Hypoxia-responsive LncRNA G077640 Promotes ESCC Tumorigenesis Via the H2AX-HIF1α-glycolysis Axis

Long noncoding RNAs (lncRNAs) contribute to esophageal squamous cell carcinoma (ESCC) progression, but the underlying mechanisms remain elusive. In this study, we verified a hitherto uncharacterized hypoxia-responsive lncRNA, G077640, which is upregulated in human ESCC cells and tissues, supporting the proliferation and migration of ESCC cells. Mechanistically, G077640 prevented hypoxia-inducible factor-1α (HIF1α) from being degraded by directly interacting with histone H2AX and further modulated the interaction of HIF1α and H2AX. In addition, G077640 reprogrammed glycolytic metabolism by regulating the expression of glucose transporter 4 (GLUT4), hexokinase 2 (HK2) and pyruvate dehydrogenase kinase 1 (PDK1) for ESCC proliferation and migration. Clinically, G077640 was associated with poor prognosis in ESCC patients. Taken together, our findings identified a hypoxia-responsive lncRNA that contributes to ESCC cells proliferation and migration, and targeting G077640 and its pathway might be a potential therapeutic strategy for ESCC.