RESUMO
The unfolded protein response is an intricate system of sensor proteins in the endoplasmic reticulum (ER) that recognizes misfolded proteins and transmits information via transcription factors to either regain proteostasis or, depending on the severity, to induce apoptosis. The main transmembrane sensor is IRE1α, which contains cytoplasmic kinase and RNase domains relevant for its activation and the mRNA splicing of the transcription factor XBP1. Mast cell leukemia (MCL) is a severe form of systemic mastocytosis. The inhibition of IRE1α in the MCL cell line HMC-1.2 has anti-proliferative and pro-apoptotic effects, motivating us to elucidate the IRE1α interactors/regulators in HMC-1.2 cells. Therefore, the TurboID proximity labeling technique combined with MS analysis was applied. Gene Ontology and pathway enrichment analyses revealed that the majority of the enriched proteins are involved in vesicle-mediated transport, protein stabilization, and ubiquitin-dependent ER-associated protein degradation pathways. In particular, the AAA ATPase VCP and the oncoprotein MTDH as IRE1α-interacting proteins caught our interest for further analyses. The pharmacological inhibition of VCP activity resulted in the increased stability of IRE1α and MTDH as well as the activation of IRE1α. The interaction of VCP with both IRE1α and MTDH was dependent on ubiquitination. Moreover, MTDH stability was reduced in IRE1α-knockout cells. Hence, pharmacological manipulation of IRE1α-MTDH-VCP complex(es) might enable the treatment of MCL.
Assuntos
Degradação Associada com o Retículo Endoplasmático , Endorribonucleases , Leucemia de Mastócitos , Proteínas Serina-Treonina Quinases , Humanos , Linhagem Celular Tumoral , Degradação Associada com o Retículo Endoplasmático/genética , Endorribonucleases/metabolismo , Leucemia de Mastócitos/metabolismo , Leucemia de Mastócitos/patologia , Proteínas de Membrana/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Serina-Treonina Quinases/genética , Proteína com Valosina/metabolismo , Proteína com Valosina/genéticaRESUMO
We identified 71 patients with AdvSM (aggressive SM [ASM], SM with an associated hematologic neoplasm [SM-AHN, e.g., acute myeloid leukemia, SM-AML], mast cell leukemia [MCL]) in two national registries (DRST/GREM) who received an allogeneic hematopoietic cell transplantation (alloHCT) performed in Germany from 1999-2021. Median overall survival (OS) of ASM/SM-AHN (n = 30, 45%), SM-AML (n = 28, 39%) and MCL ± AHN (n = 13, 19%) was 9.0, 3.3 and 0.9 years (P = 0.007). Improved median OS was associated with response of SM (17/41, 41%; HR 0.4 [0.2-0.9], P = 0.035) and/or of AHN (26/43, 60%, HR 0.3 [0.1-0.7], P = 0.004) prior to alloHCT. Adverse predictors for OS included absence of KIT D816V (10/61, 16%, HR 2.9 [1.2-6.5], P < 0.001) and a complex karyotype (9/60, 15%, HR 4.2 [1.8-10.0], P = 0.016). HLA-match, conditioning type or transplantation at centers reporting above-average alloHCTs (≥7) had no impact on OS. Taking into account competing events at years 1, 3 and 5, relapse-related mortality and non-relapse mortality rate were 15%/23%, 20%/30% and 23%/35%, respectively. Irrespective of subtype, subsequent treatment response was achieved in 13/30 (43%) patients and was highest on midostaurin/avapritinib (7/9, 78%). We conclude that outcome of alloHCT in AdvSM is more affected by disease phenotype and treatment response prior to transplant than by transplant characteristics.
