title: Antiproliferative activity of angiotensin II receptor blocker through cross-talk between stromal and epithelial prostate cancer cells.
abstract: We showed previously that angiotensin II activated the proliferation of prostate cancer cells and that angiotensin II receptor blockers (ARB) could inhibit it. Here, we investigated whether angiotensin II exerts mitogenic effects on the cross-talk between stromal and cancer cells and whether an ARB can inhibit tumor growth through actions on stromal cells. Cell proliferation and interleukin-6 secretion of prostate stromal PrSC cells stimulated with angiotensin II, tumor necrosis factor-alpha, or epidermal growth factor were examined in the absence and presence of ARB. We examined the effect of ARB on mitogen-activated protein kinase (MAPK) phosphorylation of PrSC and PC-3 cells treated with conditioned medium of PrSC cells and determined the effect of ARB on tumor growth induced by paracrine factors from PrSC cells. Angiotensin II activated the cell proliferation and interleukin-6 secretion of PrSC cells, and ARB inhibited it. Angiotensin II, tumor necrosis factor-alpha, or epidermal growth factor induced MAPK phosphorylation in PrSC cells, and this phosphorylation was inhibited by ARB. Conditioned medium of PrSC cells with angiotensin II activated MAPK phosphorylation in PC-3 cells, and ARB-treated conditioned medium of PrSC cells inhibited it. The tumor growth and angiogenesis of a mixture of PC-3 with PrSC were inhibited by ARB administration, whereas those of PC-3 xenografts were not inhibited. ARB exerted an antiproliferative effect on prostate cancer through paracrine factors from stromal cells. Because prostate stromal cells are thought to be involved in the initiation and development of prostate cancer, the present data suggest the possibility that ARBs are a novel therapeutic class of agents for prostate cancer.
authors.affiliation: Department of Urology, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan. hu0428@med.yokohama-cu.ac.jp
authors.forename: Hiroji
authors.initials: H
authors.lastname: Uemura
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Ishiguro
authors.forename: Yoji
authors.initials: Y
authors.lastname: Nagashima
authors.forename: Takeshi
authors.initials: T
authors.lastname: Sasaki
authors.forename: Noboru
authors.initials: N
authors.lastname: Nakaigawa
authors.forename: Hisashi
authors.initials: H
authors.lastname: Hasumi
authors.forename: Shingo
authors.initials: S
authors.lastname: Kato
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Kubota
mesh_terms: D000804:Angiotensin II / Q000378:metabolism; D057911:Angiotensin Receptor Antagonists; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D017209:Apoptosis; D015153:Blotting, Western; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D017077:Culture Media, Conditioned / Q000494:pharmacology; D016207:Cytokines / Q000378:metabolism; D004815:Epidermal Growth Factor / Q000378:metabolism; D004847:Epithelial Cells / Q000166:cytology*; D006801:Humans; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D015850:Interleukin-6 / Q000378:metabolism; D020935:MAP Kinase Signaling System; D008297:Male; D051379:Mice; D008819:Mice, Nude; D008833:Microcirculation; D008954:Models, Biological; D009368:Neoplasm Transplantation; D009389:Neovascularization, Pathologic; D010766:Phosphorylation; D011471:Prostatic Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology*; D011945:Receptors, Angiotensin / Q000378:metabolism; D017154:Stromal Cells / Q000166:cytology / Q000473:pathology; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D057911:Angiotensin Receptor Antagonists; D000970:Antineoplastic Agents; D017077:Culture Media, Conditioned; D016207:Cytokines; D015850:Interleukin-6; D011945:Receptors, Angiotensin; D014409:Tumor Necrosis Factor-alpha; D000804:Angiotensin II; D004815:Epidermal Growth Factor