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1.
PLoS One ; 16(10): e0258653, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34669746

RESUMO

BACKGROUND AND AIM: A fraction of children with obesity have increased serum cortisol levels. In this study, we describe the clinical characteristics of obese children and adolescents with elevated morning serum cortisol levels and the relationship between the cortisol levels and components of the metabolic syndrome. METHODS: Retrospective medical record review study of children aged 4 to 18 years with overweight or obesity seen for obesity management in the Pediatric Obesity Clinic of the UZ Brussel between 2013 and 2015. RESULTS: A total of 234 children (99 boys and 135 girls) with overweight (BMI z-score > 1.3) without underlying endocrine or genetic conditions were included. Mean (SD) age was 10.1 (2.8) years, BMI SD-score 2.5 (0.6), and body fat percentage 37% (7.9). Serum fasting cortisol levels were elevated (>180 µg/L) in 49 children, normal (62-180 µg/L) in 168, and decreased (<62 µg/L) in 12. Serum fasting cortisol was not significantly correlated with gender, age, or degree of adiposity. But correlated significantly with fasting glucose (Rs = 0.193; p < 0.005), triglycerides (Rs = 0. 143; p < 0.05), fibrinogen (Rs = 0.144; p < 0.05) and leptin levels (Rs = 0.145; p < 0.05). After adjustment for serum insulin and leptin, the correlation between serum cortisol and fasting glucose remained significant. CONCLUSION: Elevated morning serum cortisol levels were found in 20% of overweight or obese children and adolescents, irrespective of the degree of adiposity, and were associated with higher fasting glucose, irrespective of underlying insulin resistance. The long-term cardiometabolic consequences of hypercortisolemia in childhood obesity needs further study.


Assuntos
Glicemia/análise , Jejum/sangue , Hidrocortisona/sangue , Síndrome Metabólica/diagnóstico , Sobrepeso/metabolismo , Obesidade Infantil/metabolismo , Adolescente , Bélgica , Criança , Pré-Escolar , Feminino , Humanos , Leptina/sangue , Masculino , Síndrome Metabólica/sangue , Sobrepeso/sangue , Obesidade Infantil/sangue , Estudos Retrospectivos
3.
JBMR Plus ; 4(1): e10247, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31956851

RESUMO

Multiple myeloma is characterized by accumulation of malignant plasma cells in the bone marrow. Most patients suffer from an osteolytic bone disease, caused by increased bone degradation and reduced bone formation. Bone morphogenetic protein 4 (BMP4) is important for both pre- and postnatal bone formation and induces growth arrest and apoptosis of myeloma cells. BMP4-treatment of myeloma patients could have the potential to reduce tumor growth and restore bone formation. We therefore explored BMP4 gene therapy in a human-mouse model of multiple myeloma where humanized bone scaffolds were implanted subcutaneously in RAG2-/- γC-/-mice. Mice were treated with adeno-associated virus serotype 8 BMP4 vectors (AAV8-BMP4) to express BMP4 in the liver. When mature BMP4 was detectable in the circulation, myeloma cells were injected into the scaffolds and tumor growth was examined by weekly imaging. Strikingly, the tumor burden was reduced in AAV8-BMP4 mice compared with the AAV8-CTRL mice, suggesting that increased circulating BMP4 reduced tumor growth. BMP4-treatment also prevented bone loss in the scaffolds, most likely due to reduced tumor load. To delineate the effects of BMP4 overexpression on bone per se, without direct influence from cancer cells, we examined the unaffected, non-myeloma femurs by µCT. Surprisingly, the AAV8-BMP4 mice had significantly reduced trabecular bone volume, trabecular numbers, as well as significantly increased trabecular separation compared with the AAV8-CTRL mice. There was no difference in cortical bone parameters between the two groups. Taken together, BMP4 gene therapy inhibited myeloma tumor growth, but also reduced the amount of trabecular bone in mice. Our data suggest that care should be taken when considering using BMP4 as a therapeutic agent. © 2019 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.

