RESUMEN
Trastuzumab deruxtecan (T-DXd; DS-8201; ENHERTU®) is a human epithelial growth factor receptor 2 (HER2)-directed antibody drug conjugate (ADC) with demonstrated antitumor activity against a range of tumor types. Aiming to understand the relationship between antigen expression and downstream efficacy outcomes, T-DXd was administered in tumor-bearing mice carrying NCI-N87, Capan-1, JIMT-1, and MDA-MB-468 xenografts, characterized by varying HER2 levels. Plasma pharmacokinetics (PK) of total antibody, T-DXd, and released DXd and tumor concentrations of released DXd were evaluated, in addition to monitoring γΗ2AX and pRAD50 pharmacodynamic (PD) response. A positive relationship was observed between released DXd concentrations in tumor and HER2 expression, with NCI-N87 xenografts characterized by the highest exposures compared to the remaining cell lines. γΗ2AX and pRAD50 demonstrated a sustained increase over several days occurring with a time delay relative to tumoral-released DXd concentrations. In vitro investigations of cell-based DXd disposition facilitated the characterization of DXd kinetics across tumor cells. These outputs were incorporated into a mechanistic mathematical model, utilized to describe PK/PD trends. The model captured plasma PK across dosing arms as well as tumor PK in NCI-N87, Capan-1, and MDA-MB-468 models; tumor concentrations in JIMT-1 xenografts required additional parameter adjustments reflective of complex receptor dynamics. γΗ2AX longitudinal trends were well characterized via a unified PD model implemented across xenografts demonstrating the robustness of measured PD trends. This work supports the application of a mechanistic model as a quantitative tool, reliably projecting tumor payload concentrations upon T-DXd administration, as the first step towards preclinical-to-clinical translation.
Asunto(s)
Inmunoconjugados , Receptor ErbB-2 , Trastuzumab , Ensayos Antitumor por Modelo de Xenoinjerto , Animales , Trastuzumab/farmacocinética , Trastuzumab/farmacología , Receptor ErbB-2/metabolismo , Ratones , Humanos , Inmunoconjugados/farmacocinética , Inmunoconjugados/farmacología , Línea Celular Tumoral , Femenino , Camptotecina/análogos & derivados , Camptotecina/farmacocinética , Camptotecina/farmacología , Antineoplásicos Inmunológicos/farmacocinética , Antineoplásicos Inmunológicos/farmacología , Antineoplásicos Inmunológicos/administración & dosificación , Ratones DesnudosRESUMEN
PARP inhibitors are synthetically lethal with BRCA1/2 mutations, and in this setting, accumulation of DNA damage leads to cell death. Because increased DNA damage and subsequent immune activation can prime an anti-tumor immune response, we studied the impact of olaparib ± immune checkpoint blockade (ICB) on anti-tumor activity and the immune microenvironment. Concurrent combination of olaparib, at clinically relevant exposures, with ICB gave durable and deeper anti-tumor activity in the Brca1m BR5 model vs. monotherapies. Olaparib and combination treatment modulated the immune microenvironment, including increases in CD8+ T cells and NK cells, and upregulation of immune pathways, including type I IFN and STING signaling. Olaparib also induced a dose-dependent upregulation of immune pathways, including JAK/STAT, STING and type I IFN, in the tumor cell compartment of a BRCA1m (HBCx-10) but not a BRCA WT (HBCx-9) breast PDX model. In vitro, olaparib induced BRCAm tumor cell-specific dendritic cell transactivation. Relevance to human disease was assessed using patient samples from the MEDIOLA (NCT02734004) trial, which showed increased type I IFN, STING, and JAK/STAT pathway expression following olaparib treatment, in line with preclinical findings. These data together provide evidence for a mechanism and schedule underpinning potential benefit of ICB combination with olaparib.
