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Title	Gene therapy approach utilizing Adenovirus to deliver the pro-apototic gene, Bax, for tissue-specific treatment of prostate cancer
Author	Lowe, Stephanie L.
Date	2001
Affiliation/College	College of Graduate Studies
Department	Microbiology and Immunology
Extent	xiv, 142 leaves : ill.; 29 cm
Source	QZ 50 L913g 2001
Subject.MeSH	Academic Dissertations Academic Dissertations--South Carolina Prostatic Neoplasms--therapy Genetic Therapy--trends
Collection	MUSC Theses and Dissertations
Contributing Institution	Waring Historical Library (MUSC)
Rights	Copyright is held by the author.
Language	English
Type	Text
Format	application/pdf
Media Type	Manuscripts
Resource Identifier	mtd2001_lowe_sl
Abstract	In this study, we describe the development of a novel approach for treating prostate cancer with cytoreductive gene therapy. The necessity of limiting cytotoxic gene expression to specific cell populations can be achieved through the use of tissue-specific nd promoters. However, viral regulatory elements retained in the commonly used 1st and 2nd generation adenoviral vectors have been shown to interfere with promoter activity. Here we confirm the adenoviral E1A enhancer element can interfere with tissue-specific and regulatable promoter activities inserted directly proximal and describe an alternate transgene insertion site to retain promoter specificity. Following these findings, we constructed a 2 a prostate-specific promoter, ARR2PB, to direct expression of the proapoptotic gene, Bax, for induction of apoptosis in prostate cancer. ARR2PB promoter activity is prostate- specific and responsive to androgens and glucocorticoids. LNCaP PCa cells infected with ARR2PB.Bax.GFP adenovirus showed high levels of Bax expression resulting in a significant reduction in cell viability. Importantly, LNCaP cells stably-transfected to overexpress anti-apoptotic Bcl-2 (as is found frequently in advanced prostate cancer) were not resistant, but showed similar patterns of cell death when infected with ARR2PB.Bax.GFP adenovirus. Tissue-specificity of ARR2PB promoter was evaluated using A549 (lung), SK-Hep-l (liver), and Hela (cervical) cancer cells, which did not show detectable expression of virally delivered Bax protein or any increase in cell death. To evaluate in vivo activity of the prostate-specific promoter and Bax-mediated apoptosis, LNCaP xenografts were established in male nude mice and treated with intratumoral injections of ARR2PB.Bax.GFP adenovirus. Androgen receptor-positive LNCaP xenografts showed significant growth suppression with high levels of Bax expression and extensive apoptosis in tumor sections treated with ARR2PB.Bax.GFP adenovirus. Evaluation of promoter activity in androgen receptor-negative PC3 cells and PC3-AR cells (stably-transfected to express wild type AR) showed that promoter activity was limited to AR-positive cells which could activate the ARR2PB promoter with significant growth reduction in PC3-AR cells. Systemic administration of ARR2PB.Bax.GFP Ad showed no toxicity in any of the vital organs examined including lung, liver, spleen, and kidney. Thus, results ofthis investigation represent an efficacious approach for the treatment of prostate cancer with cytoreductive gene therapy.

Gene therapy approach utilizing Adenovirus to deliver the pro-apototic gene, Bax, for tissue-specific treatment of prostate cancer

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