Constitutive nuclear factor-kappa B mRNA, protein overexpression and enhanced DNA-binding activity in thymidylate synthase inhibitor-resistant tumour cells

Wang, W. and Cassidy, J. (2003) Constitutive nuclear factor-kappa B mRNA, protein overexpression and enhanced DNA-binding activity in thymidylate synthase inhibitor-resistant tumour cells. British Journal of Cancer, 88(4), pp. 624-629. (doi: 10.1038/sj.bjc.6600753)

Full text not currently available from Enlighten.

Abstract

In this study, the gene copy number, mRNA and protein expression levels and nuclear DNA-binding activity of nuclear factor kappa B (NF-kappaB) were compared in a panel of five pairs of thymidylate synthase (TS) inhibitor-resistant and wild-type parent cancer cell lines. High constitutive NF-kappaB DNA-binding activity was detected in all chemoresistant cell lines. The upregulated NF-kappaB activity was composed of NF-kappaB subunits p50 and p65. Four out of five resistant cell lines constitutively overexpressed NF-kappaB p50 and p63 mRNA and protein. One resistant cell line with the highest NF-kappaB DNA-binding activity showed normal p50 and p65 protein expression. No NF-kappaB gene amplification was detected in resistant cell lines. Transient exposure of wild-type RKOWT and H630(WT) cells to 5-FU induced NF-kappaB DNA-binding activity but had no effect on NF-kappaB protein expression in these cells, Our results indicate that high constitutive NF-kappaB activity caused by its gene overexpression is an intrinsic character of TS inhibitor-resistant cells. NF-kappaB can antagonise anticancer drug-induced apoptosis. High NF-kappaB expression and nuclear activity in TS inhibitor-resistant cancer cells may play an important role in the chemoresistance.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Cassidy, Professor James
Authors: Wang, W., and Cassidy, J.
College/School:College of Medical Veterinary and Life Sciences > School of Cancer Sciences
Journal Name:British Journal of Cancer
ISSN:0007-0920

University Staff: Request a correction | Enlighten Editors: Update this record