 . _:b291653186 . _:b291653197 . . . _:b291653196 . . . _:b291653199 . . _:b291653198 . . _:b291653694 . _:b291653193 . _:b291653192 . . _:b291653502 . _:b291653696 . _:b291653195 . . . _:b291653194 . . . _:b291653386 . _:b291653205 . . _:b291653204 . _:b780398 . . _:b291653207 . . _:b291653334 . _:b291653206 . _:b291653201 . _:b291653200 . _:b291653557 . _:b780355 "We found that this regulation of SOX9 occurs at the RNA level using LS174T human colon carcinoma cells stably transfected with an inducible \u0394NTCF4 construct (van de Wetering et al., >>2002<<). As noted above, LS174T cells express high levels of endogenous SOX9 mRNA and protein." . _:b780336 "materials and methods" . _:b291653203 . _:b291653202 . . _:b291653213 . . _:b291653212 . _:b291653716 . _:b291653308 . _:b291653215 . _:b291653214 . _:b291653209 . _:b780372 . _:b291653208 . _:b291653211 . _:b780343 "Stably transfected LS174T cell lines with inducible \u0394NTCF4 have been described previously (van de Wetering et al., >>2002<<). HT29-16E human colorectal carcinoma cells were given by C. Laboisse (INSERM U539, Nantes, France). The T-RexTM system (Invitrogen) was used for the generation of stable SOX9-inducible HT29-16E cells. In brief, tetracycline-inducible" . _:b780413 "We found that SOX9 negatively regulates the CDX2 tumor suppressor gene, which is frequently very weakly expressed in colon cancers (Ee et al., >>1995<<; Mallo et al., 1997), especially in poorly differentiated lesions (Hinoi et al., 2001)." . _:b291653210 . _:b291653221 . _:b291653220 . . _:b780301 . _:b291653223 . _:b780356 "The Wnt\u2013\u03B2-catenin\u2013TCF4 pathway is necessary for the maintenance of a functional crypt-villus axis in the mouse intestinal epithelium (Pinto et al., >>2003<<). The gene knockout of its transcriptional effector, TCF4, leads to the loss of the proliferative compartment of the epithelium." . _:b291653222 . _:b291653555 . _:b291653217 . _:b291653216 . _:b780396 . _:b291653219 . _:b291653218 . _:b291653229 . _:b291653228 . _:b291653231 . _:b291653230 . _:b291653579 . _:b291653225 . _:b291653224 . . _:b291653227 . _:b291653569 . _:b780298 . _:b291653226 . _:b291653242 . _:b291653195 . _:b291653507 . _:b291653237 . _:b291653236 . _:b291653449 . _:b291653239 . _:b291653357 . _:b291653238 . _:b291653293 . _:b291653267 . _:b291653233 . _:b780375 "More recently, SOX9 was found to be essential for the development of the neural crests and the central nervous system (Xie et al., 1999; Spokony et al., 2002; Mori-Akiyama et al., >>2003<<). Here, we report that SOX9 is also expressed in the intestinal epithelium. In this highly organized structure, the SOX9 protein is only expressed in the lower third of the crypts of Lieberk\u00FChn, in both the small intestine and colon." . _:b291653232 . _:b291653235 . _:b291653234 . _:b291653657 . _:b291653245 . _:b291653244 . _:b291653247 . _:b291653687 . _:b291653444 . . _:b780346 . _:b291653246 . . _:b291653650 . _:b291653241 . _:b291653420 . _:b780336 . . . _:b291653240 . _:b291653243 . _:b291653167 . _:b291653642 . _:b291653242 . _:b291653161 . . _:b291653253 . _:b291653166 . . _:b291653285 . _:b291653252 . _:b291653255 . _:b291653254 . _:b291653249 . _:b780370 . _:b291653248 . _:b291653665 . _:b291653251 . . _:b291653425 . _:b291653250 . _:b291653261 . . . _:b291653312 . _:b291653260 . . _:b291653263 . _:b780302 "In the intestine, the Wnt signaling pathway has been implicated in the regulation of the proliferation/differentiation balance (van de Wetering et al., >>2002<<). Consistent with this, no proliferation can be detected, and all epithelial cells appear differentiated, in the intestine of mice null for TCF4, the main Wnt pathway transcription factor in the intestinal epithelium (Korinek et al.," . _:b291653262 . . _:b291653257 . _:b291653362 . . _:b291653256 . . _:b291653259 . _:b291653258 . _:b291653633 . . _:b291653269 . . . _:b291653323 . _:b291653268 . _:b291653391 . . _:b291653271 . _:b291653390 . _:b291653270 . _:b291653265 . _:b291653264 . _:b291653317 . _:b291653267 . _:b780382 "Indeed, although this promoter has been poorly characterized, scattered regulatory enhancer elements