[Mice transduced with double-mutant dihydrofolate reductase-cytidine deaminase fusion gene attained protection from high dose chemotherapy].
OBJECTIVE
To explore the feasibility of transferring fusion gene of dihydrofolate reductase (DHFR) gene and cytidine deaminase (CD) gene into mouse bone marrow cells in order to observe the drug resistance of high dose methotrexate (MTX) and cytosine arabinoside (Ara-C) in the bone marrow cells and to improve the tolerance of myelosuppression following combination chemotherapy.


METHODS
Human double-mutant dihydrofolate reductase-cytidine deaminase fusion gene was transferred into two mice bone marrow cells by retroviral vector. Resistant colony-forming unit granulocyte-macrophage (CFU-GM) assays were performed in mouse bone marrow cells by retroviral infection and after treatment by drugs (Ara-C, MTX, and Ara-C + MTX). DNA was extracted from mouse bone marrow cells. The expression of drug resistant genes in mouse bone marrow cells after transferring by retroviral vector was checked by polymerase chain reaction (PCR).


RESULTS
Bone marrow cells after coculture with the retroviral producer cells transduced with the genes (SFG-F/S-CD) showed the drug resistance colonies yield (Colony formation after exposure to Ara-C, MTX and Ara-C + MTX were 56%, 22% and 14%, respectively) and the increase in drug resistant to both MTX and Ara-C (P < 0.005). Expression of DHFR and CD gene in extracted DNA of transfected mice were demonstrated by PCR.


CONCLUSIONS
Double drug resistant gene can not only integrate and co-express in mice bone marrow cells but also increase the drug resistance to MTX and Ara-C.
Lu
Ping
P
Department of Oncology, the First Affiliated Hospital, China Medical University, Shenyang 110001, China. lupinglp1999@163.com
Lu
Yang
Y
Pang
Kui
K
Wang
Shu-bao
SB
Chen
Jun-qing
JQ
Xu
Hui-mian
HM
Wang
Jun-ke
JK
Zhao
Shi-cheng
SC
D000818:Animals; D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology; D019677:Artificial Gene Fusion; D001854:Bone Marrow Cells / Q000166:cytology / Q000187:drug effects; D002478:Cells, Cultured; D003561:Cytarabine / Q000494:pharmacology*; D003564:Cytidine Deaminase / Q000235:genetics*; D018432:Drug Resistance, Multiple / Q000235:genetics*; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D005822:Genetic Vectors; D006801:Humans; D008297:Male; D008727:Methotrexate / Q000494:pharmacology*; D051379:Mice; D008807:Mice, Inbred BALB C; D013762:Tetrahydrofolate Dehydrogenase / Q000235:genetics*; D014162:Transfection
D000964:Antimetabolites, Antineoplastic; D003561:Cytarabine; D013762:Tetrahydrofolate Dehydrogenase; D003564:Cytidine Deaminase; D008727:Methotrexate