The use of aberrant methylated genes SEPT9 and ViM for clinical diagnosis of colorectal cancer

Definition of epigenetic disorders is important for early diagnosis of colorectal cancer. To obtain a model of diagnostic test system with high sensitivity and specificity, we determined the frequency of methylation in SEPT9 and VIM genes. Epigenetic events also were compared with mutations in the RAS family genes. It was confirmed the presence of aberrant methylation in SEPT9 and VIM genes in tumor cells. DNA of tumor samples was significantly more methylated than samples with DNA from adjacent tissue (P = 8,67E-19 for SEPT9 gene and P=8,68E-19 for VIM gene). In the group of patients carried mutations in KRAS or NRAS genes tumor DNA significantly more methylated in gene SEPT9 (P = 0.0018), in contrast to the tumor DNA from patients not carried mutations. We have demonstrated that the combined use of methylation markers can improve the sensitivity of the test systems used in the diagnostics of colon cancer.