RESUMEN
Small cell lung cancer (SCLC) presents as a highly chemosensitive malignancy but acquires cross-resistance after relapse. This transformation is nearly inevitable in patients but has been difficult to capture in laboratory models. Here, we present a preclinical system that recapitulates acquired cross-resistance, developed from 51 patient-derived xenograft (PDX) models. Each model was tested in vivo against three clinical regimens: cisplatin plus etoposide, olaparib plus temozolomide, and topotecan. These drug-response profiles captured hallmark clinical features of SCLC, such as the emergence of treatment-refractory disease after early relapse. For one patient, serial PDX models revealed that cross-resistance was acquired through MYC amplification on extrachromosomal DNA (ecDNA). Genomic and transcriptional profiles of the full PDX panel revealed that MYC paralog amplifications on ecDNAs were recurrent in relapsed cross-resistant SCLC, and this was corroborated in tumor biopsies from relapsed patients. We conclude that ecDNAs with MYC paralogs are recurrent drivers of cross-resistance in SCLC. SIGNIFICANCE: SCLC is initially chemosensitive, but acquired cross-resistance renders this disease refractory to further treatment and ultimately fatal. The genomic drivers of this transformation are unknown. We use a population of PDX models to discover that amplifications of MYC paralogs on ecDNA are recurrent drivers of acquired cross-resistance in SCLC. This article is featured in Selected Articles from This Issue, p. 695.
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Resistencia a Antineoplásicos , Amplificación de Genes , Neoplasias Pulmonares , Carcinoma Pulmonar de Células Pequeñas , Humanos , Carcinoma Pulmonar de Células Pequeñas/genética , Carcinoma Pulmonar de Células Pequeñas/tratamiento farmacológico , Carcinoma Pulmonar de Células Pequeñas/patología , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/patología , Resistencia a Antineoplásicos/genética , Ratones , Animales , Proteínas Proto-Oncogénicas c-myc/genética , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Small cell lung cancer (SCLC) presents as a highly chemosensitive malignancy but acquires cross-resistance after relapse. This transformation is nearly inevitable in patients but has been difficult to capture in laboratory models. Here we present a pre-clinical system that recapitulates acquired cross-resistance in SCLC, developed from 51 patient-derived xenografts (PDXs). Each model was tested for in vivo sensitivity to three clinical regimens: cisplatin plus etoposide, olaparib plus temozolomide, and topotecan. These functional profiles captured hallmark clinical features, such as the emergence of treatment-refractory disease after early relapse. Serially derived PDX models from the same patient revealed that cross-resistance was acquired through a MYC amplification on extrachromosomal DNA (ecDNA). Genomic and transcriptional profiles of the full PDX panel revealed that this was not unique to one patient, as MYC paralog amplifications on ecDNAs were recurrent among cross-resistant models derived from patients after relapse. We conclude that ecDNAs with MYC paralogs are recurrent drivers of cross-resistance in SCLC. SIGNIFICANCE: SCLC is initially chemosensitive, but acquired cross-resistance renders this disease refractory to further treatment and ultimately fatal. The genomic drivers of this transformation are unknown. We use a population of PDX models to discover that amplifications of MYC paralogs on ecDNA are recurrent drivers of acquired cross-resistance in SCLC.
RESUMEN
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
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The outcomes of patients with SCLC have not yet been substantially impacted by the revolution in precision oncology, primarily owing to a paucity of genetic alterations in actionable driver oncogenes. Nevertheless, systemic therapies that include immunotherapy are beginning to show promise in the clinic. Although, these results are encouraging, many patients do not respond to, or rapidly recur after, current regimens, necessitating alternative or complementary therapeutic strategies. In this review, we discuss ongoing investigations into the pathobiology of this recalcitrant cancer and the therapeutic vulnerabilities that are exposed by the disease state. Included within this discussion, is a snapshot of the current biomarker and clinical trial landscapes for SCLC. Finally, we identify key knowledge gaps that should be addressed to advance the field in pursuit of reduced SCLC mortality. This review largely summarizes work presented at the Third Biennial International Association for the Study of Lung Cancer SCLC Meeting.
