Acquisition of drug-resistant phenotypes is often associated with chemotherapy in osteosarcoma. A number of studies have demonstrated a critical role for autophagy in osteosarcoma development, therapy and drug resistance. However, the molecular mechanisms underlying the autophagy-mediated chemotherapy resistance of osteosarcoma cells remain largely unknown. In the present study, we determined the autophagy and microRNA-140 (miR-140-5p, miRBase ID: MIMAT0000431) expression induced by chemotherapeutic drugs in osteosarcoma cells. Then we determined the promotory role of miR-140-5p to the chemotherapy-induced autophagy. Our results demonstrated that miR-140-5p expression was highly induced during chemotherapy of osteosarcoma cells, and this was accompanied by upregulated autophagy. The increased miR-140-5p expression levels upregulated anticancer drug-induced autophagy in osteosarcoma cells and ameliorated the anticancer drug-induced cell proliferation and viability decrease. Importantly, miR-140-5p regulates this context-specific autophagy through its target, inositol 1,4,5-trisphosphate kinase 2 (IP3k2). Therefore, the results of the present study demonstrated that miR-140-5p mediated drug-resistance in osteosarcoma cells by inducing autophagy. This study provides evidence of microRNA regulation of autophagy through modulation of IP3 signaling. The present study recognized a novel mechanism of chemoresistance in osteosarcoma cancers.
- drug resistance
- osteosarcoma cell
- 1,4,5-trisphosphate (IP3) signaling
- ©2016 The Author(s)
This is an Accepted Manuscript; not the final Version of Record. You are encouraged to use the final Version of Record that, when published, will replace this manuscript and be freely available under a Creative Commons licence.