MicroRNA-126 enhances the sensitivity of osteosarcoma cells to cisplatin and methotrexate.

The establishment of novel chemotherapy drugs for osteosarcoma is urgently required, and the mechanisms and effects of cisplatin (DDP) and methotrexate (MTX) in the current treatment of osteosarcoma have not been fully elucidated. The present study aimed to observe the effect of DDP, MTX and rapamycin on osteosarcoma cell proliferation and apoptosis, and to investigate the association between miR-126 and the effects of DDP and MTX in osteosarcoma cells. miR-126-overexpressing and -silencing lentiviral vectors were constructed, and MG63 and U-2 OS osteosarcoma cells were infected. An MTT assay was conducted to detect transfected cell proliferation, and the effects of the chemotherapy drugs on transfected cell apoptosis were detected by flow cytometry. The cell cycle of the transfected cells was analyzed via flow cytometry. As the miR-126-overexpressing and -silencing osteosarcoma cell lines were successfully constructed, it was observed that DDP and MTX inhibited osteosarcoma cell proliferation. With the decreased expression of miR-126, the sensitivity of osteosarcoma cells to DDP and MTX was reduced at the same concentration. The flow cytometry suggested that DDP and MTX could promote the apoptosis of osteosarcoma cells with overexpressed miR-126, whereas they could not significantly impact the apoptosis of the miR-126-silenced osteosarcoma cells. Meanwhile, DDP inhibited the cell cycle of the miR-126-overexpressing osteosarcoma cells. In conclusion, DDP and MTX inhibited the proliferation and promoted the apoptosis of the osteosarcoma cells, and these processes were dependent upon the expression of miR-126.