Transduction and apoptosis induction in the rat prostate, using adenovirusvectors

Proapoptotic adenovirus vectors offer great promise for the treatment of ca ncer and nonmalignant conditions. Benign prostate hyperplasia (BPH) is a co mmon nonmalignant enlargement of the prostate that involves epithelial, str omal, and smooth muscle components of the gland. We tested the hypothesis t hat an adenovirus vector expressing Fas ligand can be used to induce apopto sis in the prostate. We analyzed the efficiency of transduction and apoptos is induction in primary cultures of human prostate cells after adenovirus-m ediated gene transfer. Efficient transduction was observed in primary prost ate epithelial cells. Stromal and smooth muscle cells were more difficult t o transduce, as no coxsackie-adenovirus receptor (CAR) expression was detec table on these cells. However, transduction was achieved in these cells whe n the multiplicity of infection was increased to 100 focal-forming units pe r cell, or when the vectors were delivered as calcium phosphate precipitate s. Infection of all three primary prostate cell types with an adenovirus ve ctor that expresses Fas ligand (AdFasL/G) resulted in rapid apoptosis. Dire ct injection of the rat prostate with an adenovirus vector carrying lucifer ase resulted in substantial luciferase expression. TUNEL analysis demonstra ted that AdFasL/G administration induced low-level apoptosis in prostatic e pithelial cells throughout the gland. As a first step toward enhancing the efficiency of prostate transduction in vivo, we tested an adenovirus vector that was engineered to have an expanded tropism. This vector, AdZ.F2K(pK7) , was 10- to 500-fold more efficient than unmodified vectors in transducing prostate epithelial, smooth muscle, and stromal cells in culture. Moreover , AdZ.F2K(pK7) was more efficient than an unmodified vector at transducing the rat prostate in vivo, although the effect was dose dependent.