Transduction of yeast cytosine deaminase mediated by HIV-1 Tat basic domain into tumor cells induces chemosensitivity to 5-fluorocytosine.
- Author:
Hakjoo LEE
1
;
Jiyoon RYU
;
Kyung Ae KIM
;
Kil Soo LEE
;
Jae Young LEE
;
Jae Bong PARK
;
Jinseu PARK
;
Soo Young CHOI
Author Information
1. Division of Life Sciences, College of Natural Sciences and College of Medicine, Hallym University, Chuncheon 200-702, Korea. sychoi@hallym.ac.kr
- Publication Type:Original Article ; Research Support, Non-U.S. Gov't
- Keywords:
cancer;
cytosine deaminase;
prodrug;
transduction;
Tat
- MeSH:
Animals;
Antimetabolites/*metabolism/pharmacology;
Bystander Effect;
Cytosine Deaminase/genetics/*metabolism;
Flucytosine/*metabolism/pharmacology;
Gene Products, tat/chemistry/genetics/*metabolism;
Genetic Vectors/genetics/metabolism;
HIV-1/metabolism;
Hela Cells/drug effects/physiology;
Humans;
Prodrugs/metabolism/therapeutic use;
Recombinant Fusion Proteins/genetics/*metabolism;
Research Support, Non-U.S. Gov't;
Saccharomyces cerevisiae Proteins/genetics/*metabolism;
*Transduction, Genetic
- From:Experimental & Molecular Medicine
2004;36(1):43-51
- CountryRepublic of Korea
- Language:English
-
Abstract:
Enzyme/prodrug approach is one of the actively developing areas for cancer therapy. In an effort to develop more effective enzyme/prodrug systems, cell-permeable cytosine deaminase was produced by fusing yeast cytosine deaminase (yCD) in frame with RKKRRQRRR domain of HIV-1 Tat which is an efficient delivery peptide of the foreign proteins into cells. The purified Tat-yCD fusion protein expressed in Escherichia coli was readily transduced into mammalian cells in a time- and dose-dependent manner. A significant level of the transduced Tat-yCD protein was recovered in the cell and was stable for 24 h as indicated by both results of the enzymatic assay of 5-fluorocytosine (5-FC) conversion to 5-fluorouracil (5-FU) and Western blot analysis. The cells transduced with Tat-yCD become highly sensitive to the cytotoxicity of 5-FC, while cells treated with yCD are unaffected by 5-FC. In addition, a strong bystander effect was observed with conditioned media from cells transduced with Tat-yCD added to non-transduced cells. Tat-yCD fusion protein demonstrated here for its ability to transduce into cells and convert nontoxic prodrug 5-FC to the toxic antimetabolite 5-FU, may be a useful approach for cancer therapy.
