title: Vitamin D3 analog, EB1089, inhibits growth of subcutaneous xenografts of the human colon cancer cell line, LoVo, in a nude mouse model.
abstract: OBJECTIVE
  In this study, we investigated the effect of the vitamin D3 analog, EB1089, on the growth of subcutaneous xenografts of the human colon cancer cell line, LoVo, in a nude mouse model.
  
  
  METHODS
  BALB/c Nu/Nu nude mice were inoculated subcutaneously with 10(6) LoVo cells. EB1089 dissolved in isopropanol was administered intraperitoneally and orally on alternate days at doses of 0.1, 0.5, and 2.5 microg/kg/day. Control animals received isopropanol alone. Tumor volumes estimated using the formula 0.5 X length X (width)2. The tumor kinetic index was determined by immunohistochemical detection of proliferating cell nuclear antigen.
  
  
  RESULTS
  Significant dose-dependent inhibition of tumor growth was seen. After 20 days of treatment with 0.1 microg/kg/day EB1089, mean tumor volume in treated mice was 41 to 49 percent less than that in control animals (P < 0.01). Significant inhibition of tumor growth was also seen with 0.5 microg/kg/day EB1089 after 22 days of treatment (51 percent of control P < 0.01). Treatment with 2.5 microg/kg/day resulted in weight loss that required termination of this group; these mice were subsequently found to be hypercalcemic. The tumor kinetic index was significantly lower in tumors treated with 0.1 microg/kg/day EB1089 compared with that for control tumors (8 vs. 30 percent in controls).
  
  
  CONCLUSIONS
  These findings suggest that the vitamin D3 analog, EB1089, is a potent antiproliferative agent for some human colon cancers.
authors.affiliation: University of New South Wales, Department of Surgery, Sydney, Australia.
authors.forename: J
authors.initials: J
authors.lastname: Akhter
authors.forename: X
authors.initials: X
authors.lastname: Chen
authors.forename: P
authors.initials: P
authors.lastname: Bowrey
authors.forename: E J
authors.initials: EJ
authors.lastname: Bolton
authors.forename: D L
authors.initials: DL
authors.lastname: Morris
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D018938:Caco-2 Cells / Q000187:drug effects*; D002117:Calcitriol / Q000031:analogs & derivatives* / Q000494:pharmacology; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004353:Drug Evaluation, Preclinical; D006801:Humans; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D008940:Mitotic Index / Q000187:drug effects; D009368:Neoplasm Transplantation; D014183:Transplantation, Heterologous
chemical_list: D000970:Antineoplastic Agents; D002117:Calcitriol; C078903:seocalcitol