RESUMO
Increased expression of the chemokine CX3CL1 and its sole receptor, CX3CR1 have been correlated with poor pancreatic cancer patient survival and time to recurrence, as well as with pancreatic perineural invasion. We have previously shown that metastasis of prostate and breast cancer is in part driven by CX3CL1, and have developed small molecule inhibitors against the CX3CR1 receptor that diminish metastatic burden. Here we ask if inhibition of this chemokine receptor affects the phenotype of PDAC tumor cells. Our findings demonstrate that motility, invasion, and contact-independent growth of PDAC cells all increase following CX3CL1 exposure, and that antagonism of CX3CR1 by the inhibitor JMS-17-2 reduces each of these phenotypes and correlates with a downregulation of AKT phosphorylation. These data suggest that PDAC tumor cell migration and growth, elements critical in metastatic progression, may susceptible to pharmacologic intervention.
Assuntos
Receptor 1 de Quimiocina CX3C/metabolismo , Carcinoma Ductal Pancreático/metabolismo , Carcinoma Ductal Pancreático/patologia , Movimento Celular , Sobrevivência Celular , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Biomarcadores Tumorais/metabolismo , Linhagem Celular Tumoral , Humanos , Invasividade NeoplásicaRESUMO
PURPOSE: The importance of cellular context to the synergy of DNA damage response (DDR)-targeted agents is important for tumors with mutations in DDR pathways, but less well-established for tumors driven by oncogenic transcription factors. In this study, we exploit the widespread transcriptional dysregulation of the EWS-FLI1 transcription factor to identify an effective DDR-targeted combination therapy for Ewing sarcoma. EXPERIMENTAL DESIGN: We used matrix drug screening to evaluate synergy between a DNA-PK inhibitor (M9831) or an ATR inhibitor (berzosertib) and chemotherapy. The combination of berzosertib and cisplatin was selected for broad synergy, mechanistically evaluated for Ewing sarcoma selectivity, and optimized for in vivo schedule. RESULTS: Berzosertib combined with cisplatin demonstrates profound synergy in multiple Ewing sarcoma cell lines at clinically achievable concentrations. The synergy is due to loss of expression of the ATR downstream target CHEK1, loss of cell-cycle check-points, and mitotic catastrophe. Consistent with the goals of the project, EWS-FLI1 drives the expression of CHEK1 and five other ATR pathway members. The loss of CHEK1 expression is not due to transcriptional repression and instead caused by degradation coupled with suppression of protein translation. The profound synergy is realized in vivo with a novel optimized schedule of this combination in subsets of Ewing sarcoma models, leading to durable complete responses in 50% of animals bearing two different Ewing sarcoma xenografts. CONCLUSIONS: These data exploit EWS-FLI1 driven alterations in cell context to broaden the therapeutic window of berzosertib and cisplatin to establish a promising combination therapy and a novel in vivo schedule. See related commentary by Ohmura and Grünewald, p. 3358.
Assuntos
Proteínas Mutadas de Ataxia Telangiectasia , Cisplatino , Sinergismo Farmacológico , Proteína Proto-Oncogênica c-fli-1 , Proteína EWS de Ligação a RNA , Sarcoma de Ewing , Ensaios Antitumorais Modelo de Xenoenxerto , Sarcoma de Ewing/tratamento farmacológico , Sarcoma de Ewing/patologia , Sarcoma de Ewing/genética , Humanos , Cisplatino/farmacologia , Animais , Proteínas Mutadas de Ataxia Telangiectasia/antagonistas & inibidores , Camundongos , Proteína EWS de Ligação a RNA/genética , Proteína EWS de Ligação a RNA/antagonistas & inibidores , Linhagem Celular Tumoral , Proteína Proto-Oncogênica c-fli-1/genética , Proteína Proto-Oncogênica c-fli-1/antagonistas & inibidores , Proteínas de Fusão Oncogênica/genética , Proteínas de Fusão Oncogênica/antagonistas & inibidores , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Quinase 1 do Ponto de Checagem/antagonistas & inibidores , Dano ao DNA/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Isoxazóis , PirazinasRESUMO
RAS is the most commonly mutated driver of tumorigenesis, seen in about 30% of all cancer cases. There is a subset of tumors termed RAS-driven cancers in which RAS mutation or overactivation is evident, including as much as 95% in pancreatic and 50% in colon cancer. RAS is a family of small membrane bound GTPases that act as a signaling node to control both normal and cancer biology. Since the discovery of RAS' overall prominence in many tumor types and specifically in RAS-dependent cancers, it has been an obvious therapeutic target for drug development. However, RAS has proved a very elusive target, and after a few prominent RAS targeted drugs failed in clinical trials after decades of research, RAS was termed "undruggable" and research in this field was greatly hampered. An increase in knowledge about basic RAS biology has led to a resurgence in the generation of novel therapeutics targeting RAS signaling utilizing various and distinct approaches. These new drugs target RAS activation directly, block downstream signaling effectors and inhibit proper post-translational processing and trafficking/recycling of RAS. This review will cover how these new drugs were developed and how they have fared in preclinical and early phase clinical trials.
