T-cell factor-4 frameshift mutations occur frequently in human microsatellite instability-high colorectal carcinomas but do not contribute to carcinogenesis.
T-cell factor-4 (TCF4) is a member of the TCF/LEF (lymphoid enhancer factor) family of transcription factors, and dysregulation of β-catenin is decisive for the initiation and progression of colorectal cancer.
A further analysis revealed gender-specific effects: the TCF7L2_rs7903146_T allele was associated with an increased risk of CRC in women (P(trend) = 0.003) but not in men (P(interaction) = 0.06); the LTA_rs1041981_A allele was associated with a decreased risk for CRC in women (P(trend) = 0.02), with an opposite effect in men (P(trend) = 0.05; P(interaction) = 0.002); the CDKAL1_rs7754840_C allele was associated with a decreased risk for CRC in men (P(trend) = 0.03), with no effect in women (P(interaction) = 0.03).
hTERT may promote CRC by recruiting β-catenin/TCF-4 complex to transactivate CCL2 expression, which is a novel crosstalk mechanism likely involved in the pathogenesis of CRC.
In conclusion, we have identified novel variants of VTI1A-TCF7L2 fusion transcripts, including a novel fusion partner gene, RP11-57H14.3, and demonstrated detectable levels in a large fraction of CRC samples, as well as in normal colonic mucosa and other tissue types.
In summary, the marginal association of the TCF7L2 SNP with CRC might be due to chance, but warrants further laboratory and epidemiological investigation.
In the present study, we investigated whether CRNDE was involved in the development of colorectal cancer via the binding of microRNA (miR)-217 with transcription factor 7-like 2 (TCF7L2) to enhance the Wnt signaling pathway.
Mutations of BAX (G8) and TCF-4 (A9), which are common in MSI-positive colorectal cancer, occurred at rates of 22.7 and 0%, respectively, which suggests that the MSI target gene may differ between endometrial and colorectal cancers.
Of interest, we described a frequent TCF-4 frameshift mutation in mismatch-repair deficient colorectal cancers (MSI-H cancers) that leads to the selective loss of TCF-4 isoforms with CtBP binding abilities.
The intestine-specific transcription factor CDX2 and Wnt effector TCF7L2 bound near rs16969681, with significantly higher affinity for the risk allele, and CDX2 overexpression in CDX2/GREM1-negative cells caused re-expression of GREM1. rs16969681 influences CRC risk through effects on Wnt-driven GREM1 expression in colorectal tumors.
The overexpression of some proproliferative and antiapoptotic genes, such as survivin, telomerase catalytic subunit (hTERT), integrin-linked kinase (ILK), and regulatory factors c-MYB and Tcf-4, has been implicated in the development and progression of several human malignancies including CRC.