4.
Blood ; 134(14): 1176-1189, 2019 10 03.
Artigo em Inglês | MEDLINE | ID: mdl-31383640

RESUMO

Dysregulation of polycomb repressive complex 2 (PRC2) promotes oncogenesis partly through its enzymatic function for inducing trimethylation of histone H3 lysine 27 (H3K27me3). However, it remains to be determined how PRC2 activity is regulated in normal and diseased settings. We here report a PRC2-associated cofactor, PHD finger protein 19 (PHF19; also known as polycomb-like 3), as a crucial mediator of tumorigenicity in multiple myeloma (MM). Overexpression and/or genomic amplification of PHF19 is found associated with malignant progression of MM and plasma cell leukemia, correlating to worse treatment outcomes. Using various MM models, we demonstrated a critical requirement of PHF19 for tumor growth in vitro and in vivo. Mechanistically, PHF19-mediated oncogenic effect relies on its PRC2-interacting and chromatin-binding functions. Chromatin immunoprecipitation followed by sequencing profiling showed a critical role for PHF19 in maintaining the H3K27me3 landscape. PHF19 depletion led to loss of broad H3K27me3 domains, possibly due to impaired H3K27me3 spreading from cytosine guanine dinucleotide islands, which is reminiscent to the reported effect of an "onco"-histone mutation, H3K27 to methionine (H3K27M). RNA-sequencing-based transcriptome profiling in MM lines also demonstrated a requirement of PHF19 for optimal silencing of PRC2 targets, which include cell cycle inhibitors and interferon-JAK-STAT signaling genes critically involved in tumor suppression. Correlation studies using patient sample data sets further support a clinical relevance of the PHF19-regulated pathways. Lastly, we show that MM cells are generally sensitive to PRC2 inhibitors. Collectively, this study demonstrates that PHF19 promotes MM tumorigenesis through enhancing H3K27me3 deposition and PRC2's gene-regulatory functions, lending support for PRC2 blockade as a means for MM therapeutics.


Assuntos
Carcinogênese/metabolismo , Proteínas de Ligação a DNA/metabolismo , Histonas/metabolismo , Mieloma Múltiplo/metabolismo , Complexo Repressor Polycomb 2/metabolismo , Fatores de Transcrição/metabolismo , Animais , Carcinogênese/patologia , Linhagem Celular Tumoral , Humanos , Metilação , Camundongos , Mieloma Múltiplo/patologia
5.
J Immunol Res ; 2019: 3538963, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31205954

RESUMO

Humanized mouse models can well be modified to study specific aspects of Graft-versus-Host Disease (GvHD). This paper shows the results of both macrophage depletion and (early) B-cell depletion in a humanized mouse model using RAG2-/- γc-/- mice injected with HuPBMCs. Macrophage depletion showed a significant decrease in survival and also lead to a change in the histomorphology of the xenogeneic reaction. Higher levels of infiltrating B-cells were observed in various organs of mice depleted for macrophages. With (early) B-cell depletion using Rituximab, a clear improvement on clinical symptoms was observed, even when probably only inactivated B-cells were deleted. However, the histological examinations only showed a significant morphological effect on liver fibrosis. This may be related to a difference in the mRNA levels of TGF-ß. Also, lower mRNA levels of Tregs in some organs were observed after Rituximab treatment, which contradicts that a higher number of Tregs would always be related to less severe GvHD. Our data show that both macrophage depletion and (early) B-cell depletion in a xenogeneic mouse model can influence the clinical, histological, and cytokine production of a GvHD response.


Assuntos
Linfócitos B/imunologia , Doença Enxerto-Hospedeiro/imunologia , Transplante de Células-Tronco Hematopoéticas , Leucócitos Mononucleares/imunologia , Cirrose Hepática/imunologia , Macrófagos/imunologia , Linfócitos T Reguladores/imunologia , Animais , Modelos Animais de Doenças , Feminino , Humanos , Depleção Linfocítica , Camundongos , Camundongos SCID
6.
J Control Release ; 296: 232-240, 2019 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-30682443

RESUMO

Glucocorticoids are the cornerstone in the clinic for treatment of hematological malignancies, including multiple myeloma. Nevertheless, poor pharmacokinetic properties of glucocorticoids require high and frequent dosing with the off-target adverse effects defining the maximum dose. Recently, nanomedicine formulations of glucocorticoids have been developed that improve the pharmacokinetic profile, limit adverse effects and improve solid tumor accumulation. Multiple myeloma is a hematological malignancy characterized by uncontrolled growth of plasma cells. These tumors initiate increased angiogenesis and microvessel density in the bone marrow, which might be exploited using nanomedicines, such as liposomes. Nano-sized particles can accumulate as a result of the increased vascular leakiness at the bone marrow tumor lesions. Pre-clinical screening of novel anti-myeloma therapeutics in vivo requires a suitable animal model that represents key features of the disease. In this study, we show that fluorescently labeled long circulating liposomes were found in plasma up to 24 h after injection in an advanced human-mouse hybrid model of multiple myeloma. Besides the organs involved in clearance, liposomes were also found to accumulate in tumor bearing human-bone scaffolds. The therapeutic efficacy of liposomal dexamethasone phosphate was evaluated in this model showing strong tumor growth inhibition while free drug being ineffective at an equivalent dose (4 mg/kg) regimen. The liposomal formulation slightly reduced total body weight of myeloma-bearing mice during the course of treatment, which appeared reversible when treatment was stopped. Liposomal dexamethasone could be further developed as monotherapy or could fit in with existing therapy regimens to improve therapeutic outcomes for multiple myeloma.


