No abstract

Increasing reports suggest that discovery of microRNAs (miRNAs) might provide a novel therapeutical target for human cancers, including osteosarcoma. Previous studies have shown that miR-32 was dysregulated in breast and endometrial cancer. However, its biological roles in osteosarcoma remain unclear. In the current study, we found that miR-32 was significantly down-regulated in osteosarcoma tissues, compared with the adjacent normal tissues. In vitro studies further demonstrated that miR-32 mimics were able to suppress, while its antisense oligos promoted cell proliferation in Saos-2 and U2OS cells. At the molecular level, our data further revealed that expression of Sox9 was negatively regulated by miR-32. Therefore, our results identify an important role for miR-32 in the osteosarcoma through regulating Sox9 expression.

Menin, encoded by MEN1 gene, has been viewed as a tumor suppressor in several types of tumors, such as insulinoma, parathyroid tumor, and adrenocortical and lung carcinoma. However, its expression and molecular regulation mechanism in osteosarcoma has not been elucidated. Here, our results show menin expression is significantly down-regulated in osteosarcoma tissues, compared with adjacent normal tissues. Besides, we report that MicroRNA-142-3p as a novel target of menin. Up-regulation of MicroRNA-142-3p by menin overexpression inhibits cell proliferation in U2OS and MG63 cells. At the molecular level, MicroRNA-142-3p inhibits the protein expression of FASN through binding to its 3'-untranslated region. Therefore, we elucidate a novel regulation pathway in osteosarcoma cells and suggest a potential therapeutic approach for the tumor therapy.