title: Susceptibility to colon carcinogenesis in C3H<-->C57BL/6 chimeric mice reflects both tissue microenvironment and genotype.
abstract: Considerable rodent strain differences have been documented with regard to susceptibility to colon carcinogens. To clarify mechanisms, chimeras of susceptible strain C3H and relatively resistant strain C57BL/6N (B6) mice were exposed to a colonotropic carcinogen, 1,2-dimethylhydrazine (DMH) and tumor incidence and multiplicity were assessed. In the chimeras, incidence was as high as the C3H level. Multiplicity of lesions of B6 cells was also increased (P<0.001), but maintenance of the strain difference. When tumor localization was analyzed, tumors of B6 genotype in chimeras demonstrated a greater spread of distribution than in the parental case. The chimeric environment may thus stimulate tumor initiation but cell autonomous suppressive factors may be retained.
authors.affiliation: Division of Oncological Pathology, Aichi Cancer Center Research Institute, 1-1 Kanokoden, Chikusa-ku, Nagoya 464-8681, Japan. ttsukamt@aichi-cc.jp
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Tsukamoto
authors.forename: Masami
authors.initials: M
authors.lastname: Yamamoto
authors.forename: Hiroko
authors.initials: H
authors.lastname: Fukami
authors.forename: Akemi
authors.initials: A
authors.lastname: Yoshikawa
authors.forename: Hiroki
authors.initials: H
authors.lastname: Sakai
authors.forename: Akihiro
authors.initials: A
authors.lastname: Hirata
authors.forename: Moriaki
authors.initials: M
authors.lastname: Kusakabe
authors.forename: Masae
authors.initials: M
authors.lastname: Tatematsu
mesh_terms: D000818:Animals; D002678:Chimera; D003110:Colonic Neoplasms / Q000235:genetics* / Q000473:pathology*; D004198:Disease Susceptibility; D005838:Genotype; D007150:Immunohistochemistry; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL