ABSTRACT 778(P1-9)
P53 遺伝子 欠失 マウスにおける MeIQx の 発癌性 ;朴 哲範, 金 大中, 関根ー則, 牛田吉彦, 久原徹哉,マルカム.ムーア, 高須賀信夫, 津田洋幸 (国立がんセ 研 化療)
MeIQx induced tumorigenesis in p53-deficient mice: Cheol Beom PARK, Dae Joong KIM, Kazunori SEKINE, Yoshihiko USHIDA, Tetsuya KUHARA, Malcolm A MOORE, Nobuo TAKASUKA, Hiroyuki TSUDA (Exp.Pathol. & Chemother. Div., Natl. Cancer Ctr.Res. Inst.)
MeIQx is a very potent mutagen which induces tumors in the liver, lung and hematopoietic system of CDF1 mice. P53 gene deficient mice have been found to demonstrate a high rate of spontaneous tumor development and heterozygotes mice display a high incidence of lymphomas when treated with chemical carcinogens. In the present study, the effects of MeIQx at low doses in p53 heterozygous mice were examined. Male and female p53 heterozygotes and wild type littermates were continuously given diets containing 0, 0.1, 1, 10, and 100ppm MeIQx for 1 year. The resultant liver tumor incidences were 10, 20, 10, 50, and 10% in males, and 0, 0, 0, 0, and 10% in females respectively, and in the wild type were 20, 0, 0, 20, and 40% in males and 0, 0, 0, 0, and 10% in females. The incidences of lung tumors, lymphomas and leukemia did not significantly differ between the groups. MeIQx at low doses did not exert potent carcinogenicity in p53 heterozygous mice.(Supported by a Grant-in-Aid for the second Term Comprehensive 10-Year Strategy for Cancer Control, a Grant-in-Aid for Cancer Research from the Ministry of Health and Welfare)