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BACKGROUND: Activating mutations in RAS are present in the majority of pancreatic cancer cases and represent an ideal therapeutic target. Reolysin is a proprietary formulation of oncolytic reovirus that is currently being evaluated in multiple clinical trials due to its ability to selectively replicate in cells harboring an activated RAS pathway. Here we report for the first time the presence of reovirus replication and induction of endoplasmic reticular (ER) stress in a primary tumor specimen collected from a pancreatic cancer patient receiving intravenous Reolysin and gemcitabine. CASE PRESENTATION: We describe the case of a 54-year old patient diagnosed with pancreatic adenocarcinoma in February 2012. Analysis of a tumor biopsy revealed an activating KRAS mutation (G12D) and the patient was started on first-line treatment with Reolysin in combination with gemcitabine in March 2012. Stable disease was achieved with significant improvement in cancer-related pain. Following 25 cycles of treatment over 23 months, a second biopsy was collected and immunohistochemical analyses revealed the presence of reovirus replication and induction of the ER stress-related gene GRP78/BIP and the pro-apoptotic protein NOXA. Importantly, co-localization of reoviral protein and active caspase-3 was also observed in the biopsy specimen. CONCLUSION: This is the first report of reoviral protein detection in primary tumor biopsies taken from a pancreatic cancer patient receiving intravenous Reolysin therapy. The accumulation of reoviral protein was associated with ER stress induction and caspase-3 processing suggesting that Reolysin and gemcitabine treatment exhibited direct pro-apoptotic activity against the tumor.
Assuntos
Antineoplásicos , Desoxicitidina/análogos & derivados , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Neoplasias Pancreáticas/tratamento farmacológico , Reoviridae/genética , Antineoplásicos/administração & dosagem , Antineoplásicos/uso terapêutico , Desoxicitidina/administração & dosagem , Desoxicitidina/uso terapêutico , Chaperona BiP do Retículo Endoplasmático , Humanos , Masculino , Pessoa de Meia-Idade , Pâncreas/patologia , Pâncreas/virologia , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/virologia , Proteínas Proto-Oncogênicas p21(ras) , Reoviridae/metabolismo , GencitabinaRESUMO
Patients with breast tumors that metastasize to the brain have limited treatment options and a very poor prognosis. More effective therapeutic strategies are desperately needed for this patient population. Recent evidence demonstrates that brain metastases arising from breast tumors display altered energy production that results in enhanced autophagy. Preclinical studies have shown that genetically or pharmacologically disrupting the autophagy pathway significantly decreases the brain metastatic burden, resulting in improved animal survival and increased sensitivity to lapatinib. These findings pave the way for the development of novel strategies targeting autophagy for breast cancer patients with brain metastatic disease.
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Although the selective and effective clearance of senescent cancer cells can improve cancer treatment, their development is confronted by many challenges. As part of efforts designed to overcome these problems, prodrugs, whose design is based on senescence-associated ß-galactosidase (SA-ß-gal), have been developed to selectively eliminate senescent cells. However, chemotherapies relying on targeted molecular inhibitors as senolytic drugs can induce drug resistance. In the current investigation, we devised a new strategy for selective degradation of target proteins in senescent cancer cells that utilizes a prodrug composed of the SA-ß-gal substrate galactose (galacto) and the proteolysis-targeting chimeras (PROTACs) as senolytic agents. Prodrugs Gal-ARV-771 and Gal-MS99 were found to display senolytic indexes higher than those of ARV-771 and MS99. Significantly, results of in vivo studies utilizing a human lung A549 xenograft mouse model demonstrated that concomitant treatment with etoposide and Gal-ARV-771 leads to a significant inhibition of tumor growth without eliciting significant toxicity.
