RESUMEN
Despite tremendous advances in treatments for myeloma in the past decade, the disease remains incurable in the majority of patients. Here, we review recent data demonstrating an association between obesity and increased risk of myeloma development. This may be due to the pro-inflammatory cytokine profile caused by obesity. Currently, there are no screening or prevention strategies for myeloma, but we propose that obesity-associated inflammatory pathways, or obesity itself, may be amenable to intervention, thereby preventing the transition from pre-malignancy to myeloma. In addition, we suggest that the morbidity, mortality and the significant costs associated with myeloma treatment could be reduced by addressing modifiable risk factors, and that research efforts should explore this novel hypothesis.
Asunto(s)
Mieloma Múltiple , Obesidad , Lesiones Precancerosas , Humanos , Mieloma Múltiple/epidemiología , Mieloma Múltiple/etiología , Mieloma Múltiple/metabolismo , Obesidad/complicaciones , Obesidad/epidemiología , Obesidad/metabolismo , Lesiones Precancerosas/epidemiología , Lesiones Precancerosas/etiología , Lesiones Precancerosas/metabolismo , Factores de RiesgoRESUMEN
Proteasome inhibitors (PIs), namely bortezomib, have become a cornerstone therapy for multiple myeloma (MM), potently reducing tumor burden and inhibiting pathologic bone destruction. In clinical trials, carfilzomib, a next generation epoxyketone-based irreversible PI, has exhibited potent anti-myeloma efficacy and decreased side effects compared with bortezomib. Carfilzomib and its orally bioavailable analog oprozomib, effectively decreased MM cell viability following continual or transient treatment mimicking in vivo pharmacokinetics. Interactions between myeloma cells and the bone marrow (BM) microenvironment augment the number and activity of bone-resorbing osteoclasts (OCs) while inhibiting bone-forming osteoblasts (OBs), resulting in increased tumor growth and osteolytic lesions. At clinically relevant concentrations, carfilzomib and oprozomib directly inhibited OC formation and bone resorption in vitro, while enhancing osteogenic differentiation and matrix mineralization. Accordingly, carfilzomib and oprozomib increased trabecular bone volume, decreased bone resorption and enhanced bone formation in non-tumor bearing mice. Finally, in mouse models of disseminated MM, the epoxyketone-based PIs decreased murine 5TGM1 and human RPMI-8226 tumor burden and prevented bone loss. These data demonstrate that, in addition to anti-myeloma properties, carfilzomib and oprozomib effectively shift the bone microenvironment from a catabolic to an anabolic state and, similar to bortezomib, may decrease skeletal complications of MM.
Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Resorción Ósea/tratamiento farmacológico , Mieloma Múltiple/tratamiento farmacológico , Osteogénesis/efectos de los fármacos , Inhibidores de Proteasoma/uso terapéutico , Administración Oral , Animales , Western Blotting , Médula Ósea/efectos de los fármacos , Médula Ósea/metabolismo , Médula Ósea/patología , Resorción Ósea/etiología , Ácidos Borónicos/administración & dosificación , Bortezomib , Calcificación Fisiológica/efectos de los fármacos , Diferenciación Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Compuestos Epoxi/farmacología , Humanos , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos NOD , Ratones SCID , Mieloma Múltiple/complicaciones , Oligopéptidos/administración & dosificación , Osteoblastos/efectos de los fármacos , Osteoblastos/patología , Osteoclastos/efectos de los fármacos , Osteoclastos/patología , Pirazinas/administración & dosificación , ARN Mensajero/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Células del Estroma/efectos de los fármacos , Células del Estroma/metabolismo , Células del Estroma/patología , Células Tumorales Cultivadas , Microambiente Tumoral/efectos de los fármacosRESUMEN
The appropriate induction therapy before and the role of maintenance therapy after auto-SCT for patients with multiple myeloma remain areas of active investigation. We conducted a study in 40 patients with bortezomib given sequentially pre-auto-SCT and as maintenance therapy post auto-SCT. Pre-transplant bortezomib was administered for two cycles followed by high-dose melphalan 200 mg/m(2) with auto-SCT of G-CSF-mobilized PBMCs. Post transplant bortezomib was administered weekly for 5 out of 6 weeks for six cycles. No adverse effects were observed on stem cell mobilization or engraftment. An overall response rate of 83% with a CR+very good partial remission (VGPR) of 50% was observed with this approach. Three-year Kaplan-Meier estimates of disease-free survival and overall survival (OS) were 38.2 and 63.1%, respectively. Bortezomib reduced CD8(+) cytotoxic T cell and CD56(+) natural killer cell PBL subsets and was clinically associated with high rates of viral reactivation to varicella zoster.
