MicroRNAs in osteosarcoma.

Osteosarcoma (OS) is a primary malignant bone tumor with high morbidity that principally emerges in children and adolescents. Presently, the prognosis of OS patients remains poor due to resistance to chemotherapy, highlighting the need for new therapeutic approaches. MicroRNAs (miRNAs), a class of small noncoding RNA molecules, can negatively modulate protein expression at the post-transcriptional level. miRNAs regulate a variety of normal physiologic processes and are involved in tumorigenesis and development of multiple malignancies, including OS. Some miRNAs are differentially expressed in OS tissues, cell lines and serum, and have been shown to correlate with the malignant phenotype and prognosis. These altered miRNAs function as oncogenes or tumor suppressor genes in this process. Moreover, restoration of miRNA expression has shown promise for the treatment of OS. Here, we describe miRNA biochemistry with a focus on expression profile, role and therapeutic potential in OS. A better understanding will facilitate the identification and characterization of novel biomarkers and development of miRNA-targeted therapies.