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Senescência Celular , Galactose , Pró-Fármacos , Proteólise , Humanos , Animais , Senescência Celular/efeitos dos fármacos , Galactose/química , Galactose/farmacologia , Pró-Fármacos/farmacologia , Pró-Fármacos/química , Pró-Fármacos/uso terapêutico , Camundongos , Proteólise/efeitos dos fármacos , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/síntese química , Antineoplásicos/uso terapêutico , Ensaios Antitumorais Modelo de Xenoenxerto , beta-Galactosidase/metabolismo , Camundongos Nus , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Células A549 , Etoposídeo/farmacologia , Senoterapia/farmacologia , Senoterapia/química , Quimera de Direcionamento de ProteóliseRESUMO
BACKGROUND: Among the solid tumors, human pancreatic ductal adenocarcinoma (PDAC) has the worst prognosis. Gemcitabine is the standard first line of therapy for pancreatic cancer but has limited efficacy due to inherent or rapid development of resistance and combining EGFR inhibitors with this regimen results in only a modest clinical benefit. The goal of this study was to identify molecular targets that are activated during gemcitabine therapy alone or in combination with an EGFR inhibitor. METHODS: PDAC cell lines were used to determine molecular changes and rates of growth after treatment with gemcitabine or an EGFR inhibitor, AG1478, by Western blot analysis and MTT assays respectively. Flow cytometric analysis was performed to study the cell cycle progression and rate of apoptosis after gemcitabine treatment. ShRNA was used to knockdown STAT3. An in vivo orthotopic animal model was used to evaluate STAT3 as a target. Immunohistochemical analysis was performed to analyze Ki67 and STAT3 expression in tumors. RESULTS: Treatment with gemcitabine increased the levels of EGFRTyr1068 and ERK phosphorylation in the PDAC cell lines tested. The constitutive STAT3Tyr705 phosphorylation observed in PDAC cell lines was not altered by treatment with gemcitabine. Treatment of cells with gemcitabine or AG1478 resulted in differential rate of growth inhibition. AG1478 efficiently blocked the phosphorylation of EGFRTyr1068 and inhibited the phosphorylation of down-stream effectors AKT and ERKs, while STAT3Tyr705 phosphorylation remained unchanged. Combining these two agents neither induced synergistic growth suppression nor inhibited STAT3Tyr705 phosphorylation, thus prompting further studies to assess whether targeting STAT3 improves the response to gemcitabine or AG1478. Indeed, knockdown of STAT3 increased sensitivity to gemcitabine by inducing pro-apoptotic signals and by increasing G1 cell cycle arrest. However, knockdown of STAT3 did not enhance the growth inhibitory potential of AG1478. In vivo orthotopic animal model results show that knockdown of STAT3 caused a significant reduction in tumor burden and delayed tumor progression with increased response to gemcitabine associated with a decrease in the Ki-67 positive cells. CONCLUSIONS: This study suggests that STAT3 should be considered an important molecular target for therapy of PDAC for enhancing the response to gemcitabine.
Assuntos
Antimetabólitos Antineoplásicos/farmacologia , Carcinoma Ductal Pancreático/metabolismo , Desoxicitidina/análogos & derivados , Neoplasias Pancreáticas/metabolismo , Fator de Transcrição STAT3/metabolismo , Animais , Apoptose/efeitos dos fármacos , Carcinoma Ductal Pancreático/tratamento farmacológico , Carcinoma Ductal Pancreático/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Desoxicitidina/farmacologia , Progressão da Doença , Resistencia a Medicamentos Antineoplásicos , Sinergismo Farmacológico , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Técnicas de Silenciamento de Genes , Humanos , Camundongos , Camundongos Nus , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/patologia , Fosforilação , Processamento de Proteína Pós-Traducional , Quinazolinas/farmacologia , RNA Interferente Pequeno/genética , Fator de Transcrição STAT3/genética , Tirfostinas/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto , GencitabinaRESUMO
Urothelial carcinoma (UC) is the most common form of bladder cancer (BC) and is the variant with the most immunogenic response. This makes urothelial carcinoma an ideal candidate for immunotherapy with immune checkpoint inhibitors. Key immune checkpoint proteins PD-1 and CTLA-4 are frequently expressed on T-cells in urothelial carcinoma. The blockade of this immune checkpoint can lead to the reactivation of lymphocytes and augment the anti-tumor immune response. The only immune checkpoint inhibitors that are FDA-approved for metastatic urothelial carcinoma target the programmed death-1 receptor and its ligand (PD-1/PD-L1) axis. However, the overall response rate and progression-free survival rates of these agents are limited in this patient population. Therefore, there is a need to find further immune-bolstering treatment combinations that may positively impact survival for patients with advanced UC. In this review, the current immune checkpoint inhibition treatment landscape is explored with an emphasis on combination therapy in the form of PD-1/PD-L1 with CTLA-4 blockade. The investigation of the current literature on immune checkpoint inhibition found that preclinical data show a decrease in tumor volumes and size when PD-1/PD-L1 is blocked, and similar results were observed with CTLA-4 blockade. However, there are limited investigations evaluating the combination of CTLA-4 and PD-1/PD-L1 blockade. We anticipate this review to provide a foundation for a deeper experimental investigation into combination immune checkpoint inhibition therapy in metastatic urothelial carcinoma.