Asunto(s)
Ácidos Borónicos/administración & dosificación , Mieloma Múltiple/terapia , Trasplante de Células Madre de Sangre Periférica/métodos , Pirazinas/administración & dosificación , Adulto , Anciano , Ácidos Borónicos/efectos adversos , Bortezomib , Femenino , Factor Estimulante de Colonias de Granulocitos/administración & dosificación , Movilización de Célula Madre Hematopoyética , Herpesvirus Humano 3/efectos de los fármacos , Humanos , Células Asesinas Naturales/efectos de los fármacos , Subgrupos Linfocitarios , Masculino , Melfalán/administración & dosificación , Persona de Mediana Edad , Mieloma Múltiple/tratamiento farmacológico , Pirazinas/efectos adversos , Inducción de Remisión , Análisis de Supervivencia , Linfocitos T Citotóxicos/efectos de los fármacos , Trasplante Autólogo , Resultado del Tratamiento , Activación Viral/efectos de los fármacosRESUMEN
The TEL/PDGFbetaR gene, which encodes a fusion protein containing the ETS-family member TEL fused to the protein-tyrosine kinase domain of the platelet-derived growth factor receptor-beta (PDGFbetaR), confers interleukin 3 (IL-3)-independent growth on Ba/F3 hematopoietic cells. TEL/PDGFbetaR mutants have been generated that contain tyrosine-to-phenylalanine (Tyr-->Phe) substitutions at phosphorylation sites present in the native PDGFbetaR to assess the role of these sites in cell transformation by TEL/PDGFbetaR. Similar to previous findings in a murine bone marrow transplantation model, full transformation of Ba/F3 cells to IL-3-independent survival and proliferation required the TEL/PDGFbetaR juxtamembrane and carboxy terminal phosphorylation sites. In contrast to previous reports concerning comparable mutants in the native PDGFbetaR, each of the TEL/PDGFbetaR mutants is fully active as a protein-tyrosine kinase. Expression of the TEL/PDGFbetaR fusion protein causes hyperphosphorylation and activation of signal transducer and activator of transcription (STAT5), and this activation of STAT5 requires the juxtamembrane Tyr579 and Tyr581 in the TEL/PDGFbetaR fusion. Hyperphosphosphorylation of phospholipase Cgamma (PLCgamma) and the p85 subunit of phosphatidylinositol 3-kinase (PI3K) requires the carboxy terminal tyrosine residues of TEL/PDGFbetaR. Thus, full transformation of Ba/F3 cells by TEL/PDGFbetaR requires engagement of PI3K and PLCgamma and activation of STAT5. Taken together with the growth properties of cells transformed by the TEL/PDGFbetaR variants, these findings indicate that a minimal combination of these signaling intermediates contributes to hematopoietic transformation by the wild-type TEL/PDGFbetaR fusion. (Blood. 2001;98:3390-3397)
Asunto(s)
Proteínas de Unión al ADN/fisiología , Leucemia Mielomonocítica Crónica/patología , Proteínas de la Leche , Proteínas de Fusión Oncogénica/fisiología , Transducción de Señal , Transactivadores/fisiología , Animales , Sitios de Unión , Línea Celular , Leucemia Mielomonocítica Crónica/genética , Ratones , Mutación , Proteínas de Fusión Oncogénica/química , Proteínas de Fusión Oncogénica/genética , Fosfatidilinositol 3-Quinasas/metabolismo , Fosforilación , Fosfotirosina/metabolismo , Proteínas Tirosina Quinasas/metabolismo , Factor de Transcripción STAT5 , Relación Estructura-ActividadRESUMEN
