MicroRNAs (miRNAs) are important regulators of many physiological and pathological processes, including cell proliferation, apoptosis, and cell cycle arrest. In this study, we aimed to investigate the biological role of miR-155 in cervical cancer and the underlying molecular mechanism involved in tumorigenesis. The expression of miR-155 in human cervical cancer tissues was detected by real-time PCR. MTT assay and BrdU incorporation assay were used to measure the proliferation of cervical cancer cells. Apoptosis cells and cell cycle distribution were analyzed by flow cytometry. We found that the expression of miR-155 was upregulated in cervical cancer tissues compared to the adjacent non-cancer tissues. Overexpression of miR-155 promoted the proliferation of Hela and SiHa cells. By contrast, downregulation of miR-155 inhibited the growth of cervical cancer cells. Flow cytometry analysis showed that low expression of miR-155 promoted apoptosis and induced cell cycle arrest in Hela and SiHa cells. Moreover, the mRNA and protein expression of LKB1 was significantly reduced in cervical cancer tissues. Luciferase reporter assay demonstrated that LKB1 was a target gene of miR-155, suggesting that miRNA-155 promoted the proliferation of cervical cancer cells by regulating LKB1 expression.
a b s t r a c tMicroRNAs negatively regulate target gene expression at the post-transcriptional level during carcinogenesis. Recent advances revealed that the expression levels of several miRNAs are up-or downregulated in endometrial carcinoma (EC). Here we identify dysregulated miRNAs in EC and we elucidate the essential role of let-7a. The expression of 86 miRNAs in EC was found to be different from adjacent normal endometrial tissues. Moreover, miR-let-7 members are down-regulated in EC and let-7 miRNAs are highly associated with endometrial cancer. A functional investigation revealed that let-7a suppressed proliferation of HeLa cells by targeting Aurora-B. Let-7a also antagonizes Aurora-B functions in promoting carcinoma cell proliferation by down-regulating Aurora-B protein level. Let-7a could be applied for gene therapy against endometrial carcinogenesis.
BackgroundTo investigate the role of total cellular microRNA (miRNA) in regulating epithelial-to-mesenchymal transition (EMT) during human endometrial endometrioid adenocarcinoma (EEC).MethodsA miRCURY LNA microRNA array was used to evaluate the miRNA profiles of human EEC tissues and corresponding nontumorous endometriums. An in vitro model of TGF-β induced EMT in HEC-1-A cells was used to investigate the role of miRNAs in the EEC during EMT. The expression of SMAD3, SMAD5, and a panel of EMT markers was detected by Western blot and quantitative PCR.ResultsThe results of miRNA profiling in human EEC tissues and corresponding nontumorous endometriums demonstrated that miR-23a expression was down-regulated. Using bioinformatics, we identified SMAD3 or SMAD5 maybe as a predicted target of miR-23a. The results of luciferase reporter assay showed miR-23a directly targets and down-regulates human SMAD3 protein levels, not SMAD5 protein levels. Furthermore, overexpression of miR-23a in HEC-1-A cells increased E-cadherin expression and decreased the expression of vimentin and alpha smooth muscle actin, markers of mesenchymal cellular phenotype.ConclusionsOur data provide firm evidence of a role for miR-23a in the direct regulation of EMT through its targeting of SMAD3. Due to its ability to repress the EMT, miR-23a may be a novel target for EER therapeutic intervention.Electronic supplementary materialThe online version of this article (doi:10.1186/s12935-016-0342-1) contains supplementary material, which is available to authorized users.
BackgroundThe aim of this study is to find the potential miRNA expression signature capable of predicting survival time for cervical squamous cell carcinoma (CSCC) patients.MethodsThe expression of 332 miRNAs was measured in 131 (Training cohort) and 130 (Validation cohort) patients with CSCC in the Cancer Genome Atlas (TCGA) data portal. The miRNA expression signature was identified by Cox Proportion Hazard regression model to the Training data set, and subsequently validated in an independent Validation set. Kaplan-Meier curves and the receiver operating characteristic analyses of 5 years were used to access the overall survival of miRNA signature. MiRNA signature-gene target analysis was performed, followed by the construction of the regulatory network. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis were used to explore the function of target genes of miRNA signature.ResultsA 2-miRNA expression signature of hsa-mir-642a and hsa-mir-378c associated with survivability was identified in CSCC. Both of them had a significant diagnostic and prognostic value of patients with CSCC. A total of 345 miRNA signature-target pairs were obtained in the miRNA signature-gene target regulatory network, in which 316 genes were targets of has-mir-378c and has-mir-642a. Functional analysis of target genes showed that MAPK signaling pathway, VEGF signaling pathway and endocytosis were the significantly enriched signal pathways that covered most genes.ConclusionsThe 2-miRNA signature adds to the prognostic value of CSCC. In-depth interrogation of the 2-miRNAs will provide important biological insights that finding and developing novel molecularly prediction to improve prognosis for CSCC patients.
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