Epithelial-mesenchymal Transition (EMT) Induced By Human Papillomavirus (HPV) In Invasion And Metastasis Of Cervical Cancer

Objective:Cervical cancer is the most common malignant tumor of female genital system. Invasion and metastasis are the primary causes of therapy failure and subsequent death in cervical cancer patients. The exact mechanism of cervical cancer metastasis is still unclear, which strictly restricts therapy progression. The aim of this study was to identify the possible role of HPV16E7on regulating invasive and metastatic phenotype, although HPV is an important etiological factor in cervical cancer.Materials and methods:We observed and performed Real-time PCR and Western blot to investigate the role of HPV16E7on the alteration of EMT phenotype and correlated EMT markers in two paried cervical cancer cell line C33a(HPV-) and SiHa(HPV+). Transwell assay and stem cell colony formation assay were used to exam the influences of HPV16E7induced EMT on cell motility and stem cell like characteristics. Then we used Realtime-PCR to explore the potential relationship of HPV16E7and EMT/CSC-related genes and used immunohistochemistry to further validate the correlation among HPV16E7/Twist2/E-cadherin in cervical cancer tissues. Finally, we validated the role of Twist2in HPV16E7induced EMT at both mRNA and protein levels and used co-immunoprecipitation assay to explore the interact mode between HPV16E7and Twist2.Results:1. HPV16E7induces EMT in cervical caner cells.2. HPV16E7induces EMT concomitant with the acquisition of motility and stem-cell like characteristics3. HPV16E7is a key regulator of the EMT/CSC gene network.4. Correlation between HPV16E7/Twist2and E-cadherin in cervical cancer tissues.5. Twist2is critical and a direct target of HPV16E7in cervical cancer.Conclusion:In the present study, we demonstrated a novel role of HPV16E7in promoting progression and metastasis of cervical cancer by inducing EMT and stem-cell like characteristics via directly targeting Twist2. Objective:Based on the previous research that Twist2is the direct target of HPV16E7in inducing EMT and metastasis in cervical cancer, we further explore the role of Twist2on prognosis、invasion and metastasis in cervical cancer tissues.Materials and methods:Immunostaining against Twist2was performed on144cervical carcinoma specimens with different International Federation of Gynecology and Obstetrics (FIGO) stages and lymph-node metastasis status. Using statistics to analyze the correlation between clinicopathological data and cervical cancer prognosis.Results:1. Pelvic lymph node metastasis, FIGO stage and Twist2nuclear expression are independent predictor of cervical cancer outcome.2. Twist2nuclear expression is the most critical pronostic factor of cervical cancer after pelvic lymph node metastasis and shows more effective predictive performance than FIGO stage.3. Twist2nuclear expression correlates with FIGO stages and pelvic lymph node metastasis.Conclusion:Twist2is an important independent biomarker for prognosis of cervical cance, which also correlates with FIGO stages and pelvic lymph node metastasis. Objective:In response to tumor development, cells initially undergo invasion and metastasis followed by Epithelial-Mesenchymal Transition (EMT, a process cells acquiring motility) and senescence (an endogenous defense mechanism against tumor progression). In our previous study, Twist2has been demonstrated to be a direct target of HPV16E7and can predict outcome in cervical cancer. Here, we further investigate the the molecular mechanism responsible for Twist2induced invasion and metastasis.Materials and methods:Immunostaining against Twist2、E-cadherin and CBX3were performed on cervical carcinoma tissues with different lymph-node metastasis status. And then cervical cancer cell line SiHa was transfected with pcDNA3.1(+)/Twist2or short interfering RNA (siRNA) and subjected to senescence-related assays, migration and invasion assays in vitro.Results:1. Twist2shows negative correlation with E-cadherin and CBX3in cervical cancer tissues and positive correlation with lymph node metastasis.2. Twist2induces EMT and regulates the migration and invasion of SiHa.3. Twist2overrides cell senescence in human cervical cancer cell SiHa.Conclusion:Twist2is a key Twist isoform coupling aberrant signals from EMT to senescence to promote cervical cancer invasion and metastasis.