Asunto(s)
Neoplasias Ováricas , Inhibidores de Poli(ADP-Ribosa) Polimerasas , Proteína BRCA1/genética , Proteína BRCA1/metabolismo , Ensayos Clínicos como Asunto , Femenino , Humanos , Inmunidad , Quinasas Janus/metabolismo , Quinasas Janus/farmacología , Quinasas Janus/uso terapéutico , Neoplasias Ováricas/tratamiento farmacológico , Inhibidores de Poli(ADP-Ribosa) Polimerasas/farmacología , Inhibidores de Poli(ADP-Ribosa) Polimerasas/uso terapéutico , Factores de Transcripción STAT/metabolismo , Factores de Transcripción STAT/farmacología , Factores de Transcripción STAT/uso terapéutico , Transducción de Señal , Microambiente TumoralRESUMEN
Mutations in the STK11 (LKB1) gene regulate resistance to PD-1/PD-L1 blockade. This study evaluated this association in patients with nonsquamous non-small cell lung cancer (NSCLC) enrolled in three phase I/II trials. STK11 mutations were associated with resistance to the anti-PD-L1 antibody durvalumab (alone/with the anti-CTLA4 antibody tremelimumab) independently of KRAS mutational status, highlighting STK11 as a potential driver of resistance to checkpoint blockade. Retrospective assessments of tumor tissue, whole blood, and serum revealed a unique immune phenotype in patients with STK11 mutations, with increased expression of markers associated with neutrophils (i.e., CXCL2, IL6), Th17 contexture (i.e., IL17A), and immune checkpoints. Associated changes were observed in the periphery. Reduction of STAT3 in the tumor microenvironment using an antisense oligonucleotide reversed immunotherapy resistance in preclinical STK11 knockout models. These results suggest that STK11 mutations may hinder response to checkpoint blockade through mechanisms including suppressive myeloid cell biology, which could be reversed by STAT3-targeted therapy. SIGNIFICANCE: Patients with nonsquamous STK11-mutant (STK11mut) NSCLC are less likely than STK11 wild-type (STK11wt) patients to respond to anti-PD-L1 ± anti-CTLA4 immunotherapies, and their tumors show increased expression of genes and cytokines that activate STAT3 signaling. Preclinically, STAT3 modulation reverses this resistance, suggesting STAT3-targeted agents as potential combination partners for immunotherapies in STK11mut NSCLC.This article is highlighted in the In This Issue feature, p. 2659.
Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Quinasas de la Proteína-Quinasa Activada por el AMP , Anticuerpos Monoclonales , Anticuerpos Monoclonales Humanizados , Antígeno B7-H1/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Pulmón de Células no Pequeñas/patología , Humanos , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patología , Mutación , Proteínas Serina-Treonina Quinasas/genética , Estudios Retrospectivos , Factor de Transcripción STAT3/genética , Factor de Transcripción STAT3/metabolismo , Microambiente TumoralRESUMEN
Suppressive myeloid cells mediate resistance to immune checkpoint blockade. PI3Kγ inhibition can target suppressive macrophages, and enhance efficacy of immune checkpoint inhibitors. However, how PI3Kγ inhibitors function in different tumor microenvironments (TME) to activate specific immune cells is underexplored. The effect of the novel PI3Kγ inhibitor AZD3458 was assessed in preclinical models. AZD3458 enhanced antitumor activity of immune checkpoint inhibitors in 4T1, CT26, and MC38 syngeneic models, increasing CD8+ T-cell activation status. Immune and TME biomarker analysis of MC38 tumors revealed that AZD3458 monotherapy or combination treatment did not repolarize the phenotype of tumor-associated macrophage cells but induced gene signatures associated with LPS and type II INF activation. The activation biomarkers were present across tumor macrophages that appear phenotypically heterogenous. AZD3458 alone or in combination with PD-1-blocking antibodies promoted an increase in antigen-presenting (MHCII+) and cytotoxic (iNOS+)-activated macrophages, as well as dendritic cell activation. AZD3458 reduced IL-10 secretion and signaling in primary human macrophages and murine tumor-associated macrophages, but did not strongly regulate IL-12 as observed in other studies. Therefore, rather than polarizing tumor macrophages, PI3Kγ inhibition with AZD3458 promotes a cytotoxic switch of macrophages into antigen-presenting activated macrophages, resulting in CD8 T-cell-mediated antitumor activity with immune checkpoint inhibitors associated with tumor and peripheral immune activation.
