The effect of adenovirus expressing wild-type p53 on 5-fluorouracil chemosensitivity is related to p53 status in pancreatic cancer cell lines.
OBJECTIVE
There are conflicting data about p53 function on cellular sensitivity to the cytotoxic action of 5-fluorouracil (5-FU). Therefore the objective of this study was to determine the combined effects of adenovirus-mediated wild-type (wt) p53 gene transfer and 5-FU chemotherapy on pancreatic cancer cells with different p53 gene status.


METHODS
Human pancreatic cancer cell lines Capan-1(p53mut), Capan-2(p53wt), FAMPAC(p53mut), PANC1(p53mut), and rat pancreatic cancer cell lines AS(p53wt) and DSL6A(p53null) were used for in vitro studies. Following infection with different ratios of Ad-p53-particles (MOI) in combination with 5-FU, proliferation of tumor cells and apoptosis were quantified by cell proliferation assay (WST-1) and FACS (PI-staining). In addition, DSL6A syngeneic pancreatic tumor cells were inoculated subcutaneously in to Lewis rats for in vivo studies. Tumor size, apoptosis (TUNEL) and survival were determined.


RESULTS
Ad-p53 gene transfer combined with 5-FU significantly inhibited tumor cell proliferation and substantially enhanced apoptosis in all four cell lines with an alteration in the p53 gene compared to those two cell lines containing wt-p53. In vivo experiments showed the most effective tumor regression in animals treated with Ad-p53 plus 5-FU. Both in vitro and in vivo analyses revealed that a sublethal dose of Ad-p53 augmented the apoptotic response induced by 5-FU.


CONCLUSIONS
Our results suggest that Ad-p53 may synergistically enhance 5-FU-chemosensitivity most strikingly in pancreatic cancer cells lacking p53 function. These findings illustrate that the anticancer efficacy of this combination treatment is dependent on the p53 gene status of the target tumor cells.
Eisold
Sven
S
Department of General Surgery, Thoracic and Vascular Surgery, University of Rostock, Schillingallee 35, D-18057 Rostock, Germany. sven.eisold@med.uni-rostock.de
Linnebacher
Michael
M
Ryschich
Eduard
E
Antolovic
Dalibor
D
Hinz
Ulf
U
Klar
Ernst
E
Schmidt
Jan
J
D000256:Adenoviridae / Q000235:genetics*; D000328:Adult; D000818:Animals; D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D045744:Cell Line, Tumor; D003131:Combined Modality Therapy; D019008:Drug Resistance, Neoplasm; D005260:Female; D005472:Fluorouracil / Q000494:pharmacology*; D015972:Gene Expression Regulation, Neoplastic; D015316:Genetic Therapy; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D010190:Pancreatic Neoplasms / Q000188:drug therapy* / Q000473:pathology / Q000503:physiopathology; D051381:Rats; D011917:Rats, Inbred Lew; D014161:Transduction, Genetic; D016159:Tumor Suppressor Protein p53 / Q000235:genetics*
D000964:Antimetabolites, Antineoplastic; D016159:Tumor Suppressor Protein p53; D005472:Fluorouracil