title: A photon counting technique for quantitatively evaluating progression of peritoneal tumor dissemination.
abstract: We recently established a mouse model of peritoneal dissemination of human gastric carcinoma, including the formation of ascites, by orthotopic transplantation of cultured gastric carcinoma cells. To clarify the processes of expansion of the tumors in this model, nude mice were sacrificed and autopsied at different points of time after the orthotopic transplantation of the cancer cells for macroscopic and histopathologic examination of the tumors. The cancer cells grew actively in the gastric submucosa and invaded the deeper layers to reach the serosal plane. The tumor cells then underwent exfoliation and became free followed by the formation of metastatic lesions initially in the greater omentum and subsequent colonization and proliferation of the tumors on the peritoneum. Although this model allowed the detection of even minute metastases, it was not satisfactory from the viewpoint of quantitative and objective evaluation. To resolve these problems, we introduced a luciferase gene into this tumor cell line with a high metastasizing potential and carried out in vivo photon counting analysis. This photon counting technique was found to allow objective and quantitative evaluation of the progression of peritoneal dissemination on a real-time basis. This animal metastatic model is useful for monitoring the responses of tumors to anticancer agents.
authors.affiliation: Central Animal Laboratory, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan. kyanagih@gan2.res.ncc.go.jp
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Yanagihara
authors.forename: Misato
authors.initials: M
authors.lastname: Takigahira
authors.forename: Fumitaka
authors.initials: F
authors.lastname: Takeshita
authors.forename: Teruo
authors.initials: T
authors.lastname: Komatsu
authors.forename: Kazuto
authors.initials: K
authors.lastname: Nishio
authors.forename: Fumio
authors.initials: F
authors.lastname: Hasegawa
authors.forename: Takahiro
authors.initials: T
authors.lastname: Ochiya
mesh_terms: D000818:Animals; D002166:Camptothecin / Q000031:analogs & derivatives / Q000494:pharmacology; D045744:Cell Line, Tumor; D004195:Disease Models, Animal; D018450:Disease Progression; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D000077146:Irinotecan; D008156:Luciferases / Q000235:genetics; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D010534:Peritoneal Neoplasms / Q000473:pathology* / Q000648:ultrastructure; D017785:Photons; D013274:Stomach Neoplasms / Q000473:pathology*; D014162:Transfection
chemical_list: D000077146:Irinotecan; D008156:Luciferases; D002166:Camptothecin