Novel insights in the pathogenesis of primary biliary cholangitis and cholangiocarcinoma

El contenido del capítulo 2 está sujeto a confidencialidad por la autora. 215 p.Este trabajo de tesis doctoral se centra en el estudio de dos enfermedades biliares: la colangitis biliar primaria (del inglés primary biliary cholangitis, PBC) y el colangiocarcinoma (CCA).Por un lado, ya que el miR-506 se encuentra sobre-expresado la PBC (una enfermedad biliar asociada con procesos autoinmunes frente a los colangiocitos) y parece tener un papel fundamental en su etiopatogenia, se ha llevado a cabo un trabajo en el que se ha evaluado el papel del miR-506 en PBC.Por otro lado, se han llevado a cabo dos estudios en CCA, el cáncer que afecta a los colangiocitos. En concreto, un trabajo ha evaluado el papel de la activación de los receptores de ácidos biliares FXR y TGR5 mediante el uso de los agonistas específicos OCA (ácido obeticólico) e INT-777, respectivamente, debido a que los ácidos biliares están implicados tanto en el desarrollo como en la progresión del CCA.Finalmente, los factores de transcripción están involucrados en los procesos tumorales tales como el CCA, por lo que el tercer trabajo se ha centrado en el estudio de los factores de transcripción de tipo krüppel (KLFs) en el CCA y, más concretamente, en el factor KLF5, el cual parece participar en la progresión de diversos tipos de cáncer.BioDonostia : Instituto de investigación sanitaria , Osasun ikerketa institutua AECC: Asociación Española contra el Cánce

Novel insights in the pathogenesis of primary biliary cholangitis and cholangiocarcinoma

El contenido del capítulo 2 está sujeto a confidencialidad por la autora. 215 p.Este trabajo de tesis doctoral se centra en el estudio de dos enfermedades biliares: la colangitis biliar primaria (del inglés primary biliary cholangitis, PBC) y el colangiocarcinoma (CCA).Por un lado, ya que el miR-506 se encuentra sobre-expresado la PBC (una enfermedad biliar asociada con procesos autoinmunes frente a los colangiocitos) y parece tener un papel fundamental en su etiopatogenia, se ha llevado a cabo un trabajo en el que se ha evaluado el papel del miR-506 en PBC.Por otro lado, se han llevado a cabo dos estudios en CCA, el cáncer que afecta a los colangiocitos. En concreto, un trabajo ha evaluado el papel de la activación de los receptores de ácidos biliares FXR y TGR5 mediante el uso de los agonistas específicos OCA (ácido obeticólico) e INT-777, respectivamente, debido a que los ácidos biliares están implicados tanto en el desarrollo como en la progresión del CCA.Finalmente, los factores de transcripción están involucrados en los procesos tumorales tales como el CCA, por lo que el tercer trabajo se ha centrado en el estudio de los factores de transcripción de tipo krüppel (KLFs) en el CCA y, más concretamente, en el factor KLF5, el cual parece participar en la progresión de diversos tipos de cáncer.BioDonostia : Instituto de investigación sanitaria , Osasun ikerketa institutua AECC: Asociación Española contra el Cánce

Genetic mouse models as in vivo tools for cholangiocarcinoma research

Cholangiocarcinoma (CCA) is a genetically and histologically complex disease with a highly dismal prognosis. A deeper understanding of the underlying cellular and molecular mechanisms of human CCA will increase our current knowledge of the disease and expedite the eventual development of novel therapeutic strategies for this fatal cancer. This endeavor is effectively supported by genetic mouse models, which serve as sophisticated tools to systematically investigate CCA pathobiology and treatment response. These in vivo models feature many of the genetic alterations found in humans, recapitulate multiple hallmarks of cholangiocarcinogenesis (encompassing cell transformation, preneoplastic lesions, established tumors and metastatic disease) and provide an ideal experimental setting to study the interplay between tumor cells and the surrounding stroma. This review is intended to serve as a compendium of CCA mouse models, including traditional transgenic models but also genetically flexible approaches based on either the direct introduction of DNA into liver cells or transplantation of pre-malignant cells, and is meant as a resource for CCA researchers to aid in the selection of the most appropriate in vivo model system

FOSL1 promotes cholangiocarcinoma via transcriptional effectors that could be therapeutically targeted

