TY - JOUR AB - Although malignant glioblastoma (GBM) treatment has significantly improved in the past few decades, the prognosis of GBM remains unsatisfactory. MicroRNA (miR)‑138‑5p has been reported as a tumor suppressor in several types of human cancer; however, little is known about the function of miR‑138‑5p in GBM. The present study aimed to investigate the role of miR‑138‑5p in GBM as well as the underlying molecular mechanisms. The present study performed bioinformatics analysis, reverse transcription‑quantitative (RT‑q)PCR, western blotting, cell viability assays, colony formation assays, invasion assays and cell cycle analysis to investigate the biological function of miR‑138‑5p in both patient tissues and cell lines. In addition, miR‑138‑5p targets in GBM were predicted using Gene Expression Omnibus website and further validated by a dual luciferase reporter gene assay. The results revealed that miR‑138‑5p expression levels in patients with GBM from a Gene Expression Omnibus dataset were significantly downregulated. RT‑qPCR analysis of miR‑138‑5p expression levels also revealed similar results in GBM tissues and cell lines. The upregulation of miR‑138‑5p expression levels using a mimic significantly inhibited the cell viability, colony formation and the G0/G1 to S progression in GBM cell lines, suggesting that miR‑138‑5p may be a tumor suppressor. Moreover, miR‑138‑5p was discovered to directly target cyclin D3 (CCND3), a protein that serves an important role in the cell cycle, and inhibited its expression. Finally, silencing CCND3 using small interfering RNA suppressed the viability of GBM cells. In conclusion, the results of the present study suggested that miR‑138‑5p may function as a tumor suppressor in GBM by targeting CCND3, indicating that miR‑138‑5p may be a novel therapeutic target for patients with GBM. AD - Department of Neurosurgery, Wenrong Hospital of Hengdian, Jinhua, Zhejiang 322118, P.R. China Department of Neurosurgery, The Second Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310009, P.R. China Department of Neurosurgery, The First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310006, P.R. China AU - Wu,Henggang AU - Wang,Cheng AU - Liu,Yajun AU - Yang,Chao AU - Liang,Xiaolong AU - Zhang,Xin AU - Li,Xu DA - 2020/11/01 DO - 10.3892/ol.2020.12127 IS - 5 JO - Oncol Lett KW - microRNA‑138‑5p glioblastoma cyclin D3 PY - 2020 SN - 1792-1074 1792-1082 SP - 264 ST - miR‑138‑5p suppresses glioblastoma cell viability and leads to cell cycle arrest by targeting cyclin D3 T2 - Oncology Letters TI - miR‑138‑5p suppresses glioblastoma cell viability and leads to cell cycle arrest by targeting cyclin D3 UR - https://doi.org/10.3892/ol.2020.12127 VL - 20 ER -