Assuntos
Antineoplásicos Hormonais/administração & dosagem , Dexametasona/administração & dosagem , Glucocorticoides/administração & dosagem , Mieloma Múltiplo/tratamento farmacológico , Animais , Peso Corporal/efeitos dos fármacos , Osso e Ossos/metabolismo , Linhagem Celular Tumoral , Modelos Animais de Doenças , Feminino , Humanos , Lipossomos , Camundongos Knockout , Mieloma Múltiplo/metabolismo , Mieloma Múltiplo/patologia , Distribuição Tecidual , Carga Tumoral/efeitos dos fármacos
8.
Mol Ther ; 25(8): 1946-1958, 2017 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-28506593

RESUMO

Chimeric antigen receptors (CARs) can effectively redirect cytotoxic T cells toward highly expressed surface antigens on tumor cells. The low expression of several tumor-associated antigens (TAAs) on normal tissues, however, hinders their safe targeting by CAR T cells due to on-target/off-tumor effects. Using the multiple myeloma (MM)-associated CD38 antigen as a model system, here, we present a rational approach for effective and tumor-selective targeting of such TAAs. Using "light-chain exchange" technology, we combined the heavy chains of two high-affinity CD38 antibodies with 176 germline light chains and generated ∼124 new antibodies with 10- to >1,000-fold lower affinities to CD38. After categorizing them into three distinct affinity classes, we incorporated the single-chain variable fragments of eight antibodies from each class into new CARs. T cells carrying these CD38-CARs were extensively evaluated for their on-tumor/off-tumor cytotoxicity as well as CD38-dependent proliferation and cytokine production. We identified CD38-CAR T cells of ∼1,000- fold reduced affinity, which optimally proliferated, produced Th1-like cytokines, and effectively lysed CD382+ MM cells, but spared CD38+ healthy hematopoietic cells in vitro and in vivo. Thus, this systematic approach is highly suitable for the generation of optimal CARs for effective and selective targeting of TAAs.


Assuntos
ADP-Ribosil Ciclase 1/química , ADP-Ribosil Ciclase 1/imunologia , Receptores de Antígenos de Linfócitos T/química , Receptores de Antígenos de Linfócitos T/metabolismo , Proteínas Recombinantes de Fusão , ADP-Ribosil Ciclase 1/metabolismo , Animais , Afinidade de Anticorpos/imunologia , Citocinas/imunologia , Citocinas/metabolismo , Modelos Animais de Doenças , Humanos , Imunoterapia Adotiva , Ativação Linfocitária/imunologia , Camundongos , Mieloma Múltiplo/imunologia , Mieloma Múltiplo/metabolismo , Mieloma Múltiplo/terapia , Ligação Proteica/imunologia , Anticorpos de Cadeia Única/genética , Anticorpos de Cadeia Única/imunologia , Anticorpos de Cadeia Única/metabolismo , Linfócitos T Citotóxicos/imunologia , Linfócitos T Citotóxicos/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
9.
Blood ; 128(25): 2949-2959, 2016 12 22.
Artigo em Inglês | MEDLINE | ID: mdl-27733356

RESUMO

To begin to understand the mechanisms that regulate self-renewal, differentiation, and transformation of human hematopoietic stem cells or to evaluate the efficacy of novel treatment modalities, stem cells need to be studied in their own species-specific microenvironment. By implanting ceramic scaffolds coated with human mesenchymal stromal cells into immune-deficient mice, we were able to mimic the human bone marrow niche. Thus, we have established a human leukemia xenograft mouse model in which a large cohort of patient samples successfully engrafted, which covered all of the important genetic and risk subgroups. We found that by providing a humanized environment, stem cell self-renewal properties were better maintained as determined by serial transplantation assays and genome-wide transcriptome studies, and less clonal drift was observed as determined by exome sequencing. The human leukemia xenograft mouse models that we have established here will serve as an excellent resource for future studies aimed at exploring novel therapeutic approaches.


