Foreign-body tumorigenesis: in vitro isolation and expansion of preneoplastic clonal cell populations.

Foreign-body reactions were induced in coisogenic CBA/H and CBA/H-T6 mice by sc implantation of 15 times 22 times 0.2-mm unplasticized vinyl chloride vinyl acetate copolymer films. At 6 months' post implantation, implants and unopened tissue capsules were transferred to recipient animals of the T6-different partner strain. After another 3 months, part of the film/capsule complex was transferred to (C57BL/10ScSn times CBA/H-T6)F1 mice for tumor development. Capsule-derived and film-attached cells of the other part were separately cultured. Cultures consisting initially of euploid cells were often gradually replaced by different cells with specific aneuploid karyotypes which were identical with, or closely related to, those of the corresponding tumors. The cultured cells implanted in hybrid recipients at different passage numbers frequently gave rise to homologous tumors. Hence, it was possible to prepare in vitro cells with prefixed specific tumor determinants at different stages of preneoplastic maturation.