IDENTIFICATION OF FREQUENT PROMOTER METHYLATION OF DEATH-ASSOCIATED PROTEIN KINASE IN LIQUID-BASED PAPANICOLAOUS TEST SAMPLES IN VIETNAMESE POPULATION

Abstract

Objective: The infection of high-risk human papillomavirus (HPV) genotypes, particularly HPV-16 and HPV-18, is known to cause cervical cancer (CC); however, aberrant DNA methylation of death-associated protein kinase (DAPK), a member of tumor suppressor gene family, are required for cervical tumorigenesis. The aim of our study was to evaluate the hypermethylation frequency of CpG belonged to DAPK promoter, in Vietnamese patients, as well as to study about the association between hypermethylation, and high-risk HPV infection leading to CC.Methods: Methylation-specific-polymerase chain reaction (MSP) was performed to analyze methylation status from 109 liquid-based papanicolaous test samples, collected from local hospital and were identified whether HPV/or non-HPV, high-risk/low-risk HPV infection, then was confirmed by sequencing.Results: In the case of high-risk HPV infection, the frequency of DAPK gene hypermethylation was 66.67% (24 of 36 cases). Meanwhile, low hypermethylation status was found in low-risk and non-HPV infection, counting for 12.0% (3 of 25 cases), 2.1% (1 of 48 cases), respectively. Significant association of DAPK hypermethylation with high-risk, low-risk, and non-HPV infection was observed (p<0.0001). The DAPK hypermethylation increased the possibility to CC in the case of high-risk HPV infected with high incidence: Odds ratio=34.5 (95% confidence interval [CI]=10.15-117.23, p<0.01), relative risk=12.2 (95% CI=4.56-32.42, p<0.01).Conclusion: Based on those data, it suggested that MSP carried out on noninvasive samples will lead to potential method to screening, diagnosis and early diagnosis of cervical carcinoma in Vietnamese population.