have been detected up to 1 megabase upstream of the human SOX9 transcriptional unit (Wunderle et al., 1998; Bishop et al., >>2000<<). We performed in silico screening of the genomic region situated from 200 kb upstream to 100 kb downstream of the SOX9 transcriptional unit for putative canonical TCF binding sites. Although several putative sites were identified, the" . _:b780318 . . . . _:b291653266 . _:b291653277 . _:b291653669 . . _:b780299 . _:b291653276 . _:b291653279 . . _:b291653278 . _:b780333 "it regulates the cartilage specific genes Col2a1 (Bell et al., 1997; Lefebvre et al., 1997; Bi et al., 1999), Col11a2 (Bridgewater et al., 1998), Aggrecan (Sekiya et al., 2000), and campomelic dysplasia (CD)\u2013RAP (Xie et al., >>1999<<). During male gonad development, it controls the expression of the anti-M\u00FCllerrian hormone gene (de Santa Barbara et al., 1998)." . . _:b291653273 . "10.1083%2Fjcb.200311021" . . _:b780320 "SOX9 function is best known for its essential roles in chondrogenesis (Foster et al., 1994; Wagner et al., 1994; Wright et al., 1995; Bi et al., >>1999<<, 2001) and the development of the male gonad (Foster et al., 1994; Wagner et al., 1994; Kent et al., 1996; S\u00FCdbeck et al., 1996)." . _:b291653663 . _:b291653272 . _:b291653275 . . _:b291653274 . . _:b291653285 . _:b291653284 . _:b291653287 . _:b780309 . . _:b780299 "In the small intestine, a fourth cell type, the Paneth cells, migrates downward and settles at the bottom of the crypts as terminally differentiated cells (Potten and Moeffler, >>1990<<; Stappenbeck et al., 1998)." . _:b291653286 . _:b291653281 . _:b780376 . _:b291653280 . _:b291653283 . _:b291653282 . . _:b291653275 . _:b291653293 . . _:b291653433 . _:b291653292 . . . . _:b291653295 . _:b291653457 . _:b291653294 . _:b780323 . _:b291653600 . _:b291653289 . _:b291653288 . . _:b291653291 . _:b291653568 . . . _:b291653290 . _:b780368 "c-Myc has also been described as a direct \u03B2-catenin\u2013TCF4 target (He et al., >>1998<<), but its expression level is not altered neither by SOX9 gain/loss of function (Fig." . _:b291653301 . . _:b291653215 . _:b291653300 . _:b291653683 . _:b291653303 . _:b780315 . _:b291653302 . _:b291653297 . _:b291653296 . . . _:b291653299 . _:b291653298 . _:b291653185 . _:b291653309 . . _:b291653187 . _:b291653308 . _:b291653461 . . _:b291653311 . . . _:b291653310 . _:b291653609 . _:b291653305 . _:b291653514 . _:b291653565 . _:b291653304 . _:b780361 "In the intestinal epithelium, the CDX1 transcription factor is mostly expressed in the crypts whereas CDX2 is mostly active on the villi (Subramanian et al., >>1998<<; Silberg et al., 2000)." . _:b291653666 . _:b291653307 . . . . . _:b291653306 . _:b291653295 . _:b291653317 . _:b291653316 . _:b780317 "SOX9 function is best known for its essential roles in chondrogenesis (Foster et al., >>1994<<; Wagner et al., 1994; Wright et al., 1995; Bi et al., 1999, 2001) and the development of the male gonad (Foster et al., 1994; Wagner et al., 1994; Kent et al., 1996; S\u00FCdbeck et al., 1996)." . _:b291653319 . _:b780390 . _:b291653318 . _:b780322 . _:b291653313 . _:b291653312 . . _:b291653315 . . _:b291653621 . _:b291653485 . _:b291653314 . _:b291653325 . _:b291653611 . _:b291653324 . . _:b291653327 . . _:b291653326 . _:b780397 "al., 2000; Rings et al., 2001) and to promote cell differentiation by activating transcription of genes encoding typical differentiation markers, including MUC2, sucrase-isomaltase, and lactase (Lorentz et al., 1997; Yamamoto et al., >>2003<<). To date, SOX9 has generally been described as a transcriptional activator (S\u00FCdbeck et al., 1996; Bell et al., 1997; Lefebvre et al., 1997; Ng et al., 1997; de Santa Barbara et al., 1998; Liu et al., 2000; Sekiya et al., 2000; Liu et al." . _:b291653310 . _:b291653321 . _:b780411 "SOX9, is involved in the maintenance of neural crest stem cells multipotency and inhibition of neural differentiation (Kim et al., 2003), SOX2 maintains precursor cells of the mouse blastocyst in a multipotent state (Avilion et al., >>2003<<), and SOX1\u20133 counteract the activity of proneural proteins to keep neural cells undifferentiated (Bylund et al., 2003)." . _:b780380 . _:b291653320 . . _:b291653323 . _:b291653322 . _:b291653592 . _:b291653333 . _:b291653332 . _:b291653402 . _:b291653335 . . _:b291653334 . _:b291653329 . . _:b291653328 . . . . _:b291653331 . _:b291653330 . _:b291653341 . _:b291653340 . _:b291653343 . . . _:b780340 "The SOX9-VP16 (Kamachi et al., >>1999<<) was provided by H. Kondoh (Institute for Molecular and Cellular Biology, Osaka University, Osaka, Japan), and the MUC-2-luciferase reporter (Yamamoto et al., 2003) was a gift from Y." . . _:b291653342 . _:b291653682 . . _:b291653337 . _:b780328 . _:b291653336 . _:b291653339 . _:b780313 . _:b291653338 . _:b291653193 . _:b291653349 . _:b291653348 . _:b291653542 . . _:b291653351 . _:b780309 "Moreover, targeted mutations of APC or \u03B2-catenin are sufficient to initiate tumorigenesis in the mouse (Fodde et al., 1994; Shibata et al., >>1997<<; Harada et al., 1999), highlighting the importance of the Wnt pathway in the development of cancer." . _:b291653350 . _:b291653429 . _:b291653559 . _:b291653345 . _:b291653344 . . _:b291653347 . . _:b780384 "In an alternative model, the Wnt regulation of SOX9 might involve one or several intermediate transcription factors, such as CDX-1 or c-MYC, which have already been described as direct Wnt targets (He et al., 1998; Lickert et al., >>2000<<) and are not regulated by SOX9 in our RT-PCR experiment." . _:b291653346 . . _:b291653357 . _:b291653356 . . _:b291653359 . . . _:b780418 . _:b291653358 . _:b291653325 . _:b780405 "date, SOX9 has generally been described as a transcriptional activator (S\u00FCdbeck et al., 1996; Bell et al., 1997; Lefebvre et al., 1997; Ng et al., 1997; de Santa Barbara et al., 1998; Liu et al., 2000; Sekiya et al., 2000; Liu et al., >>2001<<; Panda et al., 2001), although it was recently found to mediate a dual transcriptional effect on the COL2A1 gene, depending on the promoter elements involved (Kypriotou et al., 2003)." . _:b291653353 . _:b291653352 . _:b291653355 . _:b780393 . _:b291653506 . . _:b291653354 . . . _:b780321 . _:b291653365 . . _:b291653364 . _:b291653671 . _:b291653367 . _:b291653366 . _:b291653361 . . _:b780414 "We found that SOX9 negatively regulates the CDX2 tumor suppressor gene, which is frequently very weakly expressed in colon cancers (Ee et al., 1995; Mallo et al., >>1997<<), especially in poorly differentiated lesions (Hinoi et al., 2001)." . . _:b291653360 . _:b780409 "Because one reported role of the Wnt pathway is the maintenance of an undifferentiated cell phenotype (van de Wetering et al., >>2002<<), our results suggest that SOX9 might be involved in mediating part of this function." . _:b291653363 . . _:b291653654 . _:b291653362 . . . _:b291653373 . _:b291653372 . _:b291653375 . _:b291653374 . . _:b291653369 . _:b780317 . _:b780411 . _:b291653368 . _:b291653371 . _:b291653370 . _:b291653260 . . _:b291653419 . . . . . _:b780377 "Rather, it corresponds to a location, the bottom of the crypt, which is also considered to be the cellular \u201Cniche\u201D of the epithelium, where cells contain nuclear \u03B2-catenin in response to Wnt signaling (Batlle et al., >>2002<<; van de Wetering et al., 2002)." . _:b291653326 . _:b291653538 . _:b291653644 . . . _:b291653474 . . _:b291653494 . . _:b291653589 . _:b291653631 . _:b291653315 . . _:b291653653 . _:b291653511 . . _:b780300 . _:b780301 . _:b780302 . _:b780303 . _:b780352 "NH2-terminally deleted mutant lacks the \u03B2-catenin-interaction domain and has been shown to interfere with the activity of the endogenous, constitutively active, \u03B2-catenin\u2013TCF4 complex present in these cells (van de Wetering et al., >>2002<<). Cells were transfected with either the \u0394NTCF4 or a mock GFP expression construct and the endogenous SOX9 protein expression was monitored by immunofluorescence." . _:b780399 . . _:b780298 . _:b780299 . . _:b780308 . _:b291653580 . . _:b780309 . _:b780310 . . _:b780311 . . _:b780375 . _:b780304 . _:b780305 . _:b780373 "More recently, SOX9 was found to be essential for the development of the neural crests and the central nervous system (Xie et al., >>1999<<; Spokony et al., 2002; Mori-Akiyama