TY - JOUR AB - Autophagy has been recognized as an important element of tumor cell migration, invasion, and chemo­resistance, and our previous results showed that Beclin-1-mediated autophagy contributed to osteosarcoma chemoresistance. However, the regulating mechanism of autophagy is still unclear. In this study, our aim was to clarify microRNA (miRNA)-related mechanisms underlying Beclin-1-mediated autophagy followed by chemotherapy in osteosarcoma. First, miRNA screening using qRT-PCR identified that miR-30a was significantly reduced in Dox-resistant osteosarcoma cells. Second, the autophagy activity in Dox-resistant increased while miR-30a expression reduced after chemotherapy agents as indicated by the enhanced expression of Beclin-1, the increased conversion of microtubule-associated protein LC3-I to LC3-II. Furthermore, overexpression of miR-30a significantly promoted chemotherapy-induced apoptosis and reduced autophagy activity responding to chemotherapy. Moreover, rapamycin, an autophagy promoter was able to partly reverse the effect of miR-30a and Luciferase reporter assay identified that miR-30a directly binds to the 3'-UTR of Beclin-1 gene, which further confirmed that miR-30a reduced chemoresistance via suppressing Beclin-1-mediated autophagy. Collectively these results indicate miR-30a and its downstream target gene Beclin-1 can be used in treatment of osteosarcoma chemo­resistance in the future. AD - Department of Orthopaedic Surgery, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200127, P.R. China AU - Xu,Ruida AU - Liu,Shuzhong AU - Chen,Haihong AU - Lao,Lifeng DA - 2016/03/01 DO - 10.3892/or.2015.4497 EP - 1763 IS - 3 JO - Oncol Rep KW - microRNA-30a autophagy Beclin-1 chemoresistance PY - 2016 SN - 1021-335X 1791-2431 SP - 1757 ST - MicroRNA-30a downregulation contributes to chemoresistance of osteosarcoma cells through activating Beclin-1-mediated autophagy T2 - Oncology Reports TI - MicroRNA-30a downregulation contributes to chemoresistance of osteosarcoma cells through activating Beclin-1-mediated autophagy UR - https://doi.org/10.3892/or.2015.4497 VL - 35 ER -