Suicide gene therapy with the yeast fusion gene cytosine deaminase/uracil phosphoribosyltransferase is not enough for pancreatic cancer.
OBJECTIVE
Suicide gene therapy with FCY1 gene, encoding cytosine deaminase (CD), together with FUR1, encoding uracil phosphoribosyltransferase (UPRT), has been proposed for pancreatic cancer therapy in vivo. We ascertained whether gene therapy with FCY1-FUR1 is effective in killing pancreatic cancer cells after 5-fluorocytosine (5-FC) treatment.


METHODS
AsPC1, BxPC3, Capan1, MIA PaCa2, and Panc1 cell lines were transfected using 2 plasmid vectors expressing CD only (pRSV-CD) or the chimera CD-UPRT (pRSV-CD-UPRT). Control and pRSV-CD- or pRSV-CD-UPRT-transfected cell lines were treated with 0, 0.1, 0.5, 1, 5, and 10 mM of 5-FC for 1, 3, 6, 8, 10, and 13 days.


RESULTS
FCY1 alone did not confer sensitivity to 5-FC. The CD-UPRT-transfected BxPC3 and Panc1 were sensitive to very low 5-FC doses (0.1 mM). 5-Fluorocytosine-sensitive transfected cell lines rapidly converted 5-FC into 5-fluorouracil, whereas the 5-FC resistant cell lines had an impaired 5-FC conversion.


CONCLUSIONS
Suicide gene therapy with the FCY1 gene alone was ineffective in the treatment of pancreatic cancer in vitro. The pRSV-CD-UPRT construct conferred 5-FC sensitivity to some pancreatic cancer cell lines. Therefore, the application in vivo of suicide gene therapy with FCY1 alone or in combination with the FUR1 gene is probably destined to fail.
Fogar
Paola
P
Department of Medical and Surgical Sciences, University of Padova, Padova, Italy.
Navaglia
Filippo
F
Basso
Daniela
D
Greco
Eliana
E
Zambon
Carlo-Federico
CF
Fadi
Elisa
E
Falda
Alessandra
A
Stranges
Alessia
A
Vannozzi
Francesca
F
Danesi
Romano
R
Pedrazzoli
Sergio
S
Plebani
Mario
M
D000230:Adenocarcinoma / Q000473:pathology / Q000628:therapy*; D000964:Antimetabolites, Antineoplastic / Q000378:metabolism / Q000494:pharmacology*; D001711:Biotransformation; D045744:Cell Line, Tumor / Q000187:drug effects; D015179:Colorectal Neoplasms / Q000473:pathology; D043525:Cytosine Deaminase / Q000235:genetics* / Q000378:metabolism; D042943:Dihydrouracil Dehydrogenase (NADP) / Q000378:metabolism; D019008:Drug Resistance, Neoplasm; D004354:Drug Screening Assays, Antitumor; D005437:Flucytosine / Q000378:metabolism / Q000494:pharmacology*; D041722:Genes, Transgenic, Suicide; D006801:Humans; D066298:In Vitro Techniques; D009363:Neoplasm Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D010190:Pancreatic Neoplasms / Q000473:pathology / Q000628:therapy*; D010430:Pentosyltransferases / Q000235:genetics* / Q000378:metabolism; D011355:Prodrugs / Q000378:metabolism / Q000494:pharmacology*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism; D013940:Thymidylate Synthase / Q000037:antagonists & inhibitors; D014162:Transfection; D014500:Uracil Nucleotides / Q000096:biosynthesis
D000964:Antimetabolites, Antineoplastic; D009363:Neoplasm Proteins; D011355:Prodrugs; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D014500:Uracil Nucleotides; C016462:5-fluorouridine 5'-phosphate; D005437:Flucytosine; D042943:Dihydrouracil Dehydrogenase (NADP); D013940:Thymidylate Synthase; D010430:Pentosyltransferases; C023269:uracil phosphoribosyltransferase; D043525:Cytosine Deaminase