, , , , , and are highly expressed in colon cancer patients and are regulated by epigenetic alterations.

Background: Colon cancer is a serious public health issue and a major cause of cancer-related mortality worldwide, including Saudi Arabia. Knowledge of genes associated with colon cancer development and progression is essential for identifying new cancer-specific biomarkers to improve the diagnosis of colon cancer.

Methods: The expression levels of , , , , , and in 15 adjacent colon cancer and normal colon tissue samples from male patients were investigated using reverse transcription polymerase chain reaction (RT-PCR) and quantitative RT-PCR (qRT-PCR) assays. qRT-PCR analysis was also used to determine whether reducing DNA methyltransferase (via 5-aza-2'-deoxycytidine treatment) or histone deacetylation (via trichostatin treatment) increased the expression levels of the tested genes.

Results: The analysis of the 15 colon cancer and adjacent normal colon tissue samples revealed that all six genes were expressed in both groups, but their expression levels were significantly higher in the colon cancer group. Furthermore, the mRNA expression levels of the , , , , and genes were considerably upregulated after treatment of HCT116 and Caco-2 cells with 5-aza-2'-deoxycytidine and trichostatin. However, the gene was activated only with trichostatin treatment.

Conclusions: The findings of this study suggest that , , , , , and are suitable candidate biomarkers of colon cancer and their expressions are regulated by hypomethylation and hyperacetylation.