Browsing by MeSH term "Mice, 129 Strain"
Now showing 1 - 7 of 7
Results Per Page
Sort Options
Publication ATR is required to complete meiotic recombination in mice(Nature Publishing Group, 2018-07-05) Pacheco, Sarai; Maldonado-Linares, Andros; Marcet-Ortega, Marina; Rojas, Cristina; Martínez-Marchal, Ana; Fuentes-Lazaro, Judit; Lange, Julian; Jasin, Maria; Keeney, Scott; Fernandez-Capetillo, Oscar; Garcia-Caldés, Montserrat; Roig, Ignasi; Ministerio de Ciencia e Innovación (España); American Cancer Society; Howard Hughes Medical Institute; National Institutes of Health (Estados Unidos)Precise execution of recombination during meiosis is essential for forming chromosomally-balanced gametes. Meiotic recombination initiates with the formation and resection of DNA double-strand breaks (DSBs). Cellular responses to meiotic DSBs are critical for efficient repair and quality control, but molecular features of these remain poorly understood, particularly in mammals. Here we report that the DNA damage response protein kinase ATR is crucial for meiotic recombination and completion of meiotic prophase in mice. Using a hypomorphic Atr mutation and pharmacological inhibition of ATR in vivo and in cultured spermatocytes, we show that ATR, through its effector kinase CHK1, promotes efficient RAD51 and DMC1 assembly at RPA-coated resected DSB sites and establishment of interhomolog connections during meiosis. Furthermore, our findings suggest that ATR promotes local accumulation of recombination markers on unsynapsed axes during meiotic prophase to favor homologous chromosome synapsis. These data reveal that ATR plays multiple roles in mammalian meiotic recombination.Publication Complete Regression of Advanced Pancreatic Ductal Adenocarcinomas upon Combined Inhibition of EGFR and C-RAF.(Cell Press, 2019-04-15) Blasco, María Teresa; Navas, Carolina; Martín-Serrano, Guillermo; Martín-Díaz, Laura; Li, Jing; Morales-Cacho, Lucia; Esteban-Burgos, Laura; Perales-Patón, Javier; Bousquet-Mur, Emilie; Castellano, Eva; Jacob, Harrys K C; Cabras, Lavinia; Sainz, Bruno; Dusetti, Nelson; Iovanna, Juan; Sánchez-Bueno, Francisco; Hidalgo, Manuel; Khiabanian, Hossein; Rabadán, Raul; Graña Castro, Osvaldo; Lechuga C, Lechuga CG; Djurec M, Djurec M; Musteanu, Mónica; Drosten, Matthias; Ortega Jimenez, Sagrario; Mulero, Francisca; Guerra, Carmen; Barbacid, Mariano; Al-Shahrour, Fatima; Unión Europea. Comisión Europea. European Research Council (ERC); Unión Europea. Comisión Europea; Asociación Española Contra el Cáncer; Ligue Nationale Contre le Cancer (Francia); United States Department of Health and Human Services; Deutsche Forschungsgemeinschaft (Alemania); Ministerio de Ciencia e Innovación (España); Fundación La Caixa; Ministerio de Economía, Industria y Competitividad (España); Fundación AXAFive-year survival for pancreatic ductal adenocarcinoma (PDAC) patients remains below 7% due to the lack of effective treatments. Here, we report that combined ablation of EGFR and c-RAF expression results in complete regression of a significant percentage of PDAC tumors driven by Kras/Trp53 mutations in genetically engineered mice. Moreover, systemic elimination of these targets induces toxicities that are well tolerated. Response to this targeted therapy correlates with transcriptional profiles that resemble those observed in human PDACs. Finally, inhibition of EGFR and c-RAF expression effectively blocked tumor progression in nine independent patient-derived xenografts carrying KRAS and TP53 mutations. These results open the door to the development of targeted therapies for PDAC patients.Publication Induction of sustained hypercholesterolemia by single adeno-associated virus-mediated gene transfer of mutant hPCSK9.