RESUMEN
Clonal evolution is a key feature of cancer progression and relapse. We studied intratumoral heterogeneity in 149 chronic lymphocytic leukemia (CLL) cases by integrating whole-exome sequence and copy number to measure the fraction of cancer cells harboring each somatic mutation. We identified driver mutations as predominantly clonal (e.g., MYD88, trisomy 12, and del(13q)) or subclonal (e.g., SF3B1 and TP53), corresponding to earlier and later events in CLL evolution. We sampled leukemia cells from 18 patients at two time points. Ten of twelve CLL cases treated with chemotherapy (but only one of six without treatment) underwent clonal evolution, predominantly involving subclones with driver mutations (e.g., SF3B1 and TP53) that expanded over time. Furthermore, presence of a subclonal driver mutation was an independent risk factor for rapid disease progression. Our study thus uncovers patterns of clonal evolution in CLL, providing insights into its stepwise transformation, and links the presence of subclones with adverse clinical outcomes.
Asunto(s)
Leucemia Linfocítica Crónica de Células B/genética , Mutación , Algoritmos , Animales , Linfocitos B/metabolismo , Variaciones en el Número de Copia de ADN , Estudio de Asociación del Genoma Completo , Humanos , Leucemia Linfocítica Crónica de Células B/tratamiento farmacológico , PloidiasRESUMEN
Tumour-associated antigens (TAAs) comprise a large set of non-mutated cellular antigens recognized by T cells in human and murine cancers. Their potential as targets for immunotherapy has been explored for more than two decades1, yet the origins of TAA-specific T cells remain unclear. While tumour cells may be an important source of TAAs for T cell priming2, several recent studies suggest that infection with some viruses, including Epstein-Barr virus and influenza virus can elicit T cell responses against abnormally expressed cellular antigens that function as TAAs3,4. However, the cellular and molecular basis of such responses remains undefined. Here we show that expression of the Epstein-Barr virus signalling protein LMP1 in B cells provokes T cell responses to multiple TAAs. LMP1 signalling leads to overexpression of many cellular antigens previously shown to be TAAs, their presentation on major histocompatibility complex classes I (MHC-I) and II (MHC-II) (mainly through the endogenous pathway) and the upregulation of costimulatory ligands CD70 and OX40L, thereby inducing potent cytotoxic CD4+ and CD8+ T cell responses. These findings delineate a mechanism of infection-induced anti-tumour immunity. Furthermore, by ectopically expressing LMP1 in tumour B cells from patients with cancer and thereby enabling them to prime T cells, we develop a general approach for rapid production of autologous cytotoxic CD4+ T cells against a wide range of endogenous tumour antigens, such as TAAs and neoantigens, for treating B cell malignancies. This work stresses the need to revisit classical concepts concerning viral and tumour immunity, which will be critical to fully understand the impact of common infections on human health and to improve the rational design of immune approaches to treatment of cancers.
Asunto(s)
Linfocitos B/inmunología , Linfocitos B/virología , Linfocitos T CD4-Positivos/inmunología , Herpesvirus Humano 4/inmunología , Neoplasias/inmunología , Neoplasias/terapia , Linfocitos T Citotóxicos/inmunología , Proteínas de la Matriz Viral/inmunología , Animales , Antígenos de Neoplasias/inmunología , Ligando CD27/inmunología , Línea Celular Tumoral , Células Cultivadas , Femenino , Células HEK293 , Humanos , Masculino , Ratones , Ligando OX40/inmunologíaRESUMEN
Although BCL2 mutations are reported as later occurring events leading to venetoclax resistance, many other mechanisms of progression have been reported though remain poorly understood. Here, we analyze longitudinal tumor samples from 11 patients with disease progression while receiving venetoclax to characterize the clonal evolution of resistance. All patients tested showed increased in vitro resistance to venetoclax at the posttreatment time point. We found the previously described acquired BCL2-G101V mutation in only 4 of 11 patients, with 2 patients showing a very low variant allele fraction (0.03%-4.68%). Whole-exome sequencing revealed acquired loss(8p) in 4 of 11 patients, of which 2 patients also had gain (1q21.2-21.3) in the same cells affecting the MCL1 gene. In vitro experiments showed that CLL cells from the 4 patients with loss(8p) were more resistant to venetoclax than cells from those without it, with the cells from 2 patients also carrying gain (1q21.2-21.3) showing increased sensitivity to MCL1 inhibition. Progression samples with gain (1q21.2-21.3) were more susceptible to the combination of MCL1 inhibitor and venetoclax. Differential gene expression analysis comparing bulk RNA sequencing data from pretreatment and progression time points of all patients showed upregulation of proliferation, B-cell receptor (BCR), and NF-κB gene sets including MAPK genes. Cells from progression time points demonstrated upregulation of surface immunoglobulin M and higher pERK levels compared with those from the preprogression time point, suggesting an upregulation of BCR signaling that activates the MAPK pathway. Overall, our data suggest several mechanisms of acquired resistance to venetoclax in CLL that could pave the way for rationally designed combination treatments for patients with venetoclax-resistant CLL.
