RESUMEN
B cell receptor (BCR) signaling is required for the survival and maturation of B cells and is deregulated in B cell lymphomas. While proximal BCR signaling is well studied, little is known about the crosstalk of downstream effector pathways, and a comprehensive quantitative network analysis of BCR signaling is missing. Here, we semi-quantitatively modelled BCR signaling in Burkitt lymphoma (BL) cells using systematically perturbed phosphorylation data of BL-2 and BL-41 cells. The models unveiled feedback and crosstalk structures in the BCR signaling network, including a negative crosstalk from p38 to MEK/ERK. The relevance of the crosstalk was verified for BCR and CD40 signaling in different BL cells and confirmed by global phosphoproteomics on ERK itself and known ERK target sites. Compared to the starting network, the trained network for BL-2 cells was better transferable to BL-41 cells. Moreover, the BL-2 network was also suited to model BCR signaling in Diffuse large B cell lymphoma cells lines with aberrant BCR signaling (HBL-1, OCI-LY3), indicating that BCR aberration does not cause a major downstream rewiring.
Asunto(s)
Linfoma de Células B , Receptores de Antígenos de Linfocitos B , Transducción de Señal , Humanos , Receptores de Antígenos de Linfocitos B/metabolismo , Línea Celular Tumoral , Linfoma de Células B/metabolismo , Linfoma de Células B/patología , Linfoma de Burkitt/metabolismo , Linfoma de Burkitt/patología , Biología Computacional , Modelos Biológicos , FosforilaciónRESUMEN
This study sheds light on the pivotal role of the oncoprotein DEK in B-cell lymphoma. We reveal DEK expression correlates with increased tumor proliferation and inferior overall survival in cases diagnosed with low-grade B-cell lymphoma (LGBCL). We also found significant correlation between DEK expression and copy number alterations in LGBCL tumors, highlighting a novel mechanism of LGBCL pathogenesis that warrants additional exploration. To interrogate the mechanistic role of DEK in B-cell lymphoma, we generated a DEK knockout cell line model, which demonstrated DEK depletion caused reduced proliferation and altered expression of key cell cycle and apoptosis-related proteins, including Bcl-2, Bcl-xL, and p53. Notably, DEK depleted cells showed increased sensitivity to apoptosis-inducing agents, including venetoclax and staurosporine, which underscores the therapeutic potential of targeting DEK in B-cell lymphomas. Overall, our study contributes to a better understanding of DEK's role as an oncoprotein in B-cell lymphomas, highlighting its potential as both a promising therapeutic target and a novel biomarker for aggressive LGBCL. Further research elucidating the molecular mechanisms underlying DEK-mediated tumorigenesis could pave the way for improved treatment strategies and better clinical outcomes for patients with B-cell lymphoma.
Asunto(s)
Proliferación Celular , Proteínas Cromosómicas no Histona , Linfoma de Células B , Proteínas Oncogénicas , Proteínas de Unión a Poli-ADP-Ribosa , Proteínas de Unión a Poli-ADP-Ribosa/genética , Proteínas de Unión a Poli-ADP-Ribosa/metabolismo , Humanos , Proteínas Oncogénicas/genética , Proteínas Oncogénicas/metabolismo , Proteínas Cromosómicas no Histona/genética , Proteínas Cromosómicas no Histona/metabolismo , Linfoma de Células B/metabolismo , Linfoma de Células B/genética , Linfoma de Células B/patología , Línea Celular Tumoral , Linfocitos B/metabolismo , Linfocitos B/patología , Apoptosis , Femenino , Regulación Neoplásica de la Expresión Génica , Masculino , Clasificación del TumorRESUMEN
PI3Kδ is a key signal transduction molecule in normal and malignant B cells, as well as in T-regulatory cells, making it a promising target for treatment of hematologic malignancies through both direct killing and anti-tumor immunity regulation. BGB-10188 is a highly selective inhibitor of PI3Kδ, showing more than 3000 folds selectivity over other PI3K isoforms and no significant inhibition across tested kinases. BGB-10188 potently inhibited PI3Kδ with IC50s ranging from 1.7-16 nM through various in vitro assays and showed a long-lasting and strong target inhibition in mouse B cells in vivo. BGB-10188 showed significant antitumor effects in human B cell lymphoma xenograft models as single agent or in combination with the BTK inhibitor zanubrutinib. BGB-10188 showed significant Treg inhibition in blood but not in colon, along with less drug accumulation in colon compared with idelalisib, which is an approved PI3Kdelta inhibitor with high incidence of gastrointestinal side effects in clinic. In summary, BGB-10188 is a novel PI3Kδ inhibitor with high selectivity, potency and improved safety profile shown in preclinical studies, which is showing the potential as a best-in-class PI3Kδ inhibitor.
