RESUMO
Pancreatic ductal adenocarcinoma (PDAC) remains a very difficult cancer to treat. Recent in vitro and in vivo studies suggest that the activation of the receptor for advanced glycation end products (RAGE) by its ligands stimulates pancreatic cancer cell proliferation and tumor growth. Additional studies show that, in the RAGE ligand, the high mobility group box 1 (HMGB1) protein plays an important role in chemoresistance against the cytotoxic agent gemcitabine by promoting cell survival through increased autophagy. We hypothesized that blocking the RAGE/HMGB1 interaction would enhance the cytotoxic effect of gemcitabine by reducing cell survival and autophagy. Using a preclinical mouse model of PDAC and a monoclonal antibody (IgG 2A11) as a RAGE inhibitor, we demonstrate that RAGE inhibition concurrent with gemcitabine treatment enhanced the cytotoxic effect of gemcitabine. The combination of IgG 2A11 and gemcitabine resulted in decreased autophagy compared to treatment with gemcitabine combined with control antibodies. Notably, we also observed that RAGE inhibition protected against excessive weight loss during treatment with gemcitabine. Our data suggest that the combination of gemcitabine with a RAGE inhibitor could be a promising therapeutic approach for the treatment of pancreatic cancer and needs to be further investigated.
Assuntos
Autofagia/efeitos dos fármacos , Desoxicitidina/análogos & derivados , Receptor para Produtos Finais de Glicação Avançada/metabolismo , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/farmacologia , Anticorpos Monoclonais/uso terapêutico , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Desoxicitidina/farmacologia , Desoxicitidina/uso terapêutico , Proteína HMGB1/metabolismo , Camundongos , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Poli(ADP-Ribose) Polimerases/metabolismo , Receptor para Produtos Finais de Glicação Avançada/antagonistas & inibidores , Receptor para Produtos Finais de Glicação Avançada/imunologia , Transplante Homólogo , GencitabinaRESUMO
The receptor for advanced glycation end products (RAGE) contributes to many cellular aspects of pancreatic cancer including cell proliferation, migration, and survival. Studies have shown that RAGE activation by its ligands promotes pancreatic tumor growth by stimulating both cell proliferation and migration. In this study, we investigated the effect of RAGE up-regulation on the proliferation and migration of the human pancreatic cancer Panc-1 cell-line. We show that moderate overexpression of RAGE in Panc-1 cells results in increased cell proliferation, but decreased cell migration. The observed cellular changes were confirmed to be RAGE-specific and reversible by using RAGE-specific siRNAs and the small molecule RAGE inhibitor FPS-ZM1. At the molecular level, we show that RAGE up-regulation was associated with decreased activity of FAK, Akt, Erk1/2, and NF-κB signaling pathways and greatly reduced levels of α2 and ß1 integrin expression, which is in agreement with the observed decreases in cell migration. We also demonstrate that RAGE up-regulation changes the expression of key molecular markers of epithelial-to-mesenchymal transition (EMT). Our results suggest that in the absence of stimulation by external ligands, RAGE up-regulation can differently modulate cell proliferation and migration in pancreatic cancer cells and regulates partly EMT.
Assuntos
Movimento Celular/genética , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Receptor para Produtos Finais de Glicação Avançada/genética , Regulação para Cima/genética , Biomarcadores Tumorais/metabolismo , Caderinas/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/genética , Regulação para Baixo , Transição Epitelial-Mesenquimal , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Proteína-Tirosina Quinases de Adesão Focal/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , Integrina alfa2/metabolismo , Integrina beta1/metabolismo , NF-kappa B/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptor para Produtos Finais de Glicação Avançada/metabolismo , Vimentina/metabolismo , Neoplasias PancreáticasRESUMO
Antiulcer activity of novel quinoline-chalcone hybrids (13-37) was investigated. Among them, eight compounds (14, 16, 17, 23, 29, 31, 32 and 35) were found to be active in various ulcer models in Sprague-Dawley (SD) rats. To understand the mechanism of action of these hybrids, the effects of the compounds on antisecretory and cytoprotective activities were studied. All these active hybrids improved the depleted levels of mucin and consequently inhibited the formation of erosions in a pyloric ligated ulcer model. In addition, they also significantly increased the gastric PGE2 content in an aspirin induced ulcer model. The additional experiments including the in vitro metabolic stability and in vivo pharmacokinetics led to the identification of compound 17 as an orally active and safe candidate that is worthy of further investigation to be developed as an antiulcer agent.