Asunto(s)
Antineoplásicos , Leucemia Linfocítica Crónica de Células B , Humanos , Antineoplásicos/farmacología , Compuestos Bicíclicos Heterocíclicos con Puentes/farmacología , Resistencia a Antineoplásicos/genética , Secuenciación del Exoma , Leucemia Linfocítica Crónica de Células B/tratamiento farmacológico , Leucemia Linfocítica Crónica de Células B/genética , Leucemia Linfocítica Crónica de Células B/patología , Proteína 1 de la Secuencia de Leucemia de Células Mieloides/genética , Proteínas Proto-Oncogénicas c-bcl-2RESUMEN
How the genomic features of a patient's cancer relate to individual disease kinetics remains poorly understood. Here we used the indolent growth dynamics of chronic lymphocytic leukaemia (CLL) to analyse the growth rates and corresponding genomic patterns of leukaemia cells from 107 patients with CLL, spanning decades-long disease courses. We found that CLL commonly demonstrates not only exponential expansion but also logistic growth, which is sigmoidal and reaches a certain steady-state level. Each growth pattern was associated with marked differences in genetic composition, the pace of disease progression and the extent of clonal evolution. In a subset of patients, whose serial samples underwent next-generation sequencing, we found that dynamic changes in the disease course of CLL were shaped by the genetic events that were already present in the early slow-growing stages. Finally, by analysing the growth rates of subclones compared with their parental clones, we quantified the growth advantage conferred by putative CLL drivers in vivo.
Asunto(s)
Progresión de la Enfermedad , Evolución Molecular , Leucemia Linfocítica Crónica de Células B/genética , Leucemia Linfocítica Crónica de Células B/patología , Proliferación Celular/efectos de los fármacos , Células Clonales/efectos de los fármacos , Células Clonales/patología , Estudios de Cohortes , Femenino , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Leucemia Linfocítica Crónica de Células B/tratamiento farmacológico , Masculino , Recurrencia Local de Neoplasia/genética , Recurrencia Local de Neoplasia/patología , Recurrencia , Reproducibilidad de los ResultadosRESUMEN
Inhibitors of Bruton tyrosine kinase (BTK) and phosphatidylinositol 3-kinase δ (PI3Kδ) that target the B-cell receptor (BCR) signaling pathway have revolutionized the treatment of chronic lymphocytic leukemia (CLL). Mutations associated with resistance to BTK inhibitors have been identified, but limited data are available on mechanisms of resistance to PI3Kδ inhibitors. Here we present findings from longitudinal whole-exome sequencing of cells from patients with multiply relapsed CLL (N = 28) enrolled in trials of PI3K inhibitors. The nonresponder subgroup was characterized by baseline activating mutations in MAP2K1, BRAF, and KRAS genes in 60% of patients. PI3Kδ inhibition failed to inhibit ERK phosphorylation (pERK) in nonresponder CLL cells with and without mutations, whereas treatment with a MEK inhibitor rescued ERK inhibition. Overexpression of MAP2K1 mutants in vitro led to increased basal and inducible pERK and resistance to idelalisib. These data demonstrate that MAPK/ERK activation plays a key role in resistance to PI3Kδ inhibitors in CLL and provide a rationale for therapy with a combination of PI3Kδ and ERK inhibitors.