Asunto(s)
Antineoplásicos , Fosfatidilinositol 3-Quinasa Clase I , Ensayos Antitumor por Modelo de Xenoinjerto , Animales , Humanos , Ratones , Línea Celular Tumoral , Fosfatidilinositol 3-Quinasa Clase I/antagonistas & inhibidores , Fosfatidilinositol 3-Quinasa Clase I/metabolismo , Antineoplásicos/farmacología , Inhibidores de las Quinasa Fosfoinosítidos-3/farmacología , Pirimidinas/farmacología , Linfoma de Células B/tratamiento farmacológico , Linfoma de Células B/patología , Linfoma de Células B/metabolismo , Inhibidores de Proteínas Quinasas/farmacología , Inhibidores de Proteínas Quinasas/uso terapéutico , Colon/efectos de los fármacos , Colon/patología , Colon/metabolismo , Modelos Animales de Enfermedad , Purinas/farmacologíaRESUMEN
The translocation t(14;18) activates BCL2 and is considered the initiating genetic lesion in most follicular lymphomas (FL). Surprisingly, FL patients fail to respond to the BCL2 inhibitor, Venetoclax. We show that mutations and deletions affecting the histone lysine methyltransferase SETD1B (KMT2G) occur in 7% of FLs and 16% of diffuse large B cell lymphomas (DLBCL). Deficiency in SETD1B confers striking resistance to Venetoclax and an experimental MCL-1 inhibitor. SETD1B also acts as a tumor suppressor and cooperates with the loss of KMT2D in lymphoma development in vivo. Consistently, loss of SETD1B in human lymphomas typically coincides with loss of KMT2D. Mechanistically, SETD1B is required for the expression of several proapoptotic BCL2 family proteins. Conversely, inhibitors of the KDM5 histone H3K4 demethylases restore BIM and BIK expression and synergize with Venetoclax in SETD1B-deficient lymphomas. These results establish SETD1B as an epigenetic regulator of cell death and reveal a pharmacological strategy to augment Venetoclax sensitivity in lymphoma.
Asunto(s)
Apoptosis , N-Metiltransferasa de Histona-Lisina , Mutación , Proteínas Proto-Oncogénicas c-bcl-2 , Animales , Humanos , Ratones , Apoptosis/genética , Compuestos Bicíclicos Heterocíclicos con Puentes/farmacología , Línea Celular Tumoral , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Resistencia a Antineoplásicos/genética , N-Metiltransferasa de Histona-Lisina/genética , N-Metiltransferasa de Histona-Lisina/metabolismo , Linfoma de Células B/genética , Linfoma de Células B/patología , Linfoma de Células B/metabolismo , Linfoma de Células B Grandes Difuso/genética , Linfoma de Células B Grandes Difuso/patología , Linfoma de Células B Grandes Difuso/metabolismo , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/genética , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Sulfonamidas/farmacologíaRESUMEN
The t(14;19)(q32;q13) is a rare recurring translocation found in B-cell lymphoproliferative malignancies, involving the Bcl-3 gene. This chromosomal translocation is often found in patients under the age of 50 and causes a more progressive disease. The Bcl-3 gene encodes a protein belonging to the IκB family of proteins, which tightly regulates NFκB signaling by acting as an activator or repressor of transcription. Previously, we developed a second-generation Bcl-3 inhibitor that could directly interfere with Bcl-3 signaling pathway, resulting in reduced melanoma cell proliferation, invasion, and migration. The present study aimed to investigate the effect of a Bcl-3 inhibitor on B-cell lymphoma and leukemia cells. It was found that treatment of cells with this inhibitor caused a decrease in cell proliferation and cell survival. Furthermore, Bcl-3 inhibition in B-cell malignant cells resulted in the loss of mitochondrial membrane potential and functionality, as well as the increased expression of cleaved caspase 3, indicating that cell death occurs through the intrinsic apoptotic pathway. This observation is further supported by reduced expression of cIAP1 protein 1 (cIAP1) upon treatment of cancer cells. Given the current lack of clinical advancements targeting Bcl-3 in oncology, this opens a novel avenue for the development and investigation of highly specific therapeutic interventions against B-cell malignancies.
