Search results for "origen"
showing 10 items of 64 documents
MYC-driven epigenetic reprogramming favors the onset of tumorigenesis by inducing a stem cell-like state
2018
Breast cancer consists of highly heterogeneous tumors, whose cell of origin and driver oncogenes are difficult to be uniquely defined. Here we report that MYC acts as tumor reprogramming factor in mammary epithelial cells by inducing an alternative epigenetic program, which triggers loss of cell identity and activation of oncogenic pathways. Overexpression of MYC induces transcriptional repression of lineage-specifying transcription factors, causing decommissioning of luminal-specific enhancers. MYC-driven dedifferentiation supports the onset of a stem cell-like state by inducing the activation of de novo enhancers, which drive the transcriptional activation of oncogenic pathways. Furthermo…
[How some commensal bacteria would exacerbate colorectal carcinogenesis?].
2016
International audience; The gut microbiota maintains a relationship with its host with strong mutual benefits. Changes in the composition of the intestinal microbiota have been detected in colorectal cancer patients to the extent that it is now considered as a real contributing factor in this pathology. In this review, we focus on three commensal bacterial species, namely Bacteroides fragilis, Fusobacterium nucleatum, and Escherichia coli, which seem to emerge as pathogens and to contribute to colorectal carcinogenesis through their inflammatory and oncogenic properties.; Le microbiote intestinal entretient une relation mutualiste forte avec l’hôte. Depuis la mise en évidence de modificatio…
Silencing of hepatic fate-conversion factors induce tumorigenesis in reprogrammed hepatic progenitor-like cells
2016
Abstract Background Several studies have reported the direct conversion of mouse fibroblasts to hepatocyte-like cells with different degrees of maturation by expression of hepatic fate-conversion factors. Methods We have used a combination of lentiviral vectors expressing hepatic fate-conversion factors with Oct4, Sox2, Klf4, and Myc to convert mouse embryonic fibroblasts into hepatic cells. Results We have generated hepatic cells with progenitor-like features (iHepL cells). iHepL cells displayed basic hepatocyte functions but failed to perform functions characteristic of mature hepatocytes such as significant Cyp450 or urea cycle activities. iHepL cells expressed multiple hepatic-specific …
DNA methylation changes and somatic mutations as tumorigenic events in Lynch syndrome-associated adenomas retaining mismatch repair protein expression
2018
Background: DNA mismatch repair (MMR) defects are a major factor in colorectal tumorigenesis in Lynch syndrome (LS) and 15% of sporadic cases. Some adenomas from carriers of inherited MMR gene mutations have intact MMR protein expression implying other mechanisms accelerating tumorigenesis. We determined roles of DNA methylation changes and somatic mutations in cancer-associated genes as tumorigenic events in LS-associated colorectal adenomas with intact MMR. Methods: We investigated 122 archival colorectal specimens of normal mucosae, adenomas and carcinomas from 57 LS patients. MMR-deficient (MMR-D, n 49) and MMR-proficient (MMR-P, n 18) adenomas were of particular interest and were inter…
Molecular chaperones in tumors of salivary glands.
2020
The salivary glands are key components of the mouth and play a central role in its physiology. Their importance may be appreciated considering their number, occurrence in pairs, and distribution in the mouth: two parotids, two submandibular, two sublingual, and many other small ones scattered throughout the mouth. They produce saliva, without which ingestion of non-liquid nutrients and speech would be practically impossible. Nevertheless, the physiology and pathology of salivary glands are poorly understood. For instance, tumors of salivary glands occur, and their incidence is on the rise, but their etiology and pathogenesis are virtually unknown, although some risk factors have been identi…
Non-coding RNAs Functioning in Colorectal Cancer Stem Cells
2016
In recent years, the hypothesis of the presence of tumor-initiating cancer stem cells (CSCs) has received a considerable support. This model suggested the existence of CSCs which, thanks to their self-renewal properties, are able to drive the expansion and the maintenance of malignant cell populations with invasive and metastatic potential in cancer. Increasing evidence showed the ability of such cells to acquire self-renewal, multipotency, angiogenic potential, immune evasion, symmetrical and asymmetrical divisions which, along with the presence of several DNA repair mechanisms, further enhance their oncogenic potential making them highly resistant to common anticancer treatments. The main…
La adopción abierta en el derecho español
2016
El reconocimiento del derecho del menor adoptado a mantener contactos o relaciones con sus familiares de origen y sus anteriores acogedores representa un nuevo modelo de adopción en el Derecho español, denominado “adopción abierta”, recientemente introducida por la Ley 26/2015, de 28 de julio, que reforma el sistema español de protección de la infancia y la adolescencia. La nueva regulación se inspira en el Derecho de otros países pero tiene precedentes en ciertas normas autonómicas españolas The recognition of the right of the adopted children to maintain contacts or relations with their families of origin and previous welcoming, represents a new model of adoption in the Spanish law, which…
Deciphering genomic heterogeneity and the internal composition of tumour activities through a hierarchical factorisation model
2021
Genomic heterogeneity constitutes one of the most distinctive features of cancer diseases, limiting the efficacy and availability of medical treatments. Tumorigenesis emerges as a strongly stochastic process, producing a variable landscape of genomic configurations. In this context, matrix factorisation techniques represent a suitable approach for modelling such complex patterns of variability. In this work, we present a hierarchical factorisation model conceived from a systems biology point of view. The model integrates the topology of molecular pathways, allowing to simultaneously factorise genes and pathways activity matrices. The protocol was evaluated by using simulations, showing a hi…
La antropología como ciencia libidinosa. Diderot y el viaje de Bougainville
2005
Son innumerables los estudios que han abordado, desde temprano, la historia de la constitución de la antropología como disciplina empírica con vocación 'científica', como una de las ciencias humanas. Se muestra así una cierta obsesión por los orígenes, quizá síntoma de una frágil identidad. Uno de esos textos, de los más tempranos, The History of Anthropology} 1 fue escrito por Boas justo al principio del siglo pasado (1904) y tiene por objeto -fue una conferencia dada ante un publico académico variopintoreflexionar históricamente sobre una disciplina que todavía se debate para delimitar cuál es su objeto y método epistemológicos. Boas advierte desde el principio que no va a proceder dicien…
¿Marxismo o diferenciación social?
2018
Para la sociología, el debate con el marxismo forma uno de los telones de fondo intelectuales y prácticos en el surgimiento de esta joven ciencia durante el siglo xix. Uno de los puntos más interesantes de esta disputa trata del grado necesario de diferenciación de las categorías analíticas para comprender los mecanismos básicos de la sociedad. La capacidad y la necesidad de reducir la compl ejidad que requiere cada ciencia, si quiere ll egar a un nivel de generalización que permita la acción social, se contrapone a una diferenciación analítica que tenga en cuenta la máxima cantidad posibl e de elementos relevantes para la comprensión de lo social. El presente artículo alumbra las relacione…