Paper Title
LNCRNA PVT1 PROMOTES GLYCOLYSIS AND TUMOR PROGRESSION BY REGULATING FGFR1/PKM2 AND MIR-532-3P/BCL9 SIGNAL PATHWAY IN RENAL CANCER

Abstract
Background - Tumor metabolism is very important for tumorigenesis and progression and has been a hot topic of research in recent years. The mechanisms involved in the regulation of glucose metabolism in renal cancer by PVT1 are unclear.In this study, we identified lncRNA PVT1 promote glycolysis by regulate FGFR1/PKM2 and miR-532-3p/BCL9 signal pathway in kidney cancer cells. Methods - The expression of PVT1 in kidney cancerfrom TCGA database was analyzed, and a PVT1-based prediction model was developed. Cell Counting Kit-8 (CCK-8) assays, colony formation, migration, invasion, glucose uptake and lactate production assays were used to confirmed the role of PVT1 in renal cancer cells. Then, RNA-pulldown followed with western blotting and RNA immunoprecipitation followed with qRT-PCR were conducted to examine the interaction between PVT1 and PKM2, FGFR1. Western blotting was used to detect the role of PVT1 on FGFR1 protein stability in 786-O cells transfected with PVT1 shRNA, with Cycloheximide inside or not. Also, it was used to figure out the role of PVT1 on the formation of PKM2 protein tetramers. Further, qRT-PCR was performed to revealed expression of miR-532-3p after PVT1 knockdown or overexpression. Luciferase reporter assays wereconducted to clarifythe regulatory role of PVT1 on miR-532-3p. Finally, miR-532-3p inhibitor was co-transfected with PVT1 shRNA into 786-O cells to estimate its role in regulating cancer progression. Result - We found that PVT1 was upregulated and could be a prognostic marker in renal cancer. PVT1 enhanced the proliferation and migration of tumor cells while strengthened glycolysis. Mechanically, PVT1 could directly bind to and prevent FGFR1 from ubiquitinated degradation. On the basis of this, stably expressed FGFR1 could phosphorylate PKM2 in the cytoplasm, changing it from a tetrameric form to a dimer, enhancing glycolysis. in addition to this, PVT1 could sponge miR-532-3p and functioned as a ceRNA to regulate BCL9, a gene downstream of miR-532-3p, also leading to the activation of the Wnt pathway, thus promoted the proliferation, migration and enhanced glycolytic capacity of tumor cells. Conclusion - This study revealed that PVT1 regulated glycolysis of kidney cancer cells in two ways, thereby enhanced kidney cancer cells proliferation, migration and invasion. Understanding the role of PVT1 for malignant progression of kidney cancer may provide new targets for future treatment. Keywords - PVT1, PKM2, glycolysis, Wnt, renal cancer