[EN] Background & Aims: Cholangiocarcinoma (CCA) is a neoplasia of the biliary tract driven by genetic, epigenetic and transcriptional mechanisms. Herein, we investigated the role of the transcription factor FOSL1, as well as its downstream transcriptional effectors, in the development and progression of CCA. Methods: FOSL1 was investigated in human CCA clinical samples. Genetic inhibition of FOSL1 in human and mouse CCA cell lines was performed in in vitro and in vivo models using constitutive and inducible short-hairpin RNAs. Conditional FOSL1 ablation was done using a genetically engineered mouse (GEM) model of CCA (mutant KRAS and Trp53 knockout). Followup RNA and chromatin immunoprecipitation (ChIP) sequencing analyses were carried out and downstream targets were validated using genetic and pharmacological inhibition. Results: An inter-species analysis of FOSL1 in CCA was conducted. First, FOSL1 was found to be highly upregulated in human and mouse CCA, and associated with poor patient survival. Pharmacological inhibition of different signalling pathways in CCA cells converged on the regulation of FOSL1 expression. Functional experiments showed that FOSL1 is required for cell proliferation and cell cycle progression in vitro, and for tumour growth and tumour maintenance in both orthotopic and subcutaneous xenograft models. Likewise, FOSL1 genetic abrogation in a GEM model of CCA extended mouse survival by decreasing the oncogenic potential of transformed cholangiocytes. RNA and ChIP sequencing studies identified direct and indirect transcriptional effectors such as HMGCS1 and AURKA, whose genetic and pharmacological inhibition phenocopied FOSL1 loss. Conclusions: Our data illustrate the functional and clinical relevance of FOSL1 in CCA and unveil potential targets amenable to pharmacological inhibition that could enable the implementation of novel therapeutic strategies. Lay summary: Understanding the molecular mechanisms involved in cholangiocarcinoma (bile duct cancer) development and progression stands as a critical step for the development of novel therapies. Through an inter-species approach, this study provides evidence of the clinical and functional role of the transcription factor FOSL1 in cholangiocarcinoma. Moreover, we report that downstream effectors of FOSL1 are susceptible to pharmacological inhibition, thus providing new opportunities for therapeutic intervention.A.V. was supported by ADA of the University of Navarra, Spain, O.E. by FSE; MINECO; FJCI-2017-34233, Spain, R.E. by a donation from Mauge Burgos de la Iglesia’s family, Spain, and P. Olaizola by the Basque Government (PRE_2016_1_0269), Basque Country, Spain. M.J.P. was funded by ISCIII [FIS PI14; 00399, PI17; 00022] cofinanced by “Fondo Europeo de Desarrollo Regional” (FEDER), Spain; Spanish Ministry of Economy and Competitiveness (MINECO: “Ramón y Cajal” Program RYC-2015-17755), Spain. M.A.A was funded by La Caixa Foundation, HEPACARE project, Spain, ISCIII FIS PI16/01126 cofinanced by “Fondo Europeo de Desarrollo Regional” (FEDER), Spain, and “Fundación Científica de la Asociación Española Contra el Cáncer’’ (AECC Scientific Foundation) Rare Cancers 2017, Spain. J.M.B. was funded by the Spanish Carlos III Health Institute (ISCIII) (FIS PI15; 01132, PI18; 01075 and Miguel Servet Program CON14; 00129 and CPII19; 00008), Spain, co-financed by “Fondo Europeo de Desarrollo Regional” (FEDER), Spain; “Euskadi RIS3” (2019222054) and BIOEF (Basque Foundation for Innovation and Health Research: EiTB Maratoia BIO15; CA; 016; BD), Basque Country, Spain; “Fundación Científica de la Asociación Española Contra el Cáncer” (AECC Scientific Foundation) Rare Cancers 2017, Spain. S.V. was supported by FEDER; MINECO (SAF2017-89944-R), Spain, by the Government of Navarra-Health Research Department (58; 2018), Navarra, Spain, by La Caixa and Caja Navarra Foundation-CIMA agreement, Spain. None of the funding sources were involved in the decision to submit the article for publication. This article is based upon work from COST Action CA18122 European Cholangiocarcinoma Network, supported by COST (European Cooperation in Science and Technology). COST (European Cooperation in Science and Technology) is a funding agency for research and innovation networks (www.cost.eu)

FOSL1 promotes cholangiocarcinoma via transcriptional effectors that could be therapeutically targeted

Understanding the molecular mechanisms involved in cholangiocarcinoma (bile duct cancer) development and progression stands as a critical step for the development of novel therapies. Through an inter-species approach, this study provides evidence of the clinical and functional role of the transcription factor FOSL1 in cholangiocarcinoma. Moreover, we report that downstream effectors of FOSL1 are susceptible to pharmacological inhibition, thus providing new opportunities for therapeutic intervention

Novel insights in the pathogenesis of primary biliary cholangitis and cholangiocarcinoma

