MiR-642a-5p Regulates The Mechanism Of Cervical Cancer Proliferation,invasion And Metastasis By Targeting PTEN

Objective: Cervical cancer(CC)remains one of the leading causes of malignancy death in women worldwide.miRNAs(micro RNAs)are a class of short non-coding RNAs that play important regulatory roles at the post-transcriptional level and are involved in the regulation of cell proliferation,metastasis,drug resistance,and tumorigenesis.More and more studies have shown that miR-642a-5p plays an important role in tumor development,however,studies on the mechanisms related to the proliferation,invasion,and migration of miR-642a-5p on cervical cancer need to be further elucidated.Methods:(1)Relevant datasets were downloaded from The Cancer Genome Atlas(TCGA)database for cervical cancer patients,and all mature miRNA sequences were downloaded from the miRBase website.Cervical cancer patients were randomly divided into training and test groups according to a 1:1 ratio;the training group was screened for miRNAs related to CC prognosis using the LASSO&COX risk regression model,and the test group performed validation of the model.Finally,linear risk models were constructed based on miRNAs expression profiles to predict patient prognosis.(2)Univariate and multifactor COX regression analyses were performed on miRNAs prognostic risk models and other clinical characteristics.(3)Prediction of miRNAs target genes by Arget Scan,miRTar Base,miRDB three-target prediction database model,taking intersection of differentially expressed m RNAs in CC patients’ tissues in TCGA database,followed by gene ontology(GO)study and Kyoto Encyclopedia of Genes and Genomes(KEGG)signaling pathway enrichment analysis to establish protein interaction network(PPI),and the network core genes were screened using Cytoscape 3.8.0 and its plugin cyto Hubba.(4)To validate the biological functions of proliferation,migration and invasion of CC cells expressing miR-642a-5p by using PCR,Western Blot,CCK-8 and Transwell assays.(5)Dual luciferase assays were performed to confirm the relationship between miR-642a-5p and the downstream target gene PTEN.(6)To analyze the expression levels of miR-642a-5p in CC tissues using two databases,TCGA and Kaplan-Meier plotter,respectively,and to study its relevant effects on the prognosis of CC patients.RESULTS:(1)A total of 309 patient miRNA and m RNA expression matrix data and corresponding clinical datasets were downloaded.A total of 194 significantly differentially expressed miRNAs were screened in CC tissues compared with paracancerous tissues.82 miRNAs with increased expression and 112 miRNAs with decreased expression were identified.(2)A total of 6 miRNAs were identified in the training group,which were related to the overall survival of CC patients,and a prognostic risk model was constructed based on the 6 miRNAs.(3)The overall survival time was significantly lower in the high-risk group than in the low-risk group in the training group,the test group,and the overall group.(4)Oneway and multi-way regression analyses were performed,and the risk model was an independent prognostic factor(one-way HR = 1.143,P < 0.001;multi-way: HR = 1.124,P <0.001).(5)On the TCGA dataset,miR-642a-5p had significantly higher expression in CC tissues relative to normal cervical tissues.Overexpression of miR-642a-5p,cervical cancer Si Ha and ME180 cell lines had significantly enhanced proliferation,migration and invasion ability.(6)The results of dual luciferase assay suggested that PTEN was a direct target of miR-642a-5p.After overexpression of miR-642a-5p,PTEN protein level was significantly decreased,while after low expression,PTEN protein level was all up-regulated.(7)miR-642a-5p showed high expression levels in CC tissues,and high miR-642a-5p expression was positively correlated with the prognosis of patients.Conclusion:(1)miR-425-5p and miR-100-3p were negatively correlated with the prognostic survival time of CC patients;miR-6507-5p,miR-502-3p,miRNA-642-5p and miR-548j-5p were positively correlated with the prognostic survival time of CC patients.(2)The prognostic risk model established by 6-miRNAs can better predict patient prognosis and can be used as a novel predictor of independent prognosis for CC patients,which is worth promoting in clinical practice.(3)PTEN,as a direct downstream target gene of miR-642a-5p,was widely low expressed in pan-cancer,but was not statistically associated with the prognosis of cervical cancer.(4)miR-642a-5p promotes cervical cancer cell proliferation,invasion and metastasis.(5)miR-642a-5p promotes proliferation,invasion and metastasis of cervical cancer cells by regulating PTEN.Low expression of miR-642a-5p was associated with poor prognosis of cervical cancer patients.(6)miR-642a-5p may become a potential therapeutic target and prognostic marker for cervical cancer.