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Although cisplatin remains a backbone of standard-of-care chemotherapy regimens for a variety of malignancies, its use is often associated with severe dose-limiting toxicities (DLT). Notably, 30%-40% of patients treated with cisplatin-based regimens are forced to discontinue treatment after experiencing nephrotoxicity as a DLT. New approaches that simultaneously prevent renal toxicity while improving therapeutic response have the potential to make a major clinical impact for patients with multiple forms of cancer. Here, we report that pevonedistat (MLN4924), a first-in-class NEDDylation inhibitor, alleviates nephrotoxicity and synergistically enhances the efficacy of cisplatin in head and neck squamous cell carcinoma (HNSCC) models. We demonstrate that pevonedistat protects normal kidney cells from injury while enhancing the anticancer activity of cisplatin through a thioredoxin-interacting protein (TXNIP)-mediated mechanism. Cotreatment with pevonedistat and cisplatin yielded dramatic HNSCC tumor regression and long-term animal survival in 100% of treated mice. Importantly, the combination decreased nephrotoxicity induced by cisplatin monotherapy as evidenced by the blockade of kidney injury molecule-1 (KIM-1) and TXNIP expression, a reduction in collapsed glomeruli and necrotic cast formation, and inhibition of cisplatin-mediated animal weight loss. Inhibition of NEDDylation represents a novel strategy to prevent cisplatin-induced nephrotoxicity while simultaneously enhancing its anticancer activity through a redox-mediated mechanism. Significance: Cisplatin therapy is associated with significant nephrotoxicity, which limits its clinical use. Here we demonstrate that NEDDylation inhibition with pevonedistat is a novel approach to selectively prevent cisplatin-induced oxidative damage to the kidneys while simultaneously enhancing its anticancer efficacy. Clinical evaluation of the combination of pevonedistat and cisplatin is warranted.
Assuntos
Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Neoplasias de Cabeça e Pescoço , Camundongos , Animais , Cisplatino/efeitos adversos , Carcinoma de Células Escamosas de Cabeça e Pescoço , Apoptose , Neoplasias de Cabeça e Pescoço/tratamento farmacológicoRESUMO
BACKGROUND: Autophagy plays an important role in the pathogenesis of pulmonary hypertension (PH). ROC-325 is a novel small molecule lysosomal autophagy inhibitor that has more potent anticancer activity than the antimalarial drug hydroxychloroquine, the latter has been prevalently used to inhibit autophagy. Here, we sought to determine the therapeutic benefit and mechanism of action of ROC-325 in experimental PH models. METHODS AND RESULTS: Hemodynamics, echocardiography, and histology measurement showed that ROC-325 treatment prevented the development of PH, right ventricular hypertrophy, fibrosis, dysfunction, and vascular remodeling after monocrotaline and Sugen5416/hypoxia administration. ROC-325 attenuated high K+ or alveolar hypoxia-induced pulmonary vasoconstriction and enhanced endothelial-dependent relaxation in isolated pulmonary artery rings. ROC-325 treatment inhibited autophagy and enhanced endothelial nitric oxide synthase activity in lung tissues of monocrotaline-PH rats. In cultured human and rat pulmonary arterial smooth muscle cell and pulmonary arterial endothelial cell under hypoxia exposure, ROC-325 increased LC3B (light chain 3 beta) and p62 accumulation, endothelial cell nitric oxide production via phosphorylation of endothelial nitric oxide synthase (Ser1177) and dephosphorylation of endothelial nitric oxide synthase (Thr495) as well as decreased HIF (hypoxia-inducible factor)-1α and HIF-2α stabilization. CONCLUSIONS: These data indicate that ROC-325 is a promising novel agent for the treatment of PH that inhibits autophagy, downregulates HIF levels, and increases nitric oxide production.
Assuntos
Hipertensão Pulmonar , Humanos , Ratos , Animais , Hipertensão Pulmonar/tratamento farmacológico , Óxido Nítrico Sintase Tipo III , Óxido Nítrico , Lisossomos , Autofagia , Hipóxia/complicações , Hipóxia/tratamento farmacológicoRESUMO
PURPOSE: Our preclinical studies showed that the oncolytic reovirus formulation pelareorep (PELA) has significant immunomodulatory anti-myeloma activity. We conducted an investigator-initiated clinical trial to evaluate PELA in combination with dexamethasone (Dex) and bortezomib (BZ) and define the tumor immune microenvironment (TiME) in patients with multiple myeloma treated with this regimen. PATIENTS AND METHODS: Patients with relapsed/refractory multiple myeloma (n = 14) were enrolled in a phase Ib clinical trial (ClinicalTrials.gov: NCT02514382) of three escalating PELA doses administered on Days 1, 2, 8, 9, 15, and 16. Patients received 40 mg Dex and 1.5 mg/m2 BZ on Days 1, 8, and 15. Cycles were repeated every 28 days. Pre- and posttreatment bone marrow specimens (IHC, n = 9; imaging mass cytometry, n = 6) and peripheral blood samples were collected for analysis (flow cytometry, n = 5; T-cell receptor clonality, n = 7; cytokine assay, n = 7). RESULTS: PELA/BZ/Dex was well-tolerated in all patients. Treatment-emergent toxicities were transient, and no dose-limiting toxicities occurred. Six (55%) of 11 response-evaluable patients showed decreased paraprotein. Treatment increased T and natural killer cell activation, inflammatory cytokine release, and programmed death-ligand 1 expression in bone marrow. Compared with nonresponders, responders had higher reovirus protein levels, increased cytotoxic T-cell infiltration posttreatment, cytotoxic T cells in significantly closer proximity to multiple myeloma cells, and larger populations of a novel immune-primed multiple myeloma phenotype (CD138+ IDO1+HLA-ABCHigh), indicating immunomodulation. CONCLUSIONS: PELA/BZ/Dex is well-tolerated and associated with anti-multiple myeloma activity in a subset of responding patients, characterized by immune reprogramming and TiME changes, warranting further investigation of PELA as an immunomodulator.
