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IMPORTANCE: Candida albicans is a leading human fungal pathogen that often causes life-threatening infections in immunocompromised individuals. The ability of C. albicans to transition between yeast and filamentous forms is key to its virulence, and this occurs in response to many host-relevant cues, including engulfment by host macrophages. While previous efforts identified C. albicans genes required for filamentation in other conditions, the genes important for this morphological transition upon internalization by macrophages remained largely enigmatic. Here, we employed a functional genomic approach to identify genes that enable C. albicans filamentation within macrophages and uncovered a role for the mitochondrial ribosome, respiration, and the SNF1 AMP-activated kinase complex. Additionally, we showed that glucose uptake and glycolysis by macrophages support C. albicans filamentation. This work provides insights into the metabolic dueling that occurs during the interaction of C. albicans with macrophages and identifies vulnerabilities in C. albicans that could serve as promising therapeutic targets.
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Candida albicans, an opportunistic human pathogen, poses a significant threat to human health and is associated with significant socio-economic burden. Current antifungal treatments fail, at least in part, because C. albicans can initiate a strong drug tolerance response that allows some cells to grow at drug concentrations above their minimal inhibitory concentration. To better characterize this cytoprotective tolerance program at the molecular single-cell level, we used a nanoliter droplet-based transcriptomics platform to profile thousands of individual fungal cells and establish their subpopulation characteristics in the absence and presence of antifungal drugs. Profiles of untreated cells exhibit heterogeneous expression that correlates with cell cycle stage with distinct metabolic and stress responses. At 2 days post-fluconazole exposure (a time when tolerance is measurable), surviving cells bifurcate into two major subpopulations: one characterized by the upregulation of genes encoding ribosomal proteins, rRNA processing machinery, and mitochondrial cellular respiration capacity, termed the Ribo-dominant (Rd) state; and the other enriched for genes encoding stress responses and related processes, termed the Stress-dominant (Sd) state. This bifurcation persists at 3 and 6 days post-treatment. We provide evidence that the ribosome assembly stress response (RASTR) is activated in these subpopulations and may facilitate cell survival.
Many drugs currently used to treat fungal diseases are becoming less effective. This is partly due to the rise of antifungal resistance, where certain fungal cells acquire mutations that enable them to thrive and proliferate despite the medication. Antifungal tolerance also contributes to this problem, wherein certain cells can continue to grow and multiply, while other genetically identical ones cannot. This variability is partly due to differences in gene expression within the cells. The specific nature of these differences has remained elusive, mainly because their study requires the use of expensive and challenging single-cell technologies. To address this challenge, Dumeaux et al. adapted an existing technique to perform single-cell transcriptomics in the pathogenic yeast Candida albicans. Their approach was cost effective and made it possible to examine the gene expression in thousands of individual cells within a population that had either been treated with antifungal drugs or were left untreated. After two to three days following exposure to the antifungal treatment, C. albicans cells commonly exhibited one of two states: one subgroup, the 'Ribo-dominant' cells, predominantly expressed genes for ribosomal proteins, while the other group, the 'Stress-dominant' cells, upregulated their expression of stress-response genes. This suggests that drug tolerance may be related to different gene expression patterns in growing cell subpopulations compared with non-growing subpopulations. The findings also indicate that the so-called 'ribosome assembly stress response' known to help baker's yeast cells to survive, might also aid C. albicans in surviving exposure to antifungal treatments. The innovative use of single-cell transcriptomics in this study could be applied to other species of fungi to study differences in cell communication under diverse growth conditions. Moreover, the unique gene expression patterns in C. albicans identified by Dumeaux et al. may help to design new antifungal treatments that target pathways linked to drug resistance.
