Influence of long noncoding RNA HOTAIR on human glioma cell metabolism and growth

Abstract

Objective To investigate the influence of long noncoding RNA HOX transcript antisense RNA (HOTAIR) on human glioma cell metabolism and growth. Methods The fluorescently labeled small interfering (si-HOTAIR) was used to transfect glioma U87 and U251 cell lines. The real-time polymerase chain reaction (RT-PCR) was used to detect the expression level of HOTAIR in glioma cells. CCK8 test and colony formation assay were used to detect the growth changes of the glioma cells. Seahorse BioScience XF glycilysis stress test kit and XF mitochondrial stress test kit were used to detect the cell aerobic glycolysis and mitochondrial function. Western blot was used to detect glycolysis related enzymes, including the expression levels of glucose-6-phosphate isomerase (GPI), Pyruvate kinase M2 (PKM2), and lactate dehydrogenase A (LDHA). Results The transfection efficiency of si-HOTAIR in U87and U251cells observed under a fluorescence microscope was more than 90%. The HOTAIR expression in the cells of the si-HOTAIR group was downregulated significantly compared with the negative control group (P<0.01). The proliferative ability and clonal formation ability of the U87and U251 glioma cells of the si-HOTAIR group were significantly lower that than those of the negative group (P<0.01). After downregulation of HOTAIR, the aerobic glycolysis capacity of glioma cells were diminished, showing reduced based glycolysis level (P<0.05), diminished maximum glycolytic capacity (P<0.01), and decreased remaining amount of glycolysis (P<0.01). The expression levels of GPI, PKM2 and LDHA of the si-HOTAIR group were lower than those of the negative control group (P<0.01). After downregulation of HOTAIR, the mitochondrial function in glioma cells was impaired, showing decreased basal respiration level (U87 cells P<0.01), decreased mitochondrial coupling efficiency, and diminished residual respiration ability (P<0.05). Conclusions Downregulation of HOTAIR expression may impair the glycolytic capacity and mitochondrial function of glioma cells, simultaneously influence the growing ability of glioma cells. Key words: Glioma; Mitochondria; Metabolism; Glycolysis; Proliferation; Long noncoding RNA; HOX transcript antisense RNA