title: Inhibitory effects of glucocorticoids on proliferation of canine mast cell tumor.
abstract: The inhibitory effect of glucocorticoids (GCs) on proliferation of canine mast cell tumor (MCT) was studied using two types of MCT cells; JuMC cells and LuMC cells derived from spontaneous canine cutaneous and intestinal MCT, respectively. In in vitro study, growth of JuMC cells was significantly inhibited with more than 1 nM GCs and apoptotic-like cell death was seen, while that of LuMC cells was never inhibited even with 10 microM GCs. Growth rate of masses in nude mice developed by inoculation of JuMC cells was reduced in a dose-dependent manner by administration of GC, while growth inhibition of masses developed by inoculation of LuMC cells was minimal with increasing GC doses. Competitive binding studies and Scatchard analysis demonstrated the presence of high-affinity, low capacity GC receptors in both JuMC and LuMC cells. Kd was estimated to be 1.30 nM in JuMC cells and 0.45 nM in LuMC cells, respectively. It is concluded that canine cutaneous MCT cells responded to GCs in vitro and in vivo, whereas intestinal MCT cells did not, though both types of cells had specific GC receptors.
authors.affiliation: Laboratory of Veterinary Surgery, Graduate School of Agricultural and Life Sciences, University of Tokyo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Takahashi
authors.forename: T
authors.initials: T
authors.lastname: Kadosawa
authors.forename: M
authors.initials: M
authors.lastname: Nagase
authors.forename: M
authors.initials: M
authors.lastname: Mochizuki
authors.forename: S
authors.initials: S
authors.lastname: Matsunaga
authors.forename: R
authors.initials: R
authors.lastname: Nishimura
authors.forename: N
authors.initials: N
authors.lastname: Sasaki
mesh_terms: D000818:Animals; D017209:Apoptosis; D002455:Cell Division; D003907:Dexamethasone / Q000378:metabolism / Q000633:toxicity; D004283:Dog Diseases; D004285:Dogs; D005938:Glucocorticoids / Q000633:toxicity*; D007414:Intestinal Neoplasms / Q000473:pathology / Q000662:veterinary*; D007700:Kinetics; D012515:Mast-Cell Sarcoma / Q000473:pathology / Q000662:veterinary*; D051379:Mice; D008819:Mice, Nude; D011239:Prednisolone / Q000633:toxicity; D011965:Receptors, Glucocorticoid / Q000378:metabolism; D012878:Skin Neoplasms / Q000473:pathology / Q000662:veterinary*; D014183:Transplantation, Heterologous; D014407:Tumor Cells, Cultured
chemical_list: D005938:Glucocorticoids; D011965:Receptors, Glucocorticoid; C028697:dexamethasone receptor; D003907:Dexamethasone; D011239:Prednisolone