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Antifúngicos , Candida albicans , Humanos , Antifúngicos/farmacología , Candida albicans/genética , Fluconazol/farmacología , Pruebas de Sensibilidad Microbiana , Mitocondrias , Farmacorresistencia FúngicaRESUMEN
We present deep learning-based approaches for exploring the complex array of morphologies exhibited by the opportunistic human pathogen Candida albicans. Our system, entitled Candescence, automatically detects C. albicans cells from differential image contrast microscopy and labels each detected cell with one of nine morphologies. This ranges from yeast white and opaque forms to hyphal and pseudohyphal filamentous morphologies. The software is based upon a fully convolutional one-stage (FCOS) object detector, a deep learning technique that uses an extensive set of images that we manually annotated with the location and morphology of each cell. We developed a novel cumulative curriculum-based learning strategy that stratifies our images by difficulty from simple yeast forms to complex filamentous architectures. Candescence achieves very good performance (~85% recall; 81% precision) on this difficult learning set, where some images contain hundreds of cells with substantial intermixing between the predicted classes. To capture the essence of each C. albicans morphology and how they intermix, we used a second technique from deep learning entitled generative adversarial networks. The resultant models allow us to identify and explore technical variables, developmental trajectories, and morphological switches. Importantly, the model allows us to quantitatively capture morphological plasticity observed with genetically modified strains or strains grown in different media and environments. We envision Candescence as a community meeting point for quantitative explorations of C. albicans morphology. IMPORTANCE The fungus Candida albicans can "shape shift" between 12 morphologies in response to environmental variables. The cytoprotective capacity provided by this polymorphism makes C. albicans a formidable pathogen to treat clinically. Microscopy images of C. albicans colonies can contain hundreds of cells in different morphological states. Manual annotation of images can be difficult, especially as a result of densely packed and filamentous colonies and of technical artifacts from the microscopy itself. Manual annotation is inherently subjective, depending on the experience and opinion of annotators. Here, we built a deep learning approach entitled Candescence to parse images in an automated, quantitative, and objective fashion: each cell in an image is located and labeled with its morphology. Candescence effectively replaces simple rules based on visual phenotypes (size, shape, and shading) with neural circuitry capable of capturing subtle but salient features in images that may be too complex for human annotators.
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Candida albicans , Aprendizaje Profundo , Candida albicans/citología , HifaRESUMEN
Coevolution of tumor cells and adjacent stromal elements is a key feature during tumor progression; however, the precise regulatory mechanisms during this process remain unknown. Here, we show stromal p53 loss enhances oncogenic KrasG12D, but not ErbB2, driven tumorigenesis in murine mammary epithelia. Stroma-specific p53 deletion increases both epithelial and fibroblast proliferation in mammary glands bearing the KrasG12D oncogene in epithelia, while concurrently increasing DNA damage and/or DNA replication stress and decreasing apoptosis in the tumor cells proper. Normal epithelia was not affected by stromal p53 deletion. Tumors with p53-null stroma had a significant decrease in total, cytotoxic, and regulatory T cells; however, there was a significant increase in myeloid-derived suppressor cells, total macrophages, and M2-polarized tumor-associated macrophages, with no impact on angiogenesis or connective tissue deposition. Stroma-specific p53 deletion reprogrammed gene expression in both fibroblasts and adjacent epithelium, with p53 targets and chemokine receptors/chemokine signaling pathways in fibroblasts and DNA replication, DNA damage repair, and apoptosis in epithelia being the most significantly impacted biological processes. A gene cluster in p53-deficient mouse fibroblasts was negatively associated with patient survival when compared with two independent datasets. In summary, stroma-specific p53 loss promotes mammary tumorigenesis in an oncogene-specific manner, influences the tumor immune landscape, and ultimately impacts patient survival. IMPLICATIONS: Expression of the p53 tumor suppressor in breast cancer tumor stroma regulates tumorigenesis in an oncogene-specific manner, influences the tumor immune landscape, and ultimately impacts patient survival.
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Neoplasias de la Mama , Oncogenes , Proteína p53 Supresora de Tumor , Animales , Neoplasias de la Mama/genética , Neoplasias de la Mama/inmunología , Carcinogénesis , Tejido Conectivo/metabolismo , Ratones , Proteínas Proto-Oncogénicas p21(ras) , Células del Estroma/patología , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/metabolismoRESUMEN
Research on incarcerated offenders trained to help prisoners change is rare because programs that equip inmates with practical capacities for helping others rehabilitate in prison hardly exist. An exception is the Field Ministry program in Texas, which enlists inmates who have graduated from a prison-based seminary to work as "Field Ministers" and serve other inmates in various capacities. We hypothesize that inmate exposure to Field Ministers is inversely related to antisocial factors and positively to prosocial ones. We applied manifest-variable structural equation modeling to analyze data from a survey of a random sample of male inmates at three maximum-security prisons where the Field Ministry program operated. We found that inmates exposed more frequently to the Field Ministry and for a longer time period tended to report lower levels of criminological risk factors and aggressiveness and higher levels of virtues and predictors of human agency as well as religiosity and spirituality.
