Necrotic, rather than apoptotic, cell death caused by cytochrome P450-activated ifosfamide.
Feline kidney cells were transfected with a vector overexpressing cytochrome P450 2B1 (CYP2B1). Transfected cells acquired a new specific biochemical activity, which could be demonstrated by a rapid CYP2B1 detection assay and showed selective sensitivity to the antitumorigenic prodrug ifosfamide (IFO). Further, the cell-killing effect was also mediated on nonmodified cells like feline kidney cells, mouse lymphoma, and human pancreatic cells in the vicinity of the CYP2B1-expressing cells due to the diffusible nature of the activated IFO metabolites. One of these, phosphoramide mustard, causes interstrand DNA cross-linking and it has been thought that the inability to repair this damage results in apoptosis. Surprisingly, our results clearly demonstrate a necrotic mechanism of IFO-induced cell death. This may have important implications for the activation of the immune system during CYP2B1/IFO suicide gene therapy of cancer.
Karle
P
P
Institute of Virology, University of Veterinary Sciences, Vienna, Austria.
Renner
M
M
Salmons
B
B
Günzburg
W H
WH
D000230:Adenocarcinoma / Q000188:drug therapy / Q000235:genetics / Q000473:pathology; D000818:Animals; D018906:Antineoplastic Agents, Alkylating / Q000627:therapeutic use*; D017209:Apoptosis; D002415:Cats; D002460:Cell Line; D002478:Cells, Cultured; D019362:Cytochrome P-450 CYP2B1 / Q000235:genetics* / Q000378:metabolism; D004847:Epithelial Cells / Q000187:drug effects / Q000648:ultrastructure; D005434:Flow Cytometry; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors; D006801:Humans; D007069:Ifosfamide / Q000378:metabolism / Q000627:therapeutic use*; D007668:Kidney / Q000473:pathology*; D009336:Necrosis; D010190:Pancreatic Neoplasms / Q000188:drug therapy / Q000235:genetics / Q000473:pathology; D011355:Prodrugs / Q000378:metabolism / Q000627:therapeutic use*; D012680:Sensitivity and Specificity; D014162:Transfection / Q000379:methods*; D014407:Tumor Cells, Cultured
D018906:Antineoplastic Agents, Alkylating; D011355:Prodrugs; D019362:Cytochrome P-450 CYP2B1; D007069:Ifosfamide