Abstract: Objective To study the expression level of microRNA-340 (miR-340) in human glioma and its relationship with the expression of IDH1, p53, CD34 and Ki-67 proteins, and the effect of miR-340 on the expression of glucose transporter 1 / 6 (GLUT1 / 6) in glioma. Methods The expression level of miR-340 was detected by qRT-PCR. Cells were transfected with miR-340 mimics or inhibitor, the expression level of GLUT1 and GLUT6 RNA was detected by qRT-PCR, and the expression level of GLUT1 and GLUT6 protein was detected by Western blotting. Results The expression levels of miR-340 in the glioma tissues and glioma cell lines were significantly lower than those in the normal brain tissues and the normal human glial cell line HEB, respectively (P< 0. 001). The expression level of miR-340 in glioma samples from patients was negatively correlated with the Ki-67 expression level (P = 0. 0012). miR-340 mimics overexpression significantly inhibited the cell proliferation, increased the apoptosis, and reduced the migration and invasion in U87 and U251 cells. Meanwhile, miR-340 mimics significantly inhibited the expression of GLUT1 and GLUT6 in the glioma cell lines (P< 0. 001). Conclusion miR-340 is lowly expressed in the glioma tissues and cells, and the expression level of miR-340 is negatively associated with the expression level of Ki-67. miR-340 affects the glucose metabolism in glioma cells by reducing the expression levels of GLUT1 and GLUT6, which inhibits the cell proliferation and reduces the malignancy of glioma cells. miR-340 can be used as a biomarker for the early diagnosis, treatment effect evaluation and prognosis prediction of glioma. 

Key words: microRNA-340, Ki-67, glucose transporter 1 / 6, glioma