et al., 2003)." . _:b780306 . . _:b780307 . _:b291653190 . _:b780316 . _:b780311 . _:b780317 . _:b780318 . _:b291653688 . _:b780319 . _:b780312 . _:b780313 . _:b291653409 . _:b780314 . . _:b780315 . _:b780324 . _:b291653690 . . _:b780325 . _:b291653616 . _:b780404 "To date, SOX9 has generally been described as a transcriptional activator (S\u00FCdbeck et al., 1996; Bell et al., 1997; Lefebvre et al., 1997; Ng et al., 1997; de Santa Barbara et al., 1998; Liu et al., 2000; Sekiya et al., >>2000<<; Liu et al., 2001; Panda et al., 2001), although it was recently found to mediate a dual transcriptional effect on the COL2A1 gene, depending on the promoter elements involved (Kypriotou et al., 2003)." . _:b291653174 . _:b780326 . _:b780371 . _:b780327 . . . _:b291653189 . _:b780320 . _:b291653170 . _:b780321 . . _:b291653172 . _:b291653162 . _:b780322 . . _:b780329 "Strikingly, SOX9 controls the transcription of target genes which are specific for each process: in chondrogenesis, it regulates the cartilage specific genes Col2a1 (Bell et al., 1997; Lefebvre et al., >>1997<<; Bi et al., 1999), Col11a2 (Bridgewater et al., 1998), Aggrecan (Sekiya et al., 2000), and campomelic dysplasia (CD)\u2013RAP (Xie et al., 1999)." . _:b780323 . _:b780338 "NH2-terminally flagged wild-type and COOH-terminally truncated SOX9-pcDNA expression constructs have been described previously (S\u00FCdbeck et al., 1996; de Santa Barbara et al., >>1998<<). The antisense SOX9 expression construct was generated by cloning the BamHI\u2013EcoRI fragment containing the SOX9 ORF from SOX9-pcDNA into the same restriction sites of pIRESneo (CLONTECH Laboratories, Inc." . _:b780332 . . _:b780418 "MUC2 deficiency also leads to spontaneous intestinal tumors (Velcich et al., >>2002<<). Conversely, restoration of CDX2 expression in human colon carcinoma cells suppressed proliferation and soft agar growth (Hinoi et al., 2003). Here, we find that overexpressing a dominant-negative version of SOX9 results in increased" . _:b780333 . . _:b291653316 . _:b780334 . _:b780390 "Wnt signals are also involved in the development of the neural crests (Yanfeng et al., >>2003<<), where SOX9 has also recently been found to be required (Spokony et al., 2002; Cheung and Briscoe, 2003; Mori-Akiyama et al., 2003)." . _:b780335 . _:b780328 . . _:b291653439 . _:b780329 . _:b780330 . _:b780331 . _:b291653340 . _:b291653367 . _:b780340 . _:b780341 . _:b291653432 . _:b780342 . _:b780343 . _:b291653271 . _:b780336 . . _:b780337 . _:b291653305 . _:b780338 . _:b291653370 . _:b780339 . . _:b780348 . . _:b291653549 . _:b780349 . _:b291653446 . . _:b780350 . _:b291653243 . _:b291653207 . _:b780351 . _:b780415 "We found that SOX9 negatively regulates the CDX2 tumor suppressor gene, which is frequently very weakly expressed in colon cancers (Ee et al., 1995; Mallo et al., 1997), especially in poorly differentiated lesions (Hinoi et al., >>2001<<). Mice heterozygous for the CDX2 gene are hypersensitive to sporadic, chemically induced, colon carcinogenesis (Bonhomme et al., 2003), and this was confirmed in a mouse model of familial adenomatous polyposis (Aoki et al., 2003)." . _:b780344 . _:b291653254 . _:b780345 . _:b780346 . _:b780347 . _:b780356 . _:b291653498 . _:b780385 . _:b780357 . _:b780358 . _:b291653381 . . _:b780359 . _:b780352 . . _:b780353 . . _:b780354 . _:b780364 "Indeed, coculture experiments, as well as loss of CDX1 expression in the gut of TCF4-deficient mice, led to the conclusion that CDX1 is a target of the Wnt\u2013\u03B2-catenin\u2013TCF4 pathway (Lickert et al., >>2000<<; Ikeya and Takada, 2001)." . _:b780355 . _:b291653320 . _:b780364 . _:b291653372 . _:b780365 . _:b291653552 . _:b780366 . . . _:b780367 . . _:b780360 . _:b780339 "NH2-truncated TCF4 (\u0394N-TCF4 dominant negative) has been described previously (van de Wetering et al., >>2002<<) and was provided by B." . _:b291653525 . _:b780361 . _:b780362 . _:b780363 . . _:b780372 . _:b291653632 . . _:b291653548 . . _:b780373 . _:b780374 . _:b780375 . _:b780368 . _:b780360 "CDX1/-2 genes, both homologues of the Drosophila homeobox Caudal gene (Duprey et al., 1988; Suh et al., >>1994<<), exemplified