Asunto(s)
Resistencia a Antineoplásicos , Leucemia Linfocítica Crónica de Células B/tratamiento farmacológico , Leucemia Linfocítica Crónica de Células B/enzimología , Sistema de Señalización de MAP Quinasas , Inhibidores de las Quinasa Fosfoinosítidos-3/uso terapéutico , Adulto , Anciano , Línea Celular Tumoral , Resistencia a Antineoplásicos/efectos de los fármacos , Activación Enzimática/efectos de los fármacos , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Femenino , Genoma Humano , Humanos , Leucemia Linfocítica Crónica de Células B/genética , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Masculino , Persona de Mediana Edad , Mutación/genética , Inhibidores de las Quinasa Fosfoinosítidos-3/farmacología , Proteínas Proto-Oncogénicas c-akt/metabolismo , Purinas/farmacología , Purinas/uso terapéutico , Quinazolinonas/farmacología , Quinazolinonas/uso terapéutico , Resultado del Tratamiento , Regulación hacia Arriba/genéticaRESUMEN
B-cell receptor (BCR) signaling and T-cell interactions play a pivotal role in chronic lymphocytic leukemia (CLL) pathogenesis and disease aggressiveness. CLL cells can use microRNAs (miRNAs) and their targets to modulate microenvironmental interactions in the lymph node niches. To identify miRNA expression changes in the CLL microenvironment, we performed complex profiling of short noncoding RNAs in this context by comparing CXCR4/CD5 intraclonal cell subpopulations (CXCR4dimCD5bright vs CXCR4brightCD5dim cells). This identified dozens of differentially expressed miRNAs, including several that have previously been shown to modulate BCR signaling (miR-155, miR-150, and miR-22) but also other candidates for a role in microenvironmental interactions. Notably, all 3 miR-29 family members (miR-29a, miR-29b, miR-29c) were consistently down-modulated in the immune niches, and lower miR-29(a/b/c) levels associated with an increased relative responsiveness of CLL cells to BCR ligation and significantly shorter overall survival of CLL patients. We identified tumor necrosis factor receptor-associated factor 4 (TRAF4) as a novel direct target of miR-29s and revealed that higher TRAF4 levels increase CLL responsiveness to CD40 activation and downstream nuclear factor-κB (NF-κB) signaling. In CLL, BCR represses miR-29 expression via MYC, allowing for concurrent TRAF4 upregulation and stronger CD40-NF-κB signaling. This regulatory loop is disrupted by BCR inhibitors (bruton tyrosine kinase [BTK] inhibitor ibrutinib or phosphatidylinositol 3-kinase [PI3K] inhibitor idelalisib). In summary, we showed for the first time that a miRNA-dependent mechanism acts to activate CD40 signaling/T-cell interactions in a CLL microenvironment and described a novel miR-29-TRAF4-CD40 signaling axis modulated by BCR activity.
Asunto(s)
Adenina/análogos & derivados , Antígenos CD40/metabolismo , Regulación Neoplásica de la Expresión Génica , Leucemia Linfocítica Crónica de Células B/patología , MicroARNs/genética , Piperidinas/farmacología , Proteínas Proto-Oncogénicas c-bcr/antagonistas & inhibidores , Factor 4 Asociado a Receptor de TNF/metabolismo , Adenina/farmacología , Adulto , Anciano , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Antígenos CD40/genética , Femenino , Estudios de Seguimiento , Humanos , Leucemia Linfocítica Crónica de Células B/tratamiento farmacológico , Leucemia Linfocítica Crónica de Células B/genética , Leucemia Linfocítica Crónica de Células B/metabolismo , Masculino , Persona de Mediana Edad , Pronóstico , Proteínas Proto-Oncogénicas c-myc/genética , Proteínas Proto-Oncogénicas c-myc/metabolismo , Tasa de Supervivencia , Factor 4 Asociado a Receptor de TNF/genética , Células Tumorales CultivadasRESUMEN
Phosphatidylinositol 3 kinase (PI3K) inhibitors such as idelalisib have been associated with potentially severe autoimmune toxicity. In the present study, we demonstrate that relapsed refractory patients with chronic lymphocytic leukaemia treated with idelalisib rituximab on the phase III registration trial show uniform decrease in regulatory T cells (Tregs) and increase in CD8 T cells with treatment. Patients who do not develop toxicity show enrichment for T cells expressing multiple chemokine receptors, while those who do develop toxicity have an activated CD8 T cell population with T helper 17 cell differentiation at baseline, which then increases, leading to an increased CD8:Treg ratio that likely triggers autoimmune toxicity.
