Murine T lymphomas in which the cellular myc oncogene has been activated by retroviral insertion

Abstract

The myc oncogene is implicated here in T lymphocyte neoplasia. Cloning revealed a retroviral insert 0.7-1.3 kb 5′ to c-myc in two T lymphomas induced by Soule murine leukemia virus and in a spontaneous T lymphoma (Tikaut) of an AKR mouse, a strain in which leukemogenesis involves recombinant retroviruses (MCF viruses). The tumor c-myc mRNAs appear normal but their level is ∼5-fold higher than in most T lymphomas lacking c-myc rearrangement. Since each insert would be transcribed away from c-myc, its activation cannot involve the promoter of the long terminal repeat (LTR) but could reflect an enhancer, like that demonstrated within the Soule LTR. The Tikaut provirus has an MCF-like recombinan..