Asunto(s)
Fosfatidilinositol 3-Quinasa Clase Ib/metabolismo , Inhibidores de Puntos de Control Inmunológico/uso terapéutico , Animales , Modelos Animales de Enfermedad , Femenino , Humanos , Inhibidores de Puntos de Control Inmunológico/farmacología , Macrófagos/efectos de los fármacos , RatonesRESUMEN
BH3 mimetics like venetoclax target prosurvival Bcl-2 family proteins and are important therapeutics in the treatment of hematological malignancies. We demonstrate that endogenous Bfl-1 expression can render preclinical lymphoma tumor models insensitive to Mcl-1 and Bcl-2 inhibitors. However, suppression of Bfl-1 alone was insufficient to fully induce apoptosis in Bfl-1-expressing lymphomas, highlighting the need for targeting additional prosurvival proteins in this context. Importantly, we demonstrated that cyclin-dependent kinase 9 (CDK9) inhibitors rapidly downregulate both Bfl-1 and Mcl-1, inducing apoptosis in BH3-mimetic-resistant lymphoma cell lines in vitro and driving in vivo tumor regressions in diffuse large B-cell lymphoma patient-derived xenograft models expressing Bfl-1. These data underscore the need to clinically develop CDK9 inhibitors, like AZD4573, for the treatment of lymphomas using Bfl-1 as a selection biomarker.
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Compuestos Bicíclicos Heterocíclicos con Puentes/farmacología , Quinasa 9 Dependiente de la Ciclina/antagonistas & inhibidores , Resistencia a Antineoplásicos/efectos de los fármacos , Linfoma de Células B Grandes Difuso/tratamiento farmacológico , Compuestos Macrocíclicos/farmacología , Terapia Molecular Dirigida , Proteínas de Neoplasias/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-bcl-2/antagonistas & inhibidores , Sulfonamidas/farmacología , Animales , Antineoplásicos/farmacología , Compuestos Bicíclicos Heterocíclicos con Puentes/uso terapéutico , Línea Celular Tumoral , Quinasa 9 Dependiente de la Ciclina/fisiología , Cicloheximida/farmacología , Femenino , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Leupeptinas/farmacología , Compuestos Macrocíclicos/uso terapéutico , Ratones , Ratones Endogámicos NOD , Ratones SCID , Antígenos de Histocompatibilidad Menor/biosíntesis , Antígenos de Histocompatibilidad Menor/genética , Proteína 1 de la Secuencia de Leucemia de Células Mieloides/biosíntesis , Proteína 1 de la Secuencia de Leucemia de Células Mieloides/genética , Proteínas de Neoplasias/biosíntesis , Proteínas de Neoplasias/genética , Fragmentos de Péptidos/antagonistas & inhibidores , Piperazinas/farmacología , Proteínas Proto-Oncogénicas/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-bcl-2/biosíntesis , Proteínas Proto-Oncogénicas c-bcl-2/genética , Piridinas/farmacología , Sulfonamidas/uso terapéutico , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Cancer immunotherapy has dramatically changed the approach to cancer treatment. The aim of targeting the immune system to recognize and destroy cancer cells has afforded many patients the prospect of achieving deep, long-term remission and potential cures. However, many challenges remain for achieving the goal of effective immunotherapy for all cancer patients. Checkpoint inhibitors have been able to achieve long-term responses in a minority of patients, yet improving response rates with combination therapies increases the possibility of toxicity. Chimeric antigen receptor T cells have demonstrated high response rates in hematological cancers, although most patients experience relapse. In addition, some cancers are notoriously immunologically "cold" and typically are not effective targets for immunotherapy. Overcoming these obstacles will require new strategies to improve upon the efficacy of current agents, identify biomarkers to select appropriate therapies, and discover new modalities to expand the accessibility of immunotherapy to additional tumor types and patient populations.
