Person: Bragado Domingo, Paloma
Loading...
First Name
Paloma
Last Name
Bragado Domingo
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Farmacia
Department
Bioquímica y Biología Molecular
Area
Bioquímica y Biología Molecular
Identifiers
8 results
Search Results
Now showing 1 - 8 of 8
Item C3G Protein, a New Player in Glioblastoma(International Journal of Molecular Sciences, 2021) Manzano, Sara; Gutierrez Uzquiza, Álvaro; Bragado Domingo, Paloma; Cuesta Martínez, Ángel; Guerrero, Carmen; Porras Gallo, AlmudenaC3G (RAPGEF1) is a guanine nucleotide exchange factor (GEF) for GTPases from the Ras superfamily, mainly Rap1, although it also acts through GEF-independent mechanisms. C3G regulates several cellular functions. It is expressed at relatively high levels in specific brain areas, playing important roles during embryonic development. Recent studies have uncovered different roles for C3G in cancer that are likely to depend on cell context, tumour type, and stage. However, its role in brain tumours remained unknown until very recently. We found that C3G expression is downregulated in GBM, which promotes the acquisition of a more mesenchymal phenotype, enhancing migration and invasion, but not proliferation. ERKs hyperactivation, likely induced by FGFR1, is responsible for this pro-invasive effect detected in C3G silenced cells. Other RTKs (Receptor Tyrosine Kinases) are also dysregulated and could also contribute to C3G effects. However, it remains undetermined whether Rap1 is a mediator of C3G actions in GBM. Various Rap1 isoforms can promote proliferation and invasion in GBM cells, while C3G inhibits migration/invasion. Therefore, other RapGEFs could play a major role regulating Rap1 activity in these tumours. Based on the information available, C3G could represent a new biomarker for GBM diagnosis, prognosis, and personalised treatment of patients in combination with other GBM molecular markers. The quantification of C3G levels in circulating tumour cells (CTCs) in the cerebrospinal liquid and/or circulating fluids might be a useful tool to improve GBM patient treatment and survival.Item Breast Mammographic Density: Stromal Implications on Breast Cancer Detection and Therapy(Journal of Clinical Medicine, 2020) Fernández-Nogueira, Patricia; Mancino, Mario; Fuster, Gemma; Bragado Domingo, Paloma; Prats de Puig, Miquel; Gascón, Pere; Casado, Francisco Javier; Carbó, NeusCurrent evidences state clear that both normal development of breast tissue as well as its malignant progression need many-sided local and systemic communications between epithelial cells and stromal components. During development, the stroma, through remarkably regulated contextual signals, affects the fate of the different mammary cells regarding their specification and differentiation. Likewise, the stroma can generate tumour environments that facilitate the neoplastic growth of the breast carcinoma. Mammographic density has been described as a risk factor in the development of breast cancer and is ascribed to modifications in the composition of breast tissue, including both stromal and glandular compartments. Thus, stroma composition can dramatically affect the progression of breast cancer but also its early detection since it is mainly responsible for the differences in mammographic density among individuals. This review highlights both the pathological and biological evidences for a pivotal role of the breast stroma in mammographic density, with particular emphasis on dense and malignant stromas, their clinical meaning and potential therapeutic implications for breast cancer patients.Item C3G Is Upregulated in Hepatocarcinoma, Contributing to Tumor Growth and Progression and to HGF/MET Pathway Activation(Cancers, 2020) Sequera, Celia; Bragado Domingo, Paloma; Manzano, Sara; Arechederra, Maria; Richelme, Sylvie; Gutierrez Uzquiza, Álvaro; Sánchez Muñoz, Aránzazu; Maina, Flavio; Guerrero, Carmen; Porras Gallo, AlmudenaThe complexity of hepatocellular carcinoma (HCC) challenges the identification of disease-relevant signals. C3G, a guanine nucleotide exchange factor for Rap and other Ras proteins, plays a dual role in cancer acting as either a tumor suppressor or promoter depending on tumor type and stage. The potential relevance of C3G upregulation in HCC patients suggested by database analysis remains unknown. We have explored C3G function in HCC and the underlying mechanisms using public patient data and in vitro and in vivo human and mouse HCC models. We found that C3G is highly expressed in progenitor cells and neonatal hepatocytes, whilst being down-regulated in adult hepatocytes and re-expressed in human HCC patients, mouse HCC models and HCC cell lines. Moreover, high C3G mRNA levels correlate with tumor progression and a lower patient survival rate. C3G expression appears to be tightly modulated within the HCC program, influencing distinct cell biological properties. Hence, high C3G expression levels are necessary for cell tumorigenic properties, as illustrated by reduced colony formation in anchorage-dependent and -independent growth assays induced by permanent C3G silencing using shRNAs. Additionally, we demonstrate that C3G down-regulation interferes with primary HCC tumor formation in xenograft assays, increasing apoptosis and decreasing proliferation. In vitro assays also revealed that C3G down-regulation enhances the pro-migratory, invasive and metastatic properties of HCC cells through an epithelial-mesenchymal switch that favors the acquisition of a more mesenchymal phenotype. Consistently, a low C3G expression in HCC cells correlates with lung metastasis formation in mice. However, the subsequent restoration of C3G levels is associated with metastatic growth. Mechanistically, C3G down-regulation severely impairs HGF/MET signaling activation in HCC cells. Collectively, our results indicate that C3G is a key player in HCC. C3G promotes tumor growth and progression, and the modulation of its levels is essential to ensure distinct biological features of HCC cells throughout the oncogenic program. Furthermore, C3G requirement for HGF/MET signaling full activation provides mechanistic data on how it works, pointing out the relevance of assessing whether high C3G levels could identify HCC responders to MET inhibitors.Item The New Antitumor Drug ABTL0812 Inhibits the Akt/mTORC1 Axis by Upregulating Tribbles-3 Pseudokinase(Clinical Cancer Research, 2016) Bragado Domingo, Paloma; Lorente Pérez, María Del Mar; Salazar Roa, María; Velasco Díez, Guillermo; Tatiana Erazo; Anna Lopez-Plana; Pau Munoz-Guardiola; Patricia Fernandez-Nogueira; Jose A. García-Martínez; Gemma Fuster; Jordi Espadaler; Javier Hernandez-Losa; Jose Ramon Bayascas; Marc Cortal; Laura Vidal; Pedro Gascon; Mariana Gomez-Ferreria; Jose Alfon; Carles Domenech; Jose M. Lizcano; Jose M. LizcanoPurpose: ABTL0812 is a novel first-in-class, small molecule which showed antiproliferative effect on tumor cells in phenotypic assays. Here we describe the mechanism of action of this antitumor drug, which is currently in clinical development. Experimental Design: We investigated the effect of ABTL0812 on cancer cell death, proliferation, and modulation of intracellular signaling pathways, using human lung (A549) and pancreatic (MiaPaCa-2) cancer cells and tumor xenografts. To identify cellular targets, we performed in silico high-throughput screening comparing ABTL0812 chemical structure against ChEMBL15 database. Results: ABTL0812 inhibited Akt/mTORC1 axis, resulting in impaired cancer cell proliferation and autophagy-mediated cell death. In silico screening led us to identify PPARs, PPARα and PPARγ as the cellular targets of ABTL0812. We showed that ABTL0812 activates both PPAR receptors, resulting in upregulation of Tribbles-3 pseudokinase (TRIB3) gene expression. Upregulated TRIB3 binds cellular Akt, preventing its activation by upstream kinases, resulting in Akt inhibition and suppression of the Akt/mTORC1 axis. Pharmacologic inhibition of PPARα/γ or TRIB3 silencing prevented ABTL0812-induced cell death. ABTL0812 treatment induced Akt inhibition in cancer cells, tumor xenografts, and peripheral blood mononuclear cells from patients enrolled in phase I/Ib first-in-human clinical trial. Conclusions: ABTL0812 has a unique and novel mechanism of action, that defines a new and drugable cellular route that links PPARs to Akt/mTORC1 axis, where TRIB3 pseudokinase plays a central role. Activation of this route (PPARα/γ-TRIB3-Akt-mTORC1) leads to autophagy-mediated cancer cell death. Given the low toxicity and high tolerability of ABTL0812, our results support further development of ABTL0812 as a promising anticancer therapy.Item Met signaling in cardiomyocytes is required for normal cardiac function in adult mice(Biochimica et Biophysica Acta (Molecular Basis of disease), 2013) Arechederra Calderón, María; Carmona Mejías, Rita; González-Nuñez, María; Gutiérrez Uzquiza, Álvaro; Bragado Domingo, Paloma; Cruz-González, Ignacio; Cano Rincón, Elena; Guerrero Arroyo, María Del Carmen; Sánchez Muñoz, Aranzazu; López-Novoa, José Miguel; Schneider, Michael D.; Maina, Flavio; Muñoz-Chápuli, Ramón; Porras Gallo, María AlmudenaHepatocyte growth factor (HGF) and its receptor, Met, are key determinants of distinct developmental processes. Although HGF exerts cardio-protective effects in a number of cardiac pathologies, it remains unknown whether HGF/Met signaling is essential for myocardial development and/or physiological function in adulthood. We therefore investigated the requirement of HGF/Met signaling in cardiomyocyte for embryonic and postnatal heart development and function by conditional inactivation of the Met receptor in cardiomyocytes using the Cre-α-MHC mouse line (referred to as α-MHCMet-KO). Although α-MHCMet-KO mice showed normal heart development and were viable and fertile, by 6 months of age, males developed cardiomyocyte hypertrophy, associated with interstitial fibrosis. A significant upregulation in markers of myocardial damage, such as β-MHC and ANF, was also observed. By the age of 9 months, α-MHCMet-KO males displayed systolic cardiac dysfunction. Mechanistically, we