Induction of mammary fibroadenomas in rats by adenovirus type 9

Abstract

Abstract After inoculation of adenovirus type 9 into newborn Wistar/Furth rats, seven out of seven females developed one or several mammary fibroadenomas within 14–25 weeks after virus inoculation. No tumours were observed in male rats inoculated with the same virus or in untreated controls. Neonatal inoculations of adenovirus type 5, produced on the same HeLa cells, gave negative results in both sexes. The results indicate that benign mammary tumours can be induced in rats by a virus and that mammary fibroadenomas are induced by adenovirus type 9, previously known to be capable of transforming cells in vitro but not of inducing tumours in vivo .