Asunto(s)
Apoptosis , Proteínas del Linfoma 3 de Células B , Proliferación Celular , Humanos , Proteínas del Linfoma 3 de Células B/metabolismo , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Linfoma de Células B/genética , Linfoma de Células B/patología , Linfoma de Células B/metabolismo , Linfoma de Células B/tratamiento farmacológico , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Caspasa 3/metabolismoRESUMEN
Assessing the prognosis of patients with aggressive non-Hodgkin B cell lymphoma mainly relies on a clinical risk score (IPI). Standard first-line therapies are based on a chemo-immunotherapy with rituximab, which mediates CD16-dependent antibody-dependent cellular cytotoxicity (ADCC). We phenotypically and functionally analyzed blood samples from 46 patients focusing on CD16+ NK cells, CD16+ T cells and CD16+ monocytes. Kaplan-Meier survival curves show a superior progression-free survival (PFS) for patients having more than 1.6% CD16+ T cells (p = 0.02; HR = 0.13 (0.007-0.67)) but an inferior PFS having more than 10.0% CD16+ monocytes (p = 0.0003; HR = 16.0 (3.1-291.9)) at diagnosis. Surprisingly, no correlation with NK cells was found. The increased risk of relapse in the presence of > 10.0% CD16+ monocytes is reversed by the simultaneous occurrence of > 1.6% CD16+ T cells. The unexpectedly strong protective function of CD16+ T cells could be explained by their high antibody-dependent cellular cytotoxicity as quantified by real-time killing assays and single-cell imaging. The combined analysis of CD16+ monocytes (> 10%) and CD16+ T cells (< 1.6%) provided a strong model with a Harrell's C index of 0.80 and a very strong power of 0.996 even with our sample size of 46 patients. CD16 assessment in the initial blood analysis is thus a precise marker for early relapse prediction.
Asunto(s)
Células Asesinas Naturales , Receptores de IgG , Humanos , Receptores de IgG/metabolismo , Pronóstico , Células Asesinas Naturales/metabolismo , Células Asesinas Naturales/inmunología , Monocitos/metabolismo , Monocitos/inmunología , Biomarcadores de Tumor , Masculino , Femenino , Recurrencia Local de Neoplasia/patología , Proteínas Ligadas a GPI/metabolismo , Proteínas Ligadas a GPI/sangre , Linfoma de Células B/metabolismo , Linfoma de Células B/sangre , Linfoma de Células B/inmunología , Linfoma de Células B/patología , Persona de Mediana Edad , Linfocitos T/metabolismo , Linfocitos T/inmunología , Citotoxicidad Celular Dependiente de Anticuerpos , Anciano , Estimación de Kaplan-MeierRESUMEN
Ibrutinib, a Bruton Tyrosine Kinase (BTK) inhibitor, has shown effectiveness against various B-cell lymphoid malignancies. However, prolonged usage can induce resistance, affecting treatment outcomes. The oncogenic microRNA, miR-155-5p, is associated with poor prognosis in B-cell lymphomas, prompting our investigation into the mechanism of acquired ibrutinib resistance in these cells. We generated ibrutinib-resistant OCI-Ly1 cells (OCI-Ly1-IbtR) through continuous exposure to 1 µM and 2 µM of ibrutinib. We conducted microRNA profiling of OCI-Ly1-IbtR and isolated exosomes via ultracentrifugation. Comparative studies of microRNA levels in cells and exosomes, as well as exploration of targets of up-regulated microRNAs in OCI-Ly1-IbtR, were performed. Target validation involved transfection of candidate microRNAs, and co-culture experiments utilized OCI-Ly1 cells with exosomes from OCI-Ly1-IbtR. Elevated levels of miR-155-5p were observed in OCI-Ly1-IbtR and its exosomes, correlating with AKT and NF-κB activation. Transfection of miR-155-5p induced AKT/NF-κB pathway activation in OCI-Ly1, resulting in ibrutinib resistance, enhanced colony formation, and sustained BTK activity. Primary cell lines from ibrutinib-refractory B-cell lymphoma patients exhibited similar signaling protein activation. Target evaluation identified KDM5B and DEPTOR as miR-155-5p targets, confirmed by downregulation after transfection. We observed KDM5B and DEPTOR enrichment in Ago2 during ibrutinib resistance and miR-155-5p transfection. Co-culture experiments demonstrated exosome-mediated transfer of miR-155-5p, inducing ibrutinib resistance and KDM5B/DEPTOR downregulation in OCI-Ly1. Our findings suggest that miR-155-5p overexpression is associated with AKT and NF-κB pathway activation in ibrutinib-resistant cells, proposing a potential role for acquired miR-155-5p upregulation in B-cell lymphoma ibrutinib resistance.
Asunto(s)
Adenina , Resistencia a Antineoplásicos , Exosomas , Linfoma de Células B , MicroARNs , Piperidinas , Humanos , MicroARNs/genética , MicroARNs/metabolismo , Piperidinas/farmacología , Resistencia a Antineoplásicos/genética , Adenina/análogos & derivados , Adenina/farmacología , Exosomas/metabolismo , Exosomas/genética , Exosomas/efectos de los fármacos , Linfoma de Células B/genética , Linfoma de Células B/tratamiento farmacológico , Linfoma de Células B/metabolismo , Linfoma de Células B/patología , Línea Celular Tumoral , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Pirimidinas/farmacología , FN-kappa B/metabolismo , FN-kappa B/genética , Proteínas Proto-Oncogénicas c-akt/metabolismo , Proteínas Proto-Oncogénicas c-akt/genética , Transducción de Señal/efectos de los fármacos , Pirazoles/farmacologíaRESUMEN
The myocyte enhancer factor 2B (MEF2B) transcription factor is frequently mutated in germinal center (GC)-derived B-cell lymphomas. Its ammino (N)-terminal mutations drive lymphomagenesis by escaping interaction with transcriptional repressors, while the function of carboxy (C)-terminal mutations remains to be elucidated. Here, we show that MEF2B C-tail is physiologically phosphorylated at specific residues and phosphorylation at serine (S)324 is impaired by lymphoma-associated mutations. Lack of phosphorylation at S324 enhances the interaction of MEF2B with the SWI/SNF chromatin remodeling complex, leading to higher transcriptional activity. In addition, these mutants show an increased protein stability due to impaired interaction with the CUL3/KLHL12 ubiquitin complex. Mice expressing a phosphorylation-deficient lymphoma-associated MEF2B mutant display GC enlargement and develop GC-derived lymphomas, when crossed with Bcl2 transgenic mice. These results unveil converging mechanisms of action for a diverse spectrum of MEF2B mutations, all leading to its dysregulation and GC B-cell lymphomagenesis.
