Gene encoding the alpha chain of the T-cell receptor is moved immediately downstream of c-myc in a chromosomal 8;14 translocation in a cell line from a human T-cell leukemia.
The SKW-3 cell line, which was established from the malignant cells of a patient with T-cell chronic lymphocytic leukemia, is characterized by a translocation involving chromosome 8 (band q24) and chromosome 14 (band q11) [t(8;14)(q24;q11)]. To determine the position of the gene encoding the alpha chain of the T-cell receptor and of the human protooncogene myc (c-myc) in relation to the breakpoint junctions and to evaluate their possible role in the pathogenesis of T-cell neoplasia, we applied the techniques of in situ chromosomal hybridization and Southern blot analysis to SKW-3 cells. Our results indicate that the breakpoint on chromosome 14 at band q11 occurs close to a joining sequence of the gene encoding the alpha chain of the T-cell receptor. Additional rearrangements within the alpha-chain locus appear to split the variable region cluster. As a result of the rearrangements, the constant region of this gene, as well as some variable region segments, are translocated to chromosome 8, to the 3' side of the c-myc-coding exons. The identification of a breakpoint to the 3' side of c-myc suggests that this translocation is analogous to the variant (2;8) and t(8;22) translocations observed in the B-cell malignancies.
D002874:Chromosome Mapping; D002901:Chromosomes, Human, 13-15; D002906:Chromosomes, Human, 6-12 and X; D003001:Cloning, Molecular; D008040:Genetic Linkage; D006801:Humans; D007621:Karyotyping; D007945:Leukemia, Lymphoid / Q000235:genetics* / Q000276:immunology; D009693:Nucleic Acid Hybridization; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D011948:Receptors, Antigen, T-Cell / Q000235:genetics*; D014178:Translocation, Genetic
D011518:Proto-Oncogene Proteins; D011948:Receptors, Antigen, T-Cell