such branching." . _:b780369 . . _:b291653434 . _:b780370 . . . _:b780371 . . _:b291653208 . _:b780380 . _:b780381 . . _:b780382 . . . _:b780383 . _:b780376 . _:b780301 "Interaction with \u03B2-catenin activates the TCF/LEF transcription factors, resulting in transcription of target genes (Brantjes et al., >>2002<<). In the intestine, the Wnt signaling pathway has been implicated in the regulation of the proliferation/differentiation balance (van de Wetering et al., 2002). Consistent with this, no proliferation can be detected, and all epithelial" . _:b780377 . . . _:b291653154 . _:b780378 . _:b780365 "Indeed, coculture experiments, as well as loss of CDX1 expression in the gut of TCF4-deficient mice, led to the conclusion that CDX1 is a target of the Wnt\u2013\u03B2-catenin\u2013TCF4 pathway (Lickert et al., 2000; Ikeya and Takada, >>2001<<). On the other hand, APC up-regulates CDX2 (da Costa et al., 1999), although the signaling pathway downstream of APC has not yet been elucidated. In our experiment, CDX1 expression was not altered by gain/loss of SOX9 function in LS174T" . . _:b780379 . . . _:b780388 . _:b780389 . . . . _:b780390 . _:b291653535 . _:b780391 . _:b291653231 . _:b291653277 . _:b291653464 . _:b780384 . . _:b780385 . _:b291653216 . _:b780386 . . _:b780387 . _:b780396 . _:b291653705 . . _:b780397 . . _:b291653681 . . _:b780398 . . _:b291653656 . _:b780399 . _:b780311 "Similarly to TCFs, SOX proteins have been widely implicated in the establishment of cell multipotency (Avilion et al., >>2003<<; Kim et al., 2003), cell commitment (Mori-Akiyama et al., 2003; Stolt et al., 2003), and differentiation (Kamachi et al., 2000; Stolt et al., 2002)." . _:b780392 . _:b780393 . . _:b780394 . . _:b291653327 . _:b780395 . _:b780404 . . . _:b780405 . _:b780406 . . . _:b780407 . _:b780400 . _:b291653610 . _:b780401 . _:b780321 "SOX9 function is best known for its essential roles in chondrogenesis (Foster et al., 1994; Wagner et al., 1994; Wright et al., 1995; Bi et al., 1999, >>2001<<) and the development of the male gonad (Foster et al., 1994; Wagner et al., 1994; Kent et al., 1996; S\u00FCdbeck et al., 1996)." . _:b780402 . _:b780403 . _:b291653724 . _:b780412 . _:b291653720 . _:b291653721 . _:b291653722 . _:b291653723 . _:b780413 . _:b291653716 . _:b291653717 . . _:b291653718 . _:b291653527 . _:b780414 . _:b291653719 . _:b291653712 . _:b291653387 . _:b291653713 . _:b291653714 . _:b291653465 . _:b780415 . _:b291653452 . _:b291653715 . _:b291653708 . _:b291653709 . _:b291653710 . . _:b291653711 . _:b780408 . _:b291653704 . _:b291653705 . . _:b291653706 . _:b291653707 . _:b780409 . _:b291653700 . _:b291653701 . _:b291653497 . _:b291653702 . _:b291653703 . _:b780410 . _:b291653696 . . _:b291653152 . _:b291653697 . _:b291653469 . _:b291653698 . _:b291653699 . _:b780411 . _:b291653607 . _:b780314 . _:b291653359 . _:b291653199 . . . _:b780416 . _:b780417 . _:b291653564 . _:b780313 "Similarly to TCFs, SOX proteins have been widely implicated in the establishment of cell multipotency (Avilion et al., 2003; Kim et al., 2003), cell commitment (Mori-Akiyama et al., >>2003<<; Stolt et al., 2003), and differentiation (Kamachi et al., 2000; Stolt et al., 2002)." . . _:b780418 . _:b780419 . _:b291653660 . _:b291653661 . _:b291653173 . _:b291653662 . _:b291653721 . _:b291653663 . _:b291653656 . _:b291653657 . _:b291653658 . _:b291653659 . _:b291653652 . _:b291653184 . . _:b291653653 . _:b291653654 . _:b291653655 . . _:b291653648 . _:b291653649 . . _:b291653650 . _:b291653672 . _:b291653651 . _:b291653644 . _:b291653645 . _:b291653313 . _:b291653646 . _:b291653647 . _:b291653280 . _:b291653640 . _:b291653641 . _:b291653642 . _:b291653643 . . _:b291653212 . _:b291653636 . _:b291653637 . _:b291653638 . _:b291653639 . _:b291653632 . _:b291653633 . _:b291653634 . _:b291653282 . _:b291653635 . _:b291653692 . _:b291653693 . _:b291653694 . _:b291653695 . _:b291653688 . _:b291653689 . _:b291653637 "2"^^ . _:b291653690 . _:b291653210 . _:b291653691 . _:b291653684 . _:b780403 . _:b291653685 . _:b291653636 "2"^^ . _:b291653686 . _:b291653687 . _:b291653201 . _:b291653680 . _:b291653681 . . _:b291653639 "2"^^ . _:b291653682 . . _:b291653683 . _:b291653462 . _:b291653676 . . _:b291653677 . _:b291653638 "2"^^ . _:b291653678 . _:b291653679 . _:b291653672 . _:b291653673 . _:b780327 . _:b291653633 "2"^^ . _:b291653338 . _:b291653674 . _:b291653675 . _:b291653668 . . _:b291653669 . _:b291653304 . _:b291653670 . _:b291653632 "2"^^ . _:b291653671 . . _:b291653545 . _:b291653664 . _:b291653665 . _:b291653635 "2"^^ . _:b291653666 . _:b291653667 . _:b291653634 "2"^^ . _:b291653472 . . . . _:b291653645 "2"^^ . _:b291653722 . . _:b291653644 "2"^^ . _:b291653647 "2"^^ . _:b780392 "Wnt signals are also involved in the development of the neural crests (Yanfeng et al., 2003), where SOX9 has also recently been found to be required (Spokony et al., 2002; Cheung and Briscoe, >>2003<<; Mori-Akiyama et al., 2003)." . . _:b291653617 . . _:b291653646 "2"^^ . _:b291653641 "2"^^ . _:b291653489 . _:b291653640 "2"^^ . _:b291653643 "2"^^ . _:b291653642 "2"^^ . _:b291653567 . _:b291653653 "2"^^ . _:b291653652 "2"^^ . _:b291653188 . . _:b291653655 "2"^^ . _:b291653654 "2"^^ . . _:b291653445 . _:b291653649 "2"^^ . _:b291653648 "2"^^ . . _:b291653651 "2"^^ . _:b291653650 "2"^^ . . _:b291653638 . _:b291653661 "2"^^ . _:b291653660 "2"^^ . _:b291653663 "2"^^ . . _:b291653662 "2"^^ . . . _:b291653422 . _:b780350 "We first tested SOX9 expression in human colon cancer\u2013derived cell lines containing activating mutations of components of the Wnt pathway, which result in constitutive expression of \u03B2-catenin/TCF4 target genes (Korinek et al., >>1997<<). In all the colon cancer cell lines we tested (DLD-1, LS174T, SW480, TC-7, and HT29), SOX9 mRNA (not depicted) and protein were strongly expressed (Fig." . _:b291653657 "2"^^ . _:b291653656 "2"^^ . _:b291653250 . _:b291653659 "2"^^ . _:b291653244 . _:b291653658 "2"^^ . _:b291653669 "2"^^ . _:b291653668 "2"^^ . _:b291653417 . _:b291653671 "2"^^ . . _:b291653670 "2"^^ . _:b291653665 "2"^^ . _:b291653619 . . _:b291653664 "2"^^ . . _:b291653273 . _:b291653667 "2"^^ . . _:b291653539 . _:b780419 "Conversely, restoration of CDX2 expression in human colon carcinoma cells suppressed proliferation and soft agar growth (Hinoi et al., >>2003<<). Here, we find that overexpressing a dominant-negative version of SOX9 results in increased CDX2 expression in cultured colon carcinoma cells. This suggests that strong SOX9 expression in tumors which contain a constitutive activation of" . _:b291653666 "2"^^ . . _:b291653677 "2"^^ . . _:b291653235 . _:b291653676 "2"^^ . . _:b291653679 "2"^^ . _:b291653178 . _:b291653678 "2"^^ . . _:b291653673 "2"^^ . _:b291653342 . _:b291653563 . _:b291653510 . _:b291653672 "2"^^ . _:b291653684 . _:b291653675 "2"^^ . _:b291653674 "2"^^ . . . . _:b291653685 "2"^^ . _:b291653480 . . _:b291653684 "2"^^ . _:b291653643 . _:b291653687 "2"^^ . _:b291653392 . _:b291653686 "2"^^ . . _:b291653681 "2"^^ . _:b291653651 . . _:b291653680 "2"^^ . _:b780306 "Finally, mutations in components of the Wnt pathway, including the tumor suppressor APC and the multifunctional \u03B2-catenin protein, are found in the vast majority of colon cancers (Morin et al., >>1997<<). Such mutations result in stabilization of \u03B2-catenin, which then continuously interacts with TCF4, leading to constitutive activation of target genes (Korinek et al., 1997). Moreover, targeted mutations of APC or \u03B2-catenin are sufficient" . _:b291653683 "2"^^ . _:b291653706 . . . _:b291653415 . _:b291653682 "2"^^ . _:b291653693 "2"^^ . _:b291653586 . _:b291653692 "2"^^ . _:b291653695 "2"^^ . _:b291653694 "2"^^ . _:b291653337 . . _:b780382 . _:b291653689 "2"^^ . _:b780395 "For instance, SOX9 represses the expression of the CDX2 transcription factor, known to be mostly active in villus cells (Silberg et al., 2000; Rings et al., >>2001<<) and to promote cell differentiation by activating transcription of genes encoding typical differentiation markers, including MUC2, sucrase-isomaltase, and lactase (Lorentz et al., 1997; Yamamoto et al., 2003)." . _:b291653688 "2"^^ . _:b291653376 . . _:b291653691 "2"^^ . _:b291653690 "2"^^ . _:b291653701 "2"^^ . _:b291653700 "2"^^ . _:b780366 "On the other hand, APC up-regulates CDX2 (da Costa et al., >>1999<<), although the signaling pathway downstream of APC has not yet been elucidated." . _:b291653703 "2"^^ . . . _:b291653702 "2"^^ . . _:b291653697 "2"^^ . _:b291653696 "2"^^ . . _:b291653699 "2"^^ . _:b291653458 . _:b291653375 . _:b291653698 "2"^^ . . _:b291653709 "2"^^ . . _:b291653708 "2"^^ . . _:b291653505 . _:b291653171 . _:b291653711 "2"^^ . _:b291653239 . _:b780336 _:b780340 . _:b780336 _:b780341 . _:b780336 _:b780342 . _:b291653710 "2"^^ . _:b780336 _:b780343 . _:b780336 _:b780337 . _:b291653496 . _:b780336 _:b780338 . _:b780412 . _:b291653705 "2"^^ . _:b780336 _:b780339 . _:b291653704 "2"^^ . _:b780336 _:b780344 . . _:b780336 _:b780345 . _:b291653707 "2"^^ . _:b291653706 "2"^^ . . _:b291653717 "2"^^ . _:b780408 . _:b291653453 . _:b291653716 "2"^^ . _:b291653443 . _:b291653670 . _:b291653719 "2"^^ . _:b780346 _:b780348 . _:b780346 _:b780349 . . _:b291653718 "2"^^ . _:b780346 _:b780350 . _:b780346 _:b780351 . _:b291653713 "2"^^ . _:b780346 _:b780347 . _:b780316 . _:b291653664 . _:b291653634 . _:b291653712 "2"^^ . . _:b291653715 "2"^^ . _:b780346 _:b780364 . _:b780346 _:b780365 . _:b291653263 . _:b780346 _:b780366 . _:b291653714 "2"^^ . _:b780346 _:b780367 . _:b780346 _:b780360 . _:b780346 _:b780361 . _:b780346 _:b780362 . _:b780346 _:b780363 . . _:b780346 _:b780356 . _:b291653513 . _:b780346 _:b780357 . _:b780346 _:b780358 . _:b291653724 "2"^^ . _:b780346 _:b780359 . _:b780346 _:b780352 . _:b291653288 . _:b780346 _:b780353 . _:b780346 _:b780354 . _:b780346 _:b780355 . . _:b291653678 . . _:b291653721 "2"^^ . _:b291653720 "2"^^ . _:b780346 _:b780368 . _:b780346 _:b780369 . _:b291653646 . _:b291653723 "2"^^ . _:b291653722 "2"^^ . . _:b291653477 . . _:b291653468 . . . . _:b291653473 . _:b291653661 . . . . . _:b291653344 . _:b291653395 . _:b291653229 . . . . _:b291653636 . _:b780298 _:b780300 . _:b780298 _:b780301 . _:b780298 _:b780302 . _:b291653406 . . _:b780298 _:b780303 . _:b780298 _:b780299 . _:b291653584 . . . _:b780298 _:b780316 . _:b780298 _:b780317 . _:b291653711 . _:b780298 _:b780318 . _:b780303 "Consistent with this, no proliferation can be detected, and all epithelial cells appear differentiated, in the intestine of mice null for TCF4, the main Wnt pathway transcription factor in the intestinal epithelium (Korinek et al., >>1998<<). The Wnt pathway also regulates the expression of the Eph/Ephrin surface molecules, responsible for the ordered positioning of epithelial cells along the crypt-villus axis (Batlle et al., 2002)." . _:b291653660 . _:b780298 _:b780319 . _:b780298 _:b780312 . _:b780298 _:b780313 . . _:b780298 _:b780314 . _:b780298 _:b780315 . _:b780298 _:b780308 . _:b780298 _:b780309 . _:b780298 _:b780310 . _:b780298 _:b780311 . . _:b780298 _:b780304 . _:b291653554 . _:b780298 _:b780305 . _:b780298 _:b780306 . . _:b780298 _:b780307 . _:b291653211 . _:b780298 _:b780332 . _:b780298 _:b780333 . _:b780298 _:b780334 . _:b780298 _:b780335 . _:b780298 _:b780328 . _:b780298 _:b780329 . _:b780298 _:b780330 . _:b780298 _:b780331 . . _:b780298 _:b780324 . _:b780298 _:b780325 . _:b780326 "SOX9 is also involved in the development of the neural crest (Spokony et al., >>2002<<) and of the spinal cord glial cells (Stolt et al., 2003)." . . _:b780298 _:b780326 . _:b780298 _:b780327 . . _:b291653353 . _:b291653720 . _:b780298 _:b780320 . _:b291653292 . _:b780298 _:b780321 . _:b780298 _:b780322 . _:b780298 _:b780323 . _:b291653613 . . . _:b291653221 . _:b291653440 . _:b291653435 . . . _:b291653487 . _:b291653466 . _:b780370 _:b780416 . _:b780351 "Such cells can be identified because they contain cytoplasmic and nuclear \u03B2-catenin (Korinek et al., >>1997<<). When we stained serial sections for \u03B2-catenin, it was clear that the same structures that strongly expressed SOX9 also contain cytoplasmic and nuclear \u03B2-catenin (Fig. 2, c and d). This result again correlates SOX9 expression with" . _:b780370 _:b780417 . _:b780370 _:b780418 . _:b780370 _:b780419 . . . _:b780417 . . _:b291653486 . _:b780403 "To date, SOX9 has generally been described as a transcriptional activator (S\u00FCdbeck et al., 1996; Bell et al., 1997; Lefebvre et al., 1997; Ng et al., 