Asunto(s)
Linfoma de Células B , Factores de Transcripción MEF2 , Mutación , Animales , Humanos , Ratones , Linfocitos B/metabolismo , Línea Celular Tumoral , Centro Germinal/metabolismo , Células HEK293 , Linfoma de Células B/genética , Linfoma de Células B/metabolismo , Linfoma de Células B/patología , Factores de Transcripción MEF2/metabolismo , Factores de Transcripción MEF2/genética , Ratones Transgénicos , Fosforilación , Estabilidad Proteica , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/genéticaRESUMEN
Bruton's tyrosine kinase (BTK), a non-receptor tyrosine kinase crucial for B cell development and function, acts downstream of the B cell receptor (BCR) in the BCR pathway. Other kinases involved downstream of the BCR besides BTK such as Syk, Lyn, PI3K, and Mitogen-activated protein (MAP) kinases also play roles in relaying signals from the BCR to provide pro-survival, activation, and proliferation cues. BTK signaling is implicated in various B-cell lymphomas such as mantle cell lymphoma, Waldenström Macroglobulinemia, follicular lymphoma, and diffuse large B cell lymphoma, leading to the development of transformative treatments like ibrutinib, the first-in-class covalent BTK inhibitor, and pirtobrutinib, the first-in-class noncovalent BTK inhibitor. However, kinase-deficient mutations C481F, C481Y, C481R, and L528W in the BTK gene confer resistance to both covalent and non-covalent BTK inhibitors, facilitating B cell survival and lymphomagenesis despite kinase inactivation. Further studies have revealed BTK's non-catalytic scaffolding function, mediating the assembly and activation of proteins including Toll-like receptor 9 (TLR9), vascular cell adhesion protein 1 (VCAM-1), hematopoietic cell kinase (HCK), and integrin-linked kinase (ILK). This non-enzymatic role promotes cell survival and proliferation independently of kinase activity. Understanding BTK's dual roles unveils opportunities for therapeutics targeting its scaffolding function, promising advancements in disrupting lymphomagenesis and refining B cell lymphoma treatments.
Asunto(s)
Agammaglobulinemia Tirosina Quinasa , Linfoma de Células B , Inhibidores de Proteínas Quinasas , Agammaglobulinemia Tirosina Quinasa/antagonistas & inhibidores , Agammaglobulinemia Tirosina Quinasa/metabolismo , Humanos , Inhibidores de Proteínas Quinasas/uso terapéutico , Inhibidores de Proteínas Quinasas/farmacología , Linfoma de Células B/tratamiento farmacológico , Linfoma de Células B/metabolismo , Linfoma de Células B/genética , Transducción de Señal/efectos de los fármacos , Animales , Receptores de Antígenos de Linfocitos B/metabolismo , Adenina/análogos & derivados , Adenina/farmacologíaRESUMEN
Despite the availability of life-extending treatments for B cell leukemias and lymphomas, many of these cancers remain incurable. Thus, the development of new molecular targets and therapeutics is needed to expand treatment options. To identify new molecular targets, we used a forward genetic screen in mice to identify genes required for development or survival of lymphocytes. Here, we describe Zfp574, an essential gene encoding a zinc finger protein necessary for normal and malignant lymphocyte survival. We show that ZFP574 interacts with zinc finger protein THAP12 and promotes the G1-to-S-phase transition during cell cycle progression. Mutation of ZFP574 impairs nuclear localization of the ZFP574-THAP12 complex. ZFP574 or THAP12 deficiency results in cell cycle arrest and impaired lymphoproliferation. Germline mutation, acute gene deletion, or targeted degradation of ZFP574 suppressed Myc-driven B cell leukemia in mice, but normal B cells were largely spared, permitting long-term survival, whereas complete lethality was observed in control animals. Our findings support the identification of drugs targeting ZFP574-THAP12 as a unique strategy to treat B cell malignancies.
