The inhibitory effects of bryostatin 1 administration on the growth of rabbit papillomas

Bryostatin 1 is a protein kinase C modulator that shows antineoplastic activity in a variety of tumor systems. This study examined the effects of bryostatin 1 administration on papilloma grow th in rabbits. Investigations of optimal route, dose, and schedule were performed. Several groups of rabbits were inoculated with cottontail rabbit papillomavirus (CRPV) DNA, Bryostatin 1 was administered i.v., both daily and weekly, and intralesionally both weekly and bi-weekly, Intralesionally dosed papillomas were examined histologically for immune cell infiltration. In weekly and daily i.v. trials, 2.5 and 1.0 mu g/kg, respectively, showed the greatest overall reduction in tumor size. Bryostatin I administered intralesionally also slowed papilloma growth. Treated lesions had significantly higher numbers of heterophils and eosinophils. (C) 1999 Elsevier Science Ireland Ltd. AU rights reserved.