Improved effects of a double suicide gene system on prostate cancer cells by targeted regulation of prostate-specific membrane antigen promoter and enhancer.

Abstract

OBJECTIVE:

To explore the specific killing effect on prostate cancer cells of a dual cytosine deaminase (CD) and uracil phosphoribosyltransferase (UPRT) expression plasmid system controlled by the prostate-specific membrane antigen (PSMA) promoter and enhancer.

METHODS:

The CD gene was used to construct the recombinant plasmid prostate-specific membrane antigen(promoter/enhancer)-CD (pPSMA(E/P)-CD). The specific regulatory function of the pPSMA(E/P) promoter was demonstrated by detection of enhanced green fluorescent protein (EGFP) expression in the LNCaP cell line. Survival of cells transfected with different plasmids and treated with 5-fluorocytosine (5-FC) was measured by microculture tetrazolium assay. Cell cycle changes were measured by flow cytometry.

RESULTS:

Target-specific expression of PSMA(E/P) was observed in the prostate cancer cell line. Cytotoxicity of 5-FC was greater against LNCaP cells transfected with pPSMA(E/P)-CD and UPRT and pPSMA(E/P)-CD than control groups. Percentages of cells in S phase were 37.5% (LNCaP) and 30.6% (5-FC treatment) in the un-transfected groups, whereas they were 23.9% and 12.4% in the double and single suicide gene groups, respectively.

CONCLUSIONS:

Our findings confirm the cytotoxic efficacy of the pPSMA(E/P)-CD + 5-FC and pPSMA(E/P)-CD and UPRT + 5-FC suicide gene systems. The CD and UPRT gene system quickly and directly converted 5-FC into 5-FU, and then into toxic metabolites. The CD and UPRT double suicide gene system was more effective in inducing tumor cell apoptosis with 5-FC than the single suicide gene system. Thus, this construct can specifically target prostate cancer cells and might have a role in gene therapy against prostate cancer.

• Authors: Peng Zhang, Hao Zeng, Qiang Wei, Yiping Lu, Xiang Li, Jia Wang, Fujun Zhao, Hong Li
• Journal: International journal of urology : official journal of the Japanese Urological Association (Int J Urol) Vol. 15 Issue 5 Pg. 442-8 (May 2008) ISSN: 1442-2042 [Electronic] Australia
• PMID: 18452463 (Publication Type: Journal Article)

Chemical References

• Antigens, Surface
• Pentosyltransferases
• uracil phosphoribosyltransferase
• FOLH1 protein, human
• Glutamate Carboxypeptidase II
• Cytosine Deaminase

Topics

• Antigens, Surface (genetics)
• Cell Line, Tumor
• Cytosine Deaminase (genetics)
• Enhancer Elements, Genetic
• Glutamate Carboxypeptidase II (genetics)
• Humans
• Male
• Pentosyltransferases (genetics)
• Promoter Regions, Genetic
• Prostatic Neoplasms (therapy)
• Targeted Gene Repair