Expression data from three human DLD-1-derived colon cancer cell lines

ABSTRACT: The LEF/TCF family of transcription factors are downstream effectors of the WNT signaling pathway, which drives colon tumorigenesis. LEF/TCFs have a DNA sequence-specific HMG box that binds Wnt Response Elements (WREs). The “E tail” isoforms of TCFs are alternatively spliced to include a second DNA binding domain called the C-clamp. We show that induction of a dominant negative C-clamp version of TCF1 (dnTCF1E) induces a p21-dependent stall in the growth of DLD1 colon cancer cells. Induction of a C-clamp mutant did not induce p21 or stall cell growth. Microarray analysis revealed that induction of p21 by dnTCF1EWT correlated with a decrease in expression of p21 suppressors that act at multiple levels from transcription (SP5, YAP1, RUNX1), to RNA stability (MSI2), and protein stability (CUL4A). We show that the C-clamp is a sequence specific DNA binding domain that can make contacts with 5’-RCCG-3’ elements upstream or downstream of WREs. The C-clamp-RCCG interaction was critical for TCF1E mediated transcriptional control of p21-connected target gene promoters. Our results indicate that a WNT/p21 circuit is driven by C-clamp target gene selection. Gene expression analysis of dnTCF and dnLEF induction in colon cancer cells. Dominant negative LEF/TCFs interferes with endogenous Wnt signaling by binding to Wnt Response Elements of target genes and displacing beta-catenin. Here we used induction of dnTCF-1 (wildtype and mutant forms of the C-clamp DNA binding domain) and dnLEF-1 to identify genes that change expression at 8 hours and 23 hours post-induction.

ORGANISM(S): Homo sapiens

PROVIDER: GSE37964 | GEO | 2012/06/01

SECONDARY ACCESSION(S): PRJNA165841

REPOSITORIES: GEO