The Long Noncoding RNA Cancer Susceptibility Candidate 9 Promotes Nasopharyngeal Carcinogenesis via Stabilizing HIF1α.

Increasing evidence has suggested that long noncoding RNAs (lncRNAs) play critical roles in cancer development. Nasopharyngeal carcinoma (NPC) is a disease with high incidence. Although remarkable progress has been made in understanding the molecular mechanism and therapy strategies in NPC, the potential involvement of lncRNAs in NPC remains largely unknown. In this study, we identified that lncRNA cancer susceptibility candidate 9 (CASC9) is highly expressed in NPC tissues, which facilitates cell growth and is correlated with a poor prognosis of cancer patients. The underlying molecular mechanism revealed that CASC9 interacts with HIF1α and enhances the stabilization of HIF1α. Activation of HIF1α by overexpressed CASC9 promotes the glycolysis and tumorigenesis of NPC cells. Downregulation of CASC9 significantly inhibits NPC cancer cell growth. Collectively, our results illustrated the oncogenic role of CASC9 in promoting the progression of NPC through regulating HIF1α, which imply that modulation of CASC9 expression may be a promising target in cancer therapy.