Asunto(s)
Leucemia Linfocítica Crónica de Células B , Linfocitos T Reguladores , Diferenciación Celular , Ensayos Clínicos Fase III como Asunto , Humanos , Leucemia Linfocítica Crónica de Células B/tratamiento farmacológico , Fosfatidilinositol 3-Quinasas , Inhibidores de las Quinasa Fosfoinosítidos-3 , Purinas , Quinazolinonas/farmacología , Quinazolinonas/uso terapéuticoRESUMEN
Chronic lymphocytic leukemia (CLL) cells cycle between lymph node (LN) and peripheral blood (PB) and display major shifts in Bcl-2 family members between those compartments. Specifically, Bcl-XL and Mcl-1, which are not targeted by the Bcl-2 inhibitor venetoclax, are increased in the LN. Because ibrutinib forces CLL cells out of the LN, we hypothesized that ibrutinib may thereby affect expression of Bcl-XL and Mcl-1 and sensitize CLL cells to venetoclax. We investigated expression of Bcl-2 family members in patients under ibrutinib or venetoclax treatment, combined with dissecting functional interactions of Bcl-2 family members, in an in vitro model of venetoclax resistance. In the PB, recent LN emigrants had higher Bcl-XL and Mcl-1 expression than did cells immigrating back to the LN. Under ibrutinib treatment, this distinction collapsed; significantly, the pretreatment profile reappeared in patients who relapsed on ibrutinib. However, in response to venetoclax, Bcl-2 members displayed an early increase, underlining the different modes of action of these 2 drugs. Profiling by BH3 mimetics was performed in CLL cells fully resistant to venetoclax due to CD40-mediated induction of Bcl-XL, Mcl-1, and Bfl-1. Several dual or triple combinations of BH3 mimetics were highly synergistic in restoring killing of CLL cells. Lastly, we demonstrated that proapoptotic Bim interacts with antiapoptotic Bcl-2 members in a sequential manner: Bcl-2 > Bcl-XL > Mcl-1 > Bfl-1. Combined, the data indicate that Bcl-XL is more important in venetoclax resistance than is Mcl-1 and provide biological rationale for potential synergy between ibrutinib and venetoclax.
Asunto(s)
Adenina/análogos & derivados , Compuestos Bicíclicos Heterocíclicos con Puentes/administración & dosificación , Resistencia a Antineoplásicos/efectos de los fármacos , Regulación Leucémica de la Expresión Génica/efectos de los fármacos , Leucemia Linfocítica Crónica de Células B , Piperidinas/administración & dosificación , Proteínas Proto-Oncogénicas c-bcl-2/biosíntesis , Sulfonamidas/administración & dosificación , Adenina/administración & dosificación , Femenino , Humanos , Leucemia Linfocítica Crónica de Células B/tratamiento farmacológico , Leucemia Linfocítica Crónica de Células B/metabolismo , Leucemia Linfocítica Crónica de Células B/patología , Masculino , Proteínas Proto-Oncogénicas c-bcl-2/antagonistas & inhibidoresRESUMEN
The L265P somatic mutation in the Myeloid Differentiation Primary Response 88 (MYD88) gene is a recurrent mutation in chronic lymphocytic leukaemia (CLL). This mutation has functional effects in various haematological malignancies but its role in CLL remains to be fully elucidated. Here, we report that MYD88 L265P mutations are associated with mutated immunoglobulin heavy-chain gene (IGHV-M) status and that among IGHV-M patients, the presence of MYD88 L265P is associated with younger age at diagnosis. Using microarray and RNA-Seq gene expression analysis, we further observe that the MYD88 L265P mutation is associated with a distinctive gene expression signature that predicts both failure-free survival and overall survival. This association was validated in an independent cohort of patients. To determine whether MYD88 L265P mutations can be therapeutically exploited in CLL, we treated primary cells with an inhibitor of interleukin 1 receptor-associated kinase 4 (IRAK4), a critical effector of the MYD88 pathway. IRAK4 inhibition decreased downstream nuclear factor-κB signalling and cell viability in CLL cells, indicating the potential of the MYD88 pathway as a therapeutic target in CLL.
