RESUMEN
The BCL2 inhibitor venetoclax has been approved to treat different hematological malignancies. Because there is no common genetic alteration causing resistance to venetoclax in chronic lymphocytic leukemia (CLL) and B-cell lymphoma, we asked if epigenetic events might be involved in venetoclax resistance. Therefore, we employed whole-exome sequencing, methylated DNA immunoprecipitation sequencing, and genome-wide clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 screening to investigate venetoclax resistance in aggressive lymphoma and high-risk CLL patients. We identified a regulatory CpG island within the PUMA promoter that is methylated upon venetoclax treatment, mediating PUMA downregulation on transcript and protein level. PUMA expression and sensitivity toward venetoclax can be restored by inhibition of methyltransferases. We can demonstrate that loss of PUMA results in metabolic reprogramming with higher oxidative phosphorylation and adenosine triphosphate production, resembling the metabolic phenotype that is seen upon venetoclax resistance. Although PUMA loss is specific for acquired venetoclax resistance but not for acquired MCL1 resistance and is not seen in CLL patients after chemotherapy-resistance, BAX is essential for sensitivity toward both venetoclax and MCL1 inhibition. As we found loss of BAX in Richter's syndrome patients after venetoclax failure, we defined BAX-mediated apoptosis to be critical for drug resistance but not for disease progression of CLL into aggressive diffuse large B-cell lymphoma in vivo. A compound screen revealed TRAIL-mediated apoptosis as a target to overcome BAX deficiency. Furthermore, antibody or CAR T cells eliminated venetoclax resistant lymphoma cells, paving a clinically applicable way to overcome venetoclax resistance.
Asunto(s)
Neoplasias Hematológicas , Leucemia Linfocítica Crónica de Células B , Linfoma de Células B Grandes Difuso , Humanos , 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-2/genética , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Proteína X Asociada a bcl-2/metabolismo , Resistencia a Antineoplásicos/genética , Proteínas Reguladoras de la Apoptosis/genética , Compuestos Bicíclicos Heterocíclicos con Puentes/farmacología , Compuestos Bicíclicos Heterocíclicos con Puentes/uso terapéutico , Linfoma de Células B Grandes Difuso/patología , Neoplasias Hematológicas/tratamiento farmacológico , Neoplasias Hematológicas/genética , Epigénesis GenéticaRESUMEN
Treatment-naïve small cell lung cancer (SCLC) is typically susceptible to standard-of-care chemotherapy consisting of cisplatin and etoposide recently combined with PD-L1 inhibitors. Yet, in most cases, SCLC patients develop resistance to first-line therapy and alternative therapies are urgently required to overcome this resistance. In this study, we tested the efficacy of dinaciclib, an FDA-orphan drug and inhibitor of the cyclin-dependent kinase (CDK) 9, among other CDKs, in SCLC. Furthermore, we report on a newly developed, highly specific CDK9 inhibitor, VC-1, with tumour-killing activity in SCLC. CDK9 inhibition displayed high killing potential in a panel of mouse and human SCLC cell lines. Mechanistically, CDK9 inhibition led to a reduction in MCL-1 and cFLIP anti-apoptotic proteins and killed cells, almost exclusively, by intrinsic apoptosis. While CDK9 inhibition did not synergise with chemotherapy, it displayed high efficacy in chemotherapy-resistant cells. In vivo, CDK9 inhibition effectively reduced tumour growth and improved survival in both autochthonous and syngeneic SCLC models. Together, this study shows that CDK9 inhibition is a promising therapeutic agent against SCLC and could be applied to chemo-refractory or resistant SCLC.
