MicroRNA-488 mediates the growth and glycolysis of human prostate cancer cells by targeting 6-phosphofructo-2-kinase 3 gene

Objective To investigate the effect of micrioRNA (miRNA, miR) -488 on glycolysis and proliferation of prostate cancer cells and the underlying mechanism. Methods Real-time quantitative polymerase chain reaction (Real-time PCR) was used to examine the expression of miR-488 in prostate cancer cells. Bioinformatics prediction and luciferase reporter gene assay were utilized for the identification of the target genes of miR-488. The expression levels of 6-phosphofructo-2-kinase 3 (PFKFB3) mRNA and protein were detected by Real-time PCR and Western blotting after the miR-488 mimic was transfected 24 h later. After miR-488 mimics was transfected, or co-transfected with PFKFB3 over-expression plasmid for 24 h, the capacity of proliferation and the glycolysis of prostate cancer cells (PC-3 and DU145) were determined by cell counting kit-8 (CCK-8), glucose uptake and lactate assay, respectively. Results Compared to the normal prostate epithelium cell RWPE-1, the expression of miR-488 in PC-3 and DU145 cell lines was 0.26±0.03 (P=0.031) and 0.19±0.04 (P=0.021), but there was no statistically significant difference in LNCaP and 22RV1 cells. The glucose uptake rate and the lactate secretion rate were 0.54±0.03 (P=0.042) and 0.52±0.01 (P=0.032), and 0.55±0.02 (P=0.037) and 0.61±0.17 (P=0.048) after up-regulating the expression of miR-488, which indicating the decline of glycolysis ability and the proliferation ability. Bioinformatics prediction and luciferase reporter gene assay showed that PFKFB3 was the target gene of miR-488. After the expression of miR-488 was up-regulated, the expression levels of PFKFB3 mRNA and protein were down-regulated. When miR-488 and PFKFB3 over-expression plasmids were co-transfected into the cells, the proliferation was elevated and the glucose uptake rate and lactate secretion rate were 0.79±0.12 and 0.82±0.11, and 0.77±0.07 (P=0.015) and 0.83±0.04 (P=0.026) respectively, indicating a higher glycolysis rate than the control. Conclusion MiR-488 can regulate the ability of proliferation and glycolsis of prostate cancer cells by targeting PFKFB3 gene. Key words: MicroRNA-488; 6-phosphofructo-2-kinase 3; Prostate cancer; Proliferation; Glycolysis