INVOLVEMENT OF A HUMAN ENDOGENOUS RETROVIRAL SEQUENCE (THE-7) IN A T(7-14)(Q21-Q32) CHROMOSOMAL TRANSLOCATION ASSOCIATED WITH A B-CELL CHRONIC LYMPHOCYTIC-LEUKEMIA

B cell chronic lymphocytic leukemias (B-CLL) like other blood cell mal ignancies are characterized by chromosomal anomalies directly involved in tumor pathogenesis. We report here the molecular characterization of a t(7;14)(q21;q32) chromosomal translocation observed during the co urse of a B-CLL. We show that this translocation led to the juxtaposit ion of the immuno-globulin heavy chain locus on chromosome 14 to an en dogenous retroviral sequence belonging to the THE family (transposable -like human element) on chromosome 7q21. RT-PCR analysis demonstrated that this sequence is transcribed in most of the tumoral and normal ti ssue analyzed and in the B-CLL described here. These data raise the qu estion of the role of transposable elements in the pathogeny of some l eukemias or at least, in the occurrence of chromosomal rearrangements. Structural rearrangements of the 7q21-22 region are frequently encoun tered in myeloid disorders, and the work presented here could help in their characterization.