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Mieloma Múltiplo , Terapia Viral Oncolítica , Humanos , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/etiologia , Terapia Viral Oncolítica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Bortezomib/uso terapêutico , Dexametasona/uso terapêutico , Citocinas/uso terapêutico , Microambiente TumoralRESUMO
Cellular stress induced by nutrient deprivation, hypoxia, and exposure to many chemotherapeutic agents activates an evolutionarily conserved cell survival pathway termed autophagy. This pathway enables cancer cells to undergo self-digestion to generate ATP and other essential biosynthetic molecules to temporarily avoid cell death. Therefore, disruption of autophagy may sensitize cancer cells to cell death and augment chemotherapy-induced apoptosis. Chloroquine and its analog hydroxychloroquine are the only clinically relevant autophagy inhibitors. Because both of these agents induce ocular toxicity, novel inhibitors of autophagy with a better therapeutic index are needed. Here we demonstrate that the small molecule lucanthone inhibits autophagy, induces lysosomal membrane permeabilization, and possesses significantly more potent activity in breast cancer models compared with chloroquine. Exposure to lucanthone resulted in processing and recruitment of microtubule-associated protein 1 light chain 3 (LC3) to autophagosomes, but impaired autophagic degradation as revealed by transmission electron microscopy and the accumulation of p62/SQSTM1. Microarray analysis, qRT-PCR, and immunoblotting determined that lucanthone stimulated a large induction in cathepsin D, which correlated with cell death. Accordingly, knockdown of cathepsin D reduced lucanthone-mediated apoptosis. Subsequent studies using p53(+/+) and p53(-/-) HCT116 cells established that lucanthone induced cathepsin D expression and reduced cancer cell viability independently of p53 status. In addition, lucanthone enhanced the anticancer activity of the histone deacetylase inhibitor vorinostat. Collectively, our results demonstrate that lucanthone is a novel autophagic inhibitor that induces apoptosis via cathepsin D accumulation and enhances vorinostat-mediated cell death in breast cancer models.
Assuntos
Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Neoplasias da Mama/tratamento farmacológico , Catepsina D/metabolismo , Lucantona/farmacologia , Esquistossomicidas/farmacologia , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Antineoplásicos/agonistas , Antineoplásicos/farmacologia , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Catepsina D/genética , Linhagem Celular Tumoral , Sinergismo Farmacológico , Perfilação da Expressão Gênica , Humanos , Ácidos Hidroxâmicos/agonistas , Ácidos Hidroxâmicos/farmacologia , Membranas Intracelulares/metabolismo , Lucantona/agonistas , Lisossomos/genética , Lisossomos/metabolismo , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , Permeabilidade/efeitos dos fármacos , Fagossomos/genética , Fagossomos/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Esquistossomicidas/agonistas , Proteína Sequestossoma-1 , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , VorinostatRESUMO
Novel therapies are urgently needed to improve clinical outcomes for patients with acute myeloid leukemia (AML). The investigational drug alisertib (MLN8237) is a novel Aurora A kinase inhibitor being studied in multiple Phase I and II studies. We investigated the preclinical efficacy and pharmacodynamics of alisertib in AML cell lines, primary AML cells and mouse models of AML. Here, we report that alisertib disrupted cell viability, diminished clonogenic survival, induced expression of the FOXO3a targets p27 and BIM and triggered apoptosis. A link between Aurora A expression and sensitivity to ara-C was established, suggesting that Aurora A inhibition may be a promising strategy to increase the efficacy of ara-C. Accordingly, alisertib significantly potentiated the antileukemic activity of ara-C in both AML cell lines and primary blasts. Targeted FOXO3a knockdown significantly blunted the pro-apoptotic effects of the alisertib/ara-C combination, indicating that it is an important regulator of sensitivity to these agents. In vivo studies demonstrated that alisertib significantly augmented the efficacy of ara-C without affecting its pharmacokinetic profile and led to the induction of p27 and BIM. Our collective data indicate that targeting Aurora A with alisertib represents a novel approach to increase the efficacy of ara-C that warrants further investigation.