In vitro evaluation of cancer-specific NF-kappaB-CEA enhancer-promoter system for 5-fluorouracil prodrug gene therapy in colon cancer cell lines

Guo, X., Evans, T.R.J. , Somanath, S., Armesilla, A.L., Darling, J.L., Schatzlein, A., Cassidy, J. and Wang, W. (2007) In vitro evaluation of cancer-specific NF-kappaB-CEA enhancer-promoter system for 5-fluorouracil prodrug gene therapy in colon cancer cell lines. British Journal of Cancer, 97(6), pp. 745-754. (doi: 10.1038/sj.bjc.6603930)

Abstract

Nuclear factor-kappa B (NF-kappaB) is a transcription factor with high transcriptional activity in cancer cells. In this study, we developed a novel enhancer-promoter system, kappaB4-CEA205, in which the basal carcinoembryonic antigen (CEA) promoter sequence (CEA205) was placed downstream of the four tandem-linked NF-kappaB DNA-binding sites (kappaB4). In combination with a kappaB4 enhancer, the transcriptional activity of the CEA promoter was significantly enhanced (three- to eight-fold) in cancer cell lines but not in normal cells. In cancer cell lines, the transcriptional activity of kappaB4-CEA205 was comparable with that of the SV40 promoter. We also constructed vectors in which the thymidine phosphorylase (TP) cDNA was under the control of CEA205, kappaB4, kappaB4-CEA205 and CMV promoters, respectively. TP protein and enzyme activity were detected at comparable levels in kappaB4-CEA205- and CMV-driven TP cDNA-transfected cancer cell lines (H630 and RKO). The kappaB4-TP and CEA205-TP-transfected cell lines, respectively, only demonstrated negligible and low levels of TP protein and enzyme activity. Both CMV- and kappaB4-CEA205-driven TP cDNA transiently transfected cells were 8- to 10-fold sensitised to 5-fluorouracil (5-FU) prodrug, 5'-deoxy-5-fluorouradine (5'-DFUR), in contrast to only 1.5- to 2-fold sensitised by the kappaB4- and CEA205-driven TP cDNA-transfected cells. The bystander killing effect of CMV- and kappaB4-CEA205-driven TP cDNA-transfected cells was comparable. This is the first report that indicates that the NF-kappaB DNA-binding site could be used as a novel cancer-specific enhancer to improve cancer-specific promoter activity in gene-directed enzyme prodrug therapy.

• Item Type: Articles
• Keywords: NF-kappaB; CEA; GDEPT; thymidine phosphorylase; colorectal cancer
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Cassidy, Professor James and Guo, Mr Xin and Evans, Professor Jeff
• Authors: Guo, X., Evans, T.R.J., Somanath, S., Armesilla, A.L., Darling, J.L., Schatzlein, A., Cassidy, J., and Wang, W.
• Subjects: R Medicine > RC Internal medicine > RC0254 Neoplasms. Tumors. Oncology (including Cancer)
• College/School: College of Medical Veterinary and Life Sciences > School of Cancer Sciences
• Research Group: Centre for Oncology & Applied Pharmacology
• Journal Name: British Journal of Cancer
• ISSN: 0007-0920