DNA Methylation as Diagnostic and Prognostic Biomarkers in Colorectal Cancer; Focus on Blood Strategies

Introduction: Colorectal cancer (CRC) is among the three most prevalent cancers. Statistics in 2018 indicate that CRC accounted for about 861000 deaths every year. Recent studies have demonstrated that colorectal oncogenesis is a multistep event resulting from the accumulation of a variety of genetic and epigenetic changes in colon epithelial cells, which can be reflected by epigenetic alterations in blood. Due to the growing prevalence of colorectal cancer (CRC), new screening and early detection methods are demanded. Among novel biomarkers, DNA methylation emerged as high potential diagnosis/screening molecular marker. In this review, we focus on DNA methylation changes as potential blood-based biomarkers for diagnosis and prognosis of CRC.Description: Several studies identified new methylation biomarkers in blood including APC, NEUROG1, SFRP2, CDKN2A/P16, hMLH1, NGFR, ALX4, RUNX3, TPEF/HPP1, TWIST1, TAC1, IGFBP3, EYA4, SST and TMEFF2. Some of them have high sensitivity and specificity until 85% and 100%, respectively. The most studied biomarker in CRC is SEPT9, which is the FDA-approved methylation-based biomarker in blood for CRC. In addition to serum and plasma, peripheral blood mononuclear cells (PBMCs) provide an intact source of biomarkers for malignancies. Studies introduced that examining promoter methylation of TFPI2 and NDRG4 genes in peripheral blood mononuclear cells (PBMCs) supply high enough sensitivity and specificity to be nominated as novel noninvasive CRC screening.Discussion and conclusion: As we extensively reviewed DNA methylation biomarkers in CRC detection. Our review shown that these types of biomarkers in blood stream are very promising for diagnosis and prognosis of CRC. In this way next research must work on specific genes that mentioned, with high sample size and facilitate methods for detection of these biomarkers.

کلیدواژه ها:

Methylation ، Biomarker ، Colorectal Cancer ، Diagnosis ، Prognosis