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Azepinas/farmacologia , Citarabina/farmacologia , Fatores de Transcrição Forkhead/metabolismo , Leucemia Mieloide Aguda/tratamento farmacológico , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Pirimidinas/farmacologia , Animais , Apoptose/efeitos dos fármacos , Proteínas Reguladoras de Apoptose/metabolismo , Aurora Quinase A , Aurora Quinases , Proteína 11 Semelhante a Bcl-2 , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Inibidor de Quinase Dependente de Ciclina p27/metabolismo , Sinergismo Farmacológico , Feminino , Proteína Forkhead Box O3 , Células HL-60 , Humanos , Leucemia Mieloide Aguda/enzimologia , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/patologia , Proteínas de Membrana/metabolismo , Camundongos , Camundongos SCID , Terapia de Alvo Molecular , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
NEDD8 activating enzyme (NAE) has been identified as an essential regulator of the NEDD8 conjugation pathway, which controls the degradation of many proteins with important roles in cell-cycle progression, DNA damage, and stress responses. Here we report that MLN4924, a novel inhibitor of NAE, has potent activity in acute myeloid leukemia (AML) models. MLN4924 induced cell death in AML cell lines and primary patient specimens independent of Fms-like tyrosine kinase 3 expression and stromal-mediated survival signaling and led to the stabilization of key NAE targets, inhibition of nuclear factor-kappaB activity, DNA damage, and reactive oxygen species generation. Disruption of cellular redox status was shown to be a key event in MLN4924-induced apoptosis. Administration of MLN4924 to mice bearing AML xenografts led to stable disease regression and inhibition of NEDDylated cullins. Our findings indicate that MLN4924 is a highly promising novel agent that has advanced into clinical trials for the treatment of AML.
Assuntos
Ciclopentanos/farmacologia , Leucemia Mieloide Aguda/tratamento farmacológico , Inibidores de Proteassoma , Pirimidinas/farmacologia , Ubiquitinas/metabolismo , Animais , Western Blotting , Linhagem Celular Tumoral , Proteínas Culina , Dano ao DNA/efeitos dos fármacos , Imunofluorescência , Humanos , Camundongos , Proteína NEDD8 , NF-kappa B/genética , NF-kappa B/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais , Ensaios Antitumorais Modelo de Xenoenxerto , Tirosina Quinase 3 Semelhante a fms/genética , Tirosina Quinase 3 Semelhante a fms/metabolismoRESUMO
Patients with late-stage and human papillomavirus (HPV)-negative head and neck squamous cell carcinoma (HNSCC) continue to have a very poor prognosis. The development of more effective novel therapies that improve overall survival and overcome drug resistance is an urgent priority. Here we report that HNSCC tumors significantly overexpress NEDD8 and exhibit high sensitivity to the first-in-class NEDD8-activating enzyme (NAE) inhibitor pevonedistat. Additional studies established that disruption of NEDD8-mediated protein turnover with pevonedistat dramatically augmented cisplatin-induced DNA damage and apoptosis in HNSCC models. Further analysis revealed that the specific pevonedistat target CUL4A played an essential role in driving the synergy of the pevonedistat and cisplatin combination. Targeted inhibition of CUL4A resulted in significant downregulation in Damage Specific DNA binding protein 2 (DDB2), a DNA-damage recognition protein that promotes nucleotide excision repair and resistance to cisplatin. Silencing of CUL4A or DDB2 enhanced cisplatin-induced DNA damage and apoptosis in a manner similar to that of pevonedistat demonstrating that targeted inhibition of CUL4A may be a novel approach to augment cisplatin therapy. Administration of pevonedistat to mice bearing HNSCC tumors significantly decreased DDB2 expression in tumor cells, increased DNA damage and potently enhanced the activity of cisplatin to yield tumor regression and long-term survival of all animals. Our findings provide strong rationale for clinical investigation of CUL4A inhibition with pevonedistat as a novel strategy to augment the efficacy of cisplatin therapy for patients with HNSCC and identify loss of DDB2 as a key pharmacodynamic mediator controlling sensitivity to this regimen.
