RESUMO
Bone marrow monocytes are primarily committed to osteoclast formation. It is, however, unknown whether potential primary alterations are specifically present in bone marrow monocytes from patients with multiple myeloma, smoldering myeloma or monoclonal gammopathy of undetermined significance. We analyzed the immunophenotypic and transcriptional profiles of bone marrow CD14+ monocytes in a cohort of patients with different types of monoclonal gammopathies to identify alterations involved in myeloma-enhanced osteoclastogenesis. The number of bone marrow CD14+CD16+ cells was higher in patients with active myeloma than in those with smoldering myeloma or monoclonal gammopathy of undetermined significance. Interestingly, sorted bone marrow CD14+CD16+ cells from myeloma patients were more pro-osteoclastogenic than CD14+CD16-cells in cultures ex vivo Moreover, transcriptional analysis demonstrated that bone marrow CD14+ cells from patients with multiple myeloma (but neither monoclonal gammopathy of undetermined significance nor smoldering myeloma) significantly upregulated genes involved in osteoclast formation, including IL21RIL21R mRNA over-expression by bone marrow CD14+ cells was independent of the presence of interleukin-21. Consistently, interleukin-21 production by T cells as well as levels of interleukin-21 in the bone marrow were not significantly different among monoclonal gammopathies. Thereafter, we showed that IL21R over-expression in CD14+ cells increased osteoclast formation. Consistently, interleukin-21 receptor signaling inhibition by Janex 1 suppressed osteoclast differentiation from bone marrow CD14+ cells of myeloma patients. Our results indicate that bone marrow monocytes from multiple myeloma patients show distinct features compared to those from patients with indolent monoclonal gammopathies, supporting the role of IL21R over-expression by bone marrow CD14+ cells in enhanced osteoclast formation.
Assuntos
Expressão Gênica , Monócitos/metabolismo , Mieloma Múltiplo/genética , Mieloma Múltiplo/patologia , Osteoclastos/metabolismo , Receptores de Interleucina-21/genética , Biomarcadores , Células da Medula Óssea/metabolismo , Células da Medula Óssea/patologia , Análise por Conglomerados , Citocinas/metabolismo , Feminino , Perfilação da Expressão Gênica , Humanos , Imunofenotipagem , Receptores de Lipopolissacarídeos/metabolismo , Masculino , Gamopatia Monoclonal de Significância Indeterminada/genética , Gamopatia Monoclonal de Significância Indeterminada/metabolismo , Gamopatia Monoclonal de Significância Indeterminada/patologia , Mieloma Múltiplo/metabolismo , Fenótipo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores de IgG/metabolismo , Receptores de Interleucina-21/metabolismoAssuntos
Regulação Neoplásica da Expressão Gênica , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Fatores Imunológicos/farmacologia , Mieloma Múltiplo/terapia , Plasmócitos/efeitos dos fármacos , Talidomida/análogos & derivados , Animais , Caspase 3/genética , Caspase 3/imunologia , Inibidor de Quinase Dependente de Ciclina p27/genética , Inibidor de Quinase Dependente de Ciclina p27/imunologia , Modelos Animais de Doenças , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/antagonistas & inibidores , Subunidade alfa do Fator 1 Induzível por Hipóxia/imunologia , Fator de Transcrição Ikaros/genética , Fator de Transcrição Ikaros/imunologia , Fatores Reguladores de Interferon/genética , Fatores Reguladores de Interferon/imunologia , Lenalidomida , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Proteína Quinase 1 Ativada por Mitógeno/genética , Proteína Quinase 1 Ativada por Mitógeno/imunologia , Proteína Quinase 3 Ativada por Mitógeno/genética , Proteína Quinase 3 Ativada por Mitógeno/imunologia , Mieloma Múltiplo/genética , Mieloma Múltiplo/imunologia , Mieloma Múltiplo/patologia , Plasmócitos/imunologia , Plasmócitos/patologia , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Proteínas Quinases Associadas a Fase S/genética , Proteínas Quinases Associadas a Fase S/imunologia , Transdução de Sinais , Talidomida/farmacologia , Transativadores/genética , Transativadores/imunologiaRESUMO
Multiple myeloma (MM)-induced osteoclast (OC) formation is mainly due to an imbalance of the receptor activator NF-κB ligand (RANKL)-osteoprotegerin (OPG) ratio in favor of RANKL in the bone microenvironment and to the CCL3 production by MM cells. The purpose of the study was to investigate the effect of the immunomodulatory drugs on RANKL/OPG ratio, the production of pro-osteoclastogenic cytokines, and MM-induced OC formation. We found that in vivo concentrations of both lenalidomide (LEN) and pomalidomide (POM) significantly blunted RANKL upregulation normalizing the RANKL/OPG ratio in human osteoprogenitor cells (PreOBs) when co-cultured with MM cells and also inhibited CCL3 production by MM cells. A reduction in CD49d expression, a molecule critically involved in RANKL upregulation in the MM microenvironment, accompanied this effect. Consistently, the pro-osteoclastogenic property of MM cells co-cultured with PreOBs was reduced by both LEN and POM. We further investigated the effect of these drugs on the transcriptional profile of both MM cells and PreOBs by microarray analysis, which showed that adhesion molecules, such as ITGA8 and ICAM2, are significantly downregulated in MM cells. Our data suggest that LEN and POM inhibit MM-induced OC formation through normalization of the RANKL/OPG ratio targeting the expression of adhesion molecules by MM cells.