TUMORS DERIVED FROM HTLV-I TAX TRANSGENIC MICE ARE CHARACTERIZED BY ENHANCED LEVELS OF APOPTOSIS AND ONCOGENE EXPRESSION

In order to investigate the role that the human T-lymphotropic virus t ype I (HTLV-I) tax oncogene plays in apoptosis and transformation in v ivo, four lines of HTLV-I tax transgenic mice were generated under the regulatory control of the CD3-epsilon promoter-enhancer sequence, The se mice develop a variety of phenotypes including mesenchymal tumours, which develop at sound sites, and salivary and mammary adenomas, In s itu DNA fragment labelling and immunocytochemical analysis of these tu mours reveals that they display enhanced levels of apoptosis,,which is associated with elevated levels of MSc, Fos, Jun, and p53 protein exp ression. Furthermore, double immunofluorescent staining shows that Tax expression and apoptosis co-localize, indicating that Tax expression is closely associated with apoptosis ill vivo. (C) 1998 John Wiley & S ons, Ltd.