Asunto(s)
Quinasa 9 Dependiente de la Ciclina , Indolizinas , Neoplasias Pulmonares , Compuestos de Piridinio , Carcinoma Pulmonar de Células Pequeñas , Quinasa 9 Dependiente de la Ciclina/antagonistas & inhibidores , Quinasa 9 Dependiente de la Ciclina/metabolismo , Carcinoma Pulmonar de Células Pequeñas/tratamiento farmacológico , Carcinoma Pulmonar de Células Pequeñas/patología , Humanos , Animales , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/patología , Línea Celular Tumoral , Ratones , Compuestos de Piridinio/farmacología , Compuestos de Piridinio/uso terapéutico , Indolizinas/farmacología , Óxidos N-Cíclicos/farmacología , Apoptosis/efectos de los fármacos , Compuestos Bicíclicos Heterocíclicos con Puentes/farmacología , Compuestos Bicíclicos Heterocíclicos con Puentes/uso terapéutico , Inhibidores de Proteínas Quinasas/farmacología , Inhibidores de Proteínas Quinasas/uso terapéuticoRESUMEN
T-cell prolymphocytic leukemia (T-PLL) is a rare and poor-prognostic mature T-cell malignancy. Here we integrated large-scale profiling data of alterations in gene expression, allelic copy number (CN), and nucleotide sequences in 111 well-characterized patients. Besides prominent signatures of T-cell activation and prevalent clonal variants, we also identify novel hot-spots for CN variability, fusion molecules, alternative transcripts, and progression-associated dynamics. The overall lesional spectrum of T-PLL is mainly annotated to axes of DNA damage responses, T-cell receptor/cytokine signaling, and histone modulation. We formulate a multi-dimensional model of T-PLL pathogenesis centered around a unique combination of TCL1 overexpression with damaging ATM aberrations as initiating core lesions. The effects imposed by TCL1 cooperate with compromised ATM toward a leukemogenic phenotype of impaired DNA damage processing. Dysfunctional ATM appears inefficient in alleviating elevated redox burdens and telomere attrition and in evoking a p53-dependent apoptotic response to genotoxic insults. As non-genotoxic strategies, synergistic combinations of p53 reactivators and deacetylase inhibitors reinstate such cell death execution.
Asunto(s)
Proteínas de la Ataxia Telangiectasia Mutada/genética , Daño del ADN , Epigénesis Genética , Leucemia Prolinfocítica de Células T/genética , Proteínas Proto-Oncogénicas/genética , Adulto , Anciano , Animales , Proteínas de la Ataxia Telangiectasia Mutada/metabolismo , Línea Celular Tumoral , Femenino , Perfilación de la Expresión Génica/métodos , Células HEK293 , Humanos , Estimación de Kaplan-Meier , Leucemia Prolinfocítica de Células T/tratamiento farmacológico , Leucemia Prolinfocítica de Células T/metabolismo , Masculino , Ratones Transgénicos , Persona de Mediana Edad , Mutación , Proteínas Proto-Oncogénicas/metabolismoRESUMEN
Treatment resistance becomes a challenge at some point in the course of most patients with chronic lymphocytic leukemia (CLL). This applies to fludarabine-based regimens, and is also an increasing concern in the era of more targeted therapies. As cells with low-replicative activity rely on repair that triggers checkpoint-independent noncanonical pathways, we reasoned that targeting the nucleotide excision repair (NER) reaction addresses a vulnerability of CLL and might even synergize with fludarabine, which blocks the NER gap-filling step. We interrogated here especially the replication-independent transcription-coupled-NER ((TC)-NER) in prospective trial patients, primary CLL cultures, cell lines and mice. We screen selected (TC)-NER-targeting compounds as experimental (illudins) or clinically approved (trabectedin) drugs. They inflict transcription-stalling DNA lesions requiring TC-NER either for their removal (illudins) or for generation of lethal strand breaks (trabectedin). Genetically defined systems of NER deficiency confirmed their specificity. They selectively and efficiently induced cell death in CLL, irrespective of high-risk cytogenetics, IGHV status or clinical treatment history, including resistance. The substances induced ATM/p53-independent apoptosis and showed marked synergisms with fludarabine. Trabectedin additionally perturbed stromal-cell protection and showed encouraging antileukemic profiles even in aggressive and transforming murine CLL. This proof-of-principle study established (TC)-NER as a mechanism to be further exploited to resensitize CLL cells.
