Open AccessEffect of an Inhibitor of Tumor Promotion, α‐Difluoromethylornithine, on Tumor Induction by Repeated Beta Irradiation in Mice
Author(s) -
Ootsuyama Akira,
Tanooka Hiroshi
Publication year - 1993
Publication title -
japanese journal of cancer research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.035
H-Index - 141
eISSN - 1349-7006
pISSN - 0910-5050
DOI - 10.1111/j.1349-7006.1993.tb02780.x
Subject(s) - eflornithine , tumor promotion , medicine , beta (programming language) , osteosarcoma , ratón , ornithine decarboxylase , endocrinology , pharmacology , cancer research , biology , carcinogenesis , enzyme , cancer , biochemistry , computer science , programming language
α‐Difluoromethylornithine (DFMO) is an inhibitor of putrescine biosynthesis and of tumor promotion. Studies were made of its effect on induction of skin and bone tumors by repeated beta irradiation of the back of female ICR mice 3 times weekly at a dose of 3 Gy per exposure. When given at a concentration of 10 mg/ml in the drinking water, DFMO significantly delayed the time of tumor emergence and decreased the yield of skin tumors, although the cumulative tumor incidence computed by the Kaplan‐Meier method finally reached 100%. These results indicate that tumor‐promoting activity is involved in repeated beta irradiation, besides its tumor‐initiating activity.