Asunto(s)
Linfocitos B , Animales , Ratones , Linfocitos B/metabolismo , Leucemia de Células B/genética , Leucemia de Células B/patología , Leucemia de Células B/metabolismo , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Proteínas Reguladoras de la Apoptosis/genética , Proteínas Reguladoras de la Apoptosis/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Ratones Endogámicos C57BL , Linfoma de Células B/genética , Linfoma de Células B/patología , Linfoma de Células B/metabolismoRESUMEN
B cell malignancies, comprising over 80 heterogeneous blood cancers, pose significant prognostic challenges due to intricate oncogenic signaling. Emerging evidence emphasizes the pivotal role of disrupted lipid metabolism in the development of these malignancies. Variations in lipid species, such as phospholipids, cholesterol, sphingolipids, and fatty acids, are widespread across B cell malignancies, contributing to uncontrolled cell proliferation and survival. Phospholipids play a crucial role in initial signaling cascades leading to B cell activation and malignant transformation through constitutive B cell receptor (BCR) signaling. Dysregulated cholesterol and sphingolipid homeostasis support lipid raft integrity, crucial for propagating oncogenic signals. Sphingolipids impact malignant B cell stemness, proliferation, and survival, while glycosphingolipids in lipid rafts modulate BCR activation. Additionally, cancer cells enhance fatty acid-related processes to meet heightened metabolic demands. In obese individuals, the obesity-derived lipids and adipokines surrounding adipocytes rewire lipid metabolism in malignant B cells, evading cytotoxic therapies. Genetic drivers such as MYC translocations also intrinsically alter lipid metabolism in malignant B cells. In summary, intrinsic and extrinsic factors converge to reprogram lipid metabolism, fostering aggressive phenotypes in B cell malignancies. Therefore, targeting altered lipid metabolism has translational potential for improving risk stratification and clinical management of diverse B cell malignancy subtypes.
Asunto(s)
Metabolismo de los Lípidos , Humanos , Animales , Linfocitos B/metabolismo , Linfoma de Células B/metabolismo , Linfoma de Células B/patología , Leucemia de Células B/metabolismo , Leucemia de Células B/patologíaRESUMEN
Aberrations in the Hedgehog (Hh) signaling pathway are significantly prevailed in various cancers, including B-cell lymphoma. A critical facet of Hh signal transduction involves the dynamic regulation of the suppressor of fused homolog (SUFU)-glioma-associated oncogene homolog (GLI) complex within the kinesin family member 7 (KIF7)-supported ciliary tip compartment. However, the specific post-translational modifications of SUFU-GLI complex within this context have remained largely unexplored. Our study reveals a novel regulatory mechanism involving prolyl 4-hydroxylase 2 (P4HA2), which forms a complex with KIF7 and is essential for signal transduction of Hh pathway. We demonstrate that, upon Hh pathway activation, P4HA2 relocates alongside KIF7 to the ciliary tip. Here, it hydroxylates SUFU to inhibit its function, thus amplifying the Hh signaling. Moreover, the absence of P4HA2 significantly impedes B lymphoma progression. This effect can be attributed to the suppression of Hh signaling in stromal fibroblasts, resulting in decreased growth factors essential for malignant proliferation of B lymphoma cells. Our findings highlight the role of P4HA2-mediated hydroxylation in modulating Hh signaling and propose a novel stromal-targeted therapeutic strategy for B-cell lymphoma.
Asunto(s)
Progresión de la Enfermedad , Proteínas Hedgehog , Linfoma de Células B , Procolágeno-Prolina Dioxigenasa , Proteínas Represoras , Transducción de Señal , Proteínas Hedgehog/metabolismo , Humanos , Linfoma de Células B/metabolismo , Linfoma de Células B/patología , Ratones , Animales , Proteínas Represoras/metabolismo , Proteínas Represoras/genética , Procolágeno-Prolina Dioxigenasa/metabolismo , Hidroxilación , Comunicación Paracrina , Proliferación Celular , Cinesinas/metabolismo , Cinesinas/genética , Línea Celular Tumoral , Prolil HidroxilasasRESUMEN
High-grade B-cell lymphoma (HGBCL), the subtype of non-Hodgkin lymphoma, to be relapsed or refractory in patients after initial therapy or salvage chemotherapy. Dual dysregulation of MYC and BCL2 is one of the important pathogenic mechanisms. Thus, combined targeting of MYC and BCL2 appears to be a promising strategy. Dihydroorotate dehydrogenase (DHODH) is the fourth rate-limiting enzyme for the de novo biosynthesis of pyrimidine. It has been shown to be a potential therapeutic target for multiple diseases. In this study, the DHODH inhibitor brequinar exhibited growth inhibition, cell cycle blockade, and apoptosis promotion in HGBCL cell lines with MYC and BCL2 rearrangements. The combination of brequinar and BCL2 inhibitors venetoclax had a synergistic inhibitory effect on the survival of DHL cells through different pathways. Venetoclax could upregulate MCL-1 and MYC expression, which has been reported as a resistance mechanism of BCL2 inhibitors. Brequinar downregulated MCL-1 and MYC, which could potentially overcome drug resistance to venetoclax in HGBCL cells. Furthermore, brequinar could downregulate a broad range of genes, including ribosome biosynthesis genes, which might contribute to its anti-tumor effects. In vivo studies demonstrated synergetic tumor growth inhibition in xenograft models with brequinar and venetoclax combination treatment. These results provide preliminary evidence for the rational combination of DHODH and BCL2 blockade in HGBCL with abnormal MYC and BCL2.