(Lippincott Williams & Wilkins (LWW), 2015-01) Roche-Molina, Marta; Sanz-Rosa, David; Cruz, Francisco M; García-Prieto, Jaime; López, Sergio; Abia, Rocío; Muriana, Francisco J G; Fuster, Valentín; Ibáñez, Borja; Bernal, Juan AOBJECTIVES Patients with mutations in the proprotein convertase subtilisin/kexin type 9 (PCSK9) gene have hypercholesterolemia and are at high risk of adverse cardiovascular events. We aimed to stably express the pathological human D374Y gain-of-function mutant form of PCSK9 (PCSK9(DY)) in adult wild-type mice to generate a hyperlipidemic and proatherogenic animal model, achieved with a single systemic injection with adeno-associated virus (AAV). APPROACH AND RESULTS We constructed an AAV-based vector to support targeted transfer of the PCSK9(DY) gene to liver. After injection with 3.5×10(10) viral particles, mice in the C57BL/6J, 129/SvPasCrlf, or FVB/NCrl backgrounds developed long-term hyperlipidemia with a strong increase in serum low-density lipoprotein. Macroscopic and histological analysis showed atherosclerotic lesions in the aortas of AAV-PCSK9(DY) mice fed a high-fat-diet. Advanced lesions in these high-fat-diet-fed mice also showed evidence of macrophage infiltration and fibrous cap formation. Hepatic AAV-PCSK9(DY) infection did not result in liver damage or signs of immunologic response. We further tested the use of AAV-PCSK9(DY) to study potential genetic interaction with the ApoE gene. Histological analysis of ApoE(-/-) AAV-PCSK9(DY) mice showed a synergistic response to ApoE deficiency, with aortic lesions twice as extensive in ApoE(-/-) AAV-PCSK9(DY)-transexpressing mice as in ApoE(-/-) AAV-Luc controls without altering serum cholesterol levels. CONCLUSIONS Single intravenous AAV-PCSK9(DY) injection is a fast, easy, and cost-effective approach, resulting in rapid and long-term sustained hyperlipidemia and atherosclerosis. We demonstrate as a proof of concept the synergy between PCSK9(DY) gain-of-function and ApoE deficiency. This methodology could allow testing of the genetic interaction of several mutations without the need for complex and time-consuming backcrosses.Publication NSMCE2 suppresses cancer and aging in mice independently of its SUMO ligase activity.(EMBO Press, 2015-11-03) Jacome, Ariana; Gutierrez-Martinez, Paula; Schiavoni, Federica; Tenaglia, Enrico; Martinez, Paula; Rodríguez-Acebes, Sara; Lecona, Emilio; Murga, Matilde; Mendez, Juan; Blasco, MA; Fernandez-Capetillo, Oscar; Fundacion Botin; Banco Santander; Howard Hughes Medical Institute; Unión Europea. Comisión Europea. European Research Council (ERC); Worldwide Cancer Research; Ministerio de Ciencia e Innovación (España)The SMC5/6 complex is the least understood of SMC complexes. In yeast, smc5/6 mutants phenocopy mutations in sgs1, the BLM ortholog that is deficient in Bloom's syndrome (BS). We here show that NSMCE2 (Mms21, in Saccharomyces cerevisiae), an essential SUMO ligase of the SMC5/6 complex, suppresses cancer and aging in mice. Surprisingly, a mutation that compromises NSMCE2-dependent SUMOylation does not have a detectable impact on murine lifespan. In contrast, NSMCE2 deletion in adult mice leads to pathologies resembling those found in patients of BS. Moreover, and whereas NSMCE2 deletion does not have a detectable impact on DNA replication, NSMCE2-deficient cells also present the cellular hallmarks of BS such as increased recombination rates and an accumulation of micronuclei. Despite the similarities, NSMCE2 and BLM foci do not colocalize and concomitant deletion of Blm and Nsmce2 in B lymphocytes further increases recombination rates and is synthetic lethal due to severe chromosome mis-segregation. Our work reveals that SUMO- and BLM-independent activities of NSMCE2 limit recombination and facilitate segregation; functions of the SMC5/6 complex that are necessary to prevent cancer and aging in mice.Publication Oncogenic stress sensitizes murine cancers to hypomorphic suppression of ATR.(American Society for Clinical Investigation (ASCI), 2012-01) Schoppy, David W; Ragland, Ryan L; Gilad, Oren; Shastri, Nishita; Peters, Ashley A; Murga, Matilde; Fernandez-Capetillo, Oscar; Diehl, J Alan; Brown, Eric J; United States Department of Health and Human Services; Abramson Family Cancer Research Institute; Mary Kay Ash Charitable TrustOncogenic Ras and p53 loss-of-function mutations are common in many advanced sporadic malignancies and together predict a limited responsiveness to conventional chemotherapy. Notably, studies in cultured cells have indicated that each of these genetic alterations creates a selective sensitivity to ataxia telangiectasia and Rad3-related (ATR) pathway inhibition. Here, we describe a genetic system to conditionally reduce ATR expression to 10% of normal levels in adult mice to compare the impact of this suppression on normal tissues and cancers in vivo. Hypomorphic suppression of ATR minimally affected normal bone marrow and intestinal homeostasis, indicating that this level