Upregulation of miR-192 inhibits cell growth and invasion and induces cell apoptosis by targeting TCF7 in human osteosarcoma

MicroRNAs (miRNAs) can function as oncogenes or tumor suppressor genes and are involved in multiple processes in cancer development and progression. For example, miR-192 is dysregulated in multiple human cancers, including osteosarcoma (OS). However, the pathophysiological role of miR-192 and its relevance to OS cell growth and invasion has not yet been clarified. This study aimed to investigate the expression of miR-192 in OS and elucidate the molecular mechanisms by which miR-192 acts as a tumor suppressor in this disease. The qRT-PCR data identified significant down-regulation of miR-192 in 20 OS tissue samples and two OS cell lines when compared with adjacent normal tissues and a human osteoblast cell line, respectively. Furthermore, Western blot analysis revealed overexpression of T cell-specific transcription factor (TCF) 7 protein in tumor tissues compared with matched adjacent normal tissues. Further in vitro studies demonstrated that enforced expression of miR-192 inhibited U2OS and MG63 cell proliferation, invasion, and migration and induced apoptosis. Finally, Western blot and Luciferase assays identified TCF7 as a target of miR-192. Collectively, these findings suggest an important role for miR-192 in regulating the proliferation, migration, invasion, and apoptosis of OS cells through the regulation of TCF7.