RESUMEN
A new NF-kappaB inhibitor, dehydroxymethylepoxyquinomicin (DHMEQ), inhibited proliferation and induced apoptosis in human Burkitt lymphoma, HS-Sultan and Daudi cell lines. The activation of caspase-3 and the cleavage of caspase substrate PARP were observed after treatment with DHMEQ. The induction of apoptosis by DHMEQ was prevented by the pretreatment of Burkitt lymphoma cells with pan-caspase inhibitor, z-VAD-FMK. The expression of anti-apoptotic factors such as IAP-1 and XIAP was suppressed by DHMEQ. Phosphorylation of ERK and JNK was induced by DHMEQ. In conclusion, these results demonstrate that NF-kappaB might be an ideal target to develop for new anti-cancer drugs for Burkitt lymphoma.
Asunto(s)
Apoptosis , Benzamidas/farmacología , Linfoma de Burkitt/patología , Ciclohexanonas/farmacología , FN-kappa B/metabolismo , Linfoma de Burkitt/metabolismo , Caspasa 3/metabolismo , Línea Celular Tumoral , Proliferación Celular , Activación Enzimática , Humanos , FN-kappa B/antagonistas & inhibidores , FosforilaciónRESUMEN
We report a case of IgG-kappa multiple myeloma associated with neutrophilia (WBC 31,300/microl, neutrophil 90.5%). Interestingly, the serum level of granulocyte colony stimulating factor (G-CSF) in this patient was elevated to 1,500 pg/ml (normal range: 5.78-27.5). Plasma cells were 35% in the bone marrow and were strongly stained with anti-G-CSF antibody. To directly study the production of G-CSF from plasma cells in this patient, CD138 positive plasma cells were purified from bone marrow of multiple myeloma patients by magnetic sorting. The expression of G-CSF mRNA was observed in CD138 positive plasma cells from this myeloma patient with neutrophilia by RT-PCR. In contrast, the expression of G-CSF mRNA was not detected in CD138 positive plasma cells from the other multiple myeloma patients without neutrophilia and 4 human myeloma cell lines (HS-Sultan, IM9, RPMI8226, U266) by RT-PCR. After the CD138 positive plasma cells were cultured in vitro for 48 h, the production of G-CSF protein was confirmed (71.8 pg/ml) in the supernatant by ELISA. These results indicated plasma cells of this myeloma patient directly produced G-CSF and that this was the primary cause of neutrophilia.
Asunto(s)
Factor Estimulante de Colonias de Granulocitos/metabolismo , Leucocitosis/etiología , Mieloma Múltiple/metabolismo , Proteínas de Neoplasias/metabolismo , Neutrófilos , Anciano , Anciano de 80 o más Años , Médula Ósea/patología , Factor Estimulante de Colonias de Granulocitos/biosíntesis , Factor Estimulante de Colonias de Granulocitos/sangre , Humanos , Cadenas kappa de Inmunoglobulina/biosíntesis , Masculino , Glicoproteínas de Membrana/análisis , Mieloma Múltiple/complicaciones , Proteínas de Mieloma/biosíntesis , Proteínas de Neoplasias/biosíntesis , Proteínas de Neoplasias/sangre , Células Madre Neoplásicas/metabolismo , Proteoglicanos/análisis , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Sindecano-1 , SindecanosRESUMEN
STI571 is a specific tyrosine kinase inhibitor of Abl kinase. It was previously reported that STI571 induced hemoglobin synthesis in the chronic myelogenous leukemia (CML) cell line K562. However, its mechanisms remain unknown. In this study, we demonstrated that STI571 induced the phosphorylation of p38 mitogen-activated protein kinase (MAPK) and dephosphorylation of extracellular signal-regulated kinase (ERK) in K562 cells. In contrast, the phosphorylation of c-Jun N-terminal kinases (JNK) in K562 cells was not altered by STI571. We also found that STI571 induced all the myeloid (CD11b, CD13), megakaryocytic (CD41a, CD42), and erythroid (glycophorin-A) markers on K562 cells. A p38 MAPK-specific inhibitor, SB203580, inhibited the STI571-induced multi-lineage differentiation of K562 cells, indicating that p38 MAPK is crucial for this differentiation. In contrast, SB203580 did not overcome the inhibitory effect for proliferation of K562 cells, indicating that p38 MAPK activation by STI571 does not affect cell numbers. Among the hematopoietic transcription factors, the expression level of c-myb mRNA was clearly downregulated after incubation with STI571 in K562 cells. STI571-induced downregulation of c-myb mRNA was prevented by the pretreatment of K562 cells by SB203580. Our data provides insights into how p38 MAPK and ERK pathways are involved in STI571-induced differentiation of K562 cells.
Asunto(s)
Diferenciación Celular/fisiología , Inhibidores Enzimáticos/farmacología , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Piperazinas/farmacología , Pirimidinas/farmacología , Benzamidas , Biomarcadores/análisis , Western Blotting , Linaje de la Célula , Cartilla de ADN , Hemoglobinas/biosíntesis , Hemoglobinas/efectos de los fármacos , Humanos , Mesilato de Imatinib , Proteínas Quinasas JNK Activadas por Mitógenos , Células K562 , Proteínas Quinasas Activadas por Mitógenos/efectos de los fármacos , Fosforilación , Proteínas Proto-Oncogénicas c-myb/efectos de los fármacos , Proteínas Proto-Oncogénicas c-myb/metabolismo , Transducción de Señal/fisiología , Factores de Transcripción/efectos de los fármacos , Factores de Transcripción/metabolismo , Proteínas Quinasas p38 Activadas por MitógenosRESUMEN
We developed a new experimental animal model of human multiple myeloma using immunodeficient NOD/SCID/gammac(null) (NOG) mice. A human myeloma cell line, U266, was intravenously inoculated into 20 NOG mice, all of which developed hind leg paralysis and distress around 6 weeks after transplantation. Pathological studies showed that only the bone marrow was infiltrated with U266 cells, and no cells were present in other organs. Osteolytic lesions in cortical bones and loss of trabecular bones were prominent in U266-transplanted NOG mice. In contrast, U266 cells were not detected in CB17scid or NOD/SCID mice 6 weeks after intravenous inoculation. Human IgE, produced by U266 cells, was detected in the serum of U266-transplanted NOG mice by ELISA. The results indicated that this hu-myeloma NOG model might be useful for studying the pathogenesis of myeloma and related osteolytic lesions, and are suggestive of its applicability to the future development of new drugs.