Background: Accumulating evidence supports the involvement of microRNAs (miRNAs) in the progression of human cancers including glioma. Recently, miR-769-5p has been reported to play a tumor suppressive role in colorectal cancer and lung cancer, whereas it exerts an oncogenic role in melanoma. However, the role of miR-769-5p and its related mechanism are poorly elucidated.
Methods: The levels of miR-769-5p in glioma tissues and adjacent non-tumor tissues were detected by qRT-PCR. In addition, the effects of miR-769-5p on cell proliferation and apoptosis were evaluated by CCK-8, EdU, colony formation and flow cytometric assays, respectively. Meanwhile, the dual-luciferase reporter assay was used to investigate the interaction of miR-769-5p and lysine methyltransferase 2A (KMT2A) in glioma.
Results: We found that miR-769-5p expression was strongly upregulated in glioma tissues and cell lines. Glioma tissues with high World Health Organization (WHO) grades had obvious higher levels of miR-769-5p compared to samples with low WHO grades. Interestingly, glioma patients highly expressing miR-769-5p showed prominent poorer survivals. Knockdown of miR-769-5p significantly suppressed cell proliferation and resulted in apoptosis in glioma cells. Additionally, miR-769-5p silencing restrained in vivo growth of glioma cells in mice. Interestingly, KMT2A was identified to be a direct target of miR-769-5p in glioma cells. The expression of KMT2A mRNA was downregulated in glioma tissues and inversely correlated with miR-769-5p level. KMT2A overexpression inhibited cell proliferation and induced the apoptosis of A172 cells. Moreover, siRNA-mediated KMT2A silencing could partially abolish miR-769-5p knockdown-induced suppressive effects on A172 cells.
Conclusion: In summary, our findings suggest that targeting miR-769-5p/KMT2A axis may be a promising therapeutic target for glioma treatment.
Keywords: miR-769-5p, glioma, KMT2A, tumor growth, apoptosis