The promising roles of exosomal microRNAs in osteosarcoma: A new insight into the clinical therapy.

Osteosarcoma is the most common malignant bone sarcoma in children. Chemotherapy drugs resistance significantly hinders the overall survival of patients. Due to high biocompatibility and immunocompatibility, exosomes have been explored extensively. Multiple parent cells can actively secrete numerous exosomes, and the membrane structure of exosomes can protect miRNAs from degradation. Based on these characteristics, exosomal miRNAs play an important role in the occurrence, development, drug resistance. Therefore, in-depth exploration of exosome biogenesis and role of exosomal miRNAs will provide new strategies and targets for understanding the pathogenesis of osteosarcoma and overcoming chemotherapy drug resistance. Moreover, advancing evidences have showed that engineering modification could attribute stronger targeting to exosomes to deliver cargos to recipient cells more effectively. In this review, we focus on the mechanisms of exosomal miRNAs on the occurrence and development of osteosarcoma and the potential to function as tumor biomarkers for diagnosis and prognosis prediction. In addition, we also summarize recent advances in the clinical application values of engineering exosomes to provide novel ideas and directions for overcoming the chemotherapy resistance in osteosarcoma.