Assuntos
Proliferação de Células/efeitos dos fármacos , Canais de Potássio Ativados por Cálcio de Condutância Intermediária/antagonistas & inibidores , Leucemia Linfocítica Crônica de Células B/patologia , Bloqueadores dos Canais de Potássio/farmacologia , Antígenos CD19/análise , Clotrimazol/farmacologia , Humanos , Canais de Potássio Ativados por Cálcio de Condutância Intermediária/fisiologia , Antígeno Ki-67/análise , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Pirazóis/farmacologiaAssuntos
Proteína Agonista de Morte Celular de Domínio Interatuante com BH3/deficiência , Proteínas de Ciclo Celular/deficiência , Proteínas de Ligação a DNA/deficiência , Leucemia de Células T/patologia , Leucemia de Células T/fisiopatologia , Proteínas Serina-Treonina Quinases/deficiência , Linfócitos T/patologia , Proteínas Supressoras de Tumor/deficiência , Animais , Proteínas Mutadas de Ataxia Telangiectasia , Feminino , MasculinoRESUMO
Chronic lymphocytic leukemia (CLL) cells require complex microenvironmental and immunologic interactions to survive and proliferate. Such interactions might be best recreated in animal models; however, this needs extensive verification. We therefore investigated the composition of the T-cell compartment in the Eµ-TCL1 transgenic mouse, currently the most widely used murine model for CLL. Immunophenotyping and transplant approaches were used to define T-cell subsets at various stages of CLL. Analogous to human CLL, we observed a skewing of T-cell subsets from naive to antigen-experienced memory T cells that was more pronounced in lymph nodes than in blood. Transplantation of CLL into non-transgenic recipients was feasible without immunosuppression in a pure C57BL/6 background and resulted in the prominent skewing of the T cells of the recipient mice. Both in spontaneously developed CLL and in the transplantation setting, a loss in T-cell receptor diversity was observed, with a relevant number of clonal T-cell populations arising. This suggests that antigen-dependent differentiation toward the T memory pool is initiated by murine CLL cells. In summary, we validate the TCL1 transgenic mouse model for analysis of T-cell phenotypes and suggest a CLL-dependent antigen-driven skewing of T cells in these mice.
Assuntos
Modelos Animais de Doenças , Leucemia Linfocítica Crônica de Células B/etiologia , Proteínas Proto-Oncogênicas/fisiologia , Linfócitos T/imunologia , Animais , Feminino , Citometria de Fluxo , Humanos , Imunofenotipagem , Leucemia Linfocítica Crônica de Células B/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Receptores de Antígenos de Linfócitos T/metabolismoRESUMO
The Hedgehog (Hh) pathway regulates cell proliferation and survival and contributes to tumorigenesis. We investigated the expression and function of this pathway in B-cell chronic lymphocytic leukemia (CLL) cells and in healthy B lymphocytes. Profiling of cognate Hh pathway members revealed reduced expression of two key Hh signaling effectors, Smoothened (SMOH) and GLI, in CLL cells, whereas transcription levels of other investigated members resembled normal B-lymphocyte levels. Examining the functional role of SMOH and GLI in cell survival, we found that CLL cells were hardly sensitive toward specific SMOH inhibition, but showed an unspecific decline in cell viability in response to high concentrations of the SMOH antagonist cyclopamine. In contrast, treatment with the novel GLI antagonist GANT61 reduced expression of the target gene Patched and preferentially decreased the viability of malignant cells. Specific RNA interference knockdown experiments in a CLL-derived cell line confirmed the autonomous role of GLI in malignant cell survival. GANT61-induced apoptosis in primary leukemic cells was partly attenuated by protective stromal cells, but not soluble sonic hedgehog ligand. In summary, our data show a downregulation of the classical Hh pathway in CLL and suggest an intrinsic SMOH-independent role of GLI in the ex vivo survival of CLL cells.