Asunto(s)
Inmunoterapia Adoptiva , Inmunoterapia/tendencias , Recurrencia Local de Neoplasia/terapia , Neoplasias/terapia , Biomarcadores de Tumor/genética , Vacunas contra el Cáncer/inmunología , Vacunas contra el Cáncer/uso terapéutico , Terapia Combinada , Humanos , Inhibidores de Puntos de Control Inmunológico/uso terapéutico , Recurrencia Local de Neoplasia/inmunología , Neoplasias/genética , Neoplasias/inmunología , Neoplasias/patología , Microambiente Tumoral/inmunologíaRESUMEN
Pancreatic ductal adenocarcinoma (PDAC) has a heterogeneous tumor microenvironment (TME) comprised of myeloid-derived suppressor cells (MDSCs), tumor-associated macrophages, neutrophils, regulatory T cells, and myofibroblasts. The precise mechanisms that regulate the composition of the TME and how they contribute to radiotherapy (RT) response remain poorly understood. In this study, we analyze changes in immune cell populations and circulating chemokines in patient samples and animal models of pancreatic cancer to characterize the immune response to radiotherapy. Further, we identify STAT3 as a key mediator of immunosuppression post-RT. We found granulocytic MDSCs (G-MDSCs) and neutrophils to be increased in response to RT in murine and human PDAC samples. We also found that RT-induced STAT3 phosphorylation correlated with increased MDSC infiltration and proliferation. Targeting STAT3 using an anti-sense oligonucleotide in combination with RT circumvented RT-induced MDSC infiltration, enhanced the proportion of effector T cells, and improved response to RT. In addition, STAT3 inhibition contributed to the remodeling of the PDAC extracellular matrix when combined with RT, resulting in decreased collagen deposition and fibrotic tissue formation. Collectively, our data provide evidence that targeting STAT3 in combination with RT can mitigate the pro-tumorigenic effects of RT and improve tumor response.
Asunto(s)
Carcinoma Ductal Pancreático/radioterapia , Rayos gamma , Células Supresoras de Origen Mieloide/inmunología , Oligonucleótidos Antisentido/genética , Neoplasias Pancreáticas/radioterapia , Factor de Transcripción STAT3/antagonistas & inhibidores , Animales , Apoptosis , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/inmunología , Carcinoma Ductal Pancreático/patología , Proliferación Celular , Femenino , Humanos , Terapia de Inmunosupresión , Ratones , Ratones Endogámicos C57BL , Ratones Desnudos , Células Supresoras de Origen Mieloide/metabolismo , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/inmunología , Neoplasias Pancreáticas/patología , Pronóstico , Factor de Transcripción STAT3/genética , Linfocitos T Reguladores/inmunología , Células Tumorales Cultivadas , Microambiente TumoralRESUMEN
A CDK9 inhibitor having short target engagement would enable a reduction of Mcl-1 activity, resulting in apoptosis in cancer cells dependent on Mcl-1 for survival. We report the optimization of a series of amidopyridines (from compound 2), focusing on properties suitable for achieving short target engagement after intravenous administration. By increasing potency and human metabolic clearance, we identified compound 24, a potent and selective CDK9 inhibitor with suitable predicted human pharmacokinetic properties to deliver transient inhibition of CDK9. Furthermore, the solubility of 24 was considered adequate to allow i.v. formulation at the anticipated effective dose. Short-term treatment with compound 24 led to a rapid dose- and time-dependent decrease of pSer2-RNAP2 and Mcl-1, resulting in cell apoptosis in multiple hematological cancer cell lines. Intermittent dosing of compound 24 demonstrated efficacy in xenograft models derived from multiple hematological tumors. Compound 24 is currently in clinical trials for the treatment of hematological malignancies.
Asunto(s)
Quinasa 9 Dependiente de la Ciclina/antagonistas & inhibidores , Inhibidores de Proteínas Quinasas/química , Piridinas/química , Animales , Apoptosis/efectos de los fármacos , Sitios de Unión , Línea Celular Tumoral , Quinasa 9 Dependiente de la Ciclina/metabolismo , Perros , Evaluación Preclínica de Medicamentos , Semivida , Neoplasias Hematológicas/tratamiento farmacológico , Neoplasias Hematológicas/patología , Humanos , Ratones , Simulación del Acoplamiento Molecular , Proteína 1 de la Secuencia de Leucemia de Células Mieloides/metabolismo , Inhibidores de Proteínas Quinasas/metabolismo , Inhibidores de Proteínas Quinasas/farmacología , Inhibidores de Proteínas Quinasas/uso terapéutico , Piridinas/metabolismo , Piridinas/farmacología , Piridinas/uso terapéutico , Ratas , Solubilidad , Relación Estructura-Actividad , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
PURPOSE: Danvatirsen is a therapeutic antisense oligonucleotide (ASO) that selectively targets STAT3 and has shown clinical activity in two phase I clinical studies. We interrogated the clinical mechanism of action using danvatirsen-treated patient samples and conducted back-translational studies to further elucidate its immunomodulatory mechanism of action. EXPERIMENTAL DESIGN: Paired biopsies and blood samples from danvatirsen-treated patients were evaluated using immunohistochemistry and gene-expression analysis. To gain mechanistic insight, we used mass cytometry, flow cytometry, and immunofluorescence analysis of CT26 tumors treated with a mouse surrogate STAT3 ASO, and human immune cells were treated in vitro with danvatirsen. RESULTS: Within the tumors of treated patients, danvatirsen uptake was observed mainly in cells of the tumor microenvironment (TME). Gene expression analysis comparing baseline and on-treatment tumor samples showed increased expression of proinflammatory genes. In mouse models, STAT3 ASO demonstrated partial tumor growth inhibition and enhanced the antitumor activity when combined with anti-PD-L1. Immune profiling revealed reduced STAT3 protein in immune and stromal cells, and decreased suppressive cytokines correlating with increased proinflammatory macrophages and cytokine production. These changes led to enhanced T-cell abundance and function in combination with anti-PD-L1. CONCLUSIONS: STAT3 ASO treatment reverses a suppressive TME and promotes proinflammatory gene expression changes in patients' tumors and mouse models. Preclinical data provide evidence that ASO-mediated inhibition of STAT3 in the immune compartment is sufficient to remodel the TME and enhance the activity of checkpoint blockade without direct STAT3 inhibition in tumor cells. Collectively, these data provide a rationale for testing this combination in the clinic.
