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.

The CSF

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The MOLT-16 cell line, which was established from the malignant cells of a patient with T-cell acute lymphoblastic leukemia, is characterized by a translocation involving chromosome 8 (band q24) and chromosome 14 (band qil) [t(8;14)(q24;qll)]. To determine the position of the gene encoding the a chain of the T-cell receptor and of the protooncogene MYC (formerly c-myc) in relation to the breakpoint junction and to evaluate their possible role in the pathogenesis of T-cell neoplasia, we applied the techniques of in situ chromosomal hybridization, Southern blot analysis, and molecular cloning to MOLT-16 cells. Our results indicate that the breakpoint on chromosome 14 at band qil occurs close to ajoining sequence of the gene encoding the a chain of the T-cell receptor. The constant region and part of the joining region of this gene are translocated to the 3' side of the MYC exons. The breakpoints on chromosomes 8 and 14 are close to, but distinct from, those found in SKW-3, another T-cell leukemia cell line, which has a t(8;14). The identification of a breakpoint to the 3' side of MYC suggests that this recurring translocation is analogous to the variant t(2;8) and t(8;22) translocations observed in the B-cell malignancies.

Rhabdomyolysis is an unusual complication of hematopoietic stem cell transplantation (HSCT). Cyclophosphamide has been one of the key drugs in the most common preparative regimen for HSCT. We present here a rare case of acute rhabdomyolysis following administration of high-dose cyclophosphamide. A 47-year-old woman with adult T-cell leukemia in remission was treated with high-dose cyclophosphamide as a preparative regimen for allogeneic bone marrow transplantation. Nineteen hours later, general convulsions and acidosis suddenly occurred. Levels of serum creatine kinase (skeletal muscle type), myoglobin, and aldolase were markedly elevated to 32870 IU/l, 640 ng/ml, and 240.3 IU/l, respectively. Rhabdomyolysis caused by high-dose cyclophosphamide was diagnosed, and the preparative chemotherapy was discontinued. Subsequently, her muscular signs and symptoms improved, and the results of laboratory examinations returned to normal after 2 weeks. She had previously been treated with conventional doses of cyclophosphamide, doxorubicin, vincristine, and prednisolone without evidence of rhabdomyolysis. Acute rhabdomyolysis may be an adverse effect specific to high-dose cyclophosphamide therapy.

E-cadherin is a transmembrane glycoprotein that mediates Ca2+-dependent intracellular adhesion in normal epithelial cells. E-cadherin levels in serum are known to be significantly elevated in patients with epithelial carcinomas. However, the role of E-cadherin in haematopoietic cells is less clear. In this study, serum E-cadherin levels were therefore determined in patients with acute or chronic leukaemia, malignant lymphoma or myelodysplastic syndromes. Significant elevation of serum E-cadherin levels was detected in patients with haematological malignancies, and between types of acute leukaemias or subtypes of myelodysplastic syndromes, stages of malignant lymphoma, and phases of chronic leukaemia, respectively, compared with those in healthy adult volunteers. These findings suggest that E-cadherin might be expressed in malignant haematopoietic cells and might be useful as a diagnostic indicator in haematological malignancies.

A 33-year-old male with refractory relapsed central nervous system lymphoma underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) from an HLA-identical sibling after reduced-intensity conditioning chemotherapy. The preparative regimen for allo-HSCT consisted of fludarabine and busulfan. Cyclosporine (CsA) and short-term methotrexate were used as prophylaxis for acute graft-versus-host disease (GVHD). Although CsA was quickly reduced to induce a graft-versus-lymphoma (GVL) effect, no symptoms of GVHD and GVL effect were evident. Donor lymphocyte infusion (DLI) was performed on day +40 following transplantation. The patient developed acute GVHD (grade III) after DLI, and lymphoma regression was observed after the occurrence of GVHD. Four months after transplantation, complete remission was achieved with extensive chronic GVHD, and the patient continues to be disease free at 15 months after transplantation.

Chromosomal rearrangements in malignant T-cell disease frequently involve the chromosome bands containing the T-cell receptor genes. The RPMI 8402 cell line, which was established from the leukemia cells of a patient with T-cell acute lymphoblastic leukemia, is characterized by a translocation involving chromosome 14 (band q11) and chromosome 11 (band p15) [t(11;14)(p15;q11)]. By using in situ chromosomal hybridization and Southern blot analysis to examine RPMI 8402 cells, we determined that the break at 14q11 occurs within the variable region sequences of the T-cell receptor alpha-chain gene (TCRA); the break at 11p15 occurs between the HRAS1 gene and the genes for insulin and the insulin-like growth factor 2. These results suggest that the TCRA sequences activate a cellular gene located at 11p15 in malignant T-cell disorders.