of ATR expression was sufficient for highly proliferative adult tissues. In contrast, hypomorphic ATR reduction potently inhibited the growth of both p53-deficient fibrosarcomas expressing H-rasG12V and acute myeloid leukemias (AMLs) driven by MLL-ENL and N-rasG12D. Notably, DNA damage increased in a greater-than-additive fashion upon combining ATR suppression with oncogenic stress (H-rasG12V, K-rasG12D, or c-Myc overexpression), indicating that this cooperative genome-destabilizing interaction may contribute to tumor selectivity in vivo. This toxic interaction between ATR suppression and oncogenic stress occurred without regard to p53 status. These studies define a level of ATR pathway inhibition in which the growth of malignancies harboring oncogenic mutations can be suppressed with minimal impact on normal tissue homeostasis, highlighting ATR inhibition as a promising therapeutic strategy.Publication Transcriptional regulation of Sox2 by the retinoblastoma family of pocket proteins.(Impact Journals, 2015-02-20) Vilas, Jéssica M; Ferreirós, Alba; Carneiro, Carmen; Morey, Lluis; Da Silva-Álvarez, Sabela; Fernandes, Tânia; Di Croce, Luciano; García-Caballero, Tomás; Rivas, Carmen; Vidal, Anxo; Serrano Marugan, Manuel; Instituto de Salud Carlos III; Xunta de Galicia (España); Ministerio de Economía y Competitividad (España)Cellular reprogramming to iPSCs has uncovered unsuspected links between tumor suppressors and pluripotency factors. Using this system, it was possible to identify tumor suppressor p27 as a repressor of Sox2 during differentiation. This led to the demonstration that defects in the repression of Sox2 can contribute to tumor development. The members of the retinoblastoma family of pocket proteins, pRb, p107 and p130, are negative regulators of the cell cycle with tumor suppressor activity and with roles in differentiation. In this work we studied the relative contribution of the retinoblastoma family members to the regulation of Sox2 expression. We found that deletion of Rb or p130 leads to impaired repression of Sox2, a deffect amplified by inactivation of p53. We also identified binding of pRb and p130 to an enhancer with crucial regulatory activity on Sox2 expression. Using cellular reprogramming we tested the impact of the defective repression of Sox2 and confirmed that Rb deficiency allows the generation of iPSCs in the absence of exogenous Sox2. Finally, partial depletion of Sox2 positive cells reduced the pituitary tumor development initiated by Rb loss in vivo. In summary, our results show that Sox2 repression by pRb is a relevant mechanism of tumor suppression.Publication Urothelial organoids originating from Cd49fhigh mouse stem cells display Notch-dependent differentiation capacity(Nature Publishing Group, 2019-09-27) Santos, Catarina P; Lapi, Eleonora; Martínez de Villarreal, Jaime; Álvaro-Espinosa, Laura; Fernández-Barral, Asunción; Barbáchano, Antonio; Dominguez, Orlando; Laughney, Ashley M; Megias Vazquez, Diego; Muñoz, Alberto; Real Arribas, Francisco; Ministerio de Economía y Competitividad (España); Centro de Investigación Biomédica en Red - CIBERONC (Cáncer); Asociación Española Contra el CáncerUnderstanding urothelial stem cell biology and differentiation has been limited by the lack of methods for their unlimited propagation. Here, we establish mouse urothelial organoids that can be maintained uninterruptedly for >1 year. Organoid growth is dependent on EGF and Wnt activators. High CD49f/ITGA6 expression features a subpopulation of organoid-forming cells expressing basal markers. Upon differentiation, multilayered organoids undergo reduced proliferation, decreased cell layer number, urothelial program activation, and acquisition of barrier function. Pharmacological modulation of PPARγ and EGFR promotes differentiation. RNA sequencing highlighted genesets enriched in proliferative organoids (i.e. ribosome) and transcriptional networks involved in differentiation, including expression of Wnt ligands and Notch components. Single-cell RNA sequencing (scRNA-Seq) analysis of the organoids revealed five clusters with distinct gene expression profiles. Together, with the use of γ-secretase inhibitors and scRNA-Seq, confirms that Notch signaling is required for differentiation. Urothelial organoids provide a powerful tool to study cell regeneration and differentiation.