| Back and ObjectiveCervical cancer is the second female’s malignant disease instead of breast cancer in the whole world, which is a serious treat to women’s health life. The infection of high-risk HPV is the main pathogenic factors, but it’s not the only cause of the disease. Object of this subject is to invest the HPV infection, the methylation level of P16gene’s CpG island in cervical exfoliated cells, P16INK4A expression and the relationship among them.MethodsImmunocytochemical assary, SPR-HPV gene analysis and MSP method were carried out in residual liquid-based cytology and specimens of150cases including30normal,30ASCUS,30LSIL,30HSIL and30cervical cancer which were diagnosed by colposcope were enrolled in the second hospital of Shanxi medical university from June2011to December2011. All inspection were agreed before checking by the patients. SPSS18.0software was selected for statistical data analysis of experiment.Results1. Of the150cases,85HPV positive had been detected, accounting for56.67%. Among them were normal for4cases(13.33%), ASCUS for5cases(16.67%), LSIL for18cases(60.00%), HSIL for28cases(93.33%),30cases for SCC(100.00%). The chi-square test(P<0.05) show that high-risk HPV positive rate had significant difference among all groups, which had statistical significance. The linear trend test(P<0.05) shows that with the aggravation of disease degree, the positive rate of high-risk HPV was significantly increased.2. Of the150cases,87p16INK4A positive had been detected, accounting for58.00%. Among them were normal for1cases(3.33%), ASCUS for14cases(46.67%), LSIL for18cases(60.00%), HSIL for25patients (93.33%),30cases for SCC(100.00%). The chi-square test(P<0.05) show that p16INK4A positivity rate had significant difference among all groups, which had statistical significance. The linear chi-square test(P<0.05) shows that with the aggravation of disease degree, the positive rate of p16INK4A was significantly increased.3. Of the150cases,22P16gene methylation positive had been detected, accounting for73.33%. Among them were normal for0cases(0%), ASCUS for1cases(3.33%), LSIL for4cases(13.33%), HSIL for7patients (23.33%),10cases for SCC(33.33%). The chi-square test(P<0.05) show that P16gene methylation positive rate had significant difference among all groups, which had statistical significance. The linear trend test(P<0.05) shows that with the aggravation of disease degree, the positive rate of P16gene promoter methylation was significantly increased.4. Of the150cases,85high-risk HPV positive had been detected. Among of them, there were50p16INK4A positive expression, and35p16INK4A negative expression, positive rate was58.82%;65high-risk HPV negative had been detected. Among of them, there were37p16INK4A positive expression, and28p16INK4A negative expression, positive rate was56.92%. The chi-square test (P>0.05)show that the positive rate of p16INK4A had no significant difference between high-risk HPV positive group and the negative one, which had no statistical significance. The result indicated that the expression of p16INK4A converged between HPV positive and negative cervical cells.5. Of the150cases,85high-risk HPV positive had been detected. Among of them, there were50p16INK4A positive expression, and2P16gene methylation positive;65high-risk HPV negative had been detected. Among of them, there were37p16INK4A positive expression, and20P16gene methylation positive. The Spearman relative analysis shows that p16INK4A positive expression and P16gene promoter methylation positive were negative correlated with high-risk HPV positive samples, with correlation coefficient-0.470(P<0.05), which had statistical significance; Both were no significant correlation in high-risk HPV negative samples(P>0.05), which had no statistical significance.Conclusion1. High-risk HPV testing, p16INK4A immunohistochemical assay and P16gene promoter methylation detection could be successfully used in liquid-based cytology test.2. p16INK4A didn’t expressed in normal, ASCUS and LSIL groups, which had significant expression in HSIL and SCC groups. Consequently, the test of p16INK4A could be used to detected HSIL and SCC in cervical liquid-based cytology.3. p16INK4A expression had little correlation with high-risk HPV infection, which could reflect that the high expression of p16INK4A may have another mechanism besides high-risk HPV. Therefor, we conjecture that it could be used as the substitution index or assistant diagnosis index in those HPV negative cervical lesions screening.4. P16gene promoter methylation was the early event of cervical cancer, which had rarely exprssed in high-risk HPV positive cervical cancer and cervical intraepithelial neoplasia samples, whose mechanism may be related to the substitution effect of HPV. And p16INK4A had high expression in P16gene promoter methylation cervical cancer cells, which indicated that methylation of this gene may be no gene silencing effect. |
