MicroRNA-145 expression in the plasma of patients with benign and malignant bone tumors and its effects on osteosarcoma cell proliferation and migration.

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.

Gene expression profiling of hybridoma cells after bursal-derived bioactive factor BP5 treatment.

Bursa of Fabricius is the acknowledged vital humoral immune system for B cell differentiation and antibody production. To study the molecular mechanism underlying the effect of bursal-derived BP5, we used gene microarray to analyze the genomic expression profiling of BP5-treated hybridoma cells. BP5 exhibited an immunomodulatory effect on antibody production in hybridoma cells and induced alterations in the gene expression profiles related to the immune-related biological processes, such as T cell activation and proliferation, B cell activation, B cell-mediated immunity, and cytokines cytokine production involved in immune response. In addition, 26 biological pathways associated with immunomodulatory functions were regulated in BP5-treated hybridoma cells, in which p53 signal pathway played an important role in antitumor. Among these regulated genes, 12 differentially expressed genes were verified by qRT-PCR. The activation of p53 activity by BP5 was further confirmed by p53 luciferase reporter assay and p53 expression. Our data revealed that bursal-derived BP5 could regulate various immune-related cellular processes, including antitumor factor p53 signal pathway, perhaps partially accounting for the reported immunomodulatory roles and novel antiproliferation on tumor cells functions of bursal-derived bioactive factor BP5.