Assuntos
Transplante de Células-Tronco Hematopoéticas , Leucemia de Mastócitos , Leucemia Mieloide Aguda , Mastocitose Sistêmica , Humanos , Mastocitose Sistêmica/genética , Estudos RetrospectivosRESUMO
Systemic Mastocytosis (SM) is a multifaceted clinically heterogeneous disease. Advanced SM (AdvSM) comprises three entities: aggressive SM (ASM), mast cell leukaemia (MCL) and SM with an associated hematologic neoplasm (SM-AHN), the latter accounting for 60-70% of all AdvSM cases. Detection of a disease-triggering mutation in the KIT gene (esp. KIT D816V) in >90% of the patients with ASM or SM-AHN has led to a significant improvement in therapeutic options by the implementation of two KIT-targeting kinase inhibitors: midostaurin and avapritinib. Although complete remissions have been reported, neither of these targeted agents is 'curative' in all patients and the duration of responses varies. The median overall survival, depending on the WHO subtype and scoring result, is approximately 1 to 4 years. Although the European Competence Network on Mastocytosis (ECNM) and American Initiative in Mast Cell Diseases (AIM) consensus groups recommend allogeneic haematopoietic cell transplantation (allo-HCT) in drug-resistant and other high-risk patients, there is a relative lack of information to guide clinicians on which patients with AdvSM should be considered for transplant, and how KIT inhibitors may fit into the transplant algorithm, including their use pre- and post-transplant to optimise outcomes. Following the generation of an expert panel with a specialist interest in allo-HCT and mastocytosis, these best practice recommendations were generated according to the European Society for Blood and Marrow Transplantation (EBMT) Practice Harmonisation and guidelines and ECNM methodology. We aim to provide a practical, clinically relevant and up-to-date framework to guide allo-HCT in AdvsM in 2024 and beyond.
Assuntos
Antineoplásicos , Transplante de Células-Tronco Hematopoéticas , Leucemia de Mastócitos , Mastocitose Sistêmica , Mastocitose , Humanos , Mastocitose Sistêmica/terapia , Mastocitose Sistêmica/tratamento farmacológico , Antineoplásicos/uso terapêutico , Mastocitose/terapia , Leucemia de Mastócitos/tratamento farmacológico , Proteínas Proto-Oncogênicas c-kit/genética , MastócitosRESUMO
Cytologic abnormalities of atypical mast cells in mastocytosis. The mature mast cells have oval-shaped nuclei, cytoplasmic hypogranulation and spindle-shaped cytology. or well-differentiated displaying a round nucleus with condensed chromatin, and abundant dense cytoplasmic granulations. Immature mast cells include promastocytes and metachromatic blast-like forms.
Assuntos
Leucemia de Mastócitos , Mastocitose , Humanos , MastócitosRESUMO
The World Health Organization (WHO) classification system categorizes advanced systemic mastocytosis (SM-Adv) into aggressive SM (ASM), mast cell leukemia (MCL), and SM with associated hematological neoplasm (SM-AHN). By contrast, the International Consensus Classification (ICC) requires "immature" MC cytomorphology for the diagnosis of MCL and limits SM-AHN to myeloid neoplasms (SM-AMN). The current study includes 329 patients with SM-Adv (median age 65 years, range 18-88; males 58%): WHO subcategories SM-AHN (N = 212; 64%), ASM (N = 99; 30%), and MCL (N = 18; 6%); ICC subcategories SM-AMN (N = 190; 64%), ASM (N = 99; 33%), and MCL (N = 9; 3%); WHO-defined MCL with "mature" MC cytomorphology and SM-AHN associated with lymphoid neoplasms were operationally labeled as "MCL-mature" (N = 9) and SM-ALN (N = 22), respectively, and distinguished from ICC-defined MCL and SM-AMN. Multivariable analysis that included the Mayo alliance risk factors for survival in SM (age >60 years, anemia, thrombocytopenia, increased alkaline phosphatase) revealed more accurate survival prediction with the ICC versus WHO classification order: (i) survival was significantly worse with MCL-immature versus MCL-mature (hazard ratio [HR] 15; p < .01), (ii) prognostic distinction between MCL and SM-AHN/AMN was confirmed in the context of ICC (HR 9.3; p < .01) but not WHO classification order (p = .99), (iii) survival was similar between MCL-mature and SM-AMN (p = .18), and (iv) SM-AMN (HR 1.7; p < .01) but not SM-ALN (p = .37) was prognostically distinct from ASM. The current study provides evidence for the independent prognostic contribution of both the ICC system for SM-Adv and the Mayo alliance risk factors for survival in SM.
