MicroRNA-181 inhibits the proliferation, drug sensitivity and invasion of human glioma cells by targeting Selenoprotein K (SELK).

ABSTRACT

Gliomas are aggressive type of brain tumors and cause significant human mortality world over. The frequent relapses, development of drug resistance, the adverse effects of the chemotherapy and dearth of the therapeutic targets form the major hurdles in glioma treatment. Several studies suggest that microRNAs (miRs) are involved in the development and progression of different cancers. Herein, the therapeutic potential of miR-181 was explored in human glioma cells. The results showed that miR-181 is significantly downregulated in human glioma cells. Overexpression of miR-181 caused significant inhibition in the proliferation of U87 and U118 glioma cells. The miR-181 triggered growth inhibition was found to be mainly due to the induction of apoptosis which was concomitant with increase in the Bax/Bcl-2 ratio. Additionally, miR-181 enhanced the chemosensitivity of the glioma cells to temozolomide and suppressed their invasion. Bioinformatic analysis showed that miR-181 exerts its effects by inhibiting the expression of Selenoprotein K (SELK). The expression of SELK was found to be significantly upregulated in glioma cells and silencing of SELK suppressed the proliferation of glioma cells. Nonetheless, overexpression of SELK could nullify the effects of miR-181 on the proliferation of the glioma cells. Taken together, miR-181 may exhibit therapeutic implications in the treatment of glioma.