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Cisplatino , Proteínas Culina , Proteínas de Ligação a DNA , Neoplasias de Cabeça e Pescoço , Carcinoma de Células Escamosas de Cabeça e Pescoço , Animais , Linhagem Celular Tumoral , Cisplatino/farmacologia , Proteínas Culina/antagonistas & inibidores , Proteínas Culina/genética , Proteínas Culina/metabolismo , Proteínas de Ligação a DNA/antagonistas & inibidores , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Sinergismo Farmacológico , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Neoplasias de Cabeça e Pescoço/genética , Neoplasias de Cabeça e Pescoço/metabolismo , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Camundongos , Carcinoma de Células Escamosas de Cabeça e Pescoço/tratamento farmacológico , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética , Carcinoma de Células Escamosas de Cabeça e Pescoço/metabolismo , Carcinoma de Células Escamosas de Cabeça e Pescoço/patologiaRESUMO
Novel therapies are urgently needed to prevent and treat tyrosine kinase inhibitor resistance in chronic myeloid leukaemia (CML). MLN8237 is a novel Aurora A kinase inhibitor under investigation in multiple phase I and II studies. Here we report that MLN8237 possessed equipotent activity against Ba/F3 cells and primary CML cells expressing unmutated and mutated forms of breakpoint cluster region-Abelson kinase (BCR-ABL). Notably, this agent retained high activity against the T315I and E255K BCR-ABL mutations, which confer the greatest degree of resistance to standard therapy. MLN8237 treatment disrupted cell cycle kinetics, induced apoptosis, caused a dose-dependent reduction in the expression of the large inhibitor of apoptosis protein Apollon, and produced a morphological phenotype consistent with Aurora A kinase inhibition. In contrast to other Aurora kinase inhibitors, MLN8237 did not significantly affect BCR-ABL activity. Moreover, inhibition of Aurora A with MLN8237 significantly increased the in vitro and in vivo efficacy of nilotinib. Targeted knockdown of Apollon sensitized CML cells to nilotinib-induced apoptosis, indicating that this is an important factor underlying MLN8237's ability to increase the efficacy of nilotinib. Our collective data demonstrate that this combination strategy represents a novel therapeutic approach for refractory CML that has the potential to suppress the emergence of T315I mutated CML clones.
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Apoptose/efeitos dos fármacos , Azepinas/farmacologia , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Leucemia Mielogênica Crônica BCR-ABL Positiva/enzimologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Pirimidinas/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Aurora Quinases , Benzamidas , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Proteínas de Fusão bcr-abl/genética , Proteínas de Fusão bcr-abl/metabolismo , Humanos , Mesilato de Imatinib , Proteínas Inibidoras de Apoptose/metabolismo , Células K562 , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Mutação , Piperazinas/farmacologia , Proteínas Tirosina Quinases/genética , Proteínas Tirosina Quinases/metabolismoRESUMO
Human T-cell leukemia virus type 1 (HTLV-1) is a retrovirus that infects at least 10 million people worldwide and is associated with the development of T-cell lymphoma (TCL). The treatment of TCL remains challenging and new treatment options are urgently needed. With the goal of developing a novel therapeutic approach for TCL, we investigated the activity of the clinical formulation of oncolytic reovirus (Reolysin, Pelareorep) in TCL models. Our studies revealed that HTLV-1-negative TCL cells were highly sensitive to Reolysin-induced cell death, but HTLV-1-positive TCL cells were resistant. Consistent with these data, reovirus displayed significant viral accumulation in HTLV-1-negative cells, but failed to efficiently replicate in HTLV-1-positive cells. Transcriptome analyses of HTLV-1-positive vs. negative cells revealed a significant increase in genes associated with retroviral infection including interleukin-13 and signal transducer and activator of transcription 5 (STAT5). To investigate the relationship between HTLV-1 status and sensitivity to Reolysin, we infected HTLV-1-negative cells with HTLV-1. The presence of HTLV-1 resulted in significantly decreased sensitivity to Reolysin. Treatment with the JAK inhibitor ruxolitinib suppressed STAT5 phosphorylation and expression of the key anti-viral response protein MX1 and enhanced the anti-TCL activity of Reolysin in both HTLV-1-positive and negative cells. Our data demonstrate that the inhibition of the JAK/STAT pathway can be used as a novel approach to antagonize the resistance of HTLV-1-positive cells to oncolytic virus therapy.