Asunto(s)
Leucemia Linfocítica Crónica de Células B/genética , Factor 88 de Diferenciación Mieloide/genética , Adulto , Anciano , Estudios de Cohortes , Citocinas/biosíntesis , Femenino , Genes de las Cadenas Pesadas de las Inmunoglobulinas , Humanos , Quinasas Asociadas a Receptores de Interleucina-1/antagonistas & inhibidores , Leucemia Linfocítica Crónica de Células B/tratamiento farmacológico , Leucemia Linfocítica Crónica de Células B/metabolismo , Masculino , Persona de Mediana Edad , Terapia Molecular Dirigida , Mutación , Factor 88 de Diferenciación Mieloide/metabolismo , Pronóstico , Transducción de Señal , TranscriptomaRESUMEN
Inhibition of B-cell receptor (BCR) signaling pathways in chronic lymphocytic leukemia (CLL) provides significant clinical benefit to patients, mainly by blocking adhesion of CLL cells in the lymph node microenvironment. The currently applied inhibitors ibrutinib and idelalisib have limited capacity however to induce cell death as monotherapy and are unlikely to eradicate the disease. Acquired resistance to therapy in CLL is often caused by mutations in the response network being targeted, both for DNA damage or BCR signaling pathways. Thus, drugs with dual targeting capacity could offer improved therapeutic value. Here, the potency of CC-115, a novel inhibitor of mammalian target of rapamycin kinase (TORK) and DNA-dependent protein kinase (DNA-PK), was evaluated in primary CLL cells in vitro and in CLL patients. Combined TORK and DNA-PK inhibition in vitro resulted in caspase-dependent cell killing irrespective of p53, ATM, NOTCH1, or SF3B1 status. Proliferation induced by CD40(+) interleukin-21 stimulation was completely blocked by CC-115, and CD40-mediated resistance to fludarabine and venetoclax could be reverted by CC-115. BCR-mediated signaling was inhibited by CC-115 and also in CLL samples obtained from patients with acquired resistance to idelalisib treatment. Clinical efficacy of CC-115 was demonstrated in 8 patients with relapsed/refractory CLL/small lymphocytic lymphoma harboring ATM deletions/mutations; all but 1 patient had a decrease in lymphadenopathy, resulting in 1 IWCLL partial response (PR) and 3 PRs with lymphocytosis. In conclusion, these preclinical results, along with early promising clinical activity, suggest that CC-115 may be developed further for treatment of CLL. The trial was registered at www.clinicaltrials.gov as #NCT01353625.
Asunto(s)
Proteína Quinasa Activada por ADN/antagonistas & inhibidores , Resistencia a Antineoplásicos/efectos de los fármacos , Leucemia Linfocítica Crónica de Células B/tratamiento farmacológico , Proteínas de Neoplasias/antagonistas & inhibidores , Proteínas Nucleares/antagonistas & inhibidores , Pirazinas/farmacología , Serina-Treonina Quinasas TOR/antagonistas & inhibidores , Triazoles/farmacología , Compuestos Bicíclicos Heterocíclicos con Puentes/farmacología , Proteína Quinasa Activada por ADN/metabolismo , Femenino , Humanos , Leucemia Linfocítica Crónica de Células B/enzimología , Leucemia Linfocítica Crónica de Células B/patología , Masculino , Proteínas de Neoplasias/metabolismo , Proteínas Nucleares/metabolismo , Purinas/farmacología , Quinazolinonas/farmacología , Sulfonamidas/farmacología , Serina-Treonina Quinasas TOR/metabolismo , Células Tumorales Cultivadas , Vidarabina/análogos & derivados , Vidarabina/farmacologíaRESUMEN
Plasmodium falciparum-induced severe malaria remains a continuing problem in areas of endemicity, with elevated morbidity and mortality. Drugs targeting mechanisms involved in severe malaria pathology, including cytoadhesion of infected red blood cells (RBCs) to host receptors and production of proinflammatory cytokines, are still necessary. Human C1-inhibitor (C1INH) is a multifunctional protease inhibitor that regulates coagulation, vascular permeability, and inflammation, with beneficial effects in inflammatory disease models, including septic shock. We found that human C1INH, at therapeutically relevant doses, blocks severe malaria pathogenic processes by 2 distinct mechanisms. First, C1INH bound to glycan moieties within P. falciparum glycosylphosphatidylinositol (PfGPI) molecules on the parasite surface, inhibiting parasite RBC invasion and proinflammatory cytokine production by parasite-stimulated monocytes in vitro and reducing parasitemia in a rodent model of experimental cerebral malaria (ECM) in vivo. Second, C1INH bound to host CD36 and chondroitin sulfate A molecules, interfering with cytoadhesion of infected RBCs by competitive binding to these receptors in vitro and reducing sequestration in specific tissues and protecting against ECM in vivo. This study reveals that C1INH is a potential therapeutic antimalarial molecule able to interfere with severe-disease etiology at multiple levels through specific interactions with both parasite PfGPIs and host cell receptors.
Asunto(s)
Adhesión Celular/efectos de los fármacos , Proteínas Inactivadoras del Complemento 1/metabolismo , Proteínas Inactivadoras del Complemento 1/farmacología , Glicosilfosfatidilinositoles/metabolismo , Interacciones Huésped-Parásitos/efectos de los fármacos , Malaria Cerebral/metabolismo , Malaria Cerebral/parasitología , Proteínas Protozoarias/metabolismo , Animales , Línea Celular Tumoral , Proteína Inhibidora del Complemento C1 , Modelos Animales de Enfermedad , Eritrocitos/parasitología , Femenino , Humanos , Malaria Cerebral/sangre , Ratones , Ratones Endogámicos C57BL , Plasmodium berghei/metabolismo , Plasmodium berghei/patogenicidad , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/farmacologíaAsunto(s)
Antígenos CD20/metabolismo , Antineoplásicos , Leucemia Linfocítica Crónica de Células B , Antineoplásicos/uso terapéutico , Humanos , Interleucina-4 , Leucemia Linfocítica Crónica de Células B/tratamiento farmacológico , Purinas/farmacología , Purinas/uso terapéutico , Quinazolinonas/farmacología , Quinazolinonas/uso terapéutico , Factor de Transcripción STAT6Asunto(s)
Antineoplásicos/uso terapéutico , Leucemia Linfocítica Crónica de Células B/tratamiento farmacológico , Proteínas de Neoplasias/antagonistas & inhibidores , Pirimetamina/uso terapéutico , Factor de Transcripción STAT3/antagonistas & inhibidores , Adulto , Anciano , Anciano de 80 o más Años , Antineoplásicos/administración & dosificación , Linfocitos B/efectos de los fármacos , Linfocitos B/metabolismo , Línea Celular Tumoral , Relación Dosis-Respuesta a Droga , Reposicionamiento de Medicamentos , Ensayos de Selección de Medicamentos Antitumorales , Femenino , Perfilación de la Expresión Génica , Regulación Leucémica de la Expresión Génica/efectos de los fármacos , Humanos , Masculino , Persona de Mediana Edad , Proteínas de Neoplasias/biosíntesis , Proteínas de Neoplasias/genética , Supervivencia sin Progresión , Pirimetamina/administración & dosificación , Pirimetamina/farmacologíaRESUMEN
BACKGROUND: The somatic genetic basis of chronic lymphocytic leukemia, a common and clinically heterogeneous leukemia occurring in adults, remains poorly understood. METHODS: We obtained DNA samples from leukemia cells in 91 patients with chronic lymphocytic leukemia and performed massively parallel sequencing of 88 whole exomes and whole genomes, together with sequencing of matched germline DNA, to characterize the spectrum of somatic mutations in this disease. RESULTS: Nine genes that are mutated at significant frequencies were identified, including four with established roles in chronic lymphocytic leukemia (TP53 in 15% of patients, ATM in 9%, MYD88 in 10%, and NOTCH1 in 4%) and five with unestablished roles (SF3B1, ZMYM3, MAPK1, FBXW7, and DDX3X). SF3B1, which functions at the catalytic core of the spliceosome, was the second most frequently mutated gene (with mutations occurring in 15% of patients). SF3B1 mutations occurred primarily in tumors with deletions in chromosome 11q, which are associated with a poor prognosis in patients with chronic lymphocytic leukemia. We further discovered that tumor samples with mutations in SF3B1 had alterations in pre-messenger RNA (mRNA) splicing. CONCLUSIONS: Our study defines the landscape of somatic mutations in chronic lymphocytic leukemia and highlights pre-mRNA splicing as a critical cellular process contributing to chronic lymphocytic leukemia.
