Abstract
BACKGROUND: Colorectal cancer (CRC) has been often the main reason for dying worldwide. Many factors are implicated in the progress of colorectal carcinoma, one of the chiefs of which is DNA methylation. Insulin-like growth factor-binding protein 3 (IGFBP3) and twist homolog 1 (TWIST1) genes have already been studied and are potential biomarkers for early colorectal diagnosis. Therefore, we designed this research to assess the levels of methylation of these genes in stool specimens of patients with CRC. MATERIALS AND METHODS: A whole of 80 specimens containing 40 stool specimens from CRC patients and 40 specimens from healthy individuals as a control group was investigated. DNA was extracted using the bisulfate method and methylation of the candidate genes was assessed using methylation-sensitive high-resolution melting method. Differences in the methylation levels between CRC patients and controls were assessed by statistical analysis. RESULTS: Our study showed significant hypomethylation in both IGFBP3 and TWIST1 promoters in patients' samples compared with normal individuals and notably the promoter hypomethylation found in these genes appeared to occur simultaneously (P < 0.0001 and P < 0.0025, respectively). Meantime, hypomethylation of these genes had not any significant connection with medical results. CONCLUSION: Our results propose that the IGFBP3 and TWIST1 genes' methylation status can serve as potential biomarkers for early CRC diagnosis. However, more studies are still necessary to better appreciate the methylation pattern of these two genes in CRC and to prove their effects on protein levels.