provide evidence of a severe imbalance in the antioxidant defenses in α-MHCMet-KO hearts involving a reduced expression and activity of catalase and superoxide dismutase, with consequent reactive oxygen species accumulation. Similar anomalies were observed in females, although with a slower kinetics. We also found that Met signaling down-regulation leads to an increase in TGF-β production and a decrease in p38MAPK activation, which may contribute to phenotypic alterations displayed in α-MHCMet-KO mice. Consistently, we show that HGF acts through p38α to upregulate antioxidant enzymes in cardiomyocytes. Our results highlight that HGF/Met signaling in cardiomyocytes plays a physiological cardio-protective role in adult mice by acting as an endogenous regulator of heart function through oxidative stress control.Item Inhibition of RAC1 activity in cancer associated fibroblasts favours breast tumour development through IL-1β upregulation(Cancer Letters, 2021) Martínez López, Angélica; García Casas, Ana; Bragado Domingo, Paloma; Orimo, Akira; Castañeda-Saucedo, Eduardo; Castillo Lluva, SoniaCancer-associated fibroblasts (CAFs) are highly abundant stromal components in the tumour microenvironment. These cells contribute to tumorigenesis and indeed, they have been proposed as a target for anti-cancer therapies. Similarly, targeting the Rho-GTPase RAC1 has also been suggested as a potential therapeutic target in cancer. Here, we show that targeting RAC1 activity, either pharmacologically or by genetic silencing, increases the pro-tumorigenic activity of CAFs by upregulating IL-1β secretion. Moreover, inhibiting RAC1 activity shifts the CAF subtype to a more aggressive phenotype. Thus, as RAC1 suppresses the secretion of IL-1β by CAFs, reducing RAC1 activity in combination with the depletion of this cytokine should be considered as an interesting therapeutic option for breast cancer in which tumour cells retain intact IL-1β signalling..- Project number: 335
Item Innovación Docente en la enseñanza de la Bioquímica y la Biología Molecular: Revistas digitales, clases invertidas y recursos didácticos para la enseñanza “en línea”(2021) Oset Gasque, María Jesús; Bragado Domingo, Paloma; Escribano Illanes, Óscar; Escrivá Pons, Fernando; Fernández Millán, Elisa; García Redondo, Alberto; Gómez Hernández, María De La Almudena; Herrera González, Blanca María; Iniesta Serrano, María Pilar; Juan Chocano, María del Carmen de; Linares Gómez, María; Martínez Ruíz, Antonio; Pacheco González, Beatriz; Roncero Romero, Cesáreo; Sánchez Muñoz, AránzazuEn este Proyecto de Innovación Docente (PID 335/20) se han realizado tres tipos de actividades: 1. Elaboración de revistas digitales 2. Implantación de la metodología de clase invertida 3. Desarrollo de materiales docentes par la implantación de la enseñanza "en línea" y formación del profesorado. En ella han participado 15 profesores del Dpto. de Bioquímica y Biología Molecular (Sección Farmacia), de 4 asignaturas diferentes: Bioquímica Aplicada y Clínica, Bioquímica, Biología Molecular y Genética. Los resultados han sido muy satisfactorios, ya que se ha conseguido la participación de un enorme número de alumnos de todas estas asignaturas, los cuales han quedado muy contentos y satisfechos, ya que ha fomentado su autoaprendizaje, su trabajo en grupo, su conocimiento del método científico y sus habilidades como divulgadores de ciencia. Item p38α Mediates Cell Survival in Response to Oxidative Stress via Induction of Antioxidant Genes(Journal of Biological Chemistry, 2012) Gutiérrez Uzquiza, Álvaro; Arechederra, María; Bragado Domingo, Paloma; Aguirre-Ghiso, Julio A.; Porras Gallo, María AlmudenaWe reveal a novel pro-survival role for mammalian p38α in response to H(2)O(2), which involves an up-regulation of antioxidant defenses. The presence of p38α increases basal and H(2)O(2)-induced expression of the antioxidant enzymes: superoxide-dismutase 1 (SOD-1), SOD-2, and catalase through different mechanisms, which protects from reactive oxygen species (ROS) accumulation and prevents cell death. p38α was found to regulate (i) H(2)O(2)-induced SOD-2 expression through a direct regulation of transcription mediated by activating transcription factor 2 (ATF-2) and (ii) H(2)O(2)-induced catalase expression through regulation of protein stability and mRNA expression and/or stabilization. As a consequence, SOD and catalase activities are higher in WT MEFs. We also found that this p38α-dependent antioxidant response allows WT cells to maintain an efficient activation of the mTOR/p70S6K pathway. Accordingly, the loss of p38α leads to ROS accumulation in response to H(2)O(2), which causes cell death and inactivation of mTOR/p70S6K signaling. This can be rescued by either p38α re-expression or treatment with the antioxidants, N-acetyl cysteine, or exogenously added catalase. Therefore, our results reveal a novel homeostatic role for p38α in response to oxidative stress, where ROS removal is favored by antioxidant enzymes up-regulation, allowing cell survival and mTOR/p70S6K activation.