Asunto(s)
ADN de Neoplasias/análisis , Leucemia Linfocítica Crónica de Células B/genética , Mutación , Empalmosomas/genética , Adulto , Deleción Cromosómica , Cromosomas Humanos Par 11/genética , Exoma/genética , Biblioteca de Genes , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Mutación Missense , Empalme del ARNRESUMEN
miR-155 acts as an oncogenic miR in B-cell lymphoproliferative disorders, including Waldenstrom macroglobulinemia (WM) and chronic lymphocytic leukemia, and is therefore a potential target for therapeutic intervention. However, efficient targeting of miRs in tumor cells in vivo remains a significant challenge for the development of miR-155-based therapeutics for the treatment of B-cell malignancies. In the present study, we show that an 8-mer locked nucleic acid anti-miR-155 oligonucleotide targeting the seed region of miR-155 inhibits WM and chronic lymphocytic leukemia cell proliferation in vitro. Moreover, anti-miR-155 delivered systemically showed uptake in the BM CD19(+) cells of WM-engrafted mice, resulting in the up-regulation of several miR-155 target mRNAs in these cells, and decreased tumor growth significantly in vivo. We also found miR-155 levels to be elevated in stromal cells from WM patients compared with control samples. Interestingly, stromal cells from miR-155-knockout mice led to significant inhibition of WM tumor growth, indicating that miR-155 may also contribute to WM proliferation through BM microenvironmental cells. The results of the present study highlight the therapeutic potential of anti-miR-155-mediated inhibition of miR-155 in the treatment of WM.
Asunto(s)
Linfoma de Células B/genética , MicroARNs/genética , Oligonucleótidos Antisentido/uso terapéutico , Oligonucleótidos/uso terapéutico , Macroglobulinemia de Waldenström/genética , Animales , Proliferación Celular , Femenino , Silenciador del Gen , Terapia Genética , Humanos , Linfoma de Células B/terapia , Ratones , Ratones Endogámicos BALB C , Oligonucleótidos/genética , Oligonucleótidos Antisentido/genética , Células Tumorales Cultivadas , Macroglobulinemia de Waldenström/patología , Macroglobulinemia de Waldenström/terapiaRESUMEN
This study assessed the safety and preliminary efficacy of escalated dose subcutaneous alemtuzumab in combination with rituximab in chronic lymphocytic leukemia. Twenty-eight patients with relapsed refractory chronic lymphocytic leukemia were treated on four dosing cohorts of weekly rituximab at 375 mg/m(2) and alemtuzumab doses that started at 30 mg three times per week and escalated to weekly dosing over four weeks, culminating with 90 mg weekly. One dose limiting toxicity of a rituximab infusion reaction was seen in cohort 2, but the regimen was otherwise well tolerated without evidence of differential toxicity by cohort. The overall response rate by National Cancer Institute-Working Group criteria was 61%, and the rate of complete bone marrow response was 43%, most of whom were negative for minimal residual disease. The addition of CT scan evaluation per International Workshop on Chronic Lymphocytic Leukemia 2008 criteria reduced the overall response rate to 14%. Median overall survival was 35 months, with 12 patients able to proceed to stem cell transplantation. Pharmacokinetic studies showed that chronic lymphocytic leukemia involving more than 80% of the bone marrow at study start was associated with lower trough concentrations of alemtuzumab and rituximab, and that higher trough serum concentrations of alemtuzumab were associated with complete bone marrow clearance. We conclude that escalated subcutaneous doses of alemtuzumab given weekly are well tolerated and result in excellent bone marrow clearance of chronic lymphocytic leukemia, helping patients to proceed to stem cell transplantation. This study is registered at ClinicalTrials.gov (Identifier:00330252).
Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Leucemia Linfocítica Crónica de Células B/tratamiento farmacológico , Anciano , Alemtuzumab , Anticuerpos Monoclonales Humanizados/administración & dosificación , Anticuerpos Monoclonales Humanizados/farmacocinética , Anticuerpos Monoclonales de Origen Murino/administración & dosificación , Anticuerpos Monoclonales de Origen Murino/farmacocinética , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Esquema de Medicación , Femenino , Humanos , Inmunofenotipificación , Leucemia Linfocítica Crónica de Células B/mortalidad , Leucemia Linfocítica Crónica de Células B/patología , Recuento de Linfocitos , Subgrupos Linfocitarios/metabolismo , Subgrupos Linfocitarios/patología , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Recurrencia , Rituximab , Resultado del TratamientoRESUMEN
PURPOSE: Germline missense variants of unknown significance in cancer-related genes are increasingly being identified with the expanding use of next-generation sequencing. The ataxia telangiectasia-mutated (ATM) gene on chromosome 11 has more than 1,000 germline missense variants of unknown significance and is a tumor suppressor. We aimed to determine if rare germline ATM variants are more frequent in chronic lymphocytic leukemia (CLL) compared with other hematologic malignancies and if they influence the clinical characteristics of CLL. METHODS: We identified 3,128 patients (including 825 patients with CLL) in our hematologic malignancy clinic who had received clinical-grade sequencing of the entire coding region of ATM. We ascertained the comparative frequencies of germline ATM variants in categories of hematologic neoplasms, and, in patients with CLL, we determined whether these variants affected CLL-associated characteristics such as somatic 11q deletion. RESULTS: Rare germline ATM variants are present in 24% of patients with CLL, significantly greater than that in patients with other lymphoid malignancies (16% prevalence), myeloid disease (15%), or no hematologic neoplasm (14%). Patients with CLL with germline ATM variants are younger at diagnosis and twice as likely to have 11q deletion. The ATM variant p.L2307F is present in 3% of patients with CLL, is associated with a three-fold increase in rates of somatic 11q deletion, and is a hypomorph in cell-based assays. CONCLUSION: Germline ATM variants cluster within CLL and affect the phenotype of CLL that develops, implying that some of these variants (such as ATM p.L2307F) have functional significance and should not be ignored. Further studies are needed to determine whether these variants affect the response to therapy or account for some of the inherited risk of CLL.
