RESUMO
OBJECTIVE: Promoter methylation of Bcl-2 family genes in cancer cells were studied to verify possible correlation between DNA methylation pattern of Bcl-2 family members and cancer. METHODS: The genomic DNAs were extracted from different cancer cell lines, HeLa, CaSki and K562, and ovarian cancer tissue from patients. The cytosine residues were converted to uracil by sodium bisulfite treatment. MSP (methylation specific PCR) was performed to determine the methylation status of Bcl-2, Mcl-1, Noxa, and Harakiri promoters. Using primers that distinguish methylated DNA from unmethylated DNA after bisulfite modification of DNA, MSP was conducted to observe the methylation pattern of Bcl-2 family genes in different cancer cells. RESULTS: The promoter regions of Bcl-2 family genes including Mcl-1, Bcl-2, and Noxa were not methylated in cancer cells, whereas the proapoptotic Bcl-2 family gene Harakiri was detected as methylated in the cancer cell lines and hypomethylated in the ovarian cancer tissue. CONCLUSION: The present study demonstrated the differential methylation profiles of Bcl-2 family genes in cancerous cells, which suggests a possible connection between the methylation pattern of some of Bcl-2 family genes and ovarian cancer.