1997; de Santa Barbara et al., 1998; Liu et al., >>2000<<; Sekiya et al., 2000; Liu et al., 2001; Panda et al., 2001), although it was recently found to mediate a dual transcriptional effect on the COL2A1 gene, depending on the promoter elements involved (Kypriotou et al., 2003)." . _:b780310 "Moreover, targeted mutations of APC or \u03B2-catenin are sufficient to initiate tumorigenesis in the mouse (Fodde et al., 1994; Shibata et al., 1997; Harada et al., >>1999<<), highlighting the importance of the Wnt pathway in the development of cancer." . . _:b291653307 . _:b780380 "fragment did not contain a canonical TCF binding sequence (ATCAAAGG), but contained several noncanonical TCF binding sites, such as described, for instance, in the Siamois (Brannon et al., 1997) and Cyclin D1 (Tetsu and McCormick, >>1999<<) promoters. However, the basal luciferase activity driven by this 2.6-kb SOX9 promoter fragment in LS174T colon carcinoma cells was not modulated by cotransfected \u0394NTCF4 (unpublished data)." . _:b780399 "To date, SOX9 has generally been described as a transcriptional activator (S\u00FCdbeck et al., 1996; Bell et al., >>1997<<; Lefebvre et al., 1997; Ng et al., 1997; de Santa Barbara et al., 1998; Liu et al., 2000; Sekiya et al., 2000; Liu et al., 2001; Panda et al., 2001), although it was recently found to mediate a dual transcriptional effect on the COL2A1" . _:b291653156 . . . _:b780315 "TCFs, SOX proteins have been widely implicated in the establishment of cell multipotency (Avilion et al., 2003; Kim et al., 2003), cell commitment (Mori-Akiyama et al., 2003; Stolt et al., 2003), and differentiation (Kamachi et al., >>2000<<; Stolt et al., 2002). Here, we screened the intestine epithelium for expressed SOX genes to investigate the possibility of a functional link with the related Tcf factors." . . . _:b780345 "The SOX9 antibody has been described previously (de Santa Barbara et al., >>1998<<). The MUC2 antibody (1:1,000) was provided by I. van Seuningen (INSERM U560, Lille, France)." . _:b291653255 . _:b291653618 . . _:b291653283 . . . . . . . _:b291653421 . _:b291653585 . _:b780383 . . _:b291653627 . _:b780406 . _:b780331 "the transcription of target genes which are specific for each process: in chondrogenesis, it regulates the cartilage specific genes Col2a1 (Bell et al., 1997; Lefebvre et al., 1997; Bi et al., 1999), Col11a2 (Bridgewater et al., >>1998<<), Aggrecan (Sekiya et al., 2000), and campomelic dysplasia (CD)\u2013RAP (Xie et al., 1999)." . _:b291653159 "11"^^ . _:b291653153 "20"^^ . . _:b291653158 "11"^^ . _:b291653154 "14"^^ . _:b291653157 "12"^^ . . _:b291653156 "12"^^ . _:b291653152 "28"^^ . _:b291653366 . _:b780370 _:b780396 . _:b291653155 "13"^^ . _:b780370 _:b780397 . _:b780370 _:b780398 . _:b780370 _:b780399 . _:b780370 _:b780392 . _:b780370 _:b780393 . _:b291653374 . _:b780370 _:b780394 . _:b780370 _:b780395 . _:b780370 _:b780388 . _:b780370 _:b780389 . _:b780370 _:b780390 . _:b780370 _:b780391 . _:b291653200 . _:b780370 _:b780384 . _:b780370 _:b780385 . _:b780370 _:b780386 . _:b780370 _:b780387 . _:b780370 _:b780412 . _:b291653166 "10"^^ . _:b780370 _:b780413 . _:b780370 _:b780414 . _:b780370 _:b780415 . _:b291653167 "9"^^ . _:b780370 _:b780408 . . _:b291653321 . _:b291653410 . _:b780370 _:b780409 . _:b291653165 "10"^^ . _:b780370 _:b780410 . _:b780370 _:b780411 . _:b780368 . _:b780370 _:b780404 . _:b291653407 . _:b780370 _:b780405 . _:b291653164 "10"^^ . _:b780370 _:b780406 . _:b780370 _:b780407 . _:b291653369 . _:b780370 _:b780400 . _:b291653163 "10"^^ . _:b780370 _:b780401 . _:b780370 _:b780402 . _:b780370 _:b780403 . . _:b291653162 "10"^^ . "PMC0" . _:b291653161 "11"^^ . _:b291653329 . _:b291653225 . _:b291653160 "11"^^ . _:b291653222 . _:b291653174 "8"^^ . _:b780370 _:b780380 . _:b780370 _:b780381 . _:b780370 _:b780382 . _:b291653175 "8"^^ . _:b780370 _:b780383 . _:b780370 _:b780376 . _:b780370 _:b780377 . _:b780370 _:b780378 . _:b780370 _:b780379 . _:b291653172 "9"^^ . _:b780370 _:b780372 . _:b780370 _:b780373 . _:b780370 _:b780374 . _:b780370 _:b780375 . _:b291653173 "9"^^ . _:b780370 _:b780371 . _:b291653430 . _:b291653170 "9"^^ . _:b291653171 "9"^^ . .