Assuntos
Medula Óssea/patologia , Leucemia Mieloide Aguda/patologia , Nicho de Células-Tronco , Alicerces Teciduais/química , Ensaios Antitumorais Modelo de Xenoenxerto , Animais , Autorrenovação Celular , Separação Celular , Células Clonais , Feminino , Perfilação da Expressão Gênica , Regulação Leucêmica da Expressão Gênica , Células-Tronco Hematopoéticas/citologia , Humanos , Leucemia Mieloide Aguda/genética , Células-Tronco Mesenquimais/citologia , Camundongos , Fenótipo , Células Estromais/patologia
11.
Haematologica ; 101(5): 616-25, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-26858358

RESUMO

Adoptive transfer of chimeric antigen receptor-transduced T cells is a promising strategy for cancer immunotherapy. The CD38 molecule, with its high expression on multiple myeloma cells, appears a suitable target for antibody therapy. Prompted by this, we used three different CD38 antibody sequences to generate second-generation retroviral CD38-chimeric antigen receptor constructs with which we transduced T cells from healthy donors and multiple myeloma patients. We then evaluated the preclinical efficacy and safety of the transduced T cells. Irrespective of the donor and antibody sequence, CD38-chimeric antigen receptor-transduced T cells proliferated, produced inflammatory cytokines and effectively lysed malignant cell lines and primary malignant cells from patients with acute myeloid leukemia and multi-drug resistant multiple myeloma in a cell-dose, and CD38-dependent manner, despite becoming CD38-negative during culture. CD38-chimeric antigen receptor-transduced T cells also displayed significant anti-tumor effects in a xenotransplant model, in which multiple myeloma tumors were grown in a human bone marrow-like microenvironment. CD38-chimeric antigen receptor-transduced T cells also appeared to lyse the CD38(+) fractions of CD34(+) hematopoietic progenitor cells, monocytes, natural killer cells, and to a lesser extent T and B cells but did not inhibit the outgrowth of progenitor cells into various myeloid lineages and, furthermore, were effectively controllable with a caspase-9-based suicide gene. These results signify the potential importance of CD38-chimeric antigen receptor-transduced T cells as therapeutic tools for CD38(+) malignancies and warrant further efforts to diminish the undesired effects of this immunotherapy using appropriate strategies.


Assuntos
ADP-Ribosil Ciclase 1/metabolismo , Imunoterapia , Mieloma Múltiplo/imunologia , Mieloma Múltiplo/metabolismo , Receptores de Antígenos de Linfócitos T/metabolismo , Proteínas Recombinantes de Fusão , Linfócitos T/imunologia , Linfócitos T/metabolismo , ADP-Ribosil Ciclase 1/genética , ADP-Ribosil Ciclase 1/imunologia , Animais , Citocinas/biossíntese , Citotoxicidade Imunológica , Modelos Animais de Doenças , Citometria de Fluxo , Expressão Gênica , Técnicas de Transferência de Genes , Genes Transgênicos Suicidas , Células-Tronco Hematopoéticas/metabolismo , Humanos , Ativação Linfocitária/imunologia , Camundongos , Camundongos Knockout , Mieloma Múltiplo/patologia , Mieloma Múltiplo/terapia , Receptores de Antígenos de Linfócitos T/genética , Linfócitos T/transplante , Transdução Genética , Carga Tumoral/genética , Carga Tumoral/imunologia
12.
Cell Rep ; 14(2): 332-46, 2016 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-26748712

RESUMO

Polycomb proteins are classical regulators of stem cell self-renewal and cell lineage commitment and are frequently deregulated in cancer. Here, we find that the non-canonical PRC1.1 complex, as identified by mass-spectrometry-based proteomics, is critically important for human leukemic stem cells. Downmodulation of PRC1.1 complex members, like the DNA-binding subunit KDM2B, strongly reduces cell proliferation in vitro and delays or even abrogates leukemogenesis in vivo in humanized xenograft models. PRC1.1 components are significantly overexpressed in primary AML CD34(+) cells. Besides a set of genes that is targeted by PRC1 and PRC2, ChIP-seq studies show that PRC1.1 also binds a distinct set of genes that are devoid of H3K27me3, suggesting a gene-regulatory role independent of PRC2. This set encompasses genes involved in metabolism, which have transcriptionally active chromatin profiles. These data indicate that PRC1.1 controls specific genes involved in unique cell biological processes required for leukemic cell viability.


