Background: The present study intends to investigate microRNA-145 expression level in the plasma and tissue of patients with benign and malignant bone tumors and its effects on the proliferation and migration of osteosarcoma cells.
Methods: Thirty-four cases of patients with bone tumors (malignant) and twenty cases with osteochondroma (benign) in the hospital were enrolled into the study. Meanwhile, thirty cases of healthy subjects admitted to the hospital for physical examination in the same period were selected as the control group. MicroRNA-145 expression levels in the plasma of patients in three groups were detected using real-time quantitative RT-PCR. The difference in microRNA-145 expression level in the tissue between patients with benign and malignant bone tumors were compared and analyzed. Human osteosarcoma cell line OS-732 was used for high and low expressions of microRNA-145. Its effect on osteosarcoma cell proliferation level was observed using CCK8 method, and its osteosarcoma cell invasion level was observed using Transwell method.
Results: MicroRNA-145 expression level in the plasma of patients with malignant bone tumors was significantly lower than that of patients with benign bone tumors; microRNA-145 expression level in the plasma of patients with benign bone tumors was significantly lower than that of healthy subjects; the differences were statistically significant (P<0.05). MicroRNA-145 expression level in the tissue of patients with malignant bone tumors was significantly lower than that of patients with benign bone tumors; the difference was statistically significant (P<0.05). Cell proliferation level of human osteosarcoma cell line OS-732 interfered with microRNA-145 was significantly increased, and its cell invasion capacity was also significantly increased; the differences were statistically significant (P < 0.05). However, cell proliferation level of OS-732 with microRNA-145 overexpression was significantly decreased, and OS-732 cell invasion capacity was also significantly decreased; the differences were statistically significant (P<0.05).
Conclusions: Low expression of microRNA-145 in patients with malignant bone tumors may be involved in cell proliferation and invasion of malignant bone tumors like osteosarcoma as a tumor suppressor.