El contenido del capítulo 2 está sujeto a confidencialidad por la autora. 215 p.Este trabajo de tesis doctoral se centra en el estudio de dos enfermedades biliares: la colangitis biliar primaria (del inglés primary biliary cholangitis, PBC) y el colangiocarcinoma (CCA).Por un lado, ya que el miR-506 se encuentra sobre-expresado la PBC (una enfermedad biliar asociada con procesos autoinmunes frente a los colangiocitos) y parece tener un papel fundamental en su etiopatogenia, se ha llevado a cabo un trabajo en el que se ha evaluado el papel del miR-506 en PBC.Por otro lado, se han llevado a cabo dos estudios en CCA, el cáncer que afecta a los colangiocitos. En concreto, un trabajo ha evaluado el papel de la activación de los receptores de ácidos biliares FXR y TGR5 mediante el uso de los agonistas específicos OCA (ácido obeticólico) e INT-777, respectivamente, debido a que los ácidos biliares están implicados tanto en el desarrollo como en la progresión del CCA.Finalmente, los factores de transcripción están involucrados en los procesos tumorales tales como el CCA, por lo que el tercer trabajo se ha centrado en el estudio de los factores de transcripción de tipo krüppel (KLFs) en el CCA y, más concretamente, en el factor KLF5, el cual parece participar en la progresión de diversos tipos de cáncer.BioDonostia : Instituto de investigación sanitaria , Osasun ikerketa institutua AECC: Asociación Española contra el Cánce

Glycolytic ATP fuels the plasma membrane calcium pump critical for pancreatic cancer cell survival

Pancreatic cancer is an aggressive cancer with poor prognosis and limited treatment options. Cancer cells rapidly proliferate and are resistant to cell death due, in part, to a shift from mitochondrial metabolism to glycolysis. We hypothesized that this shift is important in regulating cytosolic Ca(2+) ([Ca(2+)](i)), as the ATP-dependent plasma membrane Ca(2+) ATPase (PMCA) is critical for maintaining low [Ca(2+)](i) and thus cell survival. The present study aimed to determine the relative contribution of mitochondrial versus glycolytic ATP in fuelling the PMCA in human pancreatic cancer cells. We report that glycolytic inhibition induced profound ATP depletion, PMCA inhibition, [Ca(2+)](i) overload, and cell death in PANC1 and MIA PaCa-2 cells. Conversely, inhibition of mitochondrial metabolism had no effect, suggesting that glycolytic ATP is critical for [Ca(2+)](i) homeostasis and thus survival. Targeting the glycolytic regulation of the PMCA may, therefore, be an effective strategy for selectively killing pancreatic cancer while sparing healthy cells

Genetic Mouse Models as In Vivo Tools for Cholangiocarcinoma Research

Cholangiocarcinoma (CCA) is a genetically and histologically complex disease with a highly dismal prognosis. A deeper understanding of the underlying cellular and molecular mechanisms of human CCA will increase our current knowledge of the disease and expedite the eventual development of novel therapeutic strategies for this fatal cancer. This endeavor is effectively supported by genetic mouse models, which serve as sophisticated tools to systematically investigate CCA pathobiology and treatment response. These in vivo models feature many of the genetic alterations found in humans, recapitulate multiple hallmarks of cholangiocarcinogenesis (encompassing cell transformation, preneoplastic lesions, established tumors and metastatic disease) and provide an ideal experimental setting to study the interplay between tumor cells and the surrounding stroma. This review is intended to serve as a compendium of CCA mouse models, including traditional transgenic models but also genetically flexible approaches based on either the direct introduction of DNA into liver cells or transplantation of pre-malignant cells, and is meant as a resource for CCA researchers to aid in the selection of the most appropriate in vivo model system

MGMT Expression Predicts PARP-Mediated Resistance to Temozolomide.

Melanoma and other solid cancers are frequently resistant to chemotherapies based on DNA alkylating agents such as dacarbazine and temozolomide. As a consequence, clinical responses are generally poor. Such resistance is partly due to the ability of cancer cells to use a variety of DNA repair enzymes to maintain cell viability. Particularly, the expression of MGMT has been linked to temozolomide resistance, but cotargeting MGMT has proven difficult due to dose-limiting toxicities. Here, we show that the MGMT-mediated resistance of cancer cells is profoundly dependent on the DNA repair enzyme PARP. Both in vitro and in vivo, we observe that MGMT-positive cancer cells strongly respond to the combination of temozolomide and PARP inhibitors (PARPi), whereas MGMT-deficient cells do not. In melanoma cells, temozolomide induced an antiproliferative senescent response, which was greatly enhanced by PARPi in MGMT-positive cells. In summary, we provide compelling evidence to suggest that the stratification of patients with cancer upon the MGMT status would enhance the success of combination treatments using temozolomide and PARPi. (C)2015 AACR