Tyrosine kinase fusion oncogenes that occur as a result of chromosomal translocations have been shown to activate proliferative and antiapoptotic pathways in leukemic cells, but the importance of autocrine and paracrine expression of hematopoietic cytokines in leukemia pathogenesis is not understood. Evidence that leukemic transformation may be, at least in part, cytokine dependent includes data from primary human leukemia cells, cell culture experiments, and murine models of leukemia. This report demonstrates that interleukin (IL)-3 plasma levels are elevated in myeloproliferative disease (MPD) caused by the TEL/tyrosine kinase fusions TEL/platelet-derived growth factor beta receptor (PDGFbetaR), TEL/Janus kinase 2 (JAK2), and TEL/neurotrophin-3 receptor (TRKC). Plasma granulocyte-macrophage colony-stimulating factor (GM-CSF) levels were elevated by TEL/PDGFbetaR and TEL/JAK2. However, all of the fusions tested efficiently induced MPD in mice genetically deficient for both GM-CSF and IL-3, demonstrating that these cytokines are not necessary for the development of disease in this model system. Furthermore, in experiments using normal marrow transduced with TEL/PDGFbetaR retrovirus mixed with marrow transduced with an enhanced green fluorescent protein (EGFP) retrovirus, the MPD induced in these mice demonstrated minimal stimulation of normal myelopoiesis by the TEL/PDGFbetaR-expressing cells. In contrast, recipients of mixed GM-CSF-transduced and EGFP-transduced marrow exhibited significant paracrine expansion of EGFP-expressing cells. Collectively, these data demonstrate that, although cytokine levels are elevated in murine bone marrow transplant models of leukemia using tyrosine kinase fusion oncogenes, GM-CSF and IL-3 are not required for myeloproliferation by any of the oncogenes tested.
Asunto(s)
Transformación Celular Neoplásica/efectos de los fármacos , Trastornos Mieloproliferativos/etiología , Proteínas de Fusión Oncogénica/farmacología , Animales , Trasplante de Médula Ósea , Transformación Celular Neoplásica/genética , Modelos Animales de Enfermedad , Factor Estimulante de Colonias de Granulocitos y Macrófagos/genética , Factor Estimulante de Colonias de Granulocitos y Macrófagos/farmacología , Interleucina-3/genética , Interleucina-3/farmacología , Ratones , Ratones Noqueados , Trastornos Mieloproliferativos/patología , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/farmacología , Proteínas de Fusión Oncogénica/genética , Comunicación Paracrina , Transducción GenéticaRESUMEN
Primitive hematopoietic progenitors from some patients with Philadelphia chromosome (Ph)-positive chronic myeloid leukemia (CML) express aberrant transcripts for interleukin 3 (IL-3) and granulocyte colony-stimulating factor (G-CSF), and exhibit autonomous proliferation in serum-free cultures that is inhibited by anti-IL-3 and anti-IL-3 receptor antibodies. Expression of the product of the Ph chromosome, the BCR/ABL oncogene, in mice by retroviral bone marrow transduction and transplantation induces CML-like leukemia, and some leukemic mice have increased circulating IL-3, and perhaps granulocyte-macrophage colony-stimulating factor (GM-CSF). These observations raise the possibility of autocrine or paracrine cytokine production in the pathogenesis of human CML. Mice with homozygous inactivation of the Il-3 gene, the Gm-csf gene, or both, were used to test the requirement for these cytokines for induction of CML-like disease by BCR/ABL. Neither IL-3 nor GM-CSF was required in donor, recipient, or both for induction of CML-like leukemia by p210 BCR/ABL. Use of novel mice deficient in both IL-3 and GM-CSF demonstrated that the lack of effect on leukemogenesis was not due to redundancy between these hematopoietic growth factors. Analysis of cytokine levels in leukemic mice where either donor or recipient was Il-3(-/-) indicated that the increased IL-3 originated from the recipient, suggestive of a host reaction to the disease. These results demonstrate that IL-3 and GM-CSF are not required for BCR/ABL-induced CML-like leukemia in mice and suggest that autocrine production of IL-3 does not play a role in established chronic phase CML in humans.
