Effects of microRNA-195 on the Prognosis of Glioma Patients and the Proliferation and Apoptosis of Human Glioma Cells.

Abstract

Glioma is the most common and aggressive intracranial malignant tumor with poor prognosis. Acts as a tumor suppressor, microRNA-195 (miR-195) plays important roles in a variety of cancers. However, the expression of miR-195 and role of miR-195 in glioma are still not well understood. 186 patients with glioma were enrolled and the follow-up period ranges from 1 to 69months. MiR-195 was exogenously transfected into human glioma U87 cell line. The cell proliferation assay (CCK-8), colony formation assay, cell cycle analysis and cell apoptosis analysis were examined to investigate miR-195 effect on U87 cells. MiR-195 levels were reversely correlated with pathological grades (r = -0.487, p = 0.003). For patients with low miR-195 levels, their median survival time was 15months, whereas the median survival time in patients with high miR-195 levels was 56.53months. Multi-factor Cox regression analysis showed that high level of miR-195 (Odds ratio (OR): 0.347, 95% CI: 0.121-0.992) was associated with decreased mortality risk of patients. Moreover, overexpression of miR-195 inhibits proliferation and colony formation, and induces apoptosis of U87 cells. MiR-195 could block the glioma cells in G0/G1 phase, reducing S phase cells and regulating apoptosis related proteins (Caspase-3, Caspase-8, Caspase-9 and Bcl-2). Downregulation of miR-195 was associated with poor prognosis in human glioma. MiR-195 acted as tumor suppressor through inhibiting cell proliferation and promoting cell apoptosis via blockade of cell cycle and regulation of apoptosis related proteins.