Assuntos
Antineoplásicos/administração & dosagem , Genes ras/fisiologia , Terapia de Alvo Molecular/tendências , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Animais , Genes ras/efeitos dos fármacos , Humanos , Terapia de Alvo Molecular/métodos , Neoplasias/genéticaRESUMO
Pancreatic ductal adenocarcinoma (PDA) is the third leading cause of cancer-related deaths in the United States, whereas colorectal cancer is the third most common cancer. The RNA-binding protein HuR (ELAVL1) supports a pro-oncogenic network in gastrointestinal (GI) cancer cells through enhanced HuR expression. Using a publically available database, HuR expression levels were determined to be increased in primary PDA and colorectal cancer tumor cohorts as compared with normal pancreas and colon tissues, respectively. CRISPR/Cas9 technology was successfully used to delete the HuR gene in both PDA (MIA PaCa-2 and Hs 766T) and colorectal cancer (HCT116) cell lines. HuR deficiency has a mild phenotype, in vitro, as HuR-deficient MIA PaCa-2 (MIA.HuR-KO(-/-)) cells had increased apoptosis when compared with isogenic wild-type (MIA.HuR-WT(+/+)) cells. Using this isogenic system, mRNAs were identified that specifically bound to HuR and were required for transforming a two-dimensional culture into three dimensional (i.e., organoids). Importantly, HuR-deficient MIA PaCa-2 and Hs 766T cells were unable to engraft tumors in vivo compared with control HuR-proficient cells, demonstrating a unique xenograft lethal phenotype. Although not as a dramatic phenotype, CRISPR knockout HuR HCT116 colon cancer cells (HCT.HuR-KO(-/-)) showed significantly reduced in vivo tumor growth compared with controls (HCT.HuR-WT(+/+)). Finally, HuR deletion affects KRAS activity and controls a subset of pro-oncogenic genes.Implications: The work reported here supports the notion that targeting HuR is a promising therapeutic strategy to treat GI malignancies. Mol Cancer Res; 15(6); 696-707. ©2017 AACR.
Assuntos
Adenocarcinoma/genética , Carcinoma Ductal Pancreático/genética , Neoplasias do Colo/genética , Proteína Semelhante a ELAV 1/genética , Neoplasias Pancreáticas/genética , Adenocarcinoma/patologia , Animais , Carcinoma Ductal Pancreático/patologia , Linhagem Celular Tumoral , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Neoplasias do Colo/patologia , Proteína Semelhante a ELAV 1/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica , Técnicas de Inativação de Genes , Humanos , Camundongos Nus , Neoplasias Experimentais/genética , Neoplasias Pancreáticas/patologia , Fenótipo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Ras-dependent signaling is an important regulator of cell cycle progression, proliferation, senescence, and apoptosis. Several of the downstream effectors of Ras play dual roles in each of these processes. Under one set of conditions, they promote cell cycle progression and proliferation; yet, in a different paradigm, they drive cell cycle arrest and apoptosis. Furthermore, there is cross talk between certain downstream effectors of Ras including the PI3K-AKT and Raf-MEK-ERK pathways. Here we describe a series of experiments used to dissect the effect of different Ras-dependent signaling pathways on cell cycle progression, proliferation, senescence, and apoptosis. Furthermore, we highlight the importance of consistent growth conditions of cells in culture when studying Ras-dependent signaling as we show that the activation of downstream effectors of Ras changes with the confluency at which the cells are grown.