Asunto(s)
Transformación Celular Neoplásica/efectos de los fármacos , Proteínas de Fusión bcr-abl/farmacología , Factor Estimulante de Colonias de Granulocitos y Macrófagos/farmacología , Interleucina-3/farmacología , Leucemia Mielógena Crónica BCR-ABL Positiva/etiología , Animales , Trasplante de Médula Ósea , Modelos Animales de Enfermedad , Proteínas de Fusión bcr-abl/genética , Factor Estimulante de Colonias de Granulocitos y Macrófagos/genética , Factor Estimulante de Colonias de Granulocitos y Macrófagos/metabolismo , Interleucina-3/genética , Interleucina-3/metabolismo , Leucemia Mielógena Crónica BCR-ABL Positiva/metabolismo , Leucemia Mielógena Crónica BCR-ABL Positiva/patología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Trastornos Mieloproliferativos/etiología , Trastornos Mieloproliferativos/metabolismo , Trastornos Mieloproliferativos/patología , Tasa de Supervivencia , Distribución Tisular , Transducción GenéticaRESUMEN
The t(5;12)(q33;p13) translocation associated with chronic myelomonocytic leukemia (CMML) generates a TEL/PDGFbetaR fusion gene. Here, we used a murine bone marrow transplant (BMT) assay to test the transforming properties of TEL/PDGFbetaR in vivo. TEL/PDGFbetaR, introduced into whole bone marrow by retroviral transduction, caused a rapidly fatal myeloproliferative disease that closely recapitulated human CMML. TEL/PDGFbetaR transplanted mice developed leukocytosis with Gr-1(+) granulocytes, splenomegaly, evidence of extramedullary hematopoiesis, and bone marrow fibrosis, but no lymphoproliferative disease. We assayed mutant forms of the TEL/PDGFbetaR fusion protein - including 8 tyrosine to phenylalanine substitutions at phosphorylated PDGFbetaR sites to which various SH2 domain-containing signaling intermediates bind - for ability to transform hematopoietic cells. All of the phenylalanine (F-) mutants tested conferred IL-3-independence to a cultured murine hematopoietic cell line, but, in the BMT assay, different F-mutants displayed distinct transforming properties. In transplanted animals, tyrosines 579/581 proved critical for the development of myeloproliferative phenotype. F-mutants with these residues mutated showed no sign of myeloproliferation but instead developed T-cell lymphomas. In summary, TEL/PDGFbetaR is necessary and sufficient to induce a myeloproliferative disease in a murine BMT model, and PDGFbetaR residues Y579/581 are required for this phenotype.
