Transfection of murine fibroblast cells with human cytidine deaminase cDNA confers resistance to cytosine arabinoside.
One of the major limitations in the use of cytosine arabinoside (Ara-C) in cancer chemotherapy is the hematopoietic toxicity produced by this nucleoside analog. One approach to overcome this problem would be to insert a gene for drug resistance to Ara-C in normal hematopoietic cells to protect them from drug toxicity. An interesting candidate gene for this aim is cytidine deaminase which catalyzes the deamination of Arac-C, resulting in a significant loss of its antineoplastic activity. We have ligated the human cDNA for cytidine deaminase into the plasmid vector pMFG. Transfection of NIH 3T3-derived GP + E86 murine fibroblasts cells with this vector resulted in a marked increase (> 50-fold) in the expression of cytidine deaminase. In addition, the transfected cells showed resistance to the cytotoxic action and to the inhibition of DNA synthesis produced by Ara-C. Northern and Western blot analysis of the transfected cells showed increased expression of mRNA for cytidine deaminase and increased immunologically detectable enzyme. The ability to confer drug resistance to Ara-C through gene transfer of cytidine deaminase may have the potential as a selectable marker and for the protection of the bone marrow from the toxicity produced by this analog so as to increase its effectiveness in cancer chemotherapy.
Momparler
R L
RL
Département de pharmacologie, Université de Montréal, Cote Ste-Catherine, Quebec, Canada.
Laliberté
J
J
Eliopoulos
N
N
Beauséjour
C
C
Cournoyer
D
D
D016475:3T3 Cells / Q000187:drug effects; D000818:Animals; D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology*; D015139:Blotting, Southern; D003561:Cytarabine / Q000494:pharmacology*; D003564:Cytidine Deaminase / Q000235:genetics*; D004261:DNA Replication / Q000187:drug effects; D018076:DNA, Complementary; D004305:Dose-Response Relationship, Drug; D004351:Drug Resistance / Q000235:genetics; D006801:Humans; D051379:Mice; D016133:Polymerase Chain Reaction; D013234:Stem Cells; D014162:Transfection
D000964:Antimetabolites, Antineoplastic; D018076:DNA, Complementary; D003561:Cytarabine; D003564:Cytidine Deaminase