1. Lower miR-340 expression predicts poor prognosis of non-small cell lung cancer and promotes cell proliferation by targeting CDK4.
- Author
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Qin, Yingzhi, Zhou, Xiaoyun, Huang, Cheng, Li, Li, Liu, Hongsheng, Liang, Naixin, Chen, Yeye, Ma, Dongjie, Han, Zhijun, Xu, Xiaohui, He, Jia, and Li, Shanqing
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MICRORNA , *GENE expression , *NON-small-cell lung carcinoma , *CANCER cell proliferation , *GENE targeting , *CD antigens , *PROGNOSIS - Abstract
Abstract Aberrantly microRNAs (miRs) expression is reported to be involved in tumorigenesis and development in non-small cell lung cancer (NSCLC). MiR-340 had been identified to be downregulated in NSCLC in the previous study. However, the underlying mechanisms of miR-340 involved in NSCLC progression still needed to be well known. In the present study, we confirmed that miR-340 expression was notably down-regulated in NSCLC tissues compared to matched adjacent noncancerous lung tissues by quantitative real time PCR (qRT-PCR) analyses. Lower miR-340 expression positively related to lymph node metastasis, larger tumor size, advanced TNM stage and poor prognosis of NSCLC patients. In vitro assays, we demonstrated that upregulation of miR-340 expression suppressed cell proliferation ability. Bioinformatics analysis and luciferase reporter assays revealed that miR-340 directly targeted the 3′-untranslated (3′UTR) region of CDK4 mRNA. Over-expression of miR-340 suppressed cell proliferation by regulating CDK4 expression in NSCLC cells. Additionally, we showed that increased miR-340 expression promoted the expression of cell proliferation related protein CDK6 expression, but decreasing the P15 and P21 expression. In vivo, we verified that miR-340 overexpression also inhibited tumor growth by regulating CDK4 expression. Therefore, these findings revealed miR-340 functions as a tumor suppressor in NSCLC cells and may provide a potential target of NSCLC treatment. Highlights • MiR-340 expression is downregulated in NSCLC tissues and associated with tumor prognosis. • MiR-340 inhibited cell proliferation, cell colony formation and cell cycle progression of NSCLC. • MiR-340 inhibited NSCLC cell proliferation by targeting CDK4. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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