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Clero/psicología , Mentores/psicología , Prisioneros/psicología , Adulto , Anciano , Clero/estadística & datos numéricos , Humanos , Masculino , Mentores/estadística & datos numéricos , Persona de Mediana Edad , Prisioneros/estadística & datos numéricos , Prisiones/organización & administración , Factores Protectores , Religión , Espiritualidad , Texas , VirtudesRESUMEN
BACKGROUND: A better understanding underlying radiation (RT) response after breast-conserving surgery (BCS) is needed to mitigate over-treatment of DCIS. The hazard ratio (HR) measures the effect of RT but assumes the effect is constant over time. We examined the hazard function adjusted for adherence to surveillance mammography to examine variations in LR risk and the effect of RT over time. METHODS: Crude hazard estimates for the development of LR in a population cohort of DCIS treated by BCS ± RT were computed. Multivariable extended Cox models and hazard plots were used to examine the association between receipt of RT and risk of each outcome adjusted for baseline covariates and adherence to mammography. RESULTS: Population cohort includes 3262 women treated by BCS; 1635 received RT. Median follow-up was 13 years. LR developed in 364 women treated by BCS alone and 274 treated with RT. LR risk peaked at 2 years, declined until year 7, and then remained steady. The peak hazard of LR was associated with adverse features of DCIS. Early LR risk was attenuated in patients treated with RT but late annual risks of LR and invasive LR were similar among the two treatment groups. On multivariate analysis, RT was associated with a reduction in early LR risk (HR = 0.52, 95% CI 0.43-0.63, p < 0.0001) but did not reduce the risk of late LR (HR = 0.89, 95% CI: 0.67, 1.19, p = 0.44) (interaction, p = 0.002). CONCLUSIONS: The effect of RT is not uniform over time and greatest in the first 7 years after BCS for DCIS, which can guide future research to understand mechanisms underlying RT response and optimize future management of DCIS.
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Neoplasias de la Mama/diagnóstico por imagen , Neoplasias de la Mama/terapia , Carcinoma Intraductal no Infiltrante/diagnóstico por imagen , Carcinoma Intraductal no Infiltrante/terapia , Mastectomía Segmentaria/métodos , Femenino , Humanos , Mamografía , Cooperación del Paciente , Vigilancia de la Población , Modelos de Riesgos Proporcionales , Radioterapia Adyuvante , Análisis de Supervivencia , Factores de Tiempo , Resultado del TratamientoRESUMEN
Understanding the tumor immune microenvironment (TIME) promises to be key for optimal cancer therapy, especially in triple-negative breast cancer (TNBC). Integrating spatial resolution of immune cells with laser capture microdissection gene expression profiles, we defined distinct TIME stratification in TNBC, with implications for current therapies including immune checkpoint blockade. TNBCs with an immunoreactive microenvironment exhibited tumoral infiltration of granzyme B+CD8+ T cells (GzmB+CD8+ T cells), a type 1 IFN signature, and elevated expression of multiple immune inhibitory molecules including indoleamine 2,3-dioxygenase (IDO) and programmed cell death ligand 1 (PD-L1), and resulted in good outcomes. An "immune-cold" microenvironment with an absence of tumoral CD8+ T cells was defined by elevated expression of the immunosuppressive marker B7-H4, signatures of fibrotic stroma, and poor outcomes. A distinct poor-outcome immunomodulatory microenvironment, hitherto poorly characterized, exhibited stromal restriction of CD8+ T cells, stromal expression of PD-L1, and enrichment for signatures of cholesterol biosynthesis. Metasignatures defining these TIME subtypes allowed us to stratify TNBCs, predict outcomes, and identify potential therapeutic targets for TNBC.
