MTOR and osteosarcoma: On the basis that the abnormally high expression of MALAT1 in osteosarcoma was found to be similar to the high expression in hypoxia induction, by injecting osteosarcoma tumor transplanted mice with siMALAT solution, Zhang et al found that MALAT1 in osteosarcoma cells induced up-regulation of pro-angiogenic factors, including VEGF-A mainly through MALAT1/mTOR/HIF-1α pathway, and HIF-1α showed positive feedback effect and selectivity.