OBJECTIVE We previously showed that human pancreatic stellate cells(HPSCs)promote pancreatic ductal adenocarcinoma(PDAC)cell growth by activating nuclear factor erythroid2-related factor 2(Nrf2),a key transcriptional ...OBJECTIVE We previously showed that human pancreatic stellate cells(HPSCs)promote pancreatic ductal adenocarcinoma(PDAC)cell growth by activating nuclear factor erythroid2-related factor 2(Nrf2),a key transcriptional regulator of cytoprotective genes.We aim to investigate whether Nrf2-mediated metabolic reprogramming and reactive oxygen species(ROS)detoxification are involved in HPSCs-mediated cell growth.METHODS Nrf2-mediated metabolic genes expression of pentose phosphate pathway(PPP)for purine nucleotide synthesis;glutamine metabolism for nicotinamide adenine dinucleotide phosphate(NADPH)-equivalent producers and also glutathione biosynthesis both for intracellular ROS inactivation were examined using quantitative real-time PCR(qRT-PCR)after treated with conditioned media derived from HPSCs(HPSC-CM)in human PDAC cells(BxPC-3and AsPC-1)with or without Nrf2 gene silencing using siRNA-mediated technique.Metabolites involved in PPP for purine nucleotide and NADPH generation were selected and their concentration was measured using UHPLC-MS/MS.Antioxidants,tiron and N-acetylcysteine(NAC)were used to attenuate the intracellular ROS rendered by Nrf2 before measuring PDAC cell growth and also phosphorylation of extracellular signal-regulated kinase(ERK)1/2and protein kinase B(AKT)using MTT and Western blotting,respectively.RESULTS Metabolically,HPSC-CMupregulated Nrf2-mediated genes involved in three metabolic pathways(G6PD,PGD,TKT,PPAT,MTHFD2,ME1,IDH1,GCLC and GCLM)in BxPC-3and AsPC-1cells.HPSC-CM was able to upregulate all the metabolic genes after Nrf2 gene silencing,and also significantly increased the metabolite concentration of ribose 5-phosphate and inosine 5′-monophosphate,which are involved in nucleotide synthesis for cell growth.Decreasing the intracellular ROS rendered by Nrf2 suppressed PDAC cell growth and also phosphorylation of ERK 1/2and AKT protein.CONCLUSION Our findings reveal that HPSC-CM activates Nrf2-mediated metabolic reprogramming,which leads to purine nucleotide synthesis and ROS detoxification to promote PDAC cell growth.展开更多
基金The project supported by University of Malaya HIR/MOHE/MED-12(Chung)
文摘OBJECTIVE We previously showed that human pancreatic stellate cells(HPSCs)promote pancreatic ductal adenocarcinoma(PDAC)cell growth by activating nuclear factor erythroid2-related factor 2(Nrf2),a key transcriptional regulator of cytoprotective genes.We aim to investigate whether Nrf2-mediated metabolic reprogramming and reactive oxygen species(ROS)detoxification are involved in HPSCs-mediated cell growth.METHODS Nrf2-mediated metabolic genes expression of pentose phosphate pathway(PPP)for purine nucleotide synthesis;glutamine metabolism for nicotinamide adenine dinucleotide phosphate(NADPH)-equivalent producers and also glutathione biosynthesis both for intracellular ROS inactivation were examined using quantitative real-time PCR(qRT-PCR)after treated with conditioned media derived from HPSCs(HPSC-CM)in human PDAC cells(BxPC-3and AsPC-1)with or without Nrf2 gene silencing using siRNA-mediated technique.Metabolites involved in PPP for purine nucleotide and NADPH generation were selected and their concentration was measured using UHPLC-MS/MS.Antioxidants,tiron and N-acetylcysteine(NAC)were used to attenuate the intracellular ROS rendered by Nrf2 before measuring PDAC cell growth and also phosphorylation of extracellular signal-regulated kinase(ERK)1/2and protein kinase B(AKT)using MTT and Western blotting,respectively.RESULTS Metabolically,HPSC-CMupregulated Nrf2-mediated genes involved in three metabolic pathways(G6PD,PGD,TKT,PPAT,MTHFD2,ME1,IDH1,GCLC and GCLM)in BxPC-3and AsPC-1cells.HPSC-CM was able to upregulate all the metabolic genes after Nrf2 gene silencing,and also significantly increased the metabolite concentration of ribose 5-phosphate and inosine 5′-monophosphate,which are involved in nucleotide synthesis for cell growth.Decreasing the intracellular ROS rendered by Nrf2 suppressed PDAC cell growth and also phosphorylation of ERK 1/2and AKT protein.CONCLUSION Our findings reveal that HPSC-CM activates Nrf2-mediated metabolic reprogramming,which leads to purine nucleotide synthesis and ROS detoxification to promote PDAC cell growth.
