γH2AX在HPV16阳性宫颈鳞癌组织中的表达及意义

摘要

Objective To investigate the expression and significance of γH2AX in cervical squamous carcinoma.Methods Firstly,DNA were extracted from 74 cervical squamous carcinoma samples and PCR were tested for HPV infection.Secondly,formalin-fixed paraffin-embedded tissue sections (4 μm)were stained with H&E method to detect cervical lesions grading.Thirdly,HPV16 DNA were examined by in situ hybridization(ISH) and γH2AX,p16 were examined by immunohistochemical (IHC) staining.Then,30 cases typical tissue sections in which including the normal cervical tissue,cervical intraepithelial neoplasia and cervical carcinoma in situ were selected for comparing the HPV DNA loading,and the γH2AX and,pl6 expression.Finally,the feasibility of γH2AX serving as a biomarks in HPV infection-related cervical carcinogenesis were analyzed.Results In this study,HPV infection ratio is 98.65％,and HPV16 is the most common type with 74.32％ infection.In situ hybridization showed no HPV16 DNA exist in normal cervical tissues and CINI.In CIN Ⅱ HPV DNA exist mainly as episomal DNA.With the increasing of cervical lesions grade,HPV DNA was integrated into chromosome steadily.The expression of γH2AX and pl6 were positively associated with grading of cervical lesions.HPV DNA and γH2AX protein co-exist primarily in the prickle cell layer and the granular cell layer.The HPV DNA and p16 protein exist in different cell layer.Conclusion γH2AX may be employed as a biomarker for HPV positive cervical carcinogenesis.%目的 探讨γH2AX在HPV16阳性宫颈鳞癌组织中的表达及意义.方法 对74例宫颈鳞癌组织通过DNA提取,PCR检测,分析HPV的感染情况并筛选HPV16阳性宫颈癌组织;进而对HPV16阳性的宫颈癌石蜡组织连续切片HE染色明确组织型别,进行HPV16 DNA原位杂交检测HPV定位、免疫组化检测γH2 AX和p16蛋白的表达;最后选取30例典型的包括从正常宫颈组织、宫颈上皮内瘤变到宫颈原位癌渐变的组织切片,对比HPV DNA定位与γH2 AX和p16蛋白的表达,分析γH2 AX作为HPV感染导致宫颈癌发生过程中生物标记物的可行性.结果 经PCR扩增证明HPV感染率为98.65％,HPV16是最常见的型别占74.32％;原位杂交结果显示正常宫颈组织和CIN Ⅰ检测不到HPV16 DNA的存在,CINⅡ中HPV主要为游离型存在,随着宫颈病变的加重,HPV16 DNA逐渐出现整合形式;p16和γH2AX的表达均随着宫颈上皮病变级别的增加其阳性表达率增高,HPVDNA和γH2AX的表达均以颗粒细胞层和棘细胞层为主,定位具有一致性,HPV DNA和p16的表达定位不具有一致性.结论 γH2AX作为DNA损伤激活的重要蛋白,可作为HPV16感染致宫颈癌发生过程中的生物标记物.