RESUMEN
Pancreatic ductal adenocarcinoma (PDAC) is typically diagnosed at an advanced stage, which limits surgical options and portends a dismal prognosis. Current oncologic PDAC therapies confer marginal benefit and, thus, a significant unmet clinical need exists for new therapeutic strategies. To identify effective PDAC therapies, we leveraged a syngeneic orthotopic PDAC transplant mouse model to perform a large-scale, in vivo screen of 16 single-agent and 41 two-drug targeted therapy combinations in mice. Among 57 drug conditions screened, combined inhibition of heat shock protein (Hsp)-90 and MEK was found to produce robust suppression of tumor growth, leading to an 80% increase in the survival of PDAC-bearing mice with no significant toxicity. Mechanistically, we observed that single-agent MEK inhibition led to compensatory activation of resistance pathways, including components of the PI3K/AKT/mTOR signaling axis, which was overcome with the addition of HSP90 inhibition. The combination of HSP90(i) + MEK(i) was also active in vitro in established human PDAC cell lines and in vivo in patient-derived organoid PDAC transplant models. These findings encourage the clinical development of HSP90(i) + MEK(i) combination therapy and highlight the power of clinically relevant in vivo model systems for identifying cancer therapies.
Asunto(s)
Antineoplásicos/farmacología , Evaluación Preclínica de Medicamentos , Ensayos de Selección de Medicamentos Antitumorales , Adenocarcinoma/metabolismo , Adenocarcinoma/mortalidad , Adenocarcinoma/patología , Animales , Antineoplásicos/uso terapéutico , Benzodioxoles/farmacología , Biomarcadores de Tumor , Línea Celular Tumoral , Modelos Animales de Enfermedad , Evaluación Preclínica de Medicamentos/métodos , Ensayos de Selección de Medicamentos Antitumorales/métodos , Sinergismo Farmacológico , Expresión Génica , Humanos , Inmunohistoquímica , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Ratones , Terapia Molecular Dirigida , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/mortalidad , Neoplasias Pancreáticas/patología , Inhibidores de Proteínas Quinasas/farmacología , Purinas/farmacología , Piridonas/farmacología , Pirimidinonas/farmacología , Transducción de Señal/efectos de los fármacos , Tasa de Supervivencia , Resultado del Tratamiento , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Pancreatic ductal adenocarcinoma (PDAC) is driven by co-existing mutations in KRAS and TP53. However, how these mutations collaborate to promote this cancer is unknown. Here, we uncover sequence-specific changes in RNA splicing enforced by mutant p53 which enhance KRAS activity. Mutant p53 increases expression of splicing regulator hnRNPK to promote inclusion of cytosine-rich exons within GTPase-activating proteins (GAPs), negative regulators of RAS family members. Mutant p53-enforced GAP isoforms lose cell membrane association, leading to heightened KRAS activity. Preventing cytosine-rich exon inclusion in mutant KRAS/p53 PDACs decreases tumor growth. Moreover, mutant p53 PDACs are sensitized to inhibition of splicing via spliceosome inhibitors. These data provide insight into co-enrichment of KRAS and p53 mutations and therapeutics targeting this mechanism in PDAC.