Assuntos
Histona Desmetilases com o Domínio Jumonji/genética , Histona Desmetilases com o Domínio Jumonji/metabolismo , Complexo Repressor Polycomb 1/genética , Complexo Repressor Polycomb 1/metabolismo , Diferenciação Celular , Proliferação de Células , Humanos
13.
J Tissue Eng Regen Med ; 10(3): 233-44, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23255230

RESUMO

The combination of scaffolds and mesenchymal stromal cells (MSCs) is a promising approach in bone tissue engineering (BTE). Knowledge on the survival, outgrowth and bone-forming capacity of MSCs in vivo is limited. Bioluminescence imaging (BLI), histomorphometry and immunohistochemistry were combined to study the fate of gene-marked goat and human MSCs (gMSCs, hMSCs) on scaffolds with different osteoinductive properties. Luciferase-GFP-labelled MSCs were seeded on hydroxyapatite (HA) or ß-tricalcium phosphate (TCP), cultured for 7 days in vitro in osteogenic medium, implanted subcutaneously in immunodeficient mice and monitored with BLI for 6 weeks. The constructs were retrieved and processed for histomorphometry and detection of luciferase-positive cells (LPCs). For gMSCs, BLI revealed doubling of signal after 1 week, declining to 60% of input after 3 weeks and remaining constant until week 6. hMSCs showed a constant decrease of BLI signal to 25% of input, indicating no further expansion. Bone formation of gMSCs was two-fold higher on TCP than HA. hMSCs and gMSCs control samples produced equal amounts of bone on TCP. Upon transduction, there was a four-fold reduction in bone formation compared with untransduced hMSCs, and no bone was formed on HA. LPCs were detected at day 14, but were much less frequent at day 42. Striking differences were observed in spatial distribution. MSCs in TCP were found to be aligned and interconnected on the surface but were scattered in an unstructured fashion in HA. In conclusion, the spatial distribution of MSCs on the scaffold is critical for cell-scaffold-based BTE.


Assuntos
Fosfatos de Cálcio/farmacologia , Durapatita/farmacologia , Células-Tronco Mesenquimais/citologia , Animais , Sobrevivência Celular/efeitos dos fármacos , DNA/metabolismo , Cabras , Humanos , Imuno-Histoquímica , Luciferases/metabolismo , Medições Luminescentes , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo , Camundongos Endogâmicos BALB C , Osteogênese/efeitos dos fármacos , Alicerces Teciduais/química
14.
Cancer Immunol Immunother ; 64(8): 951-63, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25920521

RESUMO

Immunotherapy with allogeneic natural killer (NK) cells offers therapeutic perspectives for multiple myeloma patients. Here, we aimed to refine NK cell therapy by evaluation of the relevance of HLA-class I and HLA-E for NK anti-myeloma reactivity. We show that HLA-class I was strongly expressed on the surface of patient-derived myeloma cells and on myeloma cell lines. HLA-E was highly expressed by primary myeloma cells but only marginally by cell lines. HLA-E(low) expression on U266 cells observed in vitro was strongly upregulated after in vivo (bone marrow) growth in RAG-2(-/-) γc(-/-) mice, suggesting that in vitro HLA-E levels poorly predict the in vivo situation. Concurrent analysis of inhibitory receptors (KIR2DL1, KIR2DL2/3, KIR3DL1 and NKG2A) and NK cell degranulation upon co-culture with myeloma cells revealed that KIR-ligand-mismatched NK cells degranulate more than matched subsets and that HLA-E abrogates degranulation of NKG2A+ subsets. Inhibition by HLA-class I and HLA-E was also observed with IL-2-activated NK cells and at low oxygen levels (0.6 %) mimicking hypoxic bone marrow niches where myeloma cells preferentially reside. Our study demonstrates that NKG2A-negative, KIR-ligand-mismatched NK cells are the most potent subset for clinical application. We envision that infusion of high numbers of this subclass will enhance clinical efficacy.


Assuntos
Separação Celular/métodos , Antígenos de Histocompatibilidade Classe I/imunologia , Imunoterapia/métodos , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/transplante , Mieloma Múltiplo/terapia , Subfamília C de Receptores Semelhantes a Lectina de Células NK/imunologia , Animais , Degranulação Celular , Linhagem Celular Tumoral , Técnicas de Cocultura , Citotoxicidade Imunológica , Proteínas de Ligação a DNA/genética , Citometria de Fluxo , Humanos , Interleucina-2/imunologia , Camundongos , Camundongos Knockout , Mieloma Múltiplo/imunologia , Transplante de Neoplasias , Oxigênio/metabolismo , Antígenos HLA-E
15.
MAbs ; 7(2): 311-21, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25760767

