Effects of Linc00460 on Aerobic Glycolysis in Breast Cancer Cells via Sponge Adsorption of miR-320a

Objective To explore the effect of Linc00460 on the aerobic glycolysis of breast cancer (BC) cells through sponge adsorption of miR-320a.

Methods The qRT-PCR method was used to detect Linc00460 and miR-320a expression levels in normal breast epithelial cell line MCF-10A and five BC cell lines. The effect of interfering Linc00460 on miR-320a expression was detected by qRT-PCR. The double luciferase reporter gene experiment was used to analyze the targeting relationship between miR-320a and Linc00460. In addition, the si-Linc00460 and miR-320a inhibitor were co-transfected into MDA-MB-231 cells, and the expression level of miR-320a in the cells was detected by qRT-PCR; cell proliferation ability was measured by the MTT method; glucose uptake rate was detected by 2-NBDG method; the content of lactic acid in the cell supernatant was detected by colorimetric method; the key enzymes of glycolysis was detected by the enzyme activity kit; and the expression levels of the key proteins in the glycolysis pathway were detected by Western blot.

Results Linc00460 was highly expressed in five BC cell lines, while miR-320a was lowly expressed as compared with MCF-10A cells. The expression of miR-320a in MDA-MB-231 cells significantly increased after interfering with Linc00460. The double luciferase reporter gene experiment confirmed that miR-320a and Linc00460 could target binding. Interfering with the expression of Linc00460 could inhibit MDA-MB-231 cells proliferation (all P=0.000), reduce the rate of cellular glucose uptake and the content of lactic acid in the cell supernatant (all P=0.000), inhibit the activities of PFK, PK, and LDH enzymes (all P=0.000), and downregulate the protein expression levels of PFKM, GLUT1, and LDHA (all P=0.000). Meanwhile, inhibition of miR-320a could reverse the inhibitory effect of si-Linc00460 on the proliferation and glycolysis of MDA-MB-231 cells (all P=0.000 or 0.001).

Conclusion Linc00460 might adsorb miR-320a, consequently leading to upregulation of PFKM expression, thereby promoting aerobic glycolysis in BC cells.