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Linfocitos T CD8-positivos/inmunología , Neoplasias de la Mama Triple Negativas/inmunología , Microambiente Tumoral/inmunología , Antígeno B7-H1/inmunología , Linfocitos T CD8-positivos/patología , Colesterol/inmunología , Femenino , Granzimas/inmunología , Humanos , Interferón Tipo I/inmunología , Neoplasias de la Mama Triple Negativas/patologíaRESUMEN
Gap junction transmembrane channels allow the transfer of small molecules between the cytoplasm of adjacent cells. They are formed by proteins named connexins (Cxs) that have long been considered as a tumor suppressor. This widespread view has been challenged by recent studies suggesting that the role of Connexin 43 (Cx43) in cancer is tissue- and stage-specific and can even promote tumor progression. High throughput profiling of invasive breast cancer has allowed for the construction of subtyping schemes that partition patients into at least four distinct intrinsic subtypes. This study characterizes Cx43 expression during cancer progression with each of the tumor subtypes using a compendium of publicly available gene expression data. In particular, we show that Cx43 expression depends greatly on intrinsic subtype. Tumor grade also co-varies with patient subtype, resulting in Cx43 co-expression with grade in a subtype-dependent manner. Better survival was associated with a high expression of Cx43 in unstratified and luminal tumors but with a low expression in Her2e subtype. A better understanding of Cx43 regulation in a subtype-dependent manner is needed to clarify the context in which Cx43 is associated with tumor suppression or cancer progression.
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Neoplasias de la Mama/metabolismo , Conexina 43/metabolismo , Animales , Biomarcadores , Neoplasias de la Mama/genética , Neoplasias de la Mama/mortalidad , Neoplasias de la Mama/patología , Conexina 43/genética , Femenino , Uniones Comunicantes/metabolismo , Expresión Génica , Humanos , Inmunohistoquímica , Pronóstico , Transporte de Proteínas , Receptores de Estrógenos/genética , Receptores de Estrógenos/metabolismo , Receptores de Progesterona/genética , Receptores de Progesterona/metabolismoRESUMEN
Although systemic immunity is critical to the process of tumor rejection, cancer research has largely focused on immune cells in the tumor microenvironment. To understand molecular changes in the patient systemic response (SR) to the presence of BC, we profiled RNA in blood and matched tumor from 173 patients. We designed a system (MIxT, Matched Interactions Across Tissues) to systematically explore and link molecular processes expressed in each tissue. MIxT confirmed that processes active in the patient SR are especially relevant to BC immunogenicity. The nature of interactions across tissues (i.e. which biological processes are associated and their patterns of expression) varies highly with tumor subtype. For example, aspects of the immune SR are underexpressed proportionally to the level of expression of defined molecular processes specific to basal tumors. The catalog of subtype-specific interactions across tissues from BC patients provides promising new ways to tackle or monitor the disease by exploiting the patient SR.
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Células Sanguíneas/fisiología , Neoplasias de la Mama/fisiopatología , Microambiente Celular/fisiología , Microambiente Tumoral/fisiología , Biomarcadores de Tumor/análisis , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Estudios de Casos y Controles , Femenino , Perfilación de la Expresión Génica , Genómica , Humanos , Persona de Mediana Edad , Transducción de Señal , Biología de SistemasRESUMEN
Triple-negative breast cancer (TNBC) is a molecularly heterogeneous cancer that is difficult to treat. Despite the role it may play in tumor progression and response to therapy, microenvironmental (stromal) heterogeneity in TNBC has not been well characterized. To address this challenge, we investigated the transcriptome of tumor-associated stroma isolated from TNBC (n = 57). We identified four stromal axes enriched for T cells (T), B cells (B), epithelial markers (E), or desmoplasia (D). Our analysis method (STROMA4) assigns a score along each stromal axis for each patient and then combined the axis scores to subtype patients. Analysis of these subtypes revealed that prognostic capacity of the B, T, and E scores was governed by the D score. When compared with a previously published TNBC subtyping scheme, the STROMA4 method better captured tumor heterogeneity and predicted patient benefit from therapy with increased sensitivity. This approach produces a simple ontology that captures TNBC heterogeneity and informs how tumor-associated properties interact to affect prognosis. Cancer Res; 77(17); 4673-83. ©2017 AACR.