Asunto(s)
Compuestos Bicíclicos Heterocíclicos con Puentes , Dihidroorotato Deshidrogenasa , Sinergismo Farmacológico , Oxidorreductasas actuantes sobre Donantes de Grupo CH-CH , Proteínas Proto-Oncogénicas c-bcl-2 , Proteínas Proto-Oncogénicas c-myc , Sulfonamidas , Ensayos Antitumor por Modelo de Xenoinjerto , Humanos , Animales , Proteínas Proto-Oncogénicas c-bcl-2/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-bcl-2/genética , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Ratones , Sulfonamidas/farmacología , Sulfonamidas/uso terapéutico , Compuestos Bicíclicos Heterocíclicos con Puentes/farmacología , Compuestos Bicíclicos Heterocíclicos con Puentes/uso terapéutico , Proteínas Proto-Oncogénicas c-myc/genética , Proteínas Proto-Oncogénicas c-myc/metabolismo , Proteínas Proto-Oncogénicas c-myc/antagonistas & inhibidores , Línea Celular Tumoral , Oxidorreductasas actuantes sobre Donantes de Grupo CH-CH/antagonistas & inhibidores , Oxidorreductasas actuantes sobre Donantes de Grupo CH-CH/genética , Apoptosis/efectos de los fármacos , Linfoma de Células B/tratamiento farmacológico , Linfoma de Células B/genética , Linfoma de Células B/patología , Linfoma de Células B/metabolismo , Reordenamiento Génico , Proliferación Celular/efectos de los fármacos , Compuestos de Bifenilo , QuinaldinasRESUMEN
Bruton's tyrosine kinase (BTK) inhibitors have revolutionized the treatment of B-cell malignancies. They target BTK, a key effector in the B-cell receptor (BCR) signaling pathway, crucial for B-cell survival and proliferation. The first-in-class irreversible BTK inhibitor, ibrutinib, was approved for various B-cell malignancies but has limitations due to off-target effects. Second-generation inhibitors, such as acalabrutinib and zanubrutinib, offer improved selectivity and reduced side effects. However, resistance to BTK inhibitors, driven by BTK mutations, remains a challenge. Combinatorial therapies with PI3K inhibitors, immune checkpoint inhibitors, BH3 mimetics, and anti-CD20 antibodies show promise in overcoming resistance. Noncovalent BTK inhibitors and proteolysis-targeting chimeras (PROTACs) are emerging strategies with potential to combat resistance. Overall, advancements in BTK-targeted therapies provide hope for improved outcomes in patients with B-cell malignancies and a promising avenue to address drug resistance. Further research is needed to optimize combination therapies and identify optimal treatment regimens.
Asunto(s)
Agammaglobulinemia Tirosina Quinasa , Resistencia a Antineoplásicos , Piperidinas , Inhibidores de Proteínas Quinasas , Pirazoles , Pirimidinas , Humanos , Agammaglobulinemia Tirosina Quinasa/antagonistas & inhibidores , Pirazoles/uso terapéutico , Pirazoles/farmacología , Pirimidinas/uso terapéutico , Pirimidinas/farmacología , Inhibidores de Proteínas Quinasas/uso terapéutico , Inhibidores de Proteínas Quinasas/farmacología , Piperidinas/uso terapéutico , Piperidinas/farmacología , Linfoma de Células B/tratamiento farmacológico , Linfoma de Células B/metabolismo , Linfoma de Células B/patologíaRESUMEN
BACKGROUND: Primary mediastinal B-cell lymphoma (PMBL) and classical Hodgkin lymphoma (cHL) are distinct hematological malignancies of B-cell origin that share many biological, molecular, and clinical characteristics. In particular, the JAK/STAT signaling pathway is a driver of tumor development due to multiple recurrent mutations, particularly in STAT6. Furthermore, the XPO1 gene that encodes exportin 1 (XPO1) shows a frequent point mutation (E571K) resulting in an altered export of hundreds of cargo proteins, which may impact the success of future therapies in PMBL and cHL. Therefore, targeted therapies have been envisioned for these signaling pathways and mutations. METHODS: To identify novel molecular targets that could overcome the treatment resistance that occurs in PMBL and cHL patients, we have explored the efficacy of a first-in-class HSP110 inhibitor (iHSP110-33) alone and in combination with selinexor, a XPO1 specific inhibitor, both in vitro and in vivo. RESULTS: We show that iHSP110-33 decreased the survival of several PMBL and cHL cell lines and the size of tumor xenografts. We demonstrate that HSP110 is a cargo of XPO1wt as well as of XPO1E571K. Using immunoprecipitation, proximity ligation, thermophoresis and kinase assays, we showed that HSP110 directly interacts with STAT6 and favors its phosphorylation. The combination of iHSP110-33 and selinexor induces a synergistic reduction of STAT6 phosphorylation and of lymphoma cell growth in vitro and in vivo. In biopsies from PMBL patients, we show a correlation between HSP110 and STAT6 phosphorylation levels. CONCLUSIONS: These findings suggest that HSP110 could be proposed as a novel target in PMBL and cHL therapy.