Asunto(s)
Neoplasias Pulmonares , Carcinoma Pulmonar de Células Pequeñas , Humanos , Laboratorios , Neoplasias Pulmonares/terapia , Recurrencia Local de Neoplasia , Medicina de Precisión , Carcinoma Pulmonar de Células Pequeñas/terapiaRESUMEN
Cyclin-dependent kinase 7 (CDK7) is a central regulator of the cell cycle and gene transcription. However, little is known about its impact on genomic instability and cancer immunity. Using a selective CDK7 inhibitor, YKL-5-124, we demonstrated that CDK7 inhibition predominately disrupts cell-cycle progression and induces DNA replication stress and genome instability in small cell lung cancer (SCLC) while simultaneously triggering immune-response signaling. These tumor-intrinsic events provoke a robust immune surveillance program elicited by T cells, which is further enhanced by the addition of immune-checkpoint blockade. Combining YKL-5-124 with anti-PD-1 offers significant survival benefit in multiple highly aggressive murine models of SCLC, providing a rationale for new combination regimens consisting of CDK7 inhibitors and immunotherapies.
Asunto(s)
Quinasas Ciclina-Dependientes/antagonistas & inhibidores , Quinasas Ciclina-Dependientes/genética , Inestabilidad Genómica , Neoplasias Pulmonares/genética , Carcinoma Pulmonar de Células Pequeñas/genética , Animales , Antineoplásicos/farmacología , Linfocitos T CD4-Positivos/citología , Linfocitos T CD8-positivos/citología , Quimiocina CXCL9/metabolismo , Daño del ADN , Femenino , Humanos , Sistema Inmunológico , Inflamación , Interferón gamma/metabolismo , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/inmunología , Masculino , Ratones , Pruebas de Micronúcleos , Receptor de Muerte Celular Programada 1/antagonistas & inhibidores , Pirazoles/farmacología , Pirroles/farmacología , Transducción de Señal , Carcinoma Pulmonar de Células Pequeñas/tratamiento farmacológico , Carcinoma Pulmonar de Células Pequeñas/inmunología , Factor de Necrosis Tumoral alfa/metabolismo , Quinasa Activadora de Quinasas Ciclina-DependientesRESUMEN
More than 90% of small cell lung cancers (SCLCs) harbor loss-of-function mutations in the tumor suppressor gene RB1 The canonical function of the RB1 gene product, pRB, is to repress the E2F transcription factor family, but pRB also functions to regulate cellular differentiation in part through its binding to the histone demethylase KDM5A (also known as RBP2 or JARID1A). We show that KDM5A promotes SCLC proliferation and SCLC's neuroendocrine differentiation phenotype in part by sustaining expression of the neuroendocrine transcription factor ASCL1. Mechanistically, we found that KDM5A sustains ASCL1 levels and neuroendocrine differentiation by repressing NOTCH2 and NOTCH target genes. To test the role of KDM5A in SCLC tumorigenesis in vivo, we developed a CRISPR/Cas9-based mouse model of SCLC by delivering an adenovirus (or an adeno-associated virus [AAV]) that expresses Cre recombinase and sgRNAs targeting Rb1, Tp53, and Rbl2 into the lungs of Lox-Stop-Lox Cas9 mice. Coinclusion of a KDM5A sgRNA decreased SCLC tumorigenesis and metastasis, and the SCLCs that formed despite the absence of KDM5A had higher NOTCH activity compared to KDM5A+/+ SCLCs. This work establishes a role for KDM5A in SCLC tumorigenesis and suggests that KDM5 inhibitors should be explored as treatments for SCLC.
Asunto(s)
Diferenciación Celular/genética , Células Neuroendocrinas/citología , Receptores Notch/fisiología , Proteína 2 de Unión a Retinoblastoma/metabolismo , Transducción de Señal/genética , Carcinoma Pulmonar de Células Pequeñas/enzimología , Animales , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico , Línea Celular , Transformación Celular Neoplásica/genética , Modelos Animales de Enfermedad , Regulación Neoplásica de la Expresión Génica/genética , Histona Demetilasas/metabolismo , Humanos , Técnicas In Vitro , Ratones , Células Neuroendocrinas/patología , Carcinoma Pulmonar de Células Pequeñas/fisiopatologíaRESUMEN
Although EGFR mutant-selective tyrosine kinase inhibitors (TKI) are clinically effective, acquired resistance can occur by reactivating ERK. We show using in vitro models of acquired EGFR TKI resistance with a mesenchymal phenotype that CXCR7, an atypical G protein-coupled receptor, activates the MAPK-ERK pathway via ß-arrestin. Depletion of CXCR7 inhibited the MAPK pathway, significantly attenuated EGFR TKI resistance, and resulted in mesenchymal-to-epithelial transition. CXCR7 overexpression was essential in reactivation of ERK1/2 for the generation of EGFR TKI-resistant persister cells. Many patients with non-small cell lung cancer (NSCLC) harboring an EGFR kinase domain mutation, who progressed on EGFR inhibitors, demonstrated increased CXCR7 expression. These data suggest that CXCR7 inhibition could considerably delay and prevent the emergence of acquired EGFR TKI resistance in EGFR-mutant NSCLC. SIGNIFICANCE: Increased expression of the chemokine receptor CXCR7 constitutes a mechanism of resistance to EGFR TKI in patients with non-small cell lung cancer through reactivation of ERK signaling.