Asunto(s)
Antineoplásicos Inmunológicos/farmacología , Antígeno B7-H1/antagonistas & inhibidores , Neoplasias del Colon/terapia , Neoplasias/terapia , Oligonucleótidos/farmacología , Factor de Transcripción STAT3/antagonistas & inhibidores , Microambiente Tumoral/inmunología , Ensayos Clínicos Fase I como Asunto , Neoplasias del Colon/inmunología , Neoplasias del Colon/metabolismo , Neoplasias del Colon/patología , Quimioterapia Combinada , Humanos , Inmunomodulación , Macrófagos/inmunología , Neoplasias/inmunología , Neoplasias/metabolismo , Neoplasias/patología , Pronóstico , Factor de Transcripción STAT3/genética , Linfocitos T/inmunología , Células Tumorales CultivadasRESUMEN
PURPOSE: Cyclin-dependent kinase 9 (CDK9) is a transcriptional regulator and potential therapeutic target for many cancers. Multiple nonselective CDK9 inhibitors have progressed clinically but were limited by a narrow therapeutic window. This work describes a novel, potent, and highly selective CDK9 inhibitor, AZD4573. EXPERIMENTAL DESIGN: The antitumor activity of AZD4573 was determined across broad cancer cell line panels in vitro as well as cell line- and patient-derived xenograft models in vivo. Multiple approaches, including integrated transcriptomic and proteomic analyses, loss-of-function pathway interrogation, and pharmacologic comparisons, were employed to further understand the major mechanism driving AZD4573 activity and to establish an exposure/effect relationship. RESULTS: AZD4573 is a highly selective and potent CDK9 inhibitor. It demonstrated rapid induction of apoptosis and subsequent cell death broadly across hematologic cancer models in vitro, and MCL-1 depletion in a dose- and time-dependent manner was identified as a major mechanism through which AZD4573 induces cell death in tumor cells. This pharmacodynamic (PD) response was also observed in vivo, which led to regressions in both subcutaneous tumor xenografts and disseminated models at tolerated doses both as monotherapy or in combination with venetoclax. This understanding of the mechanism, exposure, and antitumor activity of AZD4573 facilitated development of a robust pharmacokinetic/PD/efficacy model used to inform the clinical trial design. CONCLUSIONS: Selective targeting of CDK9 enables the indirect inhibition of MCL-1, providing a therapeutic option for MCL-1-dependent diseases. Accordingly, AZD4573 is currently being evaluated in a phase I clinical trial for patients with hematologic malignancies (clinicaltrials.gov identifier: NCT03263637).See related commentary by Alcon et al., p. 761.