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Linfocitos B/metabolismo , Biomarcadores de Tumor/metabolismo , Células Epiteliales/metabolismo , Linfocitos T/metabolismo , Transcriptoma , Neoplasias de la Mama Triple Negativas/genética , Neoplasias de la Mama Triple Negativas/patología , Linfocitos B/patología , Células Epiteliales/patología , Femenino , Humanos , Pronóstico , Linfocitos T/patologíaRESUMEN
Mesodermal cells signal to neighboring epithelial cells to modulate their proliferation in both normal and disease states. We adapted a Caenorhabditis elegans organogenesis model to enable a genome-wide mesodermal-specific RNAi screen and discovered 39 factors in mesodermal cells that suppress the proliferation of adjacent Ras pathway-sensitized epithelial cells. These candidates encode components of protein complexes and signaling pathways that converge on the control of chromatin dynamics, cytoplasmic polyadenylation, and translation. Stromal fibroblast-specific deletion of mouse orthologs of several candidates resulted in the hyper-proliferation of mammary gland epithelium. Furthermore, a 33-gene signature of human orthologs was selectively enriched in the tumor stroma of breast cancer patients, and depletion of these factors from normal human breast fibroblasts increased proliferation of co-cultured breast cancer cells. This cross-species approach identified unanticipated regulatory networks in mesodermal cells with growth-suppressive function, exposing the conserved and selective nature of mesodermal-epithelial communication in development and cancer.
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Células Epiteliales/citología , Células Epiteliales/metabolismo , Redes Reguladoras de Genes , Proteínas ras/metabolismo , Animales , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Caenorhabditis elegans/citología , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Linaje de la Célula , Proliferación Celular , Femenino , Fibroblastos/metabolismo , Fibroblastos/patología , Perfilación de la Expresión Génica , Genoma , Humanos , Glándulas Mamarias Animales/citología , Mesodermo/metabolismo , Ratones , Mutación/genética , Proteínas Nucleares , Especificidad de Órganos , Fenotipo , Proteínas Quinasas , Proteínas Serina-Treonina Quinasas/metabolismo , Interferencia de ARN , Transducción de Señal/genética , Células del Estroma/citología , Células del Estroma/metabolismo , Proteínas Activadoras de ras GTPasa/metabolismoRESUMEN
This article offers an ethnographic account of the "self-projects" of inmate graduates of Louisiana State Penitentiary's (aka "Angola's") unique prison seminary program. Angola's Inmate Minister program deploys seminary graduates in bivocational pastoral service roles throughout America's largest maximum-security prison. Drawing upon the unique history of Angola, inmates establish their own churches and serve in lay-ministry capacities in hospice, cellblock visitation, tier ministry, officiating inmate funerals, and through tithing with "care packages" for indigent prisoners. Four themes of positive criminology prominently emerge from inmate narratives: (a) the importance of respectful treatment of inmates by correctional administrations, (b) the value of building trusting relationships for prosocial modeling and improved self-perception,
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Prisioneros , Religión , Humanos , Louisiana , Evaluación de Programas y Proyectos de Salud , EspiritualidadRESUMEN
Breast cancer consists of at least five main molecular "intrinsic" subtypes that are reflected in both pre-invasive and invasive disease. Although previous studies have suggested that many of the molecular features of invasive breast cancer are established early, it is unclear what mechanisms drive progression and whether the mechanisms of progression are dependent or independent of subtype. We have generated mRNA, miRNA, and DNA copy-number profiles from a total of 59 in situ lesions and 85 invasive tumors in order to comprehensively identify those genes, signaling pathways, processes, and cell types that are involved in breast cancer progression. Our work provides evidence that there are molecular features associated with disease progression that are unique to the intrinsic subtypes. We additionally establish subtype-specific signatures that are able to identify a small proportion of pre-invasive tumors with expression profiles that resemble invasive carcinoma, indicating a higher likelihood of future disease progression.
