The Molecular Genetics of Human T Cell Leukemias and Lymphomas

Abstract

Specific chromosomal translocations are consistently associated with particular malignancies suggesting they play a role in neoplastic development (Klein 1981; Yunis 1983). Studies on the translocations present in Burkitt1s lymphoma have shown they result in the association of the c-myc oncogene with the 5′ end of either the IgH locus on chromosome 14, or the C_K or C_λ loci on chromosome 2 and 22 respectively. A consequence of this juxtaposition is the deregulation of the participating c-myc oncogene (Croce and Nowell 1985). In addition the IgH locus has been implicated in the translocations present in other B cell leukemias and lymphoma (Tsujimoto et al. 1984a, 1984b). The Ig loci’s unique feature of B cell restricted DNA rearrangement prior to functional expression may be responsible for targeting the Ig loci for B cell associated translocations. Similarly, the alpha and beta chain genes which compose the serologically defined T cell receptor are rearranged and expressed specifically in T cells (Davis et al. 1984). The experiments presented in this paper demonstrate the participation of the T cell receptor a chain gene in the t(11; 14) and the t(8; 14) translocations in T cell malignancies and show that in the later case this participation may be responsible for the deregulation of the c-myc oncogene.