Asunto(s)
Transformación Celular Neoplásica , Proteínas de Unión al ADN/metabolismo , Leucemia Mielomonocítica Aguda/etiología , Proteínas de Fusión Oncogénica/metabolismo , Receptores del Factor de Crecimiento Derivado de Plaquetas/metabolismo , Proteínas Represoras , Factores de Transcripción/metabolismo , Tirosina/metabolismo , Animales , Células Clonales , Proteínas de Unión al ADN/genética , Reordenamiento Génico de Linfocito T , Técnicas de Transferencia de Gen , Vectores Genéticos , Linfoma de Células T , Ratones , Ratones Endogámicos BALB C , Proteínas Proto-Oncogénicas c-ets , Receptores del Factor de Crecimiento Derivado de Plaquetas/genética , Retroviridae/genética , Transducción de Señal , Síndrome , Trasplante de Tejidos , Factores de Transcripción/genética , Integración Viral , Proteína ETS de Variante de Translocación 6RESUMEN
The TEL/PDGFbetaR fusion protein is expressed as the consequence of a recurring t(5;12) translocation associated with chronic myelomonocytic leukemia (CMML). Unlike other activated protein tyrosine kinases associated with hematopoietic malignancies, TEL/PDGFbetaR is invariably associated with a myeloid leukemia phenotype in humans. To test the transforming properties of TEL/PDGFbetaR in vivo, and to analyze the basis for myeloid lineage specificity in humans, we constructed transgenic mice with TEL/PDGFbetaR expression driven by a lymphoid-specific immunoglobulin enhancer-promoter cassette. These mice developed lymphoblastic lymphomas of both T and B lineage, demonstrating that TEL/PDGFbetaR is a transforming protein in vivo, and that the transforming ability of this fusion is not inherently restricted to the myeloid lineage. Treatment of TEL/PDGFbetaR transgenic animals with a protein tyrosine kinase inhibitor with in vitro activity against PDGFbetaR (CGP57148) resulted in suppression of disease and a prolongation of survival. A therapeutic benefit was apparent both in animals treated before the development of overt clonal disease and in animals transplanted with clonal tumor cells. These results suggest that small-molecule tyrosine kinase inhibitors may be effective treatment for activated tyrosine kinase-mediated malignancies both early in the course of disease and after the development of additional transforming mutations.
Asunto(s)
Proteínas de Unión al ADN/genética , Inhibidores Enzimáticos/uso terapéutico , Neoplasias Hematológicas/tratamiento farmacológico , Neoplasias Hematológicas/genética , Proteínas Tirosina Quinasas/antagonistas & inhibidores , Receptores del Factor de Crecimiento Derivado de Plaquetas/genética , Proteínas Represoras , Factores de Transcripción/genética , Translocación Genética , Animales , Antineoplásicos/uso terapéutico , Ratones , Ratones Transgénicos , Proteínas Proto-Oncogénicas c-ets , Receptor beta de Factor de Crecimiento Derivado de Plaquetas , Proteína ETS de Variante de Translocación 6RESUMEN
Interactions of human immunodeficiency virus type 1 (HIV-1) with hematopoietic stem cells may define restrictions on immune reconstitution following effective antiretroviral therapy and affect stem cell gene therapy strategies for AIDS. In the present study, we demonstrated mRNA and cell surface expression of HIV-1 receptors CD4 and the chemokine receptors CCR-5 and CXCR-4 in fractionated cells representing multiple stages of hematopoietic development. Chemokine receptor function was documented in subsets of cells by calcium flux in response to a cognate ligand. Productive infection by HIV-1 via these receptors was observed with the notable exception of stem cells, in which case the presence of CD4, CXCR-4, and CCR-5, as documented by single-cell analysis for expression and function, was insufficient for infection. Neither productive infection, transgene expression, nor virus entry was detectable following exposure of stem cells to either wild-type HIV-1 or lentivirus constructs pseudotyped in HIV-1 envelopes of macrophage-tropic, T-cell-tropic, or dualtropic specificity. Successful entry into stem cells of a vesicular stomatitis virus G protein-pseudotyped HIV-1 construct demonstrated that the resistance to HIV-1 was mediated at the level of virus-cell membrane fusion and entry. These data define the hematopoietic stem cell as a sanctuary cell which is resistant to HIV-1 infection by a mechanism independent of receptor and coreceptor expression that suggests a novel means of cellular protection from HIV-1.
