Colchicine resistance in human cell lines. Pleiotropic phenotype and decreased membrane permeability.

Colchicine-resistant human cells were initially observed in patients exhibiting C-anaphases or tetraploidy in lymphocyte cultures. Cell lines established from these patients displayed cross-resistances to daunomycin, emetine, vinblastine, and vincristine and collateral sensitivity to Xylocaine, showing a pleiotropic phenotype similar to that described in permeability mutants in CHO cells. 3H colchicine uptake and binding assays confirmed a decreased permeability to the drug.