Microcell-mediated chromosome transfer from human tumor cells to human recipient cells evidenced by premature condensation of the transferred chromosomes.

Micronucleation was induced by vincristine, colcemid, and colcemid in combination with cytochalasin B in cells of a human metastatic breast carcinoma cell line (MDA MB 231). Cells treated with the latter combination were enucleated subsequently by centrifugation in the presence of cytochalasin B. The resulting "microcell" fraction was fused with mitotic human primary fibroblasts or mitotic HeLa cells using polyethyleneglycol (PEG). The success of the microcell-mediated chromosome transfer thus could be demonstrated as premature condensation in the mitotic recipient of the transferred micronuclei. This technique of cytogenetic analysis allowed a fast and simple control of the influence of different conditions on micronucleation and fusion of micronuclei with recipient cells. It could be shown that microcell-mediated chromosome transfer from human tumor cells into human normal, as well as human tumor, recipient cells is practicable if the techniques figured out by the present study are employed.