Asunto(s)
Proteínas de la Ataxia Telangiectasia Mutada , Leucemia Linfocítica Crónica de Células B , Humanos , Ataxia Telangiectasia , Proteínas de la Ataxia Telangiectasia Mutada/genética , Proteínas de Ciclo Celular/genética , Leucemia Linfocítica Crónica de Células B/tratamiento farmacológico , Mutación , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/uso terapéutico , Proteínas Supresoras de Tumor/genéticaRESUMEN
PI3Kδ inhibitors are approved for the therapy of B cell malignancies, but their clinical use has been limited by unpredictable autoimmune toxicity, despite promising efficacy and evidence that toxicity is associated with improved clinical outcomes. Prior phenotypic evaluation by CyTOF has identified increases in activated CD8 T cells with activation of Th17 T cells, as well as decreases in Tregs, particularly in patients with toxicity. Here we sought to further understand the effects of idelalisib and duvelisib in vitro, and demonstrate that both idelalisib and duvelisib can inhibit T cell proliferation as well as Th1 and Treg differentiation in vitro, while promoting Th2 and Th17 differentiation. We further demonstrate directly using intracellular flow cytometry that autoimmune toxicity in patients is associated with higher absolute numbers of CD4 and CD8 T cells with Th17 differentiation in peripheral blood prior to therapy, and that gastrointestinal tissues from patients with active autoimmune complications of PI3Kδ inhibitors show infiltration with Th17+ T cells. These same tissues show depletion of Tregs as compared to CLL patients without toxicity, suggesting that loss of Tregs may be permissive for Th17 activation to lead to autoimmune toxicity. Clinical trials to restore this balance are warranted.
Asunto(s)
Linfocitos T Reguladores , Células Th17 , Humanos , Linfocitos T CD8-positivos , Diferenciación Celular , Citometría de FlujoRESUMEN
This study investigated ibrutinib plus obinutuzumab in relapsed/refractory CLL, evaluating tolerability of 3 sequencing regimens as well as overall safety and efficacy. Fifty-two patients were initially randomized 1:1:1 to receive either obinutuzumab 1 month before ibrutinib initiation, ibrutinib 1 month prior to obinutuzumab initiation, or to start both drugs concomitantly. Higher rates of infusion-related reactions were observed with the first sequence, and only the latter 2 cohorts were expanded. Grade 4 hematologic toxicity was uncommon, and notable all-grade non-hematologic toxicities included bruising (58%), hypertension (46%), arthralgia (38%), diarrhea (37%), transaminitis (35%), atrial fibrillation (21%), and serious infection (17%). Best overall response rate was 96% (including 40% CR and 56% PR). Best rates of undetectable minimal residual disease in peripheral blood and bone marrow were 27% and 19%, respectively. With a median follow-up of 41.5 months, four-year progression-free and overall survival rates are 74% and 93%, respectively. Correlative studies demonstrated that serum CCL4 and CXCL13 levels were associated with clinical response, and BH3 profiling revealed increased BCL-2 and BCL-xL dependence in CLL cells from patients on treatment. Overall, ibrutinib plus obinutuzumab was highly active, with a manageable safety profile, supporting further investigation of this type of approach in relapsed/refractory CLL.