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Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Resistencia a Antineoplásicos , Neoplasias Pulmonares/tratamiento farmacológico , Inhibidores de Proteínas Quinasas/farmacología , Receptores CXCR/metabolismo , Animales , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/mortalidad , Línea Celular Tumoral , Resistencia a Antineoplásicos/genética , Transición Epitelial-Mesenquimal/genética , Receptores ErbB/antagonistas & inhibidores , Humanos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/mortalidad , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Sistema de Señalización de MAP Quinasas/genética , Ratones Transgénicos , Mutación , Neoplasias Experimentales/tratamiento farmacológico , Neoplasias Experimentales/genética , Receptores CXCR/genética , beta-Arrestinas/metabolismoRESUMEN
Small-cell lung cancer (SCLC) has the highest malignancy among all lung cancers, exhibiting aggressive growth and early metastasis to distant sites. For 30 years, treatment options for SCLC have been limited to chemotherapy, warranting the need for more effective treatments. Frequent inactivation of TP53 and RB1 as well as histone dysmodifications in SCLC suggest that transcriptional and epigenetic regulations play a major role in SCLC disease evolution. Here we performed a synthetic lethal screen using the BET inhibitor JQ1 and an shRNA library targeting 550 epigenetic genes in treatment-refractory SCLC xenograft models and identified HDAC6 as a synthetic lethal target in combination with JQ1. Combined treatment of human and mouse SCLC cell line-derived xenograft tumors with the HDAC6 inhibitor ricolinostat (ACY-1215) and JQ1 demonstrated significant inhibition of tumor growth; this effect was abolished upon depletion of NK cells, suggesting that these innate immune lymphoid cells play a role in SCLC tumor treatment response. Collectively, these findings suggest a potential new treatment for recurrent SCLC.Significance: These findings identify a novel therapeutic strategy for SCLC using a combination of HDAC6 and BET inhibitors. Cancer Res; 78(13); 3709-17. ©2018 AACR.
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Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Azepinas/farmacología , Histona Desacetilasa 6/antagonistas & inhibidores , Células Asesinas Naturales/inmunología , Neoplasias Pulmonares/tratamiento farmacológico , Recurrencia Local de Neoplasia/tratamiento farmacológico , Proteínas/antagonistas & inhibidores , Carcinoma Pulmonar de Células Pequeñas/tratamiento farmacológico , Triazoles/farmacología , Animales , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Azepinas/uso terapéutico , Línea Celular Tumoral , Proliferación Celular , Sinergismo Farmacológico , Histona Desacetilasa 6/genética , Humanos , Ácidos Hidroxámicos/farmacología , Ácidos Hidroxámicos/uso terapéutico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patología , Ratones , Recurrencia Local de Neoplasia/genética , Recurrencia Local de Neoplasia/patología , Pirimidinas/farmacología , Pirimidinas/uso terapéutico , ARN Interferente Pequeño/metabolismo , Carcinoma Pulmonar de Células Pequeñas/genética , Carcinoma Pulmonar de Células Pequeñas/patología , Mutaciones Letales Sintéticas/genética , Resultado del Tratamiento , Triazoles/uso terapéutico , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Small cell lung cancer (SCLC) patient-derived xenografts (PDX) can be generated from biopsies or circulating tumor cells (CTC), though scarcity of tissue and low efficiency of tumor growth have previously limited these approaches. Applying an established clinical-translational pipeline for tissue collection and an automated microfluidic platform for CTC enrichment, we generated 17 biopsy-derived PDXs and 17 CTC-derived PDXs in a 2-year timeframe, at 89% and 38% efficiency, respectively. Whole-exome sequencing showed that somatic alterations are stably maintained between patient tumors and PDXs. Early-passage PDXs maintain the genomic and transcriptional profiles of the founder PDX. In vivo treatment with etoposide and platinum (EP) in 30 PDX models demonstrated greater sensitivity in PDXs from EP-naïve patients, and resistance to EP corresponded to increased expression of a MYC gene signature. Finally, serial CTC-derived PDXs generated from an individual patient at multiple time points accurately recapitulated the evolving drug sensitivities of that patient's disease. Collectively, this work highlights the translational potential of this strategy.Significance: Effective translational research utilizing SCLC PDX models requires both efficient generation of models from patients and fidelity of those models in representing patient tumor characteristics. We present approaches for efficient generation of PDXs from both biopsies and CTCs, and demonstrate that these models capture the mutational landscape and functional features of the donor tumors. Cancer Discov; 8(5); 600-15. ©2018 AACR.This article is highlighted in the In This Issue feature, p. 517.
