Transcriptional promoters responsive to low doses of X-irradiation may be u
seful in developing a new strategy in gene therapy combined with convention
al radiotherapy. The retrovirus-mediated gene trap screening identified c-I
AP2 as one of genes possessing such promoters. The analysis of the cis-elem
ents responsive to X-irradiation in c-IAP2 promoter revealed that the NF-ka
ppaB binding sites were necessary and sufficient for the X-ray-responsivene
ss. We constructed the plasmid p4NFB-BAX, which had four tandem repeats of
the NF-kappaB binding sites of c-IAP2 promoter (4NFB) and a suicide gene BA
X under the control of 4NFB. The human tumor cells transfected with p4NFB-B
AX significantly reduced the number of cells that survived 2 Gy irradiation
. (C) 2001 Federation of European Biochemical Societies. Published by Elsev
ier Science B.V. All rights reserved.