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Appropriate subcellular localisation of prodrug‐activating enzymes has important consequences for suicide gene therapy
Author(s) -
Spooner Robert A.,
Maycroft Kevin A.,
Paterson Hugh,
Friedlos Frank,
Springer Caroline J.,
Marais Richard
Publication year - 2001
Publication title -
international journal of cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.475
H-Index - 234
eISSN - 1097-0215
pISSN - 0020-7136
DOI - 10.1002/ijc.1288
Subject(s) - prodrug , nitroreductase , suicide gene , enzyme , cytotoxicity , bystander effect , genetic enhancement , gene , chemistry , biochemistry , biology , in vitro , immunology
Escherichia coli B nitroreductase (NR) has been expressed stably in MDA‐MB‐361 human breast adenocarcinoma cells either as the wild‐type protein (wtNR), which is distributed evenly between the cytoplasmic and nuclear compartments, or targeted to the mitochondrion (mtNR). Whereas bacterial NR is active as a dimer, a proportion of wtNR is monomeric. In contrast, mtNR is mostly dimeric, suggesting that it adopts a more stable, native conformation. Despite this, when tested in gene‐directed enzyme prodrug therapy cell cytotoxicity studies, cells expressing wtNR or mtNR had similar sensitivity to the prodrug CB1954 and mounted similar bystander killing effects. Furthermore, when short prodrug exposures were given, wtNR was more efficient at killing cells than mtNR. These data demonstrate that the site of enzyme expression and prodrug activation is an important variable that requires consideration in suicide gene therapy approaches. © 2001 Wiley‐Liss, Inc.