Hypermethylation Analysis Of Cervical Cancer-associated Tumor Suppressor Genes

Cervical cancer is one of the most common gynecological cancers.The incidence and mortality of cervical cancer are decreasing worldwide.However,the incidence of cervical cancer in China is increasing and the trend is younger.Foreign studies have shown that cervical cancer screening for women of appropriate age can significantly reduce the incidence and mortality of cervical cancer.In cervical cancer,after high-risk human papillomavirus(HPV)infection of host cells,HPV can promote the occurrence and development of tumor through its own gene methylation and induction of host cell gene methylation.Thus,methylation detection has potential clinical value in cervical cancer screening.This study aimed to evaluate the potential clinical value of tumor suppressor genes PAX1,MAL and FAM19A4 as methylation molecular markers in screening cervical cancer and precancerous high-grade lesions.The research contents of this study are as follows:1)The methylation status of FAM19A4 and MAL genes in cervical cancer was analyzed by meta-analysis.The published data were collected and meta-analyzed by Rev Man 5.3 and Meta Disc 1.4 software.The pooled diagnostic odds ratio(DOR),sensitivity,specificity,positive likelihood ratio(PLR)and negative likelihood ratio(NLR)were calculated and the summary receiver operating characteristic curve(SROC)was drawn to evaluate the detection efficiency of methylation of two genes in cervical cancer and precancerous high-grade lesions.8 related studies of FAM19A4 gene and 10 related studies of MAL gene were included.The DOR,sensitivity,specificity,PLR,and NLR for FAM19A4 methylation in cervical intraepithelial neoplasia grade 3 and above(CIN3 +)were 7.62,0.76,0.71,2.59,and 0.34 respectively,while the area under curve(AUC)of SROC was 0.80.The DOR,sensitivity,specificity,PLR,and NLR for MAL methylation in CIN3 + were 12.81,0.79,0.64,3.46 and 0.29 respectively,while the AUC was 0.85.The results of meta-analysis further indicated that the methylation status of FAM19A4 gene and MAL gene was the potential auxiliary marker for cervical cancer screening.2)This part evaluated the value of PAX1,FAM19A4 and MAL genes and their combination as methylation markers in the screening of cervical cancer and precancerous high-grade lesions.The methylation of PAX1,MAL and FAM19A4 genes were detected by quantitative methylation-specific PCR in 127 samples of cervical cancer,CINs and normal controls.The clinical sensitivity,specificity,positive predictive value(PPV)and negative predictive value(NPV)of single gene and gene combination were calculated.For CIN3+samples,the sensitivity,specificity,PPV and NPV of PAX1 gene were 0.76,0.76,0.56 and0.88 respectively;the sensitivity,specificity,PPV and NPV of FAM19A4 gene were 0.68,0.72,0.50 and 0.84 respectively;the sensitivity,specificity,PPV and NPV of MAL gene were 0.65,0.73,0.50 and 0.84 respectively.Positive methylation of any two genes of PAX1,FAM19A4 and MAL could obtain the best detection efficiency,the sensitivity,specificity,PPV and NPV for CIN3+ were 0.78,0.74,0.56 and 0.89.The results showed that the methylation status of PAX1,FAM19A4 and MAL genes had important clinical value in the screening of cervical cancer,especially in the evaluation of CIN3+ lesions.The result of meta-analysis supported that the methylation detection of FAM19A4 and MAL genes could be used for cervical cancer screening.Through the detection and analysis of clinical samples,it was found that the methylation rate of PAX1,FAM19A4 and MAL genes increased with the development of the disease.The methylation rate in the CIN2 group,CIN3 group and cervical cancer group were significantly different from the normal control group(P<0.05).These results suggested that these genes were closely related to the occurrence and development of cervical cancer.The NPV of the three gene combination in CIN3+ was 0.89,which meant that the gene combination was the potential marker for cervical cancer screening(especially for CIN3+).Large-scale clinical validation and molecular mechanism analysis will be needed in the future.