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Janus Quinases/antagonistas & inibidores , Leucemia-Linfoma de Células T do Adulto/terapia , Leucemia-Linfoma de Células T do Adulto/virologia , Vírus Oncolíticos/fisiologia , Reoviridae/fisiologia , Fator de Transcrição STAT5/antagonistas & inibidores , Linhagem Celular Tumoral , Perfilação da Expressão Gênica , Vírus Linfotrópico T Tipo 1 Humano , Humanos , Nitrilas/farmacologia , Fosforilação , Pirazóis/farmacologia , Pirimidinas/farmacologia , Transdução de Sinais/efeitos dos fármacosRESUMO
Head and neck cancer is diagnosed in nearly 900,000 new patients worldwide each year. Despite this alarming number, patient outcomes, particularly for those diagnosed with late-stage and human papillomavirus (HPV)-negative disease, have only marginally improved in the last three decades. New therapeutics that target novel pathways are desperately needed. NEDDylation is a key cellular process by which NEDD8 proteins are conjugated to substrate proteins in order to modulate their function. NEDDylation is closely tied to appropriate protein degradation, particularly proteins involved in cell cycle regulation, DNA damage repair, and cellular stress response. Components of the NEDDylation pathway are frequently overexpressed or hyperactivated in many cancer types including head and neck cancer, which contribute to disease progression and drug resistance. Therefore, targeting NEDDylation could have a major impact for malignancies with alterations in the pathway, and this has already been demonstrated in preclinical studies and clinical trials. Here, we will survey the mechanisms by which aberrant NEDDylation contributes to disease pathogenesis and discuss the potential clinical implications of inhibiting NEDDylation as a novel approach for the treatment of head and neck cancer.
RESUMO
A hallmark feature of tumorigenesis is uncontrolled cell division. Autophagy is regulated by more than 30 genes and it is one of several mechanisms by which cells maintain homeostasis. Autophagy promotes cancer progression and drug resistance. Several genes play important roles in autophagy-induced tumorigenesis and drug resistance including Beclin-1, MIF, HMGB1, p53, PTEN, p62, RAC3, SRC3, NF-2, MEG3, LAPTM4B, mTOR, BRAF and c-MYC. These genes alter cell growth, cellular microenvironment and cell division. Mechanisms involved in tumorigenesis and drug resistance include microdeletions, genetic mutations, loss of heterozygosity, hypermethylation, microsatellite instability and translational modifications at a molecular level. Disrupted or altered autophagy has been reported in hematological malignancies like lymphoma, leukemia and myeloma as well as multiple solid organ tumors like colorectal, hepatocellular, gall bladder, pancreatic, gastric and cholangiocarcinoma among many other malignancies. In addition, defects in autophagy also play a role in drug resistance in cancers like osteosarcoma, ovarian and lung carcinomas following treatment with drugs such as doxorubicin, paclitaxel, cisplatin, gemcitabine and etoposide. Therapeutic approaches that modulate autophagy are a novel future direction for cancer drug development that may help to prevent issues with disease progression and overcome drug resistance.
Assuntos
Antineoplásicos/farmacologia , Autofagia , Biomarcadores Tumorais/metabolismo , Carcinogênese/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Carcinogênese/metabolismo , Carcinogênese/patologia , Humanos , Neoplasias/metabolismoRESUMO
Autophagy is an evolutionarily conserved cell survival pathway that enables cells to recoup ATP and other critical biosynthetic molecules during nutrient deprivation or exposure to hypoxia, which are hallmarks of the tumour microenvironment. Autophagy has been implicated as a potential mechanism of resistance to anticancer agents as it can promote cell survival in the face of stress induced by chemotherapeutic agents by breaking down cellular components to generate alternative sources of energy. Disruption of autophagy with chloroquine (CQ) induces the accumulation of ubiquitin-conjugated proteins in a manner similar to the proteasome inhibitor bortezomib (BZ). However, CQ-induced protein accumulation occurs at a slower rate and is localized to lysosomes in contrast to BZ, which stimulates rapid buildup of ubiquitinated proteins and aggresome formation in the cytosol. The histone deacetylase (HDAC) inhibitor vorinostat (VOR) blocked BZ-induced aggresome formation, but promoted CQ-mediated ubiquitinated protein accumulation. Disruption of autophagy with CQ strongly enhanced VOR-mediated apoptosis in colon cancer cells. Accordingly, knockdown of the essential autophagy gene Atg7 also sensitized cells to VOR-induced apoptosis. Knockdown of HDAC6 greatly enhanced BZ-induced apoptosis, but only marginally sensitized cells to CQ. Subsequent studies determined that the CQ/VOR combination promoted a large increase in superoxide generation that was required for ubiquitinated protein accumulation and cell death. Finally, treatment with the CQ/VOR combination significantly reduced tumour burden and induced apoptosis in a colon cancer xenograft model. Collectively, our results establish that inhibition of autophagy with CQ induces ubiquitinated protein accumulation and VOR potentiates CQ-mediated aggregate formation, superoxide generation and apoptosis.
