A Suicide-inducing Vector Carrying the Oct-4 Promoter for Eradication of the AGS Cancer Cell Line

Authors
R. Najafi 1
M. Sadeghizadeh 2
M. Sadeghizadeh 2
S. J. Mowla 3
1 Ph.D. Candidate, Department of Molecular Genetics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
2 Professor, Molecular Genetics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
3 Molecular Genetics, Faculty of biological sciences, Tarbiat Modares University
Abstract
Objective: In an attempt to develop safer and more effective gene therapy approaches as a realistic treatment for various forms of cancer, researchers are increasingly using tumor-specific promoters (TSP) to drive the expression of the gene of interest and eradicate cancer cells. In this study, for the first time we introduce the Oct-4 promoter as a cancer-specific promoter with a high efficacy. Methods: We cloned Oct-4 promoter and enhancers into a pGl3 control reporter vector and analyzed the expression of luciferase as a reporter gene in an AGS gastric cell line. Next, we used a suicide-inducing vector that included an Oct-4 promoter and the TK gene in the presence of the non-toxic prodrug, ganciclovir, to eradicate cancer cells. Cells were treated with PI and connexin V. FACS analysis was conducted to assess the effect of the system on cell cycle and apoptosis induction. Results: Under the activity of the Oct-4 promoter, luciferase expression was three-fold higher than the SV40 promoter. The HSV/TK/GCV system activated by the Oct-4 promoter and enhancers induced apoptosis (86.17%) in the AGS cell line. We verified that this system induced S-phase/G2-phase cell cycle arrest in the AGS cell line. Conclusion: These data indicate that the Oct-4 promoter is active in the AGS cell line. Oct-4 gene is expressed in a wide variety of tumors but not in normal cells. Thus, Oct-4 appears to be a promising tumor-specific promoter for numerous tumors.

Keywords

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Pathobiology Reserach
Volume 15, Issue 2
June 2012
Pages 61-72