title: Soluble FLT-1 expression suppresses carcinomatous ascites in nude mice bearing ovarian cancer.
abstract: Vascular endothelial growth factor (VEGF), a bifunctional protein enhancing vascular permeability and stimulating endothelial growth, is thought to be responsible for fluid accumulation and angiogenesis in ascites tumors. To investigate the effects of stable expression of the soluble form of Flt-1 VEGF receptor (sFlt-1), a known endogenous inhibitor of VEGF, on the malignant ascites tumors, we cotransduced RMG-1 human ovarian cancer cells with adeno-associated virus vectors carrying the sFlt-1 cDNA and Neo gene or Neo gene alone and isolated both the sFlt-1-expressing clone and the Neo-expressing clone. In vitro growth characteristics were essentially the same. As expected, conditioned medium collected from the sFlt-1-expressing cells significantly inhibited the human umbilical vein endothelial cell proliferation in the presence of recombinant VEGF. Expression of sFlt-1 significantly suppressed RMG-1 cell-induced angiogenesis in vivo in the mouse dorsal air sac assay model. We then inoculated sFlt-1- or Neo alone-expressing cells i.p. into female BALB/c nude mice. The average volume of ascites fluid, number of leaked RBCs, and number of cancer cells were significantly lower in mice injected with sFlt-1-expressing cells than in the controls. Survival time was significantly prolonged in mice injected with sFlt-1-expressing cells. These results suggest that inhibition of VEGF activity by sFlt-1 expression may provide a means to control carcinomatous ascites and angiogenesis of malignant ascites tumors.
authors.affiliation: Division of Genetic Therapeutics, Jichi Medical School, Tochigi 329-0498, Japan.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Hasumi
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Mizukami
authors.forename: Masashi
authors.initials: M
authors.lastname: Urabe
authors.forename: Takahiro
authors.initials: T
authors.lastname: Kohno
authors.forename: Koichi
authors.initials: K
authors.lastname: Takeuchi
authors.forename: Akihiro
authors.initials: A
authors.lastname: Kume
authors.forename: Mikio
authors.initials: M
authors.lastname: Momoeda
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yoshikawa
authors.forename: Takashi
authors.initials: T
authors.lastname: Tsuruo
authors.forename: Masabumi
authors.initials: M
authors.lastname: Shibuya
authors.forename: Yuji
authors.initials: Y
authors.lastname: Taketani
authors.forename: Keiya
authors.initials: K
authors.lastname: Ozawa
mesh_terms: D000818:Animals; D001201:Ascites / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D002455:Cell Division / Q000502:physiology; D004730:Endothelium, Vascular / Q000473:pathology; D005260:Female; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D009389:Neovascularization, Pathologic / Q000378:metabolism / Q000473:pathology; D010051:Ovarian Neoplasms / Q000098:blood supply / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis* / Q000235:genetics; D020794:Receptor Protein-Tyrosine Kinases / Q000096:biosynthesis* / Q000235:genetics; D012995:Solubility; D014161:Transduction, Genetic; D040281:Vascular Endothelial Growth Factor Receptor-1; D023041:Xenograft Model Antitumor Assays
chemical_list: D011518:Proto-Oncogene Proteins; D020794:Receptor Protein-Tyrosine Kinases; D040281:Vascular Endothelial Growth Factor Receptor-1