李梅　     张余

Osteosarcoma (OS) is the most common primary malignant bone tumor, usually arising in the long bones of adolescents and young adults. While our knowledge of the molecular pathogenesis of OS has increased in recent years, we are still far from a comprehensive understanding of the molecular mechanisms of the disease, such as its tumorigenesis, specific mediators of disease progression, occurrence of chemo- resistance, and development of metastasis. Along with the recent discovery of microRNAs (miRNAs), their critical roles in molecular biological processes have been of great interest in the cancer research field, including research on sarcomas. miRNA is a kind of universally distributed and highly conserved non-coding small molecule RNA in eukaryotic cell, and miRNA extensively participates in regulating vital movements of animals and plants. Growing evidences have indicated a strong association between miRNAs and oncogenesis. miRNAs exert their tumor suppressor or oncogenic function by suppressing the expression of protein-coding genes and in turn regulating the signaling pathways. Additionally, miRNAs and their target genes or proteins can be potential novel biomarkers or therapeutic targets for cancer. Characterization of miRNA provides us a new insight into the molecular mechanisms underlying tumorigenesis as well as the new strategy for cancer diagnosis and treatment. This review summarizes the recent progression on the research field of miRNA and its association with Osteosarcoma.