Studies On DAPK1 Expression And Its Promoter Methylation Status In Breast Cancer

Objective:To study DAPK1mRNA expression and its promoter methylation status in human breast cancer tissues and their relations to the clinical and pathological features of the patients。Methods:1,Human breast cancer tissue and paired para-cancer tissue,as well as the clinical and pathological data were collected.2.Semi-quantitative RT-PCR was performed to detect the expression of DAPK1 mRNA in human breast cancer tissue and para-cancer tissue.The results were analyzed combined with the clinical and pathological data of the patients.3.Methylation specific PCR (MSP)was performed to detect the methylation status of DAPK1promoter in human breast cancer tissue and paired para-cancer tissue. The results were analyzed combined with the clinical and pathological data of tha patients as well as the RT-PCR results.Results:1, Lower expression of DAPK1 mRNA in human breast cancer tissue was found,compared with that in their para-cancer tissue,which has no direct proportion to clinical parameters including age,TNM stages,tumor size,ER status,PR status,Her2 status (P>0.05 for each parameter),related with clinical parameters including lymph node metastasis and P53 status。(P<0.05for each parameter)。 2.Among the 43 human breast cancer tissue, DAPK1 promoter methylation was detected in 20 case(46.5%).No relationship has been found between DAPK1 promoter methylation and clinical parameters including age,TNM stages,tumor size,ER status,PR status,Her2 status (P>0.05 for each parameter).The methylation of DAPK1 promoter related with clinical parameters including lymph node metastasis and P53 status。(P<0.05 for each parameter)。3.The expression of DAPK1 mRNA was found to be lower in the specimens with DAPK1 promoter methylated than that with its unmethylated(P<0.05).Downregulated DAPK1 expression had correlation with hypermethylation of the promoter.Conclusions :1.The lower expression of DAPK1 mRNA may be involved in the development of breast cancer.2.Hypermethylalion of DAPK1 promoter is one of frequent molecular pathological events in breast cancer.3.The methylated status of DAPK1 promoter is related to its expression.DAPK1 mRNA expression is downregulated when the gene promoter hypermethylated.