Assessment of p53 gene transfer and biological activities in a clinical study of adenovirus-p53 gene therapy for recurrent ovarian cancer.

A cohort study was designed to evaluate the efficiency of gene transfer and whether biological activity from the expressed therapeutic gene resulted after administration of a recombinant adenovirus containing the human wild-type p53 (p53(wt)) gene (rAd-p53 SCH 58500). The cohort study was conducted in five trial subjects with recurrent ovarian cancer. Each trial subject received multiple cycles of rAd-p53 SCH 58500, each cycle comprised of doses of 7.5 x 10(13) particles on each of five consecutive days. Subjects were treated with rAd-p53 SCH 58500 alone during Cycle 1 and in combination with gemcitabine during the subsequent cycles. Both tumor biopsies and peritoneal aspirates were collected and evaluated for gene transfer and evidence of the biological activities of the expressed p53(wt) gene. Using quantitative PCR and RT-PCR, and in situ PCR, gene transfer and expression were documented in tumor biopsies (four of five patients) collected from Cycle 1. Furthermore, upregulation of p21/WAF1, bax and mdm-2, and downregulation of survivin were observed in these same tumor biopsy samples, suggesting that intraperitoneal administration of rAd-p53 SCH 58500 leads to detectable p53 biological activity in target tumor tissue. In addition, gene transfer and its expression were observed in cells obtained from peritoneal aspirates. These fluids were mainly comprised of polymorphonuclear neutrophils, indicating that successful gene transfer can be achieved by multiple cycle intraperitoneal administration of recombinant adenovirus.

Adenovirus-mediated gene therapy using human p21WAF-1/Cip-1 to prevent wound healing in a rabbit model of glaucoma filtration surgery.

OBJECTIVE: To determine if adenovirus-mediated p21(WAF-1/Cip-1) (p21) gene therapy can prevent fibroproliferation and wound healing in a rabbit model of glaucoma filtration surgery. METHODS: In vitro studies were performed using rabbit Tenon fibroblasts harvested from fresh tissue. In vivo studies were conducted in New Zealand white rabbits. A full-thickness sclerotomy was performed under a limbal-based conjunctival flap. Reagents tested included a replication-deficient recombinant adenovirus containing the human p21 gene (rAd.p21); the nonspecific marker gene for green fluorescent protein or beta-galactosidase; mitomycin, 0.5 mg/mL; and balanced saline solution. Each treatment was applied episclerally for 5 minutes before the sclerotomy using a soaked cellulose sponge placed under the surgically created conjunctival flap. Independent experiments were conducted to (1) monitor changes in intraocular pressure during a 30-day period after treatment and examine surgical site histological features, (2) examine changes in bleb morphologic features over 30 days, (3) determine outflow facility 14 days after treatment, and (4) examine the localization and persistence of rAd.p21 expression between 3 and 60 days after treatment. RESULTS: Treatment of Tenon fibroblasts with rAd.p21 resulted in a dose-dependent inhibition of DNA synthesis and cell growth in vitro. In vivo, rAd.p21 inhibited wound healing and fibroproliferation after filtration surgery, comparably to mitomycin. Mitomycin caused notable thinning of the bleb wall. In addition, 2 of the 5 mitomycin-treated eyes exhibited an abscess with hypopyon and hyalitis 30 days after surgery, which was not observed in any of the rAd.p21-treated eyes. None of the treatments resulted in a significantly sustained decrease in intraocular pressure during the 30-day period, although mitomycin treatment resulted in a significant (P =.02) increase in outflow facility 2 weeks after surgery in separate animals. Mitomycin- and rAd.p21-treated eyes had functioning blebs at the end of the experiment based on slitlamp examination. CONCLUSIONS: Mitomycin and rAd.p21 were effective in preventing fibroproliferation and wound healing in a rabbit model of glaucoma surgery. Mitomycin treatment increased outflow facility in normal-pressure eyes. CLINICAL RELEVANCE: Gene therapy with rAd.p21 may provide an effective antiproliferative for glaucoma filtration surgery, without the complications associated with mitomycin.