A new human T-cell lymphoma cell line (Karpas 384) of the T-cell receptor gamma/delta lineage with translocation t(7:14) (p13;q11.2).

A new human T-cell non-Hodgkin lymphoma cell line of the T-cell receptor (TCR) gamma/delta lineage has been derived from the peripheral blood of a patient with a subcutaneous T-cell lymphoma in leukemic phase. The cell line (Karpas 384) initially had the same characteristics as malignant cells from the patient. Both the original tumor and the cell line failed to express any T-cell differentiation antigens other than very weak cell-surface expression of CD3 and cytoplasmic CD7; with continued growth in vitro, surface CD3 became undetectable in the presence of maintained strong cytoplasmic expression. The cell line has a complex karyotype with six abnormal chromosomes exhibiting not only t(7;14) (p13;q11.2) but also inv7(p13;q22.1), t(1;2)(q11;q35), t(2;1;14) (q35;q11-q32.1;q22.1), interstitial deletion 12(q24.1q24.3), and an unidentified marker chromosome. DNA blot analysis showed that TCR C beta and TCR J alpha-C alpha DNA sequences were in germline configuration in all restriction endonuclease digests. TCR gamma sequences showed biallelic V gamma 9-J gamma P-C gamma 1 rearrangements, the TCR gamma rearrangement detected in the majority of normal TCR gamma/delta bearing cells. Use of a range of TCR delta probes showed biallelic deletion of both J delta 1 and J delta 2, but three rearranged fragments when probed with a 3' C delta genomic probe. Similar breakpoints at 7p13 have been reported in a wide range of hematologic malignancies. Molecular cloning of the t(7;14)(p13;q11.2) translocation breakpoint in this cell line may define new DNA sequences of oncogenic potential at the 7p13 locus.