Asunto(s)
Antígenos CD4/análisis , VIH-1/fisiología , Células Madre Hematopoyéticas/virología , Receptores CCR5/análisis , Receptores CXCR4/análisis , Síndrome de Inmunodeficiencia Adquirida/terapia , Adulto , Antígenos CD34/análisis , Terapia Genética , Células Madre Hematopoyéticas/fisiología , Humanos , ARN Mensajero/análisis , Receptores CCR5/genética , Receptores CXCR4/genéticaRESUMEN
Recent reports have demonstrated fusion of the TEL gene on 12p13 to the JAK2 gene on 9p24 in human leukemias. Three variants have been identified that fuse the TEL pointed (PNT) domain to (i) the JAK2 JH1-kinase domain, (ii) part of and (iii) all of the JH2 pseudokinase domain. We report that all of the human TEL/JAK2 variants, and a human/mouse chimeric hTEL/mJAK2(JH1) fusion gene, transform the interleukin-3 (IL-3)-dependent murine hematopoietic cell line Ba/F3 to IL-3-independent growth. Transformation requires both the TEL PNT domain and JAK2 kinase activity. Furthermore, all TEL/JAK2 variants strongly activated STAT 5 by phosphotyrosine Western blots and by electrophoretic mobility shift assays (EMSA). Mice (n = 40) transplanted with bone marrow infected with the MSCV retrovirus containing either the hTEL/mJAK2(JH1) fusion or its human counterpart developed a fatal mixed myeloproliferative and T-cell lymphoproliferative disorder with a latency of 2-10 weeks. In contrast, mice transplanted with a TEL/JAK2 mutant lacking the TEL PNT domain (n = 10) or a kinase-inactive TEL/JAK2(JH1) mutant (n = 10) did not develop the disease. We conclude that all human TEL/JAK2 fusion variants are oncoproteins in vitro that strongly activate STAT 5, and cause lethal myelo- and lymphoproliferative syndromes in murine bone marrow transplant models of leukemia.
Asunto(s)
Células Madre Hematopoyéticas , Trastornos Linfoproliferativos/genética , Proteínas de la Leche , Trastornos Mieloproliferativos/genética , Proteínas de Fusión Oncogénica/genética , Animales , Trasplante de Médula Ósea , División Celular , Línea Celular Transformada , ADN/metabolismo , ADN Recombinante , ADN Viral/análisis , Proteínas de Unión al ADN/metabolismo , Células Madre Hematopoyéticas/citología , Humanos , Interleucina-3/fisiología , Ratones , Ratones Transgénicos , Trastornos Mieloproliferativos/patología , Proteínas de Fusión Oncogénica/fisiología , Retroviridae/genética , Factor de Transcripción STAT5 , Transactivadores/metabolismo , Transformación Genética , Integración ViralRESUMEN
The TEL/PDGF beta R fusion protein is the product of the t(5;12) translocation in patients with chronic myelomonocytic leukemia. The TEL/PDGF beta R is an unusual fusion of a putative transcription factor, TEL, to a receptor tyrosine kinase. The translocation fuses the amino terminus of TEL, containing the helix-loop-helix (HLH) domain, to the transmembrane and cytoplasmic domain of the PDGF beta R. We hypothesized that TEL/PDGF beta R self-association, mediated by the HLH domain of TEL, would lead to constitutive activation of the PDGF beta R tyrosine kinase domain and cellular transformation. Analysis of in vitro-translated TEL/ PDGF beta R confirmed that the protein self-associated and that self-association was abrogated by deletion of 51 aa within the TEL HLH domain. In vivo, TEL/PDGF beta R was detected as a 100-kDa protein that was constitutively phosphorylated on tyrosine and transformed the murine hematopoietic cell line Ba/F3 to interleukin 3 growth factor independence. Transformation of Ba/F3 cells required the HLH domain of TEL and the kinase activity of the PDGF beta R portion of the fusion protein. Immunoblotting demonstrated that TEL/PDGF beta R associated with multiple signaling molecules known to associate with the activated PDGF beta R, including phospholipase C gamma 1, SHP2, and phosphoinositol-3-kinase. TEL/PDGF beta R is a novel transforming protein that self-associates and activates PDGF beta R-dependent signaling pathways. Oligomerization of TEL/PDGF beta R that is dependent on the TEL HLH domain provides further evidence that the HLH domain, highly conserved among ETS family members, is a self-association motif.