Karyotypic analysis of CCRF-CEM and drug-resistant cell lines with stable and unstable ploidy.
Karyotypic studies were performed on methotrexate (MTX)- and vincristine (VCR)-resistant cell lines derived from the human T-cell leukemia CCRF-CEM cell line. We noted karyotypic selection and additional chromosome change associated with acquisition of drug-resistance. Furthermore, we observed that both the parental and MTX-resistant sublines, CEM/MTX R1-3, had a tendency to ploidy change. Karyotypic studies of malignant cells have shown that polyploidy is frequently a consequence of a single sporadic event, followed by growth and selection of the polyploid clone [1]. In this study, however, various karyotypic clones were identified with near- and pseudotetraploid karyotypes that appeared to be derived from different near- and pseudodiploid sidelines. Polyploidy was invariably associated with loss of at least two of the four chromosomes 8 whether the pseudodiploid sideline from which it was derived carried one or both chromosomes 8. In contrast, neither polyploid clones nor loss of chromosome 8 was noted in the CEM/VCR R cells.
Pittman
S M
SM
Children's Leukaemia and Cancer Research Centre, Prince of Wales Children's Hospital, Randwick, New South Wales, Australia.
Kavallaris
M
M
Stewart
B W
BW
D002869:Chromosome Aberrations; D002898:Chromosomes, Human, Pair 8; D004351:Drug Resistance; D017353:Gene Deletion; D006801:Humans; D007621:Karyotyping; D015458:Leukemia, T-Cell / Q000235:genetics*; D008727:Methotrexate / Q000494:pharmacology*; D011003:Ploidies; D011123:Polyploidy; D014407:Tumor Cells, Cultured; D014750:Vincristine / Q000494:pharmacology*
D014750:Vincristine; D008727:Methotrexate