Up-regulation of the ectodermal-neural cortex 1 (ENC1) gene, a downstream target of the beta-catenin/T-cell factor complex, in colorectal carcinomas.
To clarify the molecular mechanisms of human carcinogenesis associated with abnormal Wnt/wingless signaling, we searched for genes the expression of which was significantly altered by introduction of wild-type AXIN1 into LoVo colon cancer cells. By means of a cDNA microarray, we compared expression profiles of LoVo cells infected with either adenoviruses expressing wild-type AXIN1 (Ad-Axin) or those expressing a control gene (Ad-LacZ). Among the genes showing altered expression, the ectodermal-neural cortex 1 (ENC1) gene was down-regulated in response to Ad-Axin. The promoter activity of ENC1 was elevated approximately 3-fold by transfection of an activated form of beta-catenin together with wild-type T-cell factor (Tcf)4 in HeLa cells. Semiquantitative reverse transcription-PCR experiments revealed that expression of ENC1 was increased in more than two-thirds of 24 primary colon cancer tissues that we examined compared with corresponding noncancerous mucosae. Introduction of exogenous ENC1 increased the growth rate of HCT116 colon cancer cells in serum-depleted medium. In other experiments, overexpression of ENC1 in HT-29 colon cancer cells suppressed the usual increase of two differentiation markers, in response to treatment with sodium butyrate, a differentiation-inducible agent. These data suggest that ENC1 is regulated by the beta-catenin/Tcf pathway and that its altered expression may contribute to colorectal carcinogenesis by suppressing differentiation of colonic cells.
Fujita
M
M
Laboratory of Molecular Medicine, Human Genome Center, Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan.
Furukawa
Y
Y
Tsunoda
T
T
Tanaka
T
T
Ogawa
M
M
Nakamura
Y
Y
D060466:Axin Protein; D002087:Butyrates / Q000494:pharmacology; D002454:Cell Differentiation / Q000502:physiology; D002455:Cell Division / Q000502:physiology; D003110:Colonic Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D003598:Cytoskeletal Proteins / Q000096:biosynthesis / Q000235:genetics*; D015972:Gene Expression Regulation, Neoplastic; D019073:HT29 Cells; D006367:HeLa Cells; D006801:Humans; D008840:Microfilament Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000502:physiology; D009479:Neuropeptides / Q000096:biosynthesis / Q000235:genetics* / Q000502:physiology; D009687:Nuclear Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000502:physiology; D011401:Promoter Regions, Genetic; D011506:Proteins / Q000235:genetics; D012097:Repressor Proteins; D051820:TCF Transcription Factors; D015534:Trans-Activators; D058118:Transcription Factor 7-Like 2 Protein; D014157:Transcription Factors / Q000096:biosynthesis / Q000235:genetics*; D014161:Transduction, Genetic; D014162:Transfection; D014407:Tumor Cells, Cultured; D015854:Up-Regulation; D051176:beta Catenin
C555451:AXIN1 protein, human; D060466:Axin Protein; D002087:Butyrates; C495270:CTNNB1 protein, human; D003598:Cytoskeletal Proteins; D008840:Microfilament Proteins; D009479:Neuropeptides; D009687:Nuclear Proteins; D011506:Proteins; D012097:Repressor Proteins; D051820:TCF Transcription Factors; C544894:TCF7L2 protein, human; D015534:Trans-Activators; D058118:Transcription Factor 7-Like 2 Protein; D014157:Transcription Factors; D051176:beta Catenin; C112302:ectodermal-neural cortex 1 protein