Asunto(s)
Antineoplásicos , Neoplasias Hematológicas , Apoptosis/efectos de los fármacos , Quinasa 9 Dependiente de la Ciclina , Humanos , Proteína 1 de la Secuencia de Leucemia de Células Mieloides , ProteómicaRESUMEN
BRAF and MEK1/2 inhibitors are effective in melanoma but resistance inevitably develops. Despite increasing the abundance of pro-apoptotic BIM and BMF, ERK1/2 pathway inhibition is predominantly cytostatic, reflecting residual pro-survival BCL2 family activity. Here, we show that uniquely low BCL-XL expression in melanoma biases the pro-survival pool towards MCL1. Consequently, BRAF or MEK1/2 inhibitors are synthetic lethal with the MCL1 inhibitor AZD5991, driving profound tumour cell death that requires BAK/BAX, BIM and BMF, and inhibiting tumour growth in vivo. Combination of ERK1/2 pathway inhibitors with BCL2/BCL-w/BCL-XL inhibitors is stronger in CRC, correlating with a low MCL1:BCL-XL ratio; indeed the MCL1:BCL-XL ratio is predictive of ERK1/2 pathway inhibitor synergy with MCL1 or BCL2/BCL-w/BCL-XL inhibitors. Finally, AZD5991 delays acquired BRAFi/MEKi resistance and enhances the efficacy of an ERK1/2 inhibitor in a model of acquired BRAFi + MEKi resistance. Thus combining ERK1/2 pathway inhibitors with MCL1 antagonists in melanoma could improve therapeutic index and patient outcomes.
Asunto(s)
Apoptosis , Sistema de Señalización de MAP Quinasas , Melanoma/patología , Terapia Molecular Dirigida , Proteína 1 de la Secuencia de Leucemia de Células Mieloides/metabolismo , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Proto-Oncogénicas B-raf/antagonistas & inhibidores , Animales , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Resistencia a Antineoplásicos/efectos de los fármacos , Humanos , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Compuestos Macrocíclicos/farmacología , Ratones , Proteínas Proto-Oncogénicas B-raf/metabolismo , Proteína bcl-X/metabolismoRESUMEN
Dysregulation of Notch signaling has been implicated in the development of many different types of cancer. Notch inhibitors are being tested in the clinic, but in most cases gastrointestinal and other toxicities have limited the dosage and, therefore, the effectiveness of these therapies. Herein, we describe the generation of a monoclonal antibody against the ligand-binding domain of the Notch1 receptor that specifically blocks ligand-induced activation. This antibody, 23814, recognizes both human and murine Notch1 with similar affinity, enabling examination of the effects on both tumor and host tissue in preclinical models. 23814 blocked Notch1 function in vivo, inhibited functional angiogenesis, and inhibited tumor growth without causing gastrointestinal toxicity. The lack of toxicity allowed for combination of 23814 and the VEGFR inhibitor tivozanib, resulting in significant growth inhibition of several VEGFR inhibitor-resistant tumor models. Analysis of the gene expression profiles of an extensive collection of murine breast tumors enabled the successful prediction of which tumors were most likely to respond to the combination of 23814 and tivozanib. Therefore, the use of a specific Notch1 antibody that does not induce significant toxicity may allow combination treatment with angiogenesis inhibitors or other targeted agents to achieve enhanced therapeutic benefit.
Asunto(s)
Anticuerpos Monoclonales/farmacología , Neovascularización Patológica/metabolismo , Receptor Notch1/agonistas , Inhibidores de la Angiogénesis/farmacología , Animales , Anticuerpos Bloqueadores/farmacología , Anticuerpos Bloqueadores/toxicidad , Anticuerpos Monoclonales/toxicidad , Línea Celular Tumoral , Modelos Animales de Enfermedad , Sinergismo Farmacológico , Femenino , Humanos , Ligandos , Ratones , Compuestos de Fenilurea/farmacología , Quinolinas/farmacología , Receptores de Factores de Crecimiento Endotelial Vascular/antagonistas & inhibidores , Receptores de Factores de Crecimiento Endotelial Vascular/metabolismo , Transducción de Señal/efectos de los fármacos , Carga Tumoral/efectos de los fármacos , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Perturbations in stem cell activity and differentiation can lead to developmental defects and cancer. We use an approach involving a quantitative model of cell-state transitions in vitro to gain insights into how SLUG/SNAI2, a key developmental transcription factor, modulates mammary epithelial stem cell activity and differentiation in vivo. In the absence of SLUG, stem cells fail to transition into basal progenitor cells, while existing basal progenitor cells undergo luminal differentiation; together, these changes result in abnormal mammary architecture and defects in tissue function. Furthermore, we show that in the absence of SLUG, mammary stem cell activity necessary for tissue regeneration and cancer initiation is lost. Mechanistically, SLUG regulates differentiation and cellular plasticity by recruiting the chromatin modifier lysine-specific demethylase 1 (LSD1) to promoters of lineage-specific genes to repress transcription. Together, these results demonstrate that SLUG plays a dual role in repressing luminal epithelial differentiation while unlocking stem cell transitions necessary for tumorigenesis.