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Genómica , Neoplasias Pulmonares/genética , Carcinoma Pulmonar de Células Pequeñas/genética , Animales , Biopsia , Modelos Animales de Enfermedad , Genómica/métodos , Humanos , Neoplasias Pulmonares/patología , Masculino , Ratones , Ratones Endogámicos NOD , Ratones SCID , Persona de Mediana Edad , Carcinoma Pulmonar de Células Pequeñas/diagnóstico , Carcinoma Pulmonar de Células Pequeñas/terapia , Tomografía Computarizada por Rayos X , Secuenciación del Exoma , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Cutaneous melanoma is an aggressive tumor that accounts for most skin cancer deaths. Among the physiological barriers against therapeutic success is a strong survival program driven by genes such as MITF that specify melanocyte identity, a phenomenon known in melanoma biology as lineage dependency. MITF overexpression is occasionally explained by gene amplification, but here we show that super-enhancers are also important determinants of MITF overexpression in some melanoma cell lines and tumors. Although compounds that directly inhibit MITF are unavailable, a covalent CDK7 inhibitor, THZ1, has recently been shown to potently suppress the growth of various cancers through the depletion of master transcription-regulating oncogenes and the disruption of their attendant super-enhancers. We also show that melanoma cells are highly sensitive to CDK7 inhibition both in vitro and in vivo and that THZ1 can dismantle the super-enhancer apparatus at MITF and SOX10 in some cell lines, thereby extinguishing their intracellular levels. Our results show a dimension to MITF regulation in melanoma cells and point to CDK7 inhibition as a potential strategy to deprive oncogenic transcription and suppress tumor growth in melanoma.
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Quinasas Ciclina-Dependientes/antagonistas & inhibidores , Elementos de Facilitación Genéticos , Melanoma/genética , Factor de Transcripción Asociado a Microftalmía/genética , Neoplasias Cutáneas/genética , Animales , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Quinasas Ciclina-Dependientes/genética , Quinasas Ciclina-Dependientes/metabolismo , Epigénesis Genética/efectos de los fármacos , Amplificación de Genes , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Sitios Genéticos/genética , Humanos , Melanoma/tratamiento farmacológico , Melanoma/patología , Ratones , Ratones Desnudos , Factor de Transcripción Asociado a Microftalmía/metabolismo , Fenilendiaminas/farmacología , Fenilendiaminas/uso terapéutico , Pirimidinas/farmacología , Pirimidinas/uso terapéutico , ARN Interferente Pequeño/metabolismo , Factores de Transcripción SOXE/genética , Factores de Transcripción SOXE/metabolismo , Neoplasias Cutáneas/tratamiento farmacológico , Neoplasias Cutáneas/patología , Regulación hacia Arriba/efectos de los fármacos , Ensayos Antitumor por Modelo de Xenoinjerto , Quinasa Activadora de Quinasas Ciclina-DependientesRESUMEN
Acquired drug resistance is a major factor limiting the effectiveness of targeted cancer therapies. Targeting tumors with kinase inhibitors induces complex adaptive programs that promote the persistence of a fraction of the original cell population, facilitating the eventual outgrowth of inhibitor-resistant tumor clones. We show that the addition of a newly identified CDK7/12 inhibitor, THZ1, to targeted therapy enhances cell killing and impedes the emergence of drug-resistant cell populations in diverse cellular and in vivo cancer models. We propose that targeted therapy induces a state of transcriptional dependency in a subpopulation of cells poised to become drug tolerant, which THZ1 can exploit by blocking dynamic transcriptional responses, promoting remodeling of enhancers and key signaling outputs required for tumor cell survival in the setting of targeted therapy. These findings suggest that the addition of THZ1 to targeted therapies is a promising broad-based strategy to hinder the emergence of drug-resistant cancer cell populations.Significance: CDK7/12 inhibition prevents active enhancer formation at genes, promoting resistance emergence in response to targeted therapy, and impedes the engagement of transcriptional programs required for tumor cell survival. CDK7/12 inhibition in combination with targeted cancer therapies may serve as a therapeutic paradigm for enhancing the effectiveness of targeted therapies. Cancer Discov; 8(1); 59-73. ©2017 AACR.See related commentary by Carugo and Draetta, p. 17This article is highlighted in the In This Issue feature, p. 1.
