A Preliminary Study Of Molecular Pathological Mechanism About HPV Genotyping And The Development Of Cervical Squamous Cell Carcinoma

To explore the molecular pathological mechanism of Humanpapilloma virus(HPV) genotyping and the development of cervicalsquamous cell carcinoma, we proceed the following research: Theapplications and significance of HPV genotyping in cervical cytologyscreening; HPV infection and its genotypes in cervical cancer andprecancerous lesions; the expression characteristics and regularity ofcyclins in cervical cancer and precancerous lesions with HPV infection; thesilencing pathway of HPV16E6/E7oncogenes in the transcription leveland the expression of cell cycle proteins.Collected2,050cases of cervical cells of of department ofgynaecology for HPV genotyping assay; Collected cervical cancer,precancerous lesions and chronic cervicitis paraffin tissue samples, fromwhich we selected129cases for the study through reviewing HE, thendivided them into cervical squamous cell carcinoma(SCC), cervicalintraepithelial neoplasia(CIN), chronic cervicitis. Detected HPVgenotyping of Cervical cancer and precancerous lesions by usingPCR-reverse dot blot hybridization. The data were statistically analysed bySPSS13.0. Selected79cases of cervical lesions paraffin specimens andImmunohistochemistry (SP) was used to detect the expression of p16, p21,p53, Rb and CyclinD1. Immunohistochemistry and RT-PCR and Westernblot were used to detect gene and protein expression of p16, p21, p53, Rb,CyclinD1in cervical cancer cells HCC94and SiHa. By using gene transfertechnology, knocked down E6and E7expression and studied apoptosis of cells and the expression of key signaling molecules p16, p21, p53, Rb,CyclinD1and ki67after E6/E7silenced.The HPV positive rate was25.85%(530/2050) in2050cases ofcervical epithelial cells and the most common types were type16,6,58,52,43. The HPV positive rate was100%in109cervical cancers andprecancerous lesions and the most common type was HPV16genotype.With the increase of the lesion degree, the proportion of single HPVinfection increased and multiple infections decreased. p16wasoverexpressed in cervical cancer and precancerous lesions of HPV positiveand was not expressed in normal tissues of HPV negative. p53did notexpress in normal cervical tissue and expressed occasionally in SCC. Rbprotein expressed in normal cervical tissue and expressed missing in CINand SCC. CyclinD1expressed in normal cervical cell and CINI andexpressed missing in CINII, CINIII and SCC. The expression of p16at themRNA and protein levels in SiHa cells of HPV16positive were higher thanHCC94cells of HPV negative. But CyclinD1expression at mRNA andprotein levels were lower than HCC94cells. RNAi technology knockeddown HPV16E6/E7in SiHa cells and silencing efficiency up to70%andthe expression of E6/E7mRNA and protein expression decreased; theapoptosis rate increased; Ki67gene expression decreased at the mRNAlevel and p21increased expression at the mRNA level.HPV genotyping in cervical cell is important for early screening anddiagnosis of cervical cancer. Cervical squamous cell carcinoma andprecancerous lesions are associated directly with HPV infection. It is thecommon results of low-risk and high-risk subtype, and the sustainedinfection of high-risk HPV is a necessary condition for cervical cancer andhigh-grade precancerous lesions. HPV16infection is the leading cause ofcervical squamous cell carcinoma in China. The expression level of geneand protein of p16, p21, p53, Rb, CyclinD1is closely related to HPVinfection, of which low expression of CyclinD1and high expression of p16 can be found in cervical cancer and precancerous lesions. So p16andCyclinD1can be used as an auxiliary marker in pathological diagnosis ofcervical precancerous lesions; Targeted silencing HPV16E6/E7genes caneffectively inhibit tumor cell proliferation and induce apoptosis. The aboveexperiments settle the foundation for further investigation of HPVgenotyping and molecular pathological mechanism in the development ofcervical cancer.