RESUMO

Daratumumab (DARA) is a human CD38-specific IgG1 antibody that is in clinical development for the treatment of multiple myeloma (MM). The potential for IgG1 antibodies to induce macrophage-mediated phagocytosis, in combination with the known presence of macrophages in the tumor microenvironment in MM and other hematological tumors, led us to investigate the contribution of antibody-dependent, macrophage-mediated phagocytosis to DARA's mechanism of action. Live cell imaging revealed that DARA efficiently induced macrophage-mediated phagocytosis, in which individual macrophages rapidly and sequentially engulfed multiple tumor cells. DARA-dependent phagocytosis by mouse and human macrophages was also observed in an in vitro flow cytometry assay, using a range of MM and Burkitt's lymphoma cell lines. Phagocytosis contributed to DARA's anti-tumor activity in vivo, in both a subcutaneous and an intravenous leukemic xenograft mouse model. Finally, DARA was shown to induce macrophage-mediated phagocytosis of MM cells isolated from 11 of 12 MM patients that showed variable levels of CD38 expression. In summary, we demonstrate that phagocytosis is a fast, potent and clinically relevant mechanism of action that may contribute to the therapeutic activity of DARA in multiple myeloma and potentially other hematological tumors.


Assuntos
Anticorpos Monoclonais/farmacologia , Anticorpos Antineoplásicos/farmacologia , Citofagocitose/efeitos dos fármacos , Linfoma/tratamento farmacológico , Macrófagos/imunologia , Mieloma Múltiplo/tratamento farmacológico , Animais , Linhagem Celular Tumoral , Humanos , Linfoma/imunologia , Linfoma/patologia , Camundongos , Mieloma Múltiplo/imunologia , Mieloma Múltiplo/patologia , Ensaios Antitumorais Modelo de Xenoenxerto
16.
Clin Cancer Res ; 21(12): 2802-10, 2015 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-25398450

RESUMO

PURPOSE: Novel therapeutic agents have significantly improved the survival of patients with multiple myeloma. Nonetheless, the prognosis of patients with multiple myeloma who become refractory to the novel agents lenalidomide and bortezomib is very poor, indicating the urgent need for new therapeutic options for these patients. The human CD38 monoclonal antibody daratumumab is being evaluated as a novel therapy for multiple myeloma. Prompted with the encouraging results of ongoing clinical phase I/II trials, we now addressed the potential value of daratumumab alone or in combination with lenalidomide or bortezomib for the treatment of lenalidomide- and bortezomib-refractory patients. EXPERIMENTAL DESIGN: In ex vivo assays, mainly evaluating antibody-dependent cell-mediated cytotoxicity, and in an in vivo xenograft mouse model, we evaluated daratumumab alone or in combination with lenalidomide or bortezomib as a potential therapy for lenalidomide- and bortezomib-refractory multiple myeloma patients. RESULTS: Daratumumab induced significant lysis of lenalidomide/bortezomib-resistant multiple myeloma cell lines and of primary multiple myeloma cells in the bone marrow mononuclear cells derived from lenalidomide- and/or bortezomib-refractory patients. In these assays, lenalidomide but not bortezomib, synergistically enhanced daratumumab-mediated multiple myeloma lysis through activation of natural killer cells. Finally, in an in vivo xenograft model, only the combination of daratumumab with lenalidomide effectively reduced the tumorigenic growth of primary multiple myeloma cells from a lenalidomide- and bortezomib-refractory patient. CONCLUSIONS: Our results provide the first preclinical evidence for the benefit of daratumumab plus lenalidomide combination for lenalidomide- and bortezomib-refractory patients.


Assuntos
ADP-Ribosil Ciclase 1/antagonistas & inibidores , ADP-Ribosil Ciclase 1/metabolismo , Bortezomib/farmacologia , Mieloma Múltiplo/imunologia , Mieloma Múltiplo/metabolismo , Talidomida/análogos & derivados , Adulto , Idoso , Animais , Citotoxicidade Celular Dependente de Anticorpos/imunologia , Bortezomib/administração & dosagem , Linhagem Celular Tumoral , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Sinergismo Farmacológico , Feminino , Humanos , Imunoterapia , Células Matadoras Naturais/efeitos dos fármacos , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/metabolismo , Lenalidomida , Ativação Linfocitária/efeitos dos fármacos , Ativação Linfocitária/imunologia , Masculino , Camundongos , Pessoa de Meia-Idade , Terapia de Alvo Molecular , Mieloma Múltiplo/diagnóstico , Mieloma Múltiplo/terapia , Talidomida/administração & dosagem , Talidomida/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto
17.
J Immunol ; 194(3): 911-20, 2015 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-25520398

