Resistance modification by PSC-833, a novel non-immunosuppressive cyclosporin [corrected].
A novel non-immunosuppressive cyclosporin [corrected], PSC-833, has been tested for its ability to circumvent resistance to doxorubicin, vincristine and colchicine in human and murine multidrug resistant (MDR) cell lines. This compound is shown to be a highly potent resistance modifier, being 7-10-fold more potent than the parent compound, cyclosporin A, whilst approximately equal to cyclosporin A in the growth inhibitory effects of compound alone. Reversal of the P-glycoprotein-associated MDR drug accumulation defect is a major component of resistance reversal for PSC-833, as it is for cyclosporin A.
Twentyman
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PR
MRC Clinical Oncology, Radiotherapeutics Unit, Cambridge, U.K.
Bleehen
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NM
D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D003078:Colchicine / Q000494:pharmacology; D016572:Cyclosporine / Q000494:pharmacology*; D003524:Cyclosporins / Q000494:pharmacology*; D004317:Doxorubicin / Q000494:pharmacology; D004351:Drug Resistance; D006801:Humans; D051379:Mice; D014407:Tumor Cells, Cultured / Q000187:drug effects; D014750:Vincristine / Q000494:pharmacology
D003524:Cyclosporins; D014750:Vincristine; D004317:Doxorubicin; D016572:Cyclosporine; C070272:valspodar; D003078:Colchicine