TATA box-binding protein-associated factor 12 is important for RAS-induced transformation properties of colorectal cancer cells.
Activating mutations in the RAS proto-oncogene result in constant stimulation of its downstream pathways, further leading to tumorigenesis. Transcription factor IID (TFIID) can be regulated by cellular signals to specifically alter transcription of particular subsets of genes. To investigate potential links between the regulation of TFIID function and the RAS-induced carcinogenesis, we monitored the expression of the TATA box-binding protein and its associated factors (TAF) in human colon carcinoma cells. We primarily identified TAF12 levels as being up-regulated in cell lines bearing natural RAS mutations or stably overexpressing a mutated RAS isoform via a mitogen-activated protein kinase/extracellular signal-regulated kinase kinase-dependent pathway. We further showed by electrophoretic mobility shift assays and chromatin immunoprecipitation that the ETS1 protein was interacting with an ETS-binding site on the TAF12 promoter and was regulating TAF12 expression. The binding was enhanced in extracts from oncogenic RAS-transformed cells, pointing to a role in the RAS-mediated regulation of TAF12 expression. Reduction of TAF12 levels by small interfering RNA treatment induced a destabilization of the TFIID complex, enhanced E-cadherin mRNA and protein levels, and reduced migration and adhesion properties of RAS-transformed cells with epithelial to mesenchymal transition. Overall, our study indicates the importance of TAF12 in the process of RAS-induced transformation properties of human colon cells and epithelial to mesenchymal transition, most notably those related to increased motility, by regulating specifically expression of genes such as E-cadherin.
Voulgari
Angeliki
A
Laboratory of Signal Mediated Gene Expression, Institute of Biological Research and Biotechnology, National Hellenic Research Foundation, 48 Vasileos Konstantinou Avenue, Athens 11635, Greece.
Voskou
Stella
S
Tora
Làszlò
L
Davidson
Irwin
I
Sasazuki
Takehiko
T
Shirasawa
Senji
S
Pintzas
Alexander
A
D000230:Adenocarcinoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D001483:Base Sequence; D001665:Binding Sites; D018938:Caco-2 Cells; D015820:Cadherins / Q000096:biosynthesis / Q000235:genetics; D002460:Cell Line; D002465:Cell Movement; D002471:Cell Transformation, Neoplastic / Q000235:genetics* / Q000378:metabolism; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D016384:Consensus Sequence; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D009154:Mutation; D009361:Neoplasm Invasiveness; D015689:Oncogene Protein p21(ras) / Q000235:genetics*; D011401:Promoter Regions, Genetic; D020033:Protein Isoforms / Q000235:genetics; D000090063:Proto-Oncogene Mas; D050784:Proto-Oncogene Protein c-ets-1 / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D035381:TATA-Binding Protein Associated Factors / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000235:genetics*; D035362:Transcription Factor TFIID / Q000378:metabolism
D015820:Cadherins; C000715470:MAS1 protein, human; D020033:Protein Isoforms; D000090063:Proto-Oncogene Mas; D050784:Proto-Oncogene Protein c-ets-1; D012333:RNA, Messenger; C470012:TAF12 protein, human; D035381:TATA-Binding Protein Associated Factors; D035362:Transcription Factor TFIID; D015689:Oncogene Protein p21(ras)