Mouse Mammary Tumour Virus and Polyoma Virus Information in Mammary Tumours of Athymic Mice Inoculated with Polyoma Virus

Publisher Website
Google Scholar
Abstract
Polyoma virus inoculation of athymic mice results in the development of mammary tumors with a much higher incidence than the development of salivary gland tumors, the latter being the most common for immunocompetent normal mice. Polyoma virus might act as a co-carcinogen in activating the expression of mouse mammary tumor virus (MMTV). Molecular hybridization studies showed that the mammary tumor development was accompanied by neither the amplification of MMTV genomic sequences nor by their more extensive transcription. Tumor tissue contained .apprx. 60-100 copies of polyoma virus genome equivalents/cell and some of these sequences were apparently transcribed into RNA. While these results do not rule out the transient involvement of MMTV expression in mammary tumor development, the mammary gland cells appear to be directly transformed by polyoma virus. Thus, polyoma virus displayed a tropism in athymic mice that was different from that in normal mice.