Background: The molecular mechanisms of ovarian cancer (OC) remain unclear. We sought to comprehensively identify microRNAs (miRNAs) that are aberrantly expressed in metastatic OC. Methods: Differentially expressed miRNAs were screened from six pairs of primary and metastatic OC tissues; their possible functions were analyzed and target genes were predicted by bioinformatics. Then gene expression profiling results were established by reverse transcription quantitative polymerase chain reaction and western blot. Targeting relationship between miR-7-5p and TGFβ2 was validated by dual-luciferase reporter assay. CCK-8, Transwell assay, scratch test and flow cytometry were used for cell function detection after miR-7-5p overexpression. Results: Twelve miRNAs and 10 target mRNAs were differentially expressed in primary and metastatic OC tissues. ITGB3, TGFβ2 and TNC correlated to miRNA function in metastatic OC. Among all 7 miRNAs, expression of hsa-miR-141-3p, hsa-miR-7-5p, hsa-miR-187-5p, hsa-miR-200a-3p, and hsa-miR-200b-3p in metastatic OC tissues was obviously lower than that in primary OC tissues ( p < 0.05). Moreover, there was a significant correlation between hsa-miR-7-5p and TGFβ2 in OC tissues. Dual-luciferase reporter assay confirmed that hsa-miR-7-5p negatively targeted TGFβ2. After miR-7-5p overexpression, the OC cell viability and invasion were reduced, the cell cycle was blocked ( p < 0.05). Conclusions: Hsa-miR-141-3p, hsa-miR-187-5p, hsa-miR-7-5p, hsa-miR-200a-3p, and hsa-miR-200b-3p expression was prominently lower in metastatic OC than in primary OC, while TGFβ2 expression was markedly increased in metastatic OC tissues. Hsa-miR-7-5p bound to TGFβ2 3’-UTR to inhibit its expression. Hsa-miR-7-5p targeted TGFβ2 to inhibit cell proliferation, invasion and cell cycle entry.

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 miRNAs were screened from six pairs of primary OC tissues and metastatic tissues using an miRStar™ Human Cancer Focus miRNA & 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 TGFβ2 was validated by dual-luciferase reporter assay. Expression of miR-7-5p and TGFβ2 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, TGFβ2 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 TGFβ2 was up-regulated in OC metastasis. Moreover, miR-7-5p targeted and negatively regulated TGFβ2. MiR-7-5p overexpression accelerated HO-8910PM cell viability and invasion, and TGFβ2 overexpression reversed the results. Meanwhile, simultaneous miR-7-5p and TGFβ2 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 TGFβ2 expression, thereby inhibiting the growth and metastasis of OC.

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 miRNAs were screened from six pairs of primary OC tissues and metastatic tissues using an miRStar™ Human Cancer Focus miRNA & 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 TGFβ2 was validated by dual-luciferase reporter assay. Expression of miR-7-5p and TGFβ2 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, TGFβ2 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 TGFβ2 was up-regulated in OC metastasis. Moreover, miR-7-5p targeted and negatively regulated TGFβ2. MiR-7-5p overexpression accelerated HO-8910PM cell viability and invasion, and TGFβ2 overexpression reversed the results. Meanwhile, simultaneous miR-7-5p and TGFβ2 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 TGFβ2 expression, thereby inhibiting the growth and metastasis of OC.