Assuntos
Neoplasias Hematológicas , Leucemia de Mastócitos , Mastocitose Sistêmica , Mastocitose , Masculino , Humanos , Adolescente , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Mastocitose Sistêmica/diagnóstico , Prognóstico , Fatores de Risco , Neoplasias Hematológicas/diagnóstico , Mastócitos , Mastocitose/diagnósticoRESUMO
Mastocytosis constitutes the neoplastic proliferation of mast cells and is broadly classified into systemic mastocytosis (SM), cutaneous mastocytosis and mast cell sarcoma. SM is further partitioned into advanced (AdvSM) and non-advanced (SM-non-Adv) subcategories. AdvSM includes aggressive SM (ASM), SM with an associated haematological neoplasm (SM-AHN) and mast cell leukaemia (MCL). In 2022, two separate expert committees representing the 5th edition of the World Health Organization (WHO5) and the International Consensus (ICC) classification systems submitted revised classification criteria for SM, highlighted by the ICC-proposed incorporation of mast cell cytomorphology in the diagnostic criteria for MCL and myeloid-lineage restriction for the AHN component in SM-AHN. Recent developments in SM also include the introduction of KIT-targeting tyrosine kinase inhibitors (KITi), including midostaurin and avapritinib, both drugs have shown potent activity in reducing mast cell and mutant KIT burden and alleviating mast cell-associated organopathy and mediator symptoms; however, their overall impact on survival or superiority over pre-KITi era treatment options (e.g. cladribine) has not been studied in a controlled setting. In the current review, we provide a summary of recent changes in disease classification and an analysis of recent clinical trials and their impact on our current treatment approach in AdvSM.
Assuntos
Leucemia de Mastócitos , Mastocitose Sistêmica , Mastocitose , Humanos , Mastocitose Sistêmica/diagnóstico , Mastócitos/metabolismo , Leucemia de Mastócitos/tratamento farmacológico , Cladribina/uso terapêutico , Mastocitose/metabolismo , Proteínas Proto-Oncogênicas c-kit/metabolismoRESUMO
Mast cell leukemia is a rare and aggressive disease, predominantly with KIT D816V mutation. With poor response to conventional poly-chemotherapy, mast cell leukemia responded to the midostaurin treatment with a 50% overall response rate (ORR), but complete remission rate is approximately 0%. Therefore, the potential mechanisms of midostaurin resistance and the exact impacts of midostaurin on both gene expression profile and mast cell leukemia microenvironment in vivo are essential for design tailored combination therapy targeting both the tumor cells and the tumor microenvironment. Here we report a 59-year-old male mast cell leukemia patient with KIT F522C mutation treated with midostaurin. Single-cell sequencing of peripheral blood and whole exome sequencing (WES) of bone marrow were performed before and 10 months after midostaurin treatment. In accordance with the clinical response, compared to the pretreatment aberration, the decline of mast cells and increase of T-, NK, B-cells in peripheral blood, and the decrease of the KIT F522C mutation burden in bone marrow were observed. Meanwhile, the emergence of RUNX1 mutation, upregulations of genes expression (RPS27A, RPS6, UBA52, RACK1) on tumor cells, and increased frequencies of T and NK cells with TIGIT, CTLA4, and LAG3 expression were observed after midostaurin treatment, predicting the disease progression of this patient. As far as we know, this is the first case reporting the clinical, immunological, and molecular changes in mast cell leukemia patients before and after midostaurin treatment, illustrating the in vivo mechanisms of midostaurin resistance in mast cell leukemia, providing important clues to develop a sequential option to circumvent tumor progression after targeting oncogene addiction and prolong patients' survival.
Assuntos
Leucemia de Mastócitos , Masculino , Humanos , Pessoa de Meia-Idade , Leucemia de Mastócitos/tratamento farmacológico , Leucemia de Mastócitos/genética , Estaurosporina/uso terapêutico , Terapia Combinada , Mastócitos , Microambiente TumoralRESUMO
OVERVIEW: Systemic mastocytosis (SM) results from clonal proliferation of mast cells (MC) in extracutaneous organs. DIAGNOSIS: The major criterion is presence of multifocal MC clusters in the bone marrow and/or extracutaneous organs. Minor diagnostic criteria include elevated serum tryptase level, MC CD25/CD2/CD30 expression, and presence of activating KIT mutations. RISK STRATIFICATION: Establishing SM subtype as per the International Consensus Classification/World Health Organization classification systems is an important first step. Patients either have indolent/smoldering SM (ISM/SSM) or advanced SM, including aggressive SM (ASM), SM with associated myeloid neoplasm (SM-AMN), and mast cell leukemia. Identification of poor-risk mutations (i.e., ASXL1, RUNX1, SRSF2, NRAS) further refines the risk stratification. Several risk models are available to help assign prognosis in SM patients. MANAGEMENT: Treatment goals for ISM patients are primarily directed toward anaphylaxis prevention/symptom control/osteoporosis treatment. Patients with advanced SM frequently need MC cytoreductive therapy to reverse disease-related organ dysfunction. Tyrosine kinase inhibitors (TKI) (midostaurin, avapritinib) have changed the treatment landscape in SM. While deep biochemical, histological and molecular responses have been documented with avapritinib treatment, its efficacy as monotherapy against a multimutated AMN disease component in SM-AMN patients remains unclear. Cladribine continues to have a role for MC debulking, whereas interferon-α has a diminishing role in the TKI era. Treatment of SM-AMN primarily targets the AMN component, particularly if an aggressive disease such as acute leukemia is present. Allogeneic stem cell transplant has a role in such patients. Imatinib has a therapeutic role only in the rare patient with an imatinib-sensitive KIT mutation.
