title: Reactive oxygen species regulate insulin-induced VEGF and HIF-1alpha expression through the activation of p70S6K1 in human prostate cancer cells.
abstract: Vascular endothelial growth factor (VEGF) and hypoxia-inducible factor 1 (HIF-1) are important regulators of angiogenesis. HIF-1 is composed of HIF-1alpha and HIF-1beta subunits, and regulates VEGF expression at transcriptional level. In this study, we demonstrated that insulin induced H2O2 production and p70S6K1 activation in PC-3 prostate cancer cells. The inhibition of H2O2 production by catalase abolished insulin-induced p70S6K1 activation. H2O2 production is also required for insulin-induced VEGF and HIF-1alpha expression in the cells. Over-expression of p70S6K1 or HIF-1alpha reversed catalase- and rapamycin-inhibited VEGF transcriptional activation. These results suggest that insulin induced HIF-1alpha and VEGF expression through H2O2 production and p70S6K1 activation in prostate cancer cells. In addition, we found that inhibition of p70S6K1 by rapamycin decreased prostate tumor angiogenesis, suggesting that p70S6K1 plays an important role in tumor angiogenesis. These results provide some useful information for prostate cancer therapy in the future.
authors.affiliation: The Institute for Nutritional Sciences, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.
authors.forename: Qiong
authors.initials: Q
authors.lastname: Zhou
authors.forename: Ling-Zhi
authors.initials: LZ
authors.lastname: Liu
authors.forename: Beibei
authors.initials: B
authors.lastname: Fu
authors.forename: Xiaowen
authors.initials: X
authors.lastname: Hu
authors.forename: Xianglin
authors.initials: X
authors.lastname: Shi
authors.forename: Jing
authors.initials: J
authors.lastname: Fang
authors.forename: Bing-Hua
authors.initials: BH
authors.lastname: Jiang
mesh_terms: D000818:Animals; D002374:Catalase / Q000378:metabolism; D045744:Cell Line, Tumor / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D004789:Enzyme Activation; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism*; D015151:Immunoblotting; D007124:Immunoenzyme Techniques; D007166:Immunosuppressive Agents / Q000494:pharmacology; D007328:Insulin / Q000494:pharmacology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009389:Neovascularization, Pathologic / Q000473:pathology; D011471:Prostatic Neoplasms / Q000378:metabolism* / Q000473:pathology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D038762:Ribosomal Protein S6 Kinases, 70-kDa / Q000378:metabolism*; D020123:Sirolimus / Q000494:pharmacology; D014158:Transcription, Genetic; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism*
chemical_list: D007004:Hypoglycemic Agents; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D007166:Immunosuppressive Agents; D007328:Insulin; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D006861:Hydrogen Peroxide; D002374:Catalase; D038762:Ribosomal Protein S6 Kinases, 70-kDa; D020123:Sirolimus