The Platelet Isoform Of Phosphofructokinase Contributes To Metabolic Reprogramming And Maintains Proliferation In CcRCC

Objective Metabolic alterations underlying clear cell renal cell carcinoma(RCC)progression include aerobic glycolysis,increased pentose phosphate pathway activity and reduced oxidative phosphorylation.Phosphofructokinase(PFK),a key enzyme of the glycolytic pathway,has L,M,and P isoforms with different tissue distributions.So far it remains unclear which isoform of PFK is abundantly expressed in cc RCC and whether it plays an important role in promoting aerobic glycolysis and macromolecular biosynthesis to support cell proliferation.Methods 1.The expression of PFKP,PFKM,and PFKL in cc RCC and non-malignant kidney tissue was detected by q PCR,Western blot.In addition,the protein level of PFKP was detected by immunohistochemistry(IHC)in cc RCC and non-malignant kidney tissue.2.The impact of PFKP knockdown on cell proliferation,cell cycle distribution,and apoptosis was detected in Caki-1,769-p,and 786-O cells.3.We established Caki-1 cells stably transfected with sh PFKP and sh Ctrl to detect the difference of glycolysis and metabolomics change caused by PFKP suppression.4.We established Caki-1 cells stably transfected with shp53 to investigate the role of p53 in the alteration of cell proliferation,cell cycle distribution,apoptosis induced by PFKP suppression.5.In vivo impact of PFKP knockdown on tumorgenesis in nude mice was evaluated by subcutaneous injection of Caki-1 cells stably transfected with sh PFKP and shCtrl.Results 1.The platelet isoform of phosphofructokinase(PFKP)was the predominant isoform of PFK and up-regulated in human cc RCC.2.Suppression of PFKP not only impaired cell proliferation by inducing cell cycle arrest and apoptosis,but also led to decreased glycolysis,pentose phosphate pathway and nucleotide biosynthesis,accompanied by activated tricarboxylic acid cycle in kidney cancer cells.3.We found that p53 activation contributed to cell proliferation and metabolic defects induced by PFKP knockdown in cc RCC cells.4.Suppression of PFKP led to reduced cc RCC tumor growth in vivo.Conclusions Our data indicate that PFKP not only is required for metabolic reprogramming and maintaining cell proliferation,but also may provide us with a valid target for anti-renal cancer pharmaceutical agents.