Spontaneous pulmonary metastasis of human cancer cells in X-irradiated and nonirradiated nude mice.
Effect of whole body X-irradiation on the spontaneous pulmonary metastasis of human cancer cells transplanted into adult nude mice was investigated. Human cancer cells were inoculated into footpads of adult nude mice following 3 Gy whole body X-irradiation. The incidence of pulmonary metastasis was increased in the irradiated mice. Cytotoxicity of the splenocytes, particularly adherent cells, was lower in the irradiated mice than in the nonirradiated mice. Histological examinations revealed decreased mononuclear cell infiltration around the primary tumor and pulmonary metastatic foci in the irradiated mice. The suppressive effect of cytotoxicity of the splenocytes by whole body X-irradiation may thus relate to ensuing metastasis both in the phase of release and intravasation from the primary tumor and in the phase of lodgement and proliferation in the target organ.
D000818:Animals; D003602:Cytotoxicity, Immunologic / Q000528:radiation effects*; D006801:Humans; D008175:Lung Neoplasms / Q000556:secondary*; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009374:Neoplasms, Experimental / Q000276:immunology / Q000473:pathology; D013154:Spleen / Q000276:immunology; D014916:Whole-Body Irradiation