Asunto(s)
Proteína Exportina 1 , Enfermedad de Hodgkin , Carioferinas , Receptores Citoplasmáticos y Nucleares , Humanos , Carioferinas/antagonistas & inhibidores , Carioferinas/metabolismo , Receptores Citoplasmáticos y Nucleares/metabolismo , Receptores Citoplasmáticos y Nucleares/antagonistas & inhibidores , Animales , Ratones , Enfermedad de Hodgkin/tratamiento farmacológico , Enfermedad de Hodgkin/patología , Enfermedad de Hodgkin/metabolismo , Enfermedad de Hodgkin/genética , Linfoma de Células B/tratamiento farmacológico , Linfoma de Células B/metabolismo , Linfoma de Células B/patología , Linfoma de Células B/genética , Proteínas del Choque Térmico HSP110/metabolismo , Proteínas del Choque Térmico HSP110/genética , Línea Celular Tumoral , Neoplasias del Mediastino/tratamiento farmacológico , Neoplasias del Mediastino/metabolismo , Neoplasias del Mediastino/patología , Neoplasias del Mediastino/genética , Ensayos Antitumor por Modelo de Xenoinjerto , Triazoles/farmacología , Triazoles/uso terapéutico , Hidrazinas/farmacología , Hidrazinas/uso terapéutico , Femenino , Factor de Transcripción STAT6/metabolismo , Terapia Molecular DirigidaAsunto(s)
Agammaglobulinemia Tirosina Quinasa , Humanos , Agammaglobulinemia Tirosina Quinasa/antagonistas & inhibidores , Agammaglobulinemia Tirosina Quinasa/metabolismo , Linfocitos B/metabolismo , Leucemia de Células B/metabolismo , Leucemia de Células B/patología , Leucemia de Células B/tratamiento farmacológico , Leucemia de Células B/genética , Linfoma de Células B/metabolismo , Linfoma de Células B/genética , Linfoma de Células B/patología , Linfoma de Células B/tratamiento farmacológico , Inhibidores de Proteínas Quinasas/farmacología , Inhibidores de Proteínas Quinasas/uso terapéutico , Proteínas Tirosina Quinasas/metabolismo , Proteínas Tirosina Quinasas/genética , ProteolisisRESUMEN
Enhancer of zeste homolog 2 (EZH2) is a promising therapeutic target for diffuse large B-cell lymphoma. In this study, based on the binding model of 1 (tazemetostat) with polycomb repressive complex 2 (PRC2), we designed and synthesized a series of tazemetostat analogs bearing a 1-methyl-2-benzimidazolinone moiety to improve the inhibitory activity of EZH2 wild-type (WT) and Y641 mutants and enhance metabolic stability. After the assessment of the structure-activity relationship at enzymatic and cellular levels, compound N40 was identified. Biochemical assays showed that compound N40 (IC50â¯=â¯0.32â¯nM) exhibited superior inhibitory activity against EZH2 WT, compared with 1 (IC50â¯=â¯1.20â¯nM), and high potency against EZH2 Y641 mutants (EZH2 Y641F, IC50â¯=â¯0.03â¯nM; EZH2 Y641N, IC50â¯=â¯0.08â¯nM), which were approximately 10-fold more active than those of 1 (EZH2 Y641F, IC50â¯=â¯0.37â¯nM; EZH2 Y641N, IC50â¯=â¯0.85â¯nM). Furthermore, compound N40 (IC50â¯=â¯3.52⯱â¯1.23â¯nM) effectively inhibited the proliferation of Karpas-422 cells and was more potent than 1 (IC50â¯=â¯35.01⯱â¯1.28â¯nM). Further cellular experiments showed that N40 arrested Karpas-422 cells in the G1 phase and induced apoptosis in a dose-dependent manner. Moreover, N40 inhibited the trimethylation of lysine 27 on histone H3 (H3K27Me3) in Karpas-422 cells bearing the EZH2 Y641N mutant. Additionally, N40 (T1/2â¯=â¯177.69â¯min) showed improved metabolic stability in human liver microsomes compared with 1 (T1/2â¯=â¯7.97â¯min). Our findings suggest N40 as a promising EZH2 inhibitor; further investigation remains warranted to confirm our findings and further develop N40.
