title: Adriamycin-induced resistance to natural killer (NK)-mediated cytotoxicity.
abstract: Studies were done to determine the susceptibility of a colon carcinoma cell line, LoVo, to natural killer (NK) mediated lysis after exposure to the tumor cells to Adriamycin (ADR) (doxorubicin; Adria Laboratories, Columbus, OH). LoVo cells were exposed to ADR (0.4 micrograms/ml) for various time intervals and then tested for sensitivity to lysis by NK cells from the peripheral blood of normal donors in a sodium chromate (Cr51) release cytotoxicity assay. Exposure of tumor targets to ADR induced a resistance to NK-mediated lysis. Susceptibility to lysis decreased progressively to approximately 60% of control levels after 72 hours of ADR exposure. The induction of resistance was dependent on ADR dose, but did not magnify with doses greater than 0.4 micrograms/ml. When target cells were allowed to recover from ADR in fresh medium for 48 hours, complete reversal of the ADR effect was seen. The effect of interleukin-2 (IL-2) stimulation on the NK lysis of LoVo also was tested. IL-2-stimulated effector cells demonstrated enhanced cytotoxicity to LoVo targets and were able to overcome the ADR-induced resistance to lysis. The mechanism of resistance does not appear to be related to the altered binding of effectors to chemotherapy-treated targets, as suggested by single cell assay results.
authors: Department of General Surgery, University of Texas, M.D. Anderson Cancer Center, Houston 77030.
authors: W J
authors: WJ
authors: Wood
authors: E
authors: E
authors: Lotzová
mesh_terms: D002454:Cell Differentiation / Q000187:drug effects; D003602:Cytotoxicity, Immunologic / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004317:Doxorubicin / Q000494:pharmacology*; D006801:Humans; D007167:Immunotherapy; D007376:Interleukin-2 / Q000494:pharmacology; D007694:Killer Cells, Natural / Q000187:drug effects* / Q000276:immunology; D014407:Tumor Cells, Cultured
chemical_list: D007376:Interleukin-2; D004317:Doxorubicin