RESUMO

The effectiveness of chimeric Ag receptor (CAR)-transduced T (CAR-T) cells has been attributed to supraphysiological signaling through CARs. Second- and later-generation CARs simultaneously transmit costimulatory signals with CD3ζ signals upon ligation, but may lead to severe adverse effects owing to the recognition of minimal Ag expression outside the target tumor. Currently, the threshold target Ag density for CAR-T cell lysis and further activation, including cytokine production, has not yet been investigated in detail. Therefore, we determined the threshold target Ag density required to induce CAR-T cell responses using novel anti-CD20 CAR-T cells with a CD28 intracellular domain and a CD20-transduced CEM cell model. The newly developed CD20CAR-T cells demonstrated Ag-specific lysis and cytokine secretion, which was a reasonable level as a second-generation CAR. For lytic activity, the threshold Ag density was determined to be ∼200 molecules per target cell, whereas the Ag density required for cytokine production of CAR-T cells was ∼10-fold higher, at a few thousand per target cell. CD20CAR-T cells responded efficiently to CD20-downregulated lymphoma and leukemia targets, including rituximab- or ofatumumab-refractory primary chronic lymphocytic leukemia cells. Despite the potential influence of the structure, localization, and binding affinity of the CAR/Ag, the threshold determined may be used for target Ag selection. An Ag density below the threshold may not result in adverse effects, whereas that above the threshold may be sufficient for practical effectiveness. CD20CAR-T cells also demonstrated significant lytic activity against CD20-downregulated tumor cells and may exhibit effectiveness for CD20-positive lymphoid malignancies.


Assuntos
Antígenos de Superfície/imunologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos de Linfócitos T/metabolismo , Subpopulações de Linfócitos T , Anticorpos Monoclonais Murinos/uso terapêutico , Antígenos CD20/imunologia , Antígenos CD20/metabolismo , Antígenos de Superfície/metabolismo , Antígenos CD28/imunologia , Antígenos CD28/metabolismo , Complexo CD3/imunologia , Complexo CD3/metabolismo , Linhagem Celular Tumoral , Citocinas/biossíntese , Citotoxicidade Imunológica , Expressão Gênica , Ordem dos Genes , Genes Reporter , Humanos , Imunofenotipagem , Espaço Intracelular , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Leucemia Linfocítica Crônica de Células B/genética , Leucemia Linfocítica Crônica de Células B/imunologia , Leucemia Linfocítica Crônica de Células B/metabolismo , Ativação Linfocitária , Linfoma de Células B/tratamento farmacológico , Linfoma de Células B/genética , Linfoma de Células B/imunologia , Linfoma de Células B/metabolismo , Ligação Proteica , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Rituximab , Transdução de Sinais , Especificidade do Receptor de Antígeno de Linfócitos T/genética , Especificidade do Receptor de Antígeno de Linfócitos T/imunologia , Transdução Genética
18.
PLoS One ; 9(9): e107009, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25255316

RESUMO

Tumoral plasma cells has retained stemness features and in particular, a polycomb-silenced gene expression signature. Therefore, epigenetic therapy could be a mean to fight for multiple myeloma (MM), still an incurable pathology. Deazaneplanocin A (DZNep), a S-adenosyl-L-homocysteine hydrolase inhibitor, targets enhancer of zest homolog 2 (EZH2), a component of polycomb repressive complex 2 (PRC2) and is capable to induce the death of cancer cells. We show here that, in some MM cell lines, DZNep induced both caspase-dependent and -independent apoptosis. However, the induction of cell death was not mediated through its effect on EZH2 and the trimethylation on lysine 27 of histone H3 (H3K27me3). DZNep likely acted through non-epigenetic mechanisms in myeloma cells. In vivo, in xenograft models, and in vitro DZNep showed potent antimyeloma activity alone or in combination with bortezomib. These preclinical data let us to envisage new therapeutic strategies for myeloma.