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Transformación Celular Neoplásica , Células Madre/metabolismo , Factores de Transcripción/metabolismo , Animales , Diferenciación Celular , Línea Celular , Linaje de la Célula , Supervivencia sin Enfermedad , Regulación de la Expresión Génica , Histonas/metabolismo , Humanos , Glándulas Mamarias Humanas/citología , Ratones , Ratones Endogámicos NOD , Ratones Noqueados , Ratones SCID , Neoplasias/metabolismo , Neoplasias/mortalidad , Neoplasias/patología , Proteínas Proto-Oncogénicas c-myc/genética , Proteínas Proto-Oncogénicas c-myc/metabolismo , ARN Mensajero/metabolismo , Regeneración , Factores de Transcripción de la Familia Snail , Trasplante de Células Madre , Células Madre/citología , Factores de Transcripción/antagonistas & inhibidores , Factores de Transcripción/genética , Trasplante HeterólogoRESUMEN
UNLABELLED: Epithelial-to-mesenchymal transition (EMT) promotes both tumor progression and drug resistance, yet few vulnerabilities of this state have been identified. Using selective small molecules as cellular probes, we show that induction of EMT greatly sensitizes cells to agents that perturb endoplasmic reticulum (ER) function. This sensitivity to ER perturbations is caused by the synthesis and secretion of large quantities of extracellular matrix (ECM) proteins by EMT cells. Consistent with their increased secretory output, EMT cells display a branched ER morphology and constitutively activate the PERK-eIF2α axis of the unfolded protein response (UPR). Protein kinase RNA-like ER kinase (PERK) activation is also required for EMT cells to invade and metastasize. In human tumor tissues, EMT gene expression correlates strongly with both ECM and PERK-eIF2α genes, but not with other branches of the UPR. Taken together, our findings identify a novel vulnerability of EMT cells, and demonstrate that the PERK branch of the UPR is required for their malignancy. SIGNIFICANCE: EMT drives tumor metastasis and drug resistance, highlighting the need for therapies that target this malignant subpopulation. Our findings identify a previously unrecognized vulnerability of cancer cells that have undergone an EMT: sensitivity to ER stress. We also find that PERK-eIF2α signaling, which is required to maintain ER homeostasis, is also indispensable for EMT cells to invade and metastasize.
Asunto(s)
Estrés del Retículo Endoplásmico/genética , Transición Epitelial-Mesenquimal/genética , Factor 2 Eucariótico de Iniciación/genética , eIF-2 Quinasa/genética , Factor de Transcripción Activador 4/genética , Animales , Antineoplásicos/farmacología , Línea Celular Tumoral , Retículo Endoplásmico/metabolismo , Factor 2 Eucariótico de Iniciación/metabolismo , Matriz Extracelular/metabolismo , Regulación Neoplásica de la Expresión Génica , Humanos , Ratones SCID , Respuesta de Proteína Desplegada , eIF-2 Quinasa/metabolismoRESUMEN
Women with inherited mutations in the BRCA1 gene have increased risk of developing breast cancer but also exhibit a predisposition for the development of aggressive basal-like breast tumors. We report here that breast epithelial cells derived from patients harboring deleterious mutations in BRCA1 (BRCA1(mut /+) give rise to tumors with increased basal differentiation relative to cells from BRCA1+/+ patients. Molecular analysis of disease-free breast tissues from BRCA1(mut /+) patients revealed defects in progenitor cell lineage commitment even before cancer incidence. Moreover, we discovered that the transcriptional repressor Slug is an important functional suppressor of human breast progenitor cell lineage commitment and differentiation and that it is aberrantly expressed in BRCA1(mut /+) tissues. Slug expression is necessary for increased basal-like phenotypes prior to and after neoplastic transformation. These findings demonstrate that the genetic background of patient populations, in addition to affecting incidence rates, significantly impacts progenitor cell fate commitment and, therefore, tumor phenotype.