MicroRNA-7-5p's role in the O-GlcNAcylation and cancer metabolism.

O-GlcNAc Transferase (OGT) is a complementary enzyme that regulates O-linked N-acetylglucosaminylation(O-GlcNAcylation) and plays a critical role in various cancer phenotypes, including invasion, migration, and metabolic reprogramming. In our previous study we found that miR-7-5p was downregulated at lung cancer cells with highly metastatic capacity. In the in-silico approach, OGT is the predicted target of miR-7-5p. To identify miR-7-5p's role in cell growth and metabolism, we transfected various lung cancer cell lines with miR-7-5p. The expression level of miR-7-5p was confirmed by qRT-PCR in lung cancer cell lines. Western blot assays and qRT-PCR were performed to demonstrate miR-7-5p's effect. Bioinformatic analysis indicated that OGT is a direct target of miR-7-5p. The binding sites of miR-7-5p in the OGT 3' UTR were verified by luciferase reporter assay. To investigate the role of miR-7-5p in the cancer metabolism of non-small cell lung cancer (NSCLC) cells, mimic of miR-7-5p was transfected into NSCLC cells, and the effect of miR-7-5p on cancer metabolism was analyzed by LDH assays, glucose uptake, and mitochondrial ATP synthase inhibitor assay. O-GlcNAcylated protein level was determined by Western blot. The role of miR-7-5p in lung cancer growth was measured by MTS assays. To identify the delivery of miR-7-5p via PLGA, an in vitro release assay of PLGA-miR-7-5p was done. miR-7-5p was highly expressed whereas OGT showed low expression in H358, H827. However, miR-7-5p exhibited low expression while OGT had high expression in H522, H460, and H1299 cell lines. OGT were repressed by binding of miR-7a-5p to the 3'-UTR. Overexpression of miR-7-5p also diminished anaerobic glycolysis. miR-181a-5p transfection induced expression levels of OGT were diminished compared to those in the control group. O-GlcNAcylation was suppressed by miR-7-5p. Moreover, the overexpression of miR-7-5a suppressed lung cancer cell growth. miR-7-5p was released via PLGA for up to 10 days. In the present study, inhibition of OGT by miR-7-5p decreased the growth and cancer metabolism of lung cancer.