Tian Fei, Jia Ligang, Chu Zhaoping, Han Hua, Zhang Yuan, Cai Jianhui
Obstetrics and Gynecology Teaching and Research Section, Hebei Medical University, Shijiazhuang, Hebei 050017, P.R. China.
Department of Gynecology, Hebei General Hospital, Shijiazhuang, Hebei 050051, P.R. China.
Exp Ther Med. 2018 Feb;15(2):1819-1824. doi: 10.3892/etm.2017.5600. Epub 2017 Dec 6.
Ovarian cancer is a highly prevalent cancer among women. Recent studies have indicated that microRNAs (miRs) may serve important roles in the pathogenesis of ovarian cancer. miR-519a was observed to be downregulated in tissue samples of patients with ovarian cancer; however, its role in ovarian cancer requires further investigation. The aim of the present study was to examine the role of miR-519a in the pathogenesis of ovarian cancer and determine its direct target. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was performed to examine the expression of miR-519a in 20 patients ovarian cancer and 20 normal ovarian tissue samples. Subsequently, SKOV3 cells were cultured and transfected with miR-519a mimics, while MTT and Annexin V assays were performed to investigate the role of miR-519a in the proliferation and apoptosis of SKOV3 cells. In addition, RT-qPCR and western blotting were used to determine the expression levels of miR-519a, signal transducer and activator of transcription 3 (STAT3), myeloid cell leukemia 1 (Mcl-1) and B-cell lymphoma-extra large (Bcl-xl) in untransfected and miR-519a mimic-transfected SKOV3 cells. Dual-luciferase reporter assay was also performed to confirm whether STAT3 was a direct target of miR-519a. The results revealed that miR-519a was significantly downregulated in tissue samples of patients with ovarian cancer as compared with the normal ovarian tissues. Furthermore, transient overexpression of miR-519a inhibited the proliferation and promoted the apoptosis of SKOV3 cells, as well as decreased the mRNA and protein expression levels of STAT3, Mcl-1 and Bcl-xl. Finally, dual-luciferase reporter assay confirmed that STAT3 was a direct target of miR-519a. In conclusion, the present study proved for the first time that miR-519a functions as a tumor suppressor by targeting STAT3 in ovarian cancer, suggesting that miR-519a may be a potential biomarker for the diagnosis and treatment of ovarian cancer.
卵巢癌是女性中一种高度常见的癌症。最近的研究表明，微小RNA（miR）可能在卵巢癌的发病机制中发挥重要作用。观察到miR-519a在卵巢癌患者的组织样本中表达下调；然而，其在卵巢癌中的作用需要进一步研究。本研究的目的是探讨miR-519a在卵巢癌发病机制中的作用，并确定其直接靶点。采用逆转录-定量聚合酶链反应（RT-qPCR）检测20例卵巢癌患者和20例正常卵巢组织样本中miR-519a的表达。随后，培养SKOV3细胞并转染miR-519a模拟物，同时进行MTT和Annexin V检测以研究miR-519a在SKOV3细胞增殖和凋亡中的作用。此外，采用RT-qPCR和蛋白质印迹法测定未转染和miR-519a模拟物转染的SKOV3细胞中miR-519a、信号转导和转录激活因子3（STAT3）、髓样细胞白血病序列1（Mcl-1）和B细胞淋巴瘤-特大（Bcl-xl）的表达水平。还进行了双荧光素酶报告基因检测以确认STAT3是否为miR-519a的直接靶点。结果显示，与正常卵巢组织相比，卵巢癌患者组织样本中miR-519a显著下调。此外，miR-519a的瞬时过表达抑制了SKOV3细胞的增殖并促进其凋亡，同时降低了STAT3、Mcl-1和Bcl-xl的mRNA和蛋白质表达水平。最后，双荧光素酶报告基因检测证实STAT3是miR-519a的直接靶点。总之，本研究首次证明miR-519a在卵巢癌中通过靶向STAT3发挥肿瘤抑制作用，提示miR-519a可能是卵巢癌诊断和治疗的潜在生物标志物。