Assuntos
Leucemia de Mastócitos , Mastocitose Sistêmica , Humanos , Adulto , Mesilato de Imatinib , Mastócitos , Medição de RiscoRESUMO
We sought to evaluate the efficacy of the purine analogue cladribine in 79 patients with advanced systemic mastocytosis (AdvSM) using data from the 'German Registry on Disorders of Eosinophils and Mast Cells (GREM)'. The overall response rate according to modified Valent criteria (46 evaluable patients) for first- (1L) and second-line (2L) cladribine treatment was 41% (12/29) and 35% (6/17, P = 0.690), respectively, and the median overall survival (OS, all patients evaluable) was 1.9 years (n = 48) and 1.2 years (n = 31; P = 0.311). Univariate and multivariable analyses of baseline and on-treatment parameters identified diagnosis of mast cell leukemia (hazard ratio [HR] 3.5, 95% confidence interval [CI, 1.3-9.1], P = 0.012), eosinophilia ≥ 1.5 × 109/L (HR 2.9 [CI 1.4-6.2], P = 0.006) and < 3 cycles of cladribine (HR 0.4 [CI 0.2-0.8], P = 0.008) as independent adverse prognostic parameters for OS. There was no impact of other laboratory (anemia, thrombocytopenia, serum tryptase) or genetic markers (mutations in SRSF2, ASXL1 or RUNX1) on OS. In consequence, none of the recently established prognostic scoring systems (MARS, IPSM, MAPS or GPSM) was predictive for OS. Modified Valent criteria were superior to a single factor-based response assessment (HR 2.9 [CI 1.3-6.6], P = 0.026). In conclusion, cladribine is effective in 1L and 2L treatment of AdvSM. Mast cell leukemia, eosinophilia, application of < 3 cycles and a lack of response are adverse prognostic markers.
Assuntos
Leucemia de Mastócitos , Mastocitose Sistêmica , Humanos , Mastocitose Sistêmica/diagnóstico , Mastocitose Sistêmica/tratamento farmacológico , Mastocitose Sistêmica/genética , Cladribina/uso terapêutico , Leucemia de Mastócitos/tratamento farmacológico , Leucemia de Mastócitos/genética , Prognóstico , Sistema de RegistrosAssuntos
Leucemia de Mastócitos , Leucemia , Humanos , Leucemia de Mastócitos/diagnóstico , Medula ÓsseaRESUMO
Activating mutations in KIT (CD117) have been associated with several diseases, including gastrointestinal stromal tumors and mastocytosis. Rapidly progressing pathologies or drug resistance highlight the need for alternative treatment strategies. Previously, we reported that the adaptor molecule SH3 binding protein 2 (SH3BP2 or 3BP2) regulates KIT expression at the transcriptional level and microphthalmia-associated transcription factor (MITF) expression at the post-transcriptional level in human mast cells and gastrointestinal stromal tumor (GIST) cell lines. Lately, we have found that the SH3BP2 pathway regulates MITF through miR-1246 and miR-5100 in GIST. In this study, miR-1246 and miR-5100 were validated by qPCR in the SH3BP2-silenced human mast cell leukemia cell line (HMC-1). MiRNA overexpression reduces MITF and MITF-dependent target expression in HMC-1. The same pattern was observed after MITF silencing. In addition, MITF inhibitor ML329 treatment reduces MITF expression and affects the viability and cell cycle progression in HMC-1. We also examine whether MITF downregulation affected IgE-dependent mast cell degranulation. MiRNA overexpression, MITF silencing, and ML329 treatment reduced IgE-dependent degranulation in LAD2- and CD34+-derived mast cells. These findings suggest MITF may be a potential therapeutic target for allergic reactions and deregulated KIT mast-cell-mediated disorders.
