Effects Of HnRNP K And HPV16 E2/L1 Integrated Genes In Cervical Carcinogenesis And Their Interaction

Objective:Cervical cancer is the third most common malignant tumor in the world,which poses a serious threat to women's health.Persistent infection of high risk human papillomaviru(HR-HPV)is the main cause of cervical cancer.The integration between HPV DNA and host genes is the key in the cervical carcinogenesis,and HPV16 E2 and L1 genes play an important role in this process.Heterogeneous nuclear ribonucleoprotein K(hnRNP K)can combine with DNA or RNA by conservative hnRNP K homology domain(KH domain).hnRNP K is involved in DNA transcription,RNA processing,transport,the regulation of cell cycle and apoptosis,and other biological processes,which regulate gene expression and play a role in signal transduction.The role of hnRNP K has drawn more and more attention in tumorigenesis and developments.However,the role of hnRNP K in cervical carcinogenesis and its relationship with the key genes of HPV16 integration,E2 and L1,is unclear.In this study,we selected HPV16 E2?L1 and hnRNP K to observe the protein expression in different stages of cervical precancerous lesions and investigated the role of hnRNP K and HPV 16 in the carcinogenesis and progression of cervical cancer to provide scientific basis for the etiology and pathogenesis of cervical cancer,and new ideas for the diagnosis and prevention of cervical cancer.Methods:The research objects were 62 women with normal cervix(NC),64 patients with low-grade cervical intraepithelial neoplasm(CIN?)and 60 patients with high-grade cervical intraepithelial neoplasm(CIN?/?)collected from the population cervical lesions cohort that established by our research group in Jiexiu of Shanxi province form June to September of 2014,and 40 patients with cervical squamous cell carcinoma(SCC)collected from Shanxi Tumor Hospital from November of 2015 to February of 2016.All the research objects were examined by the screening of liquid based thin layer cytology test(TCT),colposcopy and pathological diagnosis.The demographic characteristics and related factors of cervical cancer were collected by structured questionnaire,cervical cells and tissue specimens were collected simultaneously.HPV infection was detected by flow-through hybridization and protein expression of hnRNP K and HPV16 E2?L1 were tested by western-blot.SPSS20.0 software was used to conduct the X~2 test,Kruskal-Wallis H test and Logistic regression.The qualitative and quantitative evaluation of the interaction between two factors by additive model and its interaction index RERI,API and S.Generalized multifactor dimensionality reduction(GMDR)were used to analyses the interaction among multiple factors.Results:(1)The infection rate of HPV in NC group(24.2%),CIN I group(43.8%),CIN II/III group(68.3%)and SCC group(87.5%)was different(X~2 = 47.580,P <0.001).HPVs infection lead to CIN ?,CIN ?/? and SCC are 2.44,6.62 and 21.93 times than HPV negative.With the aggravation of cervical lesions,the infection rate increased gradually(X~2trend = 47.238,P <0.001).(2)The infection rate of HPV16 in CIN I group(15.6%),CIN II/III group(46.7%)and SCC group(67.5%)was higher than that of NC group(9.7%).HPV16 infection lead to CIN ?,CIN ?/? and SCC are 1.73,8.17 and 19.39 times than HPV16 negative.With the aggravation of cervical lesions,the infection rate increased gradually(X~2trend =48.036,P<0.001).Compared with NC group,the infection rate of HPV16 in CIN II / III group and SCC group show statistically significant(X~2=20.754,P<0.001;X~2=37.144,P<0.001).(3)The expression of hnRNP K protein in NC group,CIN I group,CIN II/III group and SCC group were different(H=36.768,P<0.001).The expression rates of hnRNP K protein in CIN group,CIN II/III group and SCC group were higher than NC group,and the differences show statistically significan.There were significant difference between the two groups except CIN?group and SCC group(P<0.05).The high expression of hnRNP K result in CIN?,CIN? / ? and SCC are 2.56,5.00 and 3.00 times than the low expression of hnRNP K.With the aggravation of cervical lesions,the expression rate of hnRNP K protein increased and then decreased(X~2trend =11.331,P=0.001).There is positive interaction between expression of hnRNP K protein and HPV16 infection in cervical lesions.(4)The expression of HPV16 E2 protein in NC group,CIN I group,CIN II/III group and SCC group were 1.86±0.08,1.61±0.80,1.02±0.60 and 0.85±0.42,the overall distribution show statistically significant(H=20.990,P<0.001).With the deepening of cervical lesions,HPV16 E2 protein expression decreased gradually,except for NC group and CIN I group,CIN I group and CIN II/III group and CIN II/III group and SCC group,the difference between the other two groups all show statistically significant(P <0.05).(5)The expression levels of HPV16 L1 protein in NC group,CIN I group,CIN II / III group and SCC group were 0.90 ± 0.66,0.93 ± 1.28,0.39 ± 0.46 and 0.21 ± 0.66 respectively.The difference was statistically significant by Kruskal-Wallis H test(H=10.701,P=0.013).The relative expression of HPV16 L1 protein was lower than that of NC group except CIN I group.In addition to the CIN I group and CIN II/III group,CIN I group and SCC group,the other two groups HPV16 L1 protein relative expression was no significant difference(P> 0.05).(6)The interaction of high expression of hnRNP K,low expression of HPV16 E2 and HPV16 L1 protein were analysised by generalized multifactor dimensionality reduction(GMDR).Based on the highest accuracy of the cross validation and the accuracy of the test samples,the best interaction model was determined.The results show that the best model are the three factor model of high expression of hnRNP K and low expression of HPV16 E2 and HPV16 L1 in CIN II/III group and SCC group,but the same effect was not seen in CIN I group.Further take relative factors of cervical cancer into GMDR analysis.The results showed that the optimal model of CIN I group was high expression of hnRNPK and passive smoking.The optimal model of CIN II/III is high expression of hnRNP K,low expression of HPV16 E2,cleaning the vagina after sexual life and spontaneous abortions.The five elements model of high expression of hnRNP K,low expression of HPV16 E2,spontaneous abortions,breast-feeding and parity is the best model in SCC group.Conclusions:(1)HPV infection,especially HPV16 infection,can increase the risk of CIN I,CIN II/III and SCC.(2)The high expression of hnRNP K may increase the risk of cervical carcinogenesis,and it can be used as a early marker of CIN.If the expression of hnRNP K increases then decreases,suggesting that the possibility of cancer increases.High expression of hnRNP K and HPV16 infection may play a synergistic role in cervical carcinogenesis,which suggest the presence of both indicating an increased risk of cervical cancer.(3)The expression levels of HPV16 E2 and L1 protein in CIN II/III and SCC are lower than those in NC and CIN I.It is suggested that both of them may be integrated in the cervical height and cervical cancer,which can be used as a new target protein for the prevention and treatment of cervical cancer.(4)The interaction among hnRNP K,HPV16 E2 and L1 protein may increase the risk of CIN II / III and SCC.It is suggested that hnRNP K may have synergistic effect with HPV16 E2 and L1 in the high cervical intraepithelial neoplasia and cervical cancer,but still need further study.(5)High expression of hnRNP K protein and passive smoking may affect the occurrence of CIN?;high expression of hnRNP K and low expression of HPV16 E2 protein,cleaning the vagina after sexual life,artificial abortion history of the four interactions may increase the risk of CIN II/III;high expression of hnRNP K and low expression of HPV16 E2 protein,breastfeeding,abortion history,the interaction between the five production may affect the occurrence of SCC.It is suggested that in the occurrence of cervical cancer,there may be environmental and viral gene interaction.