Abstract
Sublines of sarcoma 180 (S180) of varying sensitivity to adriamycin (ADR) have been selected in culture. The degree of resistance of these sublines ranged from 6- to 125-fold above that of parent S180 cells. ADR-resistant sublines demonstrated comparable degrees of cross-resistance to daunomycin (DNR), marcellomycin and AD 32, but each subline showed a uniform degree of tolerance toward actinomycin D and vincristine. Compared to the anthracycline-sensitive parent tumor, a 40% decrease in the intracellular steady-state level of [3H]-daunomycin was observed in all sublines regardless of the degree of resistance. The level of cell-associated DNR and ADR observed after administration of equipotent concentrations of drug was different for each cell line and increased in proportion to the drug concentration. Thus, altered drug permeability appeared to be of minimal importance in the expression of high levels of resistance. In addition, the extent of DNR metabolism by the anthracycline-resistant sublines was not sufficiently different from that seen in parent S180 cells to account for the observed tolerance to these agents.
Original language | English (US) |
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Pages (from-to) | 1133-1141 |
Number of pages | 9 |
Journal | European Journal of Cancer and Clinical Oncology |
Volume | 19 |
Issue number | 8 |
DOIs | |
State | Published - Aug 1983 |
Bibliographical note
Funding Information:Accepted 8 March 1983. *This research was supported in part by USPHS Grants CA-02817, CA-16359 and CA-24955 from the National Cancer Institute, Grants CH-211 and CH-212 from the American Cancer Society and a Research Career Development Award CA-00684 to Thomas R. Tritton. t Present address: University of North Carolina School of Medicine, Department of Pathology, Chapel Hill, NC27514, U.S.A. $To whom requests for reprints should be addressed. Abbreviatiorw S180, sarcoma 180; ADR, adriamycin or doxorubicin; DNR, daunomycin or daunorubicin; AD-32, N-trifluoroacetyl adriamycin-14-valerate; DNMOL, daunomycinol; DNMONE, daunomycinone; EMS, ethylmethane sulfonate; HPLC, high pressure liquid chromatography; ID,,,, drug concentration at which half-maximal effect is achieved.