Significance of Detection of hMLH1 Gene Methylation in Stool DNA for Early Diagnosis of Senile Colorectal Cancer

CAI Ke-yin; XU Mei-hua; WANG Xiao

doi:10.13730/j.issn.1009-2595.2017.12.008

Abstract：Objective To investigate the clinical value of the methylation level of human mutl homolog 1 (hMLH1) in stool DNA of senile colorectal cancer (CRC),and explore its new method for early noninvasive diagnosis of CRC.Methods A total of 30 CRC patients from authors' hospital who were aged over 60 years from June 2015 to September 2016 were selected for the observation group.At the same time,30 individuals who passed the physical examination and aged over 60 years were selected as the control group.Stool DNA of patients from two groups was extracted respectively,and the methylation status of hMLH1 gene was detected by methylation specific polymerase chain reaction (MSP).Meanwhile,the peripheral blood of CRC patients in observation group was collected and the carcinoembryonic antigen (CEA) in serum was detected.The detection rate of hMLH1 gene methylation and detection rate of CEA in observation group were compared respectively,and the differences of detection rate of methylation between two groups were compare& And the correlation between methylation of hMLH1 gene and age,sex and tumor location of CRC patients in observation group was analyzed.Results The detection rate of hMLH1 gene methylation was 63.33％ (19/30) in CRC patients in observation group,which was significantly higher than that in control group (x2 =21.172,P＜0.01) and the detection rate of MSP methylation (63.33％) was significantly higher than that of the traditional CEA detection method (36.67％,11/30) (x2 =4.67,P＜0.05).And there was no significant correlation between hMLH1 gene methylation and age,sex and tumor location of CRC patients in observation group (P＞0.05).Conclusion The detection rate of methylation of hMLH1 gene in stool DNA of CRC patients in observation group is significantly higher than that of traditional detection of CEA in peripheral blood serum.It can be used as a crucial means for early noninvasive diagnosis and screening of senile CRC.