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Neoplasias/terapia , Línea Celular Tumoral , Humanos , Neoplasias/patología , Transducción de SeñalRESUMEN
Irreversible inhibition of transcriptional cyclin-dependent kinases (CDKs) provides a therapeutic strategy for cancers that rely on aberrant transcription; however, lack of understanding of resistance mechanisms to these agents will likely impede their clinical evolution. Here, we demonstrate upregulation of multidrug transporters ABCB1 and ABCG2 as a major mode of resistance to THZ1, a covalent inhibitor of CDKs 7, 12, and 13 in neuroblastoma and lung cancer. To counter this obstacle, we developed a CDK inhibitor, E9, that is not a substrate for ABC transporters, and by selecting for resistance, determined that it exerts its cytotoxic effects through covalent modification of cysteine 1039 of CDK12. These results highlight the importance of considering this common mode of resistance in the development of clinical analogs of THZ1, identify a covalent CDK12 inhibitor that is not susceptible to ABC transporter-mediated drug efflux, and demonstrate that target deconvolution can be accomplished through selection for resistance.
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Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 2/antagonistas & inhibidores , Proteínas de Neoplasias/antagonistas & inhibidores , Fenilendiaminas/farmacología , Inhibidores de Proteínas Quinasas/farmacología , Pirimidinas/farmacología , Subfamilia B de Transportador de Casetes de Unión a ATP/antagonistas & inhibidores , Subfamilia B de Transportador de Casetes de Unión a ATP/metabolismo , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 2/metabolismo , Relación Dosis-Respuesta a Droga , Humanos , Estructura Molecular , Proteínas de Neoplasias/metabolismo , Fenilendiaminas/química , Inhibidores de Proteínas Quinasas/química , Pirimidinas/química , Relación Estructura-ActividadRESUMEN
The EZH2 histone methyltransferase is a member of the polycomb repressive complex 2 (PRC2) that is highly expressed in diverse human cancers and is associated with a poor prognosis. MUC1-C is an oncoprotein that is similarly overexpressed in carcinomas and has been linked to epigenetic regulation. A role for MUC1-C in regulating EZH2 and histone methylation is not known. Here, we demonstrate that targeting MUC1-C in diverse human carcinoma cells downregulates EZH2 and other PRC2 components. MUC1-C activates (i) the EZH2 promoter through induction of the pRBâE2F pathway, and (ii) an NF-κB p65 driven enhancer in exon 1. We also show that MUC1-C binds directly to the EZH2 CXC region adjacent to the catalytic SET domain and associates with EZH2 on the CDH1 and BRCA1 promoters. In concert with these results, targeting MUC1-C downregulates EZH2 function as evidenced by (i) global and promoter-specific decreases in H3K27 trimethylation (H3K27me3), and (ii) activation of tumor suppressor genes, including BRCA1. These findings highlight a previously unreported role for MUC1-C in activating EZH2 expression and function in cancer cells.
