Utilization Of DNA Hypermethylation In Primary Screening Of Renal Cell Carcinoma

Objective:This study aims to detect the methylation levels of related genes in renal cell carcinoma tumor tissue,renal cell carcinoma paracancer tissue and urine of renal cell carcinoma patients,to find the genes with significant differences in methylation degree in renal cell carcinoma tumor tissue and renal cell carcinoma paracancer tissue,and to evaluate the feasibility of detecting the methylation levels of each gene in urine of renal cell carcinoma patients.The methylation levels of the selected differential genes in the urine of renal cancer patients,renal hamartoma patients and healthy people were further detected and the differences were analyzed to determine the value of differential gene methylation levels in the diagnosis of renal cancer,and to find biological markers for the diagnosis of renal cancer in urine.Methods:renal cell carcinoma tumor tissue,renal cell carcinoma adjacent tissue and urine samples of renal cell carcinoma patients were collected in groups.DNA was isolated and qPCR was performed to detect methylation levels of related genes in renal cell carcinoma tumor tissue,renal cell carcinoma adjacent tissue and urine of renal cell carcinoma patients by sulfite transformation.To find out related genes with significant differences in methylation levels between renal cell carcinoma tumor tissue and renal cell carcinoma paracancer tissue,and compare the methylation levels of related genes in the above urine samples with that in the renal cell carcinoma tumor tissue to further evaluate the possibility of methylation detection of the above differential sites in urine,and screen these genes.The genes screened by the above experiments were further tested for methylation levels in the urine of another batch of patients with renal cell carcinoma,patients with kidney hamartoma and healthy people,and finally the sites with significant differences in the urine of patients with renal cell carcinoma,patients with kidney hamartoma and healthy people were screened out.Meanwhile,the correlation between the sites with significant differences and some clinical data of patients with renal cell carcinoma was analyzed.To evaluate the possibility of the selected sites as auxiliary diagnostic methods for renal carcinoma.Results:1.By qPCR after sulfite transformation of extracted and purified DNA,sites with significant differences in methylation degree,namely MST1R,RASSF1a and DAPK1,were successfully found in renal cell carcinoma tumor tissues and renal cell carcinoma paracancer tissues,and the possibility of urine methylation detection was also verified.2.The degree of DAPK1 methylation in urine was significantly different between the urine of renal cancer patients and that of renal hamartoma patients(p<0.05).The sensitivity and specificity of the ROC curve were 73%,63%,and the area under the ROC curve was 0.699.The degree of DAPK1 methylation in urine was significantly different between the urine of renal cancer patients and healthy people(p<0.05).The sensitivity and specificity of the ROC curve were 90%and 75%,respectively,and the area under the ROC curve was 0.805.There was no significant difference between the methylation degree of MST1R and RASSF1a in the urine of renal cancer patients,renal hamartoma patients and healthy people.3.There was no correlation between the degree of DAPK1 methylation in urine of renal cancer patients and pathological nuclear grade,pathological stage and maximum tumor diameter.Conclusions:There are differences in the methylation degree of DAPK1 in the urine of patients with renal cancer and patients with renal hamartoma,and there are differences in the methylation degree of DAPK1 in the urine of patients with renal cancer and healthy people.The methylation degree of DAPK1 in urine can be used as a marker for the diagnosis of renal cancer.