Asunto(s)
Carcinoma Ductal Pancreático/genética , Mutación , Neoplasias Pancreáticas/genética , Proteínas Proto-Oncogénicas p21(ras)/genética , Empalme del ARN , Transducción de Señal/genética , Proteína p53 Supresora de Tumor/genética , Animales , Carcinoma Ductal Pancreático/metabolismo , Carcinoma Ductal Pancreático/terapia , Línea Celular Tumoral , Células Cultivadas , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Estimación de Kaplan-Meier , Ratones Endogámicos C57BL , Ratones Noqueados , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/terapia , Proteínas Proto-Oncogénicas p21(ras)/metabolismo , Tratamiento con ARN de Interferencia/métodos , Ensayos Antitumor por Modelo de Xenoinjerto/métodosRESUMEN
Pancreatic ductal adenocarcinoma is a lethal cancer with fewer than 7% of patients surviving past 5 years. T-cell immunity has been linked to the exceptional outcome of the few long-term survivors, yet the relevant antigens remain unknown. Here we use genetic, immunohistochemical and transcriptional immunoprofiling, computational biophysics, and functional assays to identify T-cell antigens in long-term survivors of pancreatic cancer. Using whole-exome sequencing and in silico neoantigen prediction, we found that tumours with both the highest neoantigen number and the most abundant CD8+ T-cell infiltrates, but neither alone, stratified patients with the longest survival. Investigating the specific neoantigen qualities promoting T-cell activation in long-term survivors, we discovered that these individuals were enriched in neoantigen qualities defined by a fitness model, and neoantigens in the tumour antigen MUC16 (also known as CA125). A neoantigen quality fitness model conferring greater immunogenicity to neoantigens with differential presentation and homology to infectious disease-derived peptides identified long-term survivors in two independent datasets, whereas a neoantigen quantity model ascribing greater immunogenicity to increasing neoantigen number alone did not. We detected intratumoural and lasting circulating T-cell reactivity to both high-quality and MUC16 neoantigens in long-term survivors of pancreatic cancer, including clones with specificity to both high-quality neoantigens and predicted cross-reactive microbial epitopes, consistent with neoantigen molecular mimicry. Notably, we observed selective loss of high-quality and MUC16 neoantigenic clones on metastatic progression, suggesting neoantigen immunoediting. Our results identify neoantigens with unique qualities as T-cell targets in pancreatic ductal adenocarcinoma. More broadly, we identify neoantigen quality as a biomarker for immunogenic tumours that may guide the application of immunotherapies.
Asunto(s)
Antígenos de Neoplasias/inmunología , Proteínas Bacterianas/inmunología , Supervivientes de Cáncer , Reacciones Cruzadas/inmunología , Neoplasias Pancreáticas/inmunología , Linfocitos T Citotóxicos/inmunología , Adenocarcinoma/sangre , Adenocarcinoma/genética , Adenocarcinoma/inmunología , Antígenos de Neoplasias/genética , Proteínas Bacterianas/sangre , Proteínas Bacterianas/genética , Antígeno Ca-125/genética , Antígeno Ca-125/inmunología , Simulación por Computador , Reacciones Cruzadas/genética , Humanos , Inmunoterapia , Proteínas de la Membrana/genética , Proteínas de la Membrana/inmunología , Neoplasias Pancreáticas/sangre , Neoplasias Pancreáticas/genética , Pronóstico , Análisis de Supervivencia , Linfocitos T Citotóxicos/citología , Secuenciación del ExomaRESUMEN
Nerves are a notable feature of the tumor microenvironment in some epithelial tumors, but their role in the malignant progression of pancreatic ductal adenocarcinoma (PDAC) is uncertain. Here, we identify dense innervation in the microenvironment of precancerous pancreatic lesions, known as pancreatic intraepithelial neoplasms (PanIN), and describe a unique subpopulation of neuroendocrine PanIN cells that express the neuropeptide substance P (SP) receptor neurokinin 1-R (NK1-R). Using organoid culture, we demonstrated that sensory neurons promoted the proliferation of PanIN organoids via SP-NK1-R signaling and STAT3 activation. Nerve-responsive neuroendocrine cells exerted trophic influences and potentiated global PanIN organoid growth. Sensory denervation of a genetically engineered mouse model of PDAC led to loss of STAT3 activation, a decrease in the neoplastic neuroendocrine cell population, and impaired PanIN progression to tumor. Overall, our data provide evidence that nerves of the PanIN microenvironment promote oncogenesis, likely via direct signaling to neoplastic neuroendocrine cells capable of trophic influences. These findings identify neuroepithelial cross-talk as a potential novel target in PDAC treatment. Cancer Res; 77(8); 1868-79. ©2017 AACR.