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Proteína Potenciadora del Homólogo Zeste 2/genética , Proteína Potenciadora del Homólogo Zeste 2/metabolismo , Mucina-1/metabolismo , Neoplasias/metabolismo , Activación Transcripcional , Células A549 , Antígenos CD/genética , Proteína BRCA1/genética , Sitios de Unión , Cadherinas/genética , Línea Celular Tumoral , Proteína Potenciadora del Homólogo Zeste 2/química , Epigénesis Genética , Regulación Neoplásica de la Expresión Génica , Histonas/metabolismo , Humanos , Metilación , Neoplasias/genética , Regiones Promotoras Genéticas , Transducción de SeñalRESUMEN
Radiation therapy (RT), a critical modality in the treatment of lung cancer, induces direct tumor cell death and augments tumor-specific immunity. However, despite initial tumor control, most patients suffer from locoregional relapse and/or metastatic disease following RT. The use of immunotherapy in non-small-cell lung cancer (NSCLC) could potentially change this outcome by enhancing the effects of RT. Here, we report significant (up to 70% volume reduction of the target lesion) and durable (up to 12 weeks) tumor regressions in conditional Kras-driven genetically engineered mouse models (GEMMs) of NSCLC treated with radiotherapy and a programmed cell death 1 antibody (αPD-1). However, while αPD-1 therapy was beneficial when combined with RT in radiation-naive tumors, αPD-1 therapy had no antineoplastic efficacy in RT-relapsed tumors and further induced T cell inhibitory markers in this setting. Furthermore, there was differential efficacy of αPD-1 plus RT among Kras-driven GEMMs, with additional loss of the tumor suppressor serine/threonine kinase 11/liver kinase B1 (Stk11/Lkb1) resulting in no synergistic efficacy. Taken together, our data provide evidence for a close interaction among RT, T cells, and the PD-1/PD-L1 axis and underscore the rationale for clinical combinatorial therapy with immune modulators and radiotherapy.
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Carcinoma de Pulmón de Células no Pequeñas/terapia , Inmunoterapia , Neoplasias Pulmonares/terapia , Receptor de Muerte Celular Programada 1/antagonistas & inhibidores , Proteínas Quinasas Activadas por AMP , Animales , Anticuerpos Monoclonales/uso terapéutico , Antineoplásicos , Carcinoma de Pulmón de Células no Pequeñas/radioterapia , Línea Celular Tumoral , Femenino , Neoplasias Pulmonares/radioterapia , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Recurrencia Local de Neoplasia , Proteínas Serina-Treonina Quinasas/genética , Proteínas Proto-Oncogénicas p21(ras)/genéticaRESUMEN
Small cell lung cancer (SCLC) is an aggressive disease with high mortality, and the identification of effective pharmacological strategies to target SCLC biology represents an urgent need. Using a high-throughput cellular screen of a diverse chemical library, we observe that SCLC is sensitive to transcription-targeting drugs, in particular to THZ1, a recently identified covalent inhibitor of cyclin-dependent kinase 7. We find that expression of super-enhancer-associated transcription factor genes, including MYC family proto-oncogenes and neuroendocrine lineage-specific factors, is highly vulnerability to THZ1 treatment. We propose that downregulation of these transcription factors contributes, in part, to SCLC sensitivity to transcriptional inhibitors and that THZ1 represents a prototype drug for tailored SCLC therapy.
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Antineoplásicos/administración & dosificación , Inhibidores Enzimáticos/administración & dosificación , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/genética , Factores de Transcripción/metabolismo , Animales , Antineoplásicos/farmacología , Línea Celular Tumoral , Quinasas Ciclina-Dependientes/antagonistas & inhibidores , Inhibidores Enzimáticos/farmacología , Ensayos Analíticos de Alto Rendimiento , Humanos , Ratones , Datos de Secuencia Molecular , Neoplasias Experimentales , Análisis de Secuencia de ADN , Carcinoma Pulmonar de Células Pequeñas , Transcripción Genética/efectos de los fármacos , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Close resemblance of murine and human trials is essential to achieve the best predictive value of animal-based translational cancer research. Kras-driven genetically engineered mouse models of non-small-cell lung cancer faithfully predict the response of human lung cancers to systemic chemotherapy. Owing to development of multifocal disease, however, these models have not been usable in studies of outcomes following focal radiotherapy (RT). We report the development of a preclinical platform to deliver state-of-the-art image-guided RT in these models. Presence of a single tumour as usually diagnosed in patients is modelled by confined injection of adenoviral Cre recombinase. Furthermore, three-dimensional conformal planning and state-of-the-art image-guided dose delivery are performed as in humans. We evaluate treatment efficacies of two different radiation regimens and find that Kras-driven tumours can temporarily be stabilized upon RT, whereas additional loss of either Lkb1 or p53 renders these lesions less responsive to RT.
