Assuntos
Transplante de Células-Tronco Hematopoéticas/métodos , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Pirimidinas/uso terapêutico , Tiazóis/uso terapêutico , Quimeras de Transplante , Adulto , Dasatinibe , Humanos , Masculino , Indução de Remissão , Terapia de Salvação/métodos , Transplante HomólogoRESUMO
The translocation t(12;22)(p13;q11) has been consistently described in myeloid malignancies and shown to result from a fusion between the TEL and MN1 genes. Previously described deletions of 12p in acute lymphoblastic leukemias have been recently shown to harbor undetected translocations involving the TEL gene at 12p13. We document a case of an aggressive chronic B-cell leukemia whose cells had trisomy 12 and two unbalanced translocations involving 12p13, including a t(12;22)(p13;q11) as shown by conventional cytogenetics and fluorescence in situ hybridization (FISH). The 12p13 breakpoint of the t(12;22)(p13;q11) was telomeric to the TEL gene, and the second unbalanced translocation with breakpoint 12p13 resulted in the deletion of TEL. This case demonstrates that TEL gene deletions may be relevant in cases of mature B-lymphoproliferative diseases.
Assuntos
Cromossomos Humanos Par 12 , Cromossomos Humanos Par 22 , Proteínas de Ligação a DNA/genética , Leucemia Linfocítica Crônica de Células B/genética , Proteínas Repressoras , Fatores de Transcrição/genética , Translocação Genética , Feminino , Humanos , Imunofenotipagem , Hibridização in Situ Fluorescente , Cariotipagem , Leucemia Linfocítica Crônica de Células B/imunologia , Leucemia Linfocítica Crônica de Células B/patologia , Pessoa de Meia-Idade , Proteínas Proto-Oncogênicas c-ets , Trissomia , Variante 6 da Proteína do Fator de Translocação ETSRESUMO
Chronic lymphoid leukaemias are clonal expansions of B and T cells with mature membrane phenotype. Cytogenetic study of these cases usually requires mitogenic stimulation and can often be hindered by a lack of response of the tumour cells to mitogen, poor quality metaphases, complex markers and proliferation of normal cells. In situ hybridisation with fluorescence-labelled chromosome-specific centromeric DNA probe, single or low copy sequences and whole chromosome paints which hybridise to complementary sequences allow the detection of numerical and structural abnormalities on metaphase and interphase cells with much greater efficiency. Comparative genomic hybridisation uses whole genomic tumour DNA as probe which is hybridised to normal metaphases. It is particularly useful for detecting chromosomal changes without being dependent on the dividing tumour cells. The application of these techniques to the investigation of chronic lymphoid leukaemias is reviewed with emphasis on the work done in our laboratory on trisomy 12 and the tumour suppressor region 13q14 in chronic lymphocytic leukaemia, translocation t(11;14) (q13;q32) in mantle cell lymphoma and other chronic B cell leukaemias, inv(14) (q11q32), i(8q) and complex markers in T prolymphocytic leukaemia.