CDX1/2 and KLF5 Expression and Epigenetic Modulation of Sonic Hedgehog Signaling in Gastric Adenocarcinoma

Gastric cancer is among the commonplace causes of cancer death worldwide. Sonic hedgehog (Shh) signaling is an important pathway which may be dysregulated in many cancers.CDX1/2, and KLF5are key transcription factors involved in Shh pathway and cancer stem cells. The aim of this study was to investigate the expression and epigenetic alterations of these genes in gastric cancer patients. DNA methylation's modifications of CDX1, KLF5 and CDX2 genes alongside with the expressions of these genes in gastric cancer tissues and their non-tumoral counterparts (margin tissues) were analyzed using methylation specific sequencing, and Real time PCR Taq man assays, respectively. The expression of CDX1 (P=0.002) and KLF5 (P=0.010) were decreased significantly, but it was considerably increased for CDX2 (P=0.001). Relatively, the results for the regulatory region methylation status of each CpG site had shown a notable fluctuation in these genes with no significant difference in most places. The creation of metastatic lymph nodes in patients was significantly associated with increased expression of CDX2 gene. The modifications of these genes expression can be considered as a cancer biomarker in future studies. Methylation of the investigated genes is not the main mechanism of gastric cancer development.