Long noncoding RNA H19 contributes to the proliferation and autophagy of glioma cells through mTOR/ULK1 pathway

Abstract

Long noncoding RNA (LncRNA) H19 has been proven to be involved in many kinds of cancers including glioma, and a previous study has shown an autophagy regulation of H19. The mammalian target of rapamycin (mTOR) signaling pathway plays a key role in autophagy and Unc-51 like autophagy activating kinase 1 (ULK1) is also thought to be involved in autophagy signaling. In our study, we investigated the role of mTOR/ULK1 autophagy signaling in the H19-mediated promotion of glioma proliferation. Human glioma cells U87 and U251 and normal human astrocytes HA1800 were used in the study. First, the expression of H19 was determined in U87, U251, and HA1800 cells. Then, the cell proliferation and migration of glioma cells were detected, while the protein levels of main molecules of the mTOR/ULK1 pathway and autophagy-related proteins were also examined. Rapamycin, an inhibitor of mTOR, was used to further study the role of H19 in autophagy. We observed that overexpressed H19 promoted the proliferation and migration in glioma cells. The autophagy of U87 cells was suppressed when H19 was overexpressed and enhanced when H19 was silenced. H19 overexpression inhibited mTOR phosphorylation and promoted ULK1 phosphorylation. H19 promoted proliferation, migration, and autophagy by regulating mTOR signaling. In conclusion, we validate that H19 contributes to the proliferation and autophagy of glioma cells through the mTOR/ULK1 pathway.