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Carcinoma de Pulmón de Células no Pequeñas/radioterapia , Neoplasias Pulmonares/radioterapia , Proteínas Proto-Oncogénicas p21(ras)/genética , Radioterapia Guiada por Imagen/métodos , Proteínas Quinasas Activadas por AMP , Adenoviridae/genética , Animales , Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/patología , Modelos Animales de Enfermedad , Femenino , Expresión Génica , Vectores Genéticos , Humanos , Integrasas/genética , Integrasas/metabolismo , Lentivirus/genética , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patología , Masculino , Ratones , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Proto-Oncogénicas p21(ras)/metabolismo , Dosis de Radiación , Tolerancia a Radiación , Resultado del Tratamiento , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/metabolismoRESUMEN
The MYC oncoproteins are thought to stimulate tumor cell growth and proliferation through amplification of gene transcription, a mechanism that has thwarted most efforts to inhibit MYC function as potential cancer therapy. Using a covalent inhibitor of cyclin-dependent kinase 7 (CDK7) to disrupt the transcription of amplified MYCN in neuroblastoma cells, we demonstrate downregulation of the oncoprotein with consequent massive suppression of MYCN-driven global transcriptional amplification. This response translated to significant tumor regression in a mouse model of high-risk neuroblastoma, without the introduction of systemic toxicity. The striking treatment selectivity of MYCN-overexpressing cells correlated with preferential downregulation of super-enhancer-associated genes, including MYCN and other known oncogenic drivers in neuroblastoma. These results indicate that CDK7 inhibition, by selectively targeting the mechanisms that promote global transcriptional amplification in tumor cells, may be useful therapy for cancers that are driven by MYC family oncoproteins.
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Quinasas Ciclina-Dependientes/antagonistas & inhibidores , Modelos Animales de Enfermedad , Neuroblastoma/tratamiento farmacológico , Proteínas Nucleares/metabolismo , Proteínas Oncogénicas/metabolismo , Fenilendiaminas/uso terapéutico , Inhibidores de Proteínas Quinasas/farmacología , Pirimidinas/uso terapéutico , Animales , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Quinasas Ciclina-Dependientes/metabolismo , Humanos , Proteína Proto-Oncogénica N-Myc , Transcripción Genética/efectos de los fármacos , Quinasa Activadora de Quinasas Ciclina-DependientesRESUMEN
Mutations in isocitrate dehydrogenase 1 and 2 (IDH1/2) have been discovered in several cancer types and cause the neurometabolic syndrome D2-hydroxyglutaric aciduria (D2HGA). The mutant enzymes exhibit neomorphic activity resulting in production of D2-hydroxyglutaric acid (D-2HG). To study the pathophysiological consequences of the accumulation of D-2HG, we generated transgenic mice with conditionally activated IDH2(R140Q) and IDH2(R172K) alleles. Global induction of mutant IDH2 expression in adults resulted in dilated cardiomyopathy, white matter abnormalities throughout the central nervous system (CNS), and muscular dystrophy. Embryonic activation of mutant IDH2 resulted in more pronounced phenotypes, including runting, hydrocephalus, and shortened life span, recapitulating the abnormalities observed in D2HGA patients. The diseased hearts exhibited mitochondrial damage and glycogen accumulation with a concordant up-regulation of genes involved in glycogen biosynthesis. Notably, mild cardiac hypertrophy was also observed in nude mice implanted with IDH2(R140Q)-expressing xenografts, suggesting that 2HG may potentially act in a paracrine fashion. Finally, we show that silencing of IDH2(R140Q) in mice with an inducible transgene restores heart function by lowering 2HG levels. Together, these findings indicate that inhibitors of mutant IDH2 may be beneficial in the treatment of D2HGA and suggest that 2HG produced by IDH mutant tumors has the potential to provoke a paraneoplastic condition.
