Tetracycline-induced expression of an anti-c-Myb single-chain antibody and its inhibitory effect on proliferation of the human leukemia cell line K562.
Ablation of c-Myb function might be an effective approach for the therapy of chronic myelogenous leukemia or other c-myb-dependent malignancies. To this end, we have previously used an intracellular anti-c-Myb single-chain antibody (sFv) to achieve the functional knockout of the c-Myb oncoprotein. In this study, we have employed a tetracycline-inducible system to control the expression of the sFv. A nuclear-localizing form of an anti-c-Myb sFv was cloned into a tet-regulated plasmid vector. Using a transient expression system in COS-1 cells, we observed that doxycycline (Dox) induced expression of the sFv in a dose-dependent manner, and that the sFv was localized mainly in the nucleus. The Dox-induced anti-c-Myb sFv also inhibited the transactivating activity of c-Myb in a dose-dependent manner. We subsequently confirmed the Dox-induced expression of the sFv in the leukemia cell line K562. Proliferation of the target leukemia cells was also inhibited. These results suggest that the anti-c-Myb sFv may represent a viable method for gene therapy of c-myb-dependent hematopoietic malignancies.
Kasono
K
K
Gene Therapy Program, University of Alabama, Birmingham 35294, USA.
Heike
Y
Y
Xiang
J
J
Piché
A
A
Kim
H G
HG
Kim
M
M
Hagiwara
M
M
Nawrath
M
M
Moelling
K
K
Curiel
D T
DT
D000818:Animals; D000906:Antibodies / Q000235:genetics / Q000276:immunology* / Q000494:pharmacology; D019556:COS Cells; D002455:Cell Division / Q000187:drug effects; D004318:Doxycycline / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects; D015316:Genetic Therapy; D006801:Humans; D020014:K562 Cells; D007938:Leukemia / Q000276:immunology / Q000473:pathology / Q000628:therapy*; D020598:Proto-Oncogene Proteins c-myb / Q000235:genetics / Q000276:immunology*; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology; D014162:Transfection
D000906:Antibodies; D020598:Proto-Oncogene Proteins c-myb; D011994:Recombinant Proteins; D004318:Doxycycline