Host prostaglandin E(2)-EP3 signaling regulates tumor-associated angiogenesis and tumor growth.
Nonsteroidal antiinflammatories are known to suppress incidence and progression of malignancies including colorectal cancers. However, the precise mechanism of this action remains unknown. Using prostaglandin (PG) receptor knockout mice, we have evaluated a role of PGs in tumor-associated angiogenesis and tumor growth, and identified PG receptors involved. Sarcoma-180 cells implanted in wild-type (WT) mice formed a tumor with extensive angiogenesis, which was greatly suppressed by specific inhibitors for cyclooxygenase (COX)-2 but not for COX-1. Angiogenesis in sponge implantation model, which can mimic tumor-stromal angiogenesis, was markedly suppressed in mice lacking EP3 (EP3(-/-)) with reduced expression of vascular endothelial growth factor (VEGF) around the sponge implants. Further, implanted tumor growth (sarcoma-180, Lewis lung carcinoma) was markedly suppressed in EP3(-/-), in which tumor-associated angiogenesis was also reduced. Immunohistochemical analysis revealed that major VEGF-expressing cells in the stroma were CD3/Mac-1 double-negative fibroblasts, and that VEGF-expression in the stroma was markedly reduced in EP3(-/-), compared with WT. Application of an EP3 receptor antagonist inhibited tumor growth and angiogenesis in WT, but not in EP3(-/-). These results demonstrate significance of host stromal PGE(2)-EP3 receptor signaling in tumor development and angiogenesis. An EP3 receptor antagonist may be a candidate of chemopreventive agents effective for malignant tumors.
Amano
Hideki
H
Department of Pharmacology, Kitasato University School of Medicine, Kitasato 1-15-1, Sagamihara, Kanagawa 228-8555, Japan.
Hayashi
Izumi
I
Endo
Hirahito
H
Kitasato
Hidero
H
Yamashina
Shohei
S
Maruyama
Takayuki
T
Kobayashi
Michiyoshi
M
Satoh
Kazutoyo
K
Narita
Masami
M
Sugimoto
Yukihiko
Y
Murata
Takahiko
T
Yoshimura
Hirokuni
H
Narumiya
Shuh
S
Majima
Masataka
M
D000818:Animals; D018827:Carcinoma, Lewis Lung / Q000098:blood supply* / Q000378:metabolism* / Q000473:pathology / Q000517:prevention & control; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D015232:Dinoprostone / Q000378:metabolism*; D016228:Endothelial Growth Factors / Q000235:genetics / Q000378:metabolism; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism; D008222:Lymphokines / Q000235:genetics / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009389:Neovascularization, Pathologic; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012334:RNA, Neoplasm / Q000235:genetics / Q000378:metabolism; D018078:Receptors, Prostaglandin E / Q000037:antagonists & inhibitors / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D058308:Receptors, Prostaglandin E, EP3 Subtype; D012510:Sarcoma 180 / Q000098:blood supply* / Q000378:metabolism* / Q000473:pathology / Q000517:prevention & control; D015398:Signal Transduction; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
D016861:Cyclooxygenase Inhibitors; D016228:Endothelial Growth Factors; D036341:Intercellular Signaling Peptides and Proteins; D008222:Lymphokines; C545647:PTGER3 protein, human; C545648:Ptger3 protein, mouse; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D018078:Receptors, Prostaglandin E; D058308:Receptors, Prostaglandin E, EP3 Subtype; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D015232:Dinoprostone