MiR-138 Inhibits The Carcinogenesis And Development Of Cervical Cancer By Tagerting HTERT

Objective: A growing body of evidence suggests that the widespread deregulation of mi RNAs in virtually all types of cancer has been clearly established,as have their implications during each stage of disease initiation,progression and development.There is a growing interest particularly toward mi R-138 in context of numerous cancers.mi R-138,a family of micro RNA precursors,has been reported to function as a tumor suppressor in a variety of human cancers,including renal carcinoma,non-small lung cancer,colorectal cancer,neuroblastoma,esophageal squamous cell carcinoma,nasopharyngeal carcinoma and hepatocellular carcinoma.However,the role and the molecular mechanisms of mi R-138 in cervical remain unclear.Therefore,the purpose of this study was to investigate the clinical significance of mi R-138 expression in cervical cancer,and to evaluate its role and underlying mechanisms in cervical cancer.Method: 59 pairs of cervical cancer samples and matched normal cervical are collected from 59 patients who underwent surgery between October 2010 and July 2014 in the first hospital of Jilin University.First of all,the mi R-138 variation is proved in the occurrence and development of cervical cancer through the RT-PCR method;Secondly,the effects of mi R-138 is illustrated about proliferation apoptosis,migration and invasion of cervical cancer cells by flow cytometry and cell biology technology,and then h TERT was the target of mi R-138 through bioinformatics comparison,RT-PCR and Western blot;Finally,we transplanted mi R-138 over expression the cervical cancer cells into mouse,the role of mi R-138 in the carcinogenesis of cervical carcinoma is proved through evaluation of mice transplanted tumor size and weight.Results: The results of this study are divided into five parts as follows:1.mi R-138 was downregulated in human cervical cancer cell lines and tissue specimens.The result showed that the expression level of mi R-138 was downregulated in cervical cell lines compared with that of the normal cervical cells(Ha Ca T).Additionally,the expression level of mi R-138 in the He La cell line was lower than that of the Si Ha cell line,thus,we selected He La cells for the below study.Real-time PCR analysis showed that the expression of mi R-138 was downregulated in 83.3% of the cervical tissues compared with the adjacent normal tissues;the average magnitude of this decrease was 2.1-fold.In addition,the result showed that the aberrant expression of mi R-138 was correlated with lymph node metastasis(P<0.01)and FIGO stage(P<0.01).There was no correction between mi R-138 expression and age,histologicalgrade,and tumor size.2.Overexpression of mi R-138 inhibited cell viability and colony formation,but induced apoptosis of cervical cancer cells.The q RT-PCR analysis confirmed that transfected mi R-138 mimic caused mi R-138 expression upregulation in cervical cancer cells compared to transfected with mi R-NC.MTT assay showed that transfection with mi R-138 mimic inhibited cell proliferation compared to transfected with mi R-NC.Colony formation assay demonstrated that overexpression of mi R-138 inhibited colony formation of cervical cancer cells.Our results showed that up-regulated mi R-138 induced apoptosis.3.Overexpression of mi R-138 inhibited cell migration and invasion in cervical cancer cells.Our study has showed that overexpression of mi R-138 significantly decreased migration and invasion capacities of He La cells.4.h TERT is a direct target of mi R-138.Using prediction tools,we predicted that the h TERT might be a target of mi R-138.The luciferase reporter assays were performed.Luciferase assay showed that He La cells transfected with mi R-138 significantly decreasedwild-type h TERT-3'UTR reporter activity compared with the cells cotransfected with mi R-NC(P < 0.01),while mi R-138 had no inhibition effect on the mutant h TERT-3'UTR reporter activity,indicting the direct regulation of mi R-138 in the 3'UTR of h TERT m RNA.Western blot assay showed that mi R-138 mimics dramatically decreased the expression of endogenous h TERT expression.5.mi R-138 suppresses tumor growth in vivo.We examined the potential activity of mi R-138 in tumorigenesis using a He La xenograft model.Tumors grew slower in the He La/mi R-138 group than that of He La /mi R-NC group.At the end of treatment,a significant decrease in tumor size and weight was observed in mice injected with He La/mi R-138 group,compared to the group injected with He La /mi R-NC group.Furthermore,we also determined h TERT expression in tumor tissue by western blot.Western blot assay demonstrated that overexpression of mi R-138 significantly decreased h TERT expression.Conclusion and innovation point: The result of our study showed that mi R-138 expression was downregulated in cervical cancer tissues and cell lines.Overexpression of mi R-138 in cervical cancer cells inhibited cell growth in vitro and tumor growth in nude mice.Furthermore,we showed that h TERT wasa direct target of mi R-138 in cervical cancer.Our findings showed mi R-138 in cervical cancer constitutes a potential biomarker of sensitivity or response and target mi R-138 represented a new approach to sensitize cervical cancer to treatment.