TY - JOUR AB - Accumulating evidence has demonstrated that microRNAs (miRs/miRNAs) are implicated in carcinogenesis and cancer progression, and can function as oncogenes or tumor suppressor genes in human cancer types. Previous profile studies of miRNA expression levels have revealed that miR‑320a was downregulated in breast cancer, colon cancer, bladder cancer, glioblastoma and salivary adenoid cystic carcinoma. However, its expression level, potential functions and the mechanisms underlying its functions in non‑small cell lung cancer (NSCLC) require further investigation. The present study investigated the expression level, biological roles and underlying molecular mechanisms of miR‑320a in NSCLC. The expression levels of miR‑320a in NSCLC tissue and cell lines were detected using the reverse transcription‑quantitative polymerase chain reaction. Cell proliferation and Transwell invasion assays were performed to examine the effects of miR‑320a on NSCLC cells. In addition, bioinformatic analysis, western blot analysis and luciferase reporter assays were performed to identify the direct gene target of miR‑320a in NSCLC. In the present study it was demonstrated that miR‑320a was significantly downregulated in NSCLC tissues and cell lines. Ectopic overexpression of miR‑320a suppressed the proliferation and invasion of NSCLC cells. Further studies indicated that miR‑320a directly targeted the 3'‑untranslated region of insulin‑like growth factor 1 receptor (IGF‑1R) and suppressed its expression at the mRNA and protein levels. As well as restoring the miR‑320a expression level, the knockdown of IGF‑1R also decreased the growth and invasion of the NSCLC cells. These results suggested that miR‑320a served as a tumor suppressor in the NSCLC cells by directly targeting IGF‑1R. Therefore, miR‑320a should be investigated as a therapeutic target for the treatment of NSCLC. AD - College of Life Sciences, Agricultural University of Hebei, Baoding, Hebei 071001, P.R. China Department of Pediatrics, Baoding Children's Hospital, Baoding, Hebei 071000, P.R. China College of Life Sciences, Hebei University, Baoding, Hebei 071000, P.R. China AU - Wang,Jianguo AU - Shi,Chunyun AU - Wang,Jianfei AU - Cao,Li AU - Zhong,Li AU - Wang,Dongmei DA - 2017/05/01 DO - 10.3892/ol.2017.5863 EP - 3252 IS - 5 JO - Oncol Lett KW - microRNA‑320a non‑small cell lung cancer insulin‑like growth factor 1 receptor growth invasion PY - 2017 SN - 1792-1074 1792-1082 SP - 3247 ST - MicroRNA‑320a is downregulated in non‑small cell lung cancer and suppresses tumor cell growth and invasion by directly targeting insulin‑like growth factor 1 receptor T2 - Oncology Letters TI - MicroRNA‑320a is downregulated in non‑small cell lung cancer and suppresses tumor cell growth and invasion by directly targeting insulin‑like growth factor 1 receptor UR - https://doi.org/10.3892/ol.2017.5863 VL - 13 ER -