Asunto(s)
Reparación del ADN/genética , Resistencia a Antineoplásicos/genética , Leucemia Linfocítica Crónica de Células B/genética , Transcripción Genética , Animales , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Ensayos Clínicos como Asunto , Dioxoles/uso terapéutico , Sinergismo Farmacológico , Humanos , Leucemia Linfocítica Crónica de Células B/tratamiento farmacológico , Ratones , Tetrahidroisoquinolinas/uso terapéutico , Trabectedina , Células Tumorales Cultivadas , Vidarabina/análogos & derivados , Vidarabina/uso terapéuticoAsunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Enfermedad de Hodgkin/tratamiento farmacológico , Enfermedad de Hodgkin/patología , Adolescente , Adulto , Bleomicina/uso terapéutico , Quimiocina CCL17/genética , Quimiocina CCL17/metabolismo , Ciclofosfamida/uso terapéutico , Doxorrubicina/uso terapéutico , Etopósido/uso terapéutico , Femenino , Perfilación de la Expresión Génica/métodos , Enfermedad de Hodgkin/genética , Humanos , Antígeno Ki-1/genética , Antígeno Ki-1/metabolismo , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Valor Predictivo de las Pruebas , Prednisona/uso terapéutico , Procarbazina/uso terapéutico , Receptor alfa de Factor de Crecimiento Derivado de Plaquetas/genética , Receptor alfa de Factor de Crecimiento Derivado de Plaquetas/metabolismo , Tasa de Supervivencia , Transcriptoma , Resultado del Tratamiento , Vincristina/uso terapéutico , Adulto JovenRESUMEN
The tumor suppressor p53 is mainly involved in the transcriptional regulation of a large number of growth-arrest- and apoptosis-related genes. However, a clear understanding of which factor/s influences the choice between these two opposing p53-dependent outcomes remains largely elusive. We have previously described that in response to DNA damage, the RNA polymerase II-binding protein Che-1/AATF transcriptionally activates p53. Here, we show that Che-1 binds directly to p53. This interaction essentially occurs in the first hours of DNA damage, whereas it is lost when cells undergo apoptosis in response to posttranscriptional modifications. Moreover, Che-1 sits in a ternary complex with p53 and the oncosuppressor Brca1. Accordingly, our analysis of genome-wide chromatin occupancy by p53 revealed that p53/Che1 interaction results in preferential transactivation of growth arrest p53 target genes over its pro-apoptotic target genes. Notably, exposure of Che-1(+/-) mice to ionizing radiations resulted in enhanced apoptosis of thymocytes, compared with WT mice. These results confirm Che-1 as an important regulator of p53 activity and suggest Che-1 to be a promising yet attractive drug target for cancer therapy.
Asunto(s)
Proteínas Reguladoras de la Apoptosis/metabolismo , Apoptosis/genética , Proteína BRCA1/metabolismo , Puntos de Control del Ciclo Celular/genética , Proteínas Represoras/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Animales , Proteínas Reguladoras de la Apoptosis/genética , Línea Celular Tumoral , Daño del ADN/genética , Reparación del ADN/genética , Activación Enzimática/genética , Regulación de la Expresión Génica , Células HCT116 , Humanos , Células MCF-7 , Ratones , Ratones Transgénicos , Unión Proteica/genética , Interferencia de ARN , ARN Interferente Pequeño , Proteínas Represoras/genética , Timocitos/patología , Timocitos/efectos de la radiación , Activación Transcripcional/genética , Proteína p53 Supresora de Tumor/genéticaRESUMEN
The tumor suppressor p53 acts as a transcription factor downstream of many different stress-induced signaling pathways. Two major groups of p53-controlled genes can be distinguished. Those that mediate the initiation and maintenance of cell cycle checkpoints, and those driving apoptosis. An important determinant of the cellular reaction to DNA damage is the degree of genotoxic stress. The type of cellular response, which ranges from cell cycle arrest to apoptosis depends to a large extend on the severity of the genotoxic lesion. It remains largely unclear which molecular mechanisms govern the cellular decision between p53-driven cell cycle arrest and apoptosis. From a therapeutic perspective, this cellular decision is of utmost importance, as p53-driven apoptosis is therapeutically desired, when treating a malignant disease with DNA-damaging chemotherapy. However, a p53-driven cell cycle arrest might promote chemotherapy resistance, as it allows the tumor cells time to repair genotoxic lesions prior to the next cell division. Here, we summarize recent advances in our understanding of the molecular mechanisms controlling the functional outcome of p53 signaling. We further provide an outlook on the potential development of pharmacological interventions targeting the p53-regulating machinery to promote p53-driven apoptosis, while repressing p53-dependent cell cycle checkpoints.
Asunto(s)
Antineoplásicos/uso terapéutico , Sistemas de Liberación de Medicamentos/métodos , Modelos Biológicos , Neoplasias/tratamiento farmacológico , Neoplasias/metabolismo , Transducción de Señal/efectos de los fármacos , Proteína p53 Supresora de Tumor/metabolismo , Animales , HumanosRESUMEN
Following DNA damage, cells activate a complex DNA-damage-response (DDR) signaling network to arrest the cell cycle, repair DNA and, if the extend of damage is beyond repair capacity, induce apoptosis. DDR genes are among the most commonly mutated genes in human cancer and it is believed that these lesions promote a "MUTATOR-PHENOTYPE" that fuels the runaway proliferation of cancer cells. However, these genetic lesions can also be seen as the "Achilles heel" of cancer. These tumor cell-specific vulnerabilities are of extraordinary clinical interest, since they allow genetically-guided novel therapeutic regimens for the treatment of cancer. Here, we discuss such a novel therapeutic concept - synthetic lethality. We focus on the first successful clinical applications of synthetic lethality for the treatment of different cancer entities. In addition, we give a brief review of recently developed, synthetic lethality-based approaches that are close to clinical testing.