McMillan, Trevor J. and Kalebic, Tia and Stark, George R. and Hart, Ian R. (1990) High frequency of double resistance in the B16 melanoma cell line. European Journal of Cancer and Clinical Oncology, 26 (5). pp. 565-567. ISSN 0277-5379
Full text not available from this repository.Abstract
Methotrexate (MTX) and N-(phosphonacetyl)- -aspartate (PALA) are two agents to which cellular resistance can be conferred by gene amplification, but they do not generally show cross resistance. However, combined treatment with these two agents produced drug resistant cells in the B16 melanoma cell line at a much higher frequency than would be expected if resistance to the two agents was totally independent. An isolated doubly resistant clone, B16-F1 MP, showed a high frequency of resistance to pyrazofurin and ouabain, which are also agents to which resistance can be conferred by gene amplification. Thus MTX combined with PALA selected cells with an ‘amplificator’ phenotype (an increased ability to amplify parts of the genome). These B16-F1 MP cells had a decreased ability to form experimental lung metastases compared with the parent line but this difference was not found in baby hamster kidney cells with the amplificator phenotype. The mechanism underlying drug resistance may need to be considered when designing combination chemotherapy.