Determination of AKAP12 methylation levels in peripheral blood using methylation-sensitive high resolution melting analysis in colorectal cancer

Abstract

Objective To detect quantitatively AKAP12 methylation and evaluate its clinical significance in peripheral blood in colorectal cancer. Methods MS-HRM technology was used to detect quantitatively AKAP12 methylation in peripheral blood from 80 colorectal cancer patients and 20 healthy volunteers. They also validated the reproducibility and compared with MSP. Results Thirty-eight of the 80 colorectal cancer samples (47. 5% ) were found to be methylated at the AKAP12 promoter region by MS-HRM (the methylation levels of 24 cancer samples ranged between 1 % and 20% , the methylation levels of 12 cancer samples ranged between 20% and 60% , the methylation levels of 2 cancer samples ranged between 60% and 100% ). The methylation levels of 2 health samples were less than 10% . They also compared the results generated by MS-HRM with a traditional MSP assay. The AKAP12 MS-HRM assay was able to reproducibly detect 1% AKAP12 methylated DNA, whereas the MSP method was unable to detect less than 10% methylation. No significant correlation was observed between the AKAP12 methylation levels and patients' age and gender. However, AKAP12 methylation was significantly higher in DNA from colorectal cancer patients with high Dukes stage and differentiation (x2 =5. 93 or 8. 41, P = 0.01). Conclusions The authors demonstrate here for the first time, the utility of quantitative AKAP12 MS-HRM analysis of promoter methylation in peripheral blood samples. AKAP12 MS-HRM quantitative methods have many promising applications in the detection of colorectal cancer. Key words: A kinase anchor protein 12; Methylation; High resolution melting; Colorectal carcinoma