Assuntos
Leucemia de Mastócitos , MicroRNAs , Fator de Transcrição Associado à Microftalmia , Humanos , Morte Celular/genética , Regulação para Baixo , Tumores do Estroma Gastrointestinal/metabolismo , Tumores do Estroma Gastrointestinal/patologia , Imunoglobulina E/metabolismo , Leucemia de Mastócitos/metabolismo , Mastócitos/metabolismo , Fator de Transcrição Associado à Microftalmia/metabolismo , MicroRNAs/genéticaRESUMO
Prevention of fatal side effects during cancer therapy of cancer patients with high-dosed pharmacological inhibitors is to date a major challenge. Moreover, the development of drug resistance poses severe problems for the treatment of patients with leukemia or solid tumors. Particularly drug-mediated dimerization of RAF kinases can be the cause of acquired resistance, also called "paradoxical activation." In the present work we re-analyzed the effects of different tyrosine kinase inhibitors (TKIs) on the proliferation, metabolic activity, and survival of the Imatinib-resistant, KIT V560G, D816V-expressing human mast cell (MC) leukemia (MCL) cell line HMC-1.2. We observed that low concentrations of the TKIs Nilotinib and Ponatinib resulted in enhanced proliferation, suggesting paradoxical activation of the MAPK pathway. Indeed, these TKIs caused BRAF-CRAF dimerization, resulting in ERK1/2 activation. The combination of Ponatinib with the MEK inhibitor Trametinib, at nanomolar concentrations, effectively suppressed HMC-1.2 proliferation, metabolic activity, and induced apoptotic cell death. Effectiveness of this drug combination was recapitulated in the human KIT D816V MC line ROSAKIT D816V and in KIT D816V hematopoietic progenitors obtained from patient-derived induced pluripotent stem cells (iPS cells) and systemic mastocytosis patient samples. In conclusion, mutated KIT-driven Imatinib resistance and possible TKI-induced paradoxical activation can be efficiently overcome by a low concentration Ponatinib and Trametinib co-treatment, potentially reducing the negative side effects associated with MCL therapy.
Assuntos
Leucemia de Mastócitos , Humanos , Mesilato de Imatinib/farmacologia , Mesilato de Imatinib/uso terapêutico , Leucemia de Mastócitos/metabolismo , Leucemia de Mastócitos/patologia , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Proteínas Quinases Ativadas por Mitógeno/farmacologia , Mastócitos/metabolismo , Mastócitos/patologia , Proteínas Proto-Oncogênicas c-kit/genética , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , MutaçãoRESUMO
Mast cell leukemia (MCL) is a rare subtype of systemic mastocytosis defined by ≥20% mast cells (MC) on a bone marrow aspirate. We evaluated 92 patients with MCL from the European Competence Network on Mastocytosis registry. Thirty-one (34%) patients had a diagnosis of MCL with an associated hematologic neoplasm (MCL-AHN). Chronic MCL (lack of C-findings) comprised 14% of patients, and only 4.5% had "leukemic MCL" (≥10% circulating MCs). KIT D816V was found in 62/85 (73%) evaluable patients; 9 (11%) individuals exhibited alternative KIT mutations, and no KIT variants were detected in 14 (17%) subjects. Ten evaluable patients (17%) had an abnormal karyotype and the poor-risk SRSF2, ASXL1, and RUNX1 (S/A/R) mutations were identified in 16/36 (44%) patients who underwent next-generation sequencing. Midostaurin was the most common therapy administered to 65% of patients and 45% as first-line therapy. The median overall survival (OS) was 1.6 years. In multivariate analysis (S/A/R mutations excluded owing to low event rates), a diagnosis of MCL-AHN (hazard ratio [HR], 4.7; 95% confidence interval [CI], 1.7-13.0; P = .001) and abnormal karyotype (HR, 5.6; 95% CI, 1.4-13.3; P = .02) were associated with inferior OS; KIT D816V positivity (HR, 0.33; 95% CI, 0.11-0.98; P = .04) and midostaurin treatment (HR, 0.32; 95% CI, 0.08-0.72; P = .008) were associated with superior OS. These data provide the most comprehensive snapshot of the clinicopathologic, molecular, and treatment landscape of MCL to date, and should help further inform subtyping and prognostication of MCL.