Asunto(s)
Antineoplásicos , Benzamidas , Proliferación Celular , Ensayos de Selección de Medicamentos Antitumorales , Proteína Potenciadora del Homólogo Zeste 2 , Piridonas , Proteína Potenciadora del Homólogo Zeste 2/antagonistas & inhibidores , Proteína Potenciadora del Homólogo Zeste 2/metabolismo , Humanos , Relación Estructura-Actividad , Benzamidas/química , Benzamidas/farmacología , Benzamidas/síntesis química , Piridonas/farmacología , Piridonas/química , Piridonas/síntesis química , Antineoplásicos/farmacología , Antineoplásicos/química , Antineoplásicos/síntesis química , Proliferación Celular/efectos de los fármacos , Estructura Molecular , Linfoma de Células B/tratamiento farmacológico , Linfoma de Células B/metabolismo , Linfoma de Células B/patología , Relación Dosis-Respuesta a Droga , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Descubrimiento de Drogas , Bencimidazoles/química , Bencimidazoles/farmacología , Bencimidazoles/síntesis químicaRESUMEN
Lactate dehydrogenase A (LDHA) is highly expressed in various tumors. However, the role of LDHA in the pathogenesis of B-cell lymphoma remains unclear. Analysis of data from The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) databases revealed an elevated LDHA expression in diffuse large B-cell lymphoma (DLBC) tissues compared with normal tissues. Similarly, our results demonstrated a significant increase in LDHA expression in tumor tissues from the patients with B-cell lymphoma compared with those with lymphadenitis. To further elucidate potential roles of LDHA in B-cell lymphoma pathogenesis, we silenced LDHA in the Raji cells (a B-cell lymphoma cell line) using shRNA techniques. Silencing LDHA led to reduced mitochondrial membrane integrity, adenosine triphosphate (ATP) production, glycolytic activity, cell viability and invasion. Notably, LDHA knockdown substantially suppressed in vivo growth of Raji cells and extended survival in mice bearing lymphoma (Raji cells). Moreover, proteomic analysis identified feline sarcoma-related protein (FER) as a differential protein positively associated with LDHA expression. Treatment with E260, a FER inhibitor, significantly reduced the metabolism, proliferation and invasion of Raji cells. In summary, our findings highlight that LDHA plays multiple roles in B-cell lymphoma pathogenesis via FER pathways, establishing LDHA/FER may as a potential therapeutic target.
Asunto(s)
Transducción de Señal , Humanos , Animales , Ratones , Línea Celular Tumoral , Linfoma de Células B/genética , Linfoma de Células B/patología , Linfoma de Células B/metabolismo , Regulación Neoplásica de la Expresión Génica , Proliferación Celular/genética , Lactato Deshidrogenasa 5/metabolismo , Lactato Deshidrogenasa 5/genética , L-Lactato Deshidrogenasa/genética , L-Lactato Deshidrogenasa/metabolismo , Linfoma de Células B Grandes Difuso/genética , Linfoma de Células B Grandes Difuso/patología , Linfoma de Células B Grandes Difuso/metabolismo , FemeninoRESUMEN
Phosphatidylserine levels and distribution are tightly controlled by dedicated enzymes at the ER and plasma membrane. Nakatsu and Kawasaki discuss new work by Aoki and colleagues (https://doi.org/10.1083/jcb.202212074), which reveals an acute reliance on phosphatidylserine synthesis in B cell lymphomas needed to prevent aberrant B cell receptor activation and ensuing apoptosis.
Asunto(s)
Linfoma de Células B , Fosfatidilserinas , Receptores de Antígenos de Linfocitos B , Humanos , Apoptosis , Linfoma de Células B/metabolismo , Fosfatidilserinas/metabolismo , Fosfolípidos/metabolismo , Estructura Secundaria de Proteína , Receptores de Antígenos de Linfocitos B/metabolismoRESUMEN
Glucose catabolism, one of the essential pathways sustaining cellular bioenergetics, has been widely studied in the context of tumors. Nevertheless, the function of various branches of glucose metabolism that stem from 'classical' glycolysis have only been partially explored. This review focuses on discussing general mechanisms and pathological implications of glycolysis and its branching pathways in the biology of B cell malignancies. We summarize here what is known regarding pentose phosphate, hexosamine, serine biosynthesis, and glycogen synthesis pathways in this group of tumors. Despite most findings have been based on malignant B cells themselves, we also discuss the role of glucose metabolism in the tumor microenvironment, with a focus on T cells. Understanding the contribution of glycolysis branching pathways and how they are hijacked in B cell malignancies will help to dissect the role they have in sustaining the dissemination and proliferation of tumor B cells and regulating immune responses within these tumors. Ultimately, this should lead to deciphering associated vulnerabilities and improve current therapeutic schedules.