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Novel use of a selectable fusion gene as an “In‐Out” marker for studying genetic loss in mammalian cells
Author(s) -
Trott Deborah A.,
Cuthbert Andrew P.,
Todd Christopher M.,
Themis Michael,
Newbold Robert F.
Publication year - 1995
Publication title -
molecular carcinogenesis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.254
H-Index - 97
eISSN - 1098-2744
pISSN - 0899-1987
DOI - 10.1002/mc.2940120406
Subject(s) - biology , loss of heterozygosity , genetics , carcinogenesis , gene , selectable marker , point mutation , transgene , mutagen , genetic screen , genome , mutagenesis , genetic marker , mutation , mutant , carcinogen , allele
Recent demonstrations of loss of heterozygosity in a wide variety of human cancers suggest that large multilocus genetic deletions (presumably including tumor suppressor genes) constitute a major class of genetic alteration in human carcinogenesis. Here we show that a bifunctional fusion gene ( Hytk ), suitable for both positive and negative selection, is an effective marker for studying genetic loss in mammalian cells with minimal interference from point‐mutational changes. Studies with a transgenic V79 cell line in which a single functional copy of Hytk was stably inserted into the genome in a retroviral vector showed that loss of the marker (and presumably flanking cellular genetic material) could be induced efficiently by ionizing radiation (γ‐rays and fast neutrons) but only weakly by the powerful point‐mutagen benzo[ a ]pyrene diol epoxide. In a first application of the system, we provide evidence that radiation‐induced loss can occur through an indirect mechanism after a high‐frequency event. Collectively, our results suggest that the Hytk marker should be a valuable tool for studying genome position effects on the tolerance of genetic loss in cultured human cells that represent different stages in clonal evolution and tumor progression. © 1995 Wiley‐Liss Inc.