Human Homeobox TGIFLX Regulates CDX1, CDX2, and OCT1 Genes Expression in Colorectal Cancer Cell Lines

Background: Homeodomain transcriptional regulatory proteins, which are encoded by Homeobox (HOX) genes, play critical roles in both normal development and carcinogenesis. Previous studies have shown that the expression of HOX genes is deregulated in numerous tumors and this expression is specific to each cancer based on the arising embryonic origin tissue and the site of tumor. Method: In this in vitro study, the expression levels of HOXA10, CDX1, CDX2, TGIFLX, TGIFLY, and OCT1 genes were compared across 10 different human colorectal cancer cell lines with different differentiation stages. Subsequently, the effect of TGIFLX siRNA-mediated knockdown on the expression levels of CDX1, CDX2, and OCT1 genes was analyzed in SW948 cell line. Results: The obtained results revealed that these homeobox genes were differentially expressed in different colorectal cancer cell lines. Furthermore, the siRNA-mediated knockdown of TGIFLX led to higher levels of CDX1, CDX2, and OCT1 expression. Conclusion: Our data suggested that TGIFLX plays an important role in the upstream regulation of CDX1, CDX2, and OCT1 genes.