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.
Keywords: Apoptosis; Invasion; Osteosarcoma; Proliferation; TCF7; miR-192.