Assuntos
Adenosina/análogos & derivados , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Mieloma Múltiplo/patologia , Adenosina/farmacologia , Adenosina/uso terapêutico , Animais , Antineoplásicos/uso terapêutico , Ácidos Borônicos/farmacologia , Bortezomib , Caspases/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Interações Medicamentosas , Proteína Potenciadora do Homólogo 2 de Zeste , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Camundongos , Mieloma Múltiplo/tratamento farmacológico , Complexo Repressor Polycomb 2/genética , Pirazinas/farmacologia , Sindecana-1/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
19.
PLoS One ; 9(3): e90586, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24614182

RESUMO

Bone marrow failure syndromes and MDS represent a heterogenous group of diseases, characterized by ineffective myelopoiesis, the risk of clonal evolution and a generally poor response to chemotherapy-based treatment regimen. Nitrostyrene derivatives have been studied as protein phosphatase inhibitors in various tumor models. Pharmacological studies have identified nitrostyrene as the structural core underlying a pro-apoptotic effect in tumor cells, yet their effects on normal cells, including those of the hematopoietic system, are largely unknown. In this study, utilizing umbilical cord blood-derived myeloid progenitor cells, patient-derived bone marrow cells, and a (BALB/c) mouse model; we investigated the effects of treatment with two nitrostyrene derivatives (NTS1 and NTS2) on myeloid development. We demonstrate that these compounds stimulate the expansion and differentiation of myeloid progenitors in vitro and improve myeloid reconstitution after chemotherapy-induced bone marrow depletion in vitro and in vivo. These effects were accompanied by increased C/EBPα expression and activity and inhibition of the p38MAPK signalling pathway. Together, our data suggest that nitrostyrenes improve myelopoiesis and represent potential new treatment strategies for patients suffering from bone marrow failure syndromes, hypocellular myelodysplastic syndrome and chemotherapy-induced aplasia.


Assuntos
Proteína alfa Estimuladora de Ligação a CCAAT/metabolismo , Mielopoese/efeitos dos fármacos , Estirenos/farmacologia , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Animais , Células da Medula Óssea/citologia , Células da Medula Óssea/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Linhagem da Célula/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ensaio de Unidades Formadoras de Colônias , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Masculino , Camundongos Endogâmicos BALB C , Neutrófilos/citologia , Neutrófilos/efeitos dos fármacos , Neutrófilos/enzimologia , Células-Tronco/citologia , Células-Tronco/efeitos dos fármacos , Células-Tronco/enzimologia
20.
Arthritis Rheumatol ; 66(2): 350-6, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24504807

RESUMO

OBJECTIVE: Autologous stem cell transplantation (ASCT) induces long-term drug-free disease remission in patients with juvenile idiopathic arthritis. This study was undertaken to further unravel the immunologic mechanisms underlying ASCT by using a mouse model of proteoglycan-induced arthritis (PGIA). METHODS: For initiation of PGIA, BALB/c mice received 2 intraperitoneal injections of human PG in a synthetic adjuvant on days 0 and 21. Five weeks after the first immunization, the mice were exposed to total body irradiation (7.5 Gy) and received (un)manipulated bone marrow (BM) grafts from mice with PGIA. Clinical scores, T cell reconstitution, (antigen-specific) T cell cytokine production, and intracellular cytokine expression were determined following autologous BM transplantation (ABMT). RESULTS: ABMT resulted in amelioration and stabilization of arthritis scores. BM grafts containing T cells and T cell-depleted grafts provided the same clinical benefit, with similar reductions in PG-induced T cell proliferation and the number of PG-specific autoantibodies. In vivo reexposure to PG did not exacerbate disease. Following ABMT, basal levels of disease-associated proinflammatory cytokines (interferon-γ [IFNγ], interleukin-17 [IL-17], and tumor necrosis factor α [TNFα]) were reduced. In addition, restimulation of T cells with PG induced a strong reduction in disease-associated proinflammatory cytokine production. Finally, although the remaining host T cells displayed a proinflammatory phenotype following ABMT, IFNγ, IL-17, and TNFα production by the newly reconstituted donor-derived T cells was significantly lower. CONCLUSION: Taken together, our data suggest that ABMT restores immune tolerance by renewal and modulation of the Teff cell compartment, leading to a strong reduction in proinflammatory (self antigen-specific) T cell cytokine production.


Assuntos
Artrite Experimental/imunologia , Artrite Experimental/terapia , Tolerância Imunológica/fisiologia , Transplante de Células-Tronco , Subpopulações de Linfócitos T/patologia , Linfócitos T/patologia , Animais , Artrite Experimental/induzido quimicamente , Autoenxertos , Transplante de Medula Óssea , Modelos Animais de Doenças , Feminino , Interferon gama/metabolismo , Interleucina-17/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Proteoglicanas/efeitos adversos , Subpopulações de Linfócitos T/metabolismo , Linfócitos T/metabolismo , Linfócitos T Reguladores/metabolismo , Linfócitos T Reguladores/patologia , Fator de Necrose Tumoral alfa/metabolismo
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