Assuntos
Antineoplásicos/farmacologia , Apoptose , Autofagia , Ácidos Hidroxâmicos/farmacologia , Proteínas Ubiquitinadas/metabolismo , Animais , Antineoplásicos/metabolismo , Ácidos Borônicos/farmacologia , Bortezomib , Carcinoma/tratamento farmacológico , Carcinoma/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular , Cloroquina/farmacologia , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/metabolismo , Feminino , Células HT29 , Inibidores de Histona Desacetilases/metabolismo , Histona Desacetilases/metabolismo , Humanos , Lisossomos/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Complexo de Endopeptidases do Proteassoma/metabolismo , Pirazinas/farmacologia , Superóxidos/metabolismo , Vorinostat , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
The histone deacetylase inhibitor SAHA enhances cell death stimulated by the proteasome inhibitor bortezomib (BZ) by disrupting BZ-induced aggresome formation. Here we report that Myc regulates the sensitivity of multiple myeloma (MM) cells to BZ + SAHA-induced cell death. In MM cells, Myc expression directly correlated with intracellular ER content, protein synthesis rates, the percentage of aggresome-positive cells, and the sensitivity to BZ + SAHA-induced cell death. Accordingly, Myc knockdown markedly reduced the sensitivity of MM cells to BZ + SAHA-mediated apoptosis. Furthermore, activation of Myc was sufficient to provoke aggresome formation and thus sensitivity to BZ + SAHA, and these responses required de novo protein synthesis. BZ + SAHA-mediated stimulation of apoptosis includes the induction of the proapoptotic BH3-only protein Noxa as well as endoplasmic reticular stress, a disruption of calcium homeostasis, and activation of capase-4. Finally, knockdown studies demonstrated that both caspase-4 and Noxa play significant roles in Myc-driven sensitivity to BZ + SAHA-induced apoptosis. Collectively, our results establish a mechanistic link between Myc activity, regulation of protein synthesis, increases in HDAC6 expression and aggresome formation, induction of Noxa, and sensitivity to BZ + SAHA-induced apoptosis. These data suggest that MM patients with elevated Myc activity may be particularly sensitive to the BZ + SAHA combination.
Assuntos
Apoptose/efeitos dos fármacos , Ácidos Borônicos/farmacologia , Estruturas do Núcleo Celular/efeitos dos fármacos , Estruturas do Núcleo Celular/metabolismo , Ácidos Hidroxâmicos/farmacologia , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , Pirazinas/farmacologia , Bortezomib , Linhagem Celular Tumoral , Estruturas do Núcleo Celular/ultraestrutura , Cicloeximida/farmacologia , Diploide , Sinergismo Farmacológico , Retículo Endoplasmático/efeitos dos fármacos , Retículo Endoplasmático/patologia , Retículo Endoplasmático/ultraestrutura , Fibroblastos/efeitos dos fármacos , Fibroblastos/patologia , Desacetilase 6 de Histona , Histona Desacetilases/metabolismo , Humanos , Mieloma Múltiplo/patologia , Biossíntese de Proteínas/efeitos dos fármacos , RNA Interferente Pequeno/metabolismo , VorinostatRESUMO
Autophagy is a mechanism of lysosomal proteolysis that is utilized to degrade damaged organelles, proteins, and other cellular components. Although key studies demonstrate that autophagy functions as a mechanism of tumor suppression via the degradation of defective pre-malignant cells, autophagy can also be used as a mechanism to break down cellular components under stress conditions to generate the required metabolic materials for cell survival. Autophagy has emerged as an important mediator of resistance to radiation, chemotherapy, and targeted agents. This series of articles highlight the role of autophagy in cancer progression and drug resistance and underscores the need for new and more effective agents that target this process.
RESUMO
Kidney cancer is the 7th most prevalent form of cancer in the United States with the vast majority of cases being classified as renal cell carcinoma (RCC). Multiple targeted therapies have been developed to treat RCC, but efficacy and resistance remain a challenge. In recent years, the modulation of autophagy has been shown to augment the cytotoxicity of approved RCC therapeutics and overcome drug resistance. Inhibition of autophagy blocks a key nutrient recycling process that cancer cells utilize for cell survival following periods of stress including chemotherapeutic treatment. Classic autophagy inhibitors such as chloroquine and hydroxychloroquine have been introduced into phase I/II clinical trials, while more experimental compounds are moving forward in preclinical development. Here we examine the current state and future directions of targeting autophagy to improve the efficacy of RCC therapeutics.