High-throughput sequencing identification of differentially expressed microRNAs in metastatic ovarian cancer with experimental validations.

ABSTRACT: Background:Ovarian cancer (OC) is a common gynecological cancer and characterized by high metastatic potential. MicroRNAs (miRNAs, miRs) have the promise to be harnessed as prognostic and therapeutic biomarkers for OC. Herein, we sought to identify differentially expressed miRNAs and mRNAs in metastatic OC, and to validate them with functional experiments. Methods:Differentially expressed miRNAs and mRNAs were screened from six pairs of primary OC tissues and metastatic tissues using a miRStar™ Human Cancer Focus miRNA and Target mRNA PCR Array. Then, gene expression profiling results were verified by reverse transcription quantitative polymerase chain reaction (RT-qPCR) and western blot assays. The binding affinity between miR-7-5p and TGF?2 was validated by dual-luciferase reporter assay. Expression of miR-7-5p and TGF?2 was manipulated to assess their roles in malignant phenotypes of highly metastatic HO-8910PM cells. Results:MiRNA profiling and sequencing identified 12 miRNAs and 10 mRNAs that were differentially expressed in metastatic tissues. Gene ontology and Pathway analyses determined that 3 differentially expressed mRNAs (ITGB3, TGF?2 and TNC) were related to OC metastasis. The results of RT-qPCR confirmed that the decrease of miR-7-5p was most significant in OC metastasis, while TGF?2 was up-regulated in OC metastasis. Moreover, miR-7-5p targeted and negatively regulated TGF?2. MiR-7-5p overexpression accelerated HO-8910PM cell viability and invasion, and TGF?2 overexpression reversed the results. Meanwhile, simultaneous miR-7-5p and TGF?2 overexpression rescued the cell activities. Conclusions:This study characterizes differentially expressed miRNAs and mRNAs in metastatic OC, where miR-7-5p and its downstream target were most closely associated with metastatic OC. Overexpression of miR-7-5p targets and inhibits TGF?2 expression, thereby inhibiting the growth and metastasis of OC.

SUBMITTER: Gu Y 

PROVIDER: S-EPMC7579798 | biostudies-literature | 2020

REPOSITORIES: biostudies-literature