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Cardiomiopatías/genética , Glutaratos/metabolismo , Isocitrato Deshidrogenasa/genética , Mutación , Enfermedades Neurodegenerativas/genética , Animales , Cardiomiopatías/enzimología , Cardiomiopatías/patología , Línea Celular , Perfilación de la Expresión Génica , Regulación del Desarrollo de la Expresión Génica , Corazón/fisiopatología , Humanos , Isocitrato Deshidrogenasa/metabolismo , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Enfermedades Neurodegenerativas/enzimología , Enfermedades Neurodegenerativas/patologíaRESUMEN
UNLABELLED: The success in lung cancer therapy with programmed death (PD)-1 blockade suggests that immune escape mechanisms contribute to lung tumor pathogenesis. We identified a correlation between EGF receptor (EGFR) pathway activation and a signature of immunosuppression manifested by upregulation of PD-1, PD-L1, CTL antigen-4 (CTLA-4), and multiple tumor-promoting inflammatory cytokines. We observed decreased CTLs and increased markers of T-cell exhaustion in mouse models of EGFR-driven lung cancer. PD-1 antibody blockade improved the survival of mice with EGFR-driven adenocarcinomas by enhancing effector T-cell function and lowering the levels of tumor-promoting cytokines. Expression of mutant EGFR in bronchial epithelial cells induced PD-L1, and PD-L1 expression was reduced by EGFR inhibitors in non-small cell lung cancer cell lines with activated EGFR. These data suggest that oncogenic EGFR signaling remodels the tumor microenvironment to trigger immune escape and mechanistically link treatment response to PD-1 inhibition. SIGNIFICANCE: We show that autochthonous EGFR-driven lung tumors inhibit antitumor immunity by activating the PD-1/PD-L1 pathway to suppress T-cell function and increase levels of proinflammatory cytokines. These findings indicate that EGFR functions as an oncogene through non-cell-autonomous mechanisms and raise the possibility that other oncogenes may drive immune escape.
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Antígeno B7-H1/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/inmunología , Citocinas/metabolismo , Receptores ErbB/metabolismo , Neoplasias Pulmonares/inmunología , Receptor de Muerte Celular Programada 1/metabolismo , Linfocitos T/inmunología , Escape del Tumor , Animales , Antígeno B7-H1/genética , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Línea Celular , Receptores ErbB/genética , Regulación Neoplásica de la Expresión Génica , Humanos , Neoplasias Pulmonares/metabolismo , Activación de Linfocitos , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Oncogenes , Receptor de Muerte Celular Programada 1/genética , Transducción de Señal , Microambiente TumoralRESUMEN
BACKGROUND: Transcriptional targeted suicide gene (SG) therapy driven by the insulinoma-associated 1 (INSM1) promoter makes it possible to target suicide toxin production and cytotoxicity exclusively to small cell lung cancer (SCLC) cells and tumors. It remains to be determined whether acquired chemoresistance, as observed in the majority of SCLC patients, desensitizes SCLC cells to INSM1 promoter-driven SG therapy. METHODS: A panel of SCLC cell lines resistant to clinically relevant chemotherapeutics was characterized regarding the expression of proteins involved in response to chemotherapy and regarding INSM1 promoter activity. Sensitivity towards INSM1 promoter-driven SG therapy was tested using different systems: Yeast cytosine deaminase-uracil phosphoribosyl transferase (YCD-YUPRT) in combination with the prodrug 5-fluorocytosine (5-FC) or Escherichia coli nitroreductase (NTR) together with the bromomustard prodrug SN27686. RESULTS: The chemoresistant cell lines displayed heterogeneous expression profiles of molecules involved in multidrug resistance, apoptosis and survival pathways. Despite this, the INSM1 promoter activity was found to be unchanged or increased in SCLC chemoresistant cells and xenografts compared to chemosensitive variants. INSM1 promoter-driven SG therapy with YCD-YUPRT/5-FC or NTR/SN27686, was found to induce high levels of cytotoxicity in both chemosensitive and chemoresistant SCLC cells. Moreover, the combination of INSM1 promoter-driven YCD-YUPRT/5-FC therapy and chemotherapy, as well as the combination of INSM1 promoter-driven YCD-YUPRT/5-FC and NTR/SN27686 therapy, was observed to be superior to single agent therapy in chemoresistant SCLC cells. CONCLUSIONS: Collectively, the present study demonstrates that targeted SG therapy is a potent therapeutic approach for chemoresistant SCLC patients, with the highest efficacy achieved when applied as combination SG therapy or in combination with standard chemotherapy.