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Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Carcinoma Intraductal no Infiltrante/genética , Carcinoma Intraductal no Infiltrante/patología , Invasividad Neoplásica/genética , Invasividad Neoplásica/patología , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor/genética , Progresión de la Enfermedad , Femenino , Perfilación de la Expresión Génica/métodos , Regulación Neoplásica de la Expresión Génica/genética , Humanos , MicroARNs/genética , Persona de Mediana Edad , ARN Mensajero/genética , Transducción de Señal/genéticaRESUMEN
Rab coupling protein (FIP1C), an effector of the Rab11 GTPases, including Rab25, is amplified and overexpressed in 10% to 25% of primary breast cancers and correlates with poor clinical outcome. Rab25 is also frequently silenced in triple-negative breast cancer, suggesting its ability to function as either an oncogene or a tumor suppressor, depending on the breast cancer subtype. However, the pathobiologic role of FIP family members, such as FIP1C, in a tumor-specific setting remains elusive. In this study, we used ErbB2 mouse models of human breast cancer to investigate FIP1C function in tumorigenesis. Doxycycline-induced expression of FIP1C in the MMTV-ErbB2 mouse model resulted in delayed mammary tumor progression. Conversely, targeted deletion of FIP1C in the mammary epithelium of an ErbB2 model coexpressing Cre recombinase led to accelerated tumor onset. Genetic and biochemical characterization of these FIP1C-proficient and -deficient tumor models revealed that FIP1C regulated E-cadherin (CDH1) trafficking and ZONAB (YBX3) function in Cdk4-mediated cell-cycle progression. Furthermore, we demonstrate that FIP1C promoted lysosomal degradation of ErbB2. Consistent with our findings in the mouse, the expression of FIP1C was inversely correlated with ErbB2 levels in breast cancer patients. Taken together, our findings indicate that FIP1C acts as a tumor suppressor in the context of ErbB2-positive breast cancer and may be therapeutically exploited as an alternative strategy for targeting aberrant ErbB2 expression. Cancer Res; 76(9); 2662-74. ©2016 AACR.
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Neoplasias de la Mama/patología , Receptor ErbB-2/metabolismo , Proteínas de Unión al GTP rab/metabolismo , Animales , Neoplasias de la Mama/metabolismo , Transformación Celular Neoplásica/metabolismo , Progresión de la Enfermedad , Femenino , Técnica del Anticuerpo Fluorescente , Xenoinjertos , Humanos , Immunoblotting , Neoplasias Mamarias Experimentales/metabolismo , Neoplasias Mamarias Experimentales/patología , Ratones , Ratones NoqueadosRESUMEN
ShcA is an important mediator of ErbB2- and transforming growth factor ß (TGF-ß)-induced breast cancer cell migration, invasion, and metastasis. We show that in the context of reduced ShcA levels, the bone morphogenetic protein (BMP) antagonist chordin-like 1 (Chrdl1) is upregulated in numerous breast cancer cells following TGF-ß stimulation. BMPs have emerged as important modulators of breast cancer aggressiveness, and we have investigated the ability of Chrdl1 to block BMP-induced increases in breast cancer cell migration and invasion. Breast cancer-derived conditioned medium containing elevated concentrations of endogenous Chrdl1, as well as medium containing recombinant Chrdl1, suppresses BMP4-induced signaling in multiple breast cancer cell lines. Live-cell migration assays reveal that BMP4 induces breast cancer migration, which is effectively blocked by Chrdl1. We demonstrate that BMP4 also stimulated breast cancer cell invasion and matrix degradation, in part, through enhanced metalloproteinase 2 (MMP2) and MMP9 activity that is antagonized by Chrdl1. Finally, high Chrdl1 expression was associated with better clinical outcomes in patients with breast cancer. Together, our data reveal that Chrdl1 acts as a negative regulator of malignant breast cancer phenotypes through inhibition of BMP signaling.
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Proteína Morfogenética Ósea 4/metabolismo , Neoplasias de la Mama/patología , Medios de Cultivo Condicionados/farmacología , Proteínas del Ojo/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Proteína Morfogenética Ósea 4/genética , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Proteínas del Ojo/genética , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Invasividad Neoplásica , Proteínas del Tejido Nervioso/genética , Pronóstico , Factor de Crecimiento Transformador beta/farmacología , Regulación hacia ArribaRESUMEN
A genetic interaction (GI) is defined when the mutation of one gene modifies the phenotypic expression associated with the mutation of a second gene. Genome-wide efforts to map GIs in yeast revealed structural and functional properties of a GI network. This provided insights into the mechanisms underlying the robustness of yeast to genetic and environmental insults, and also into the link existing between genotype and phenotype. While a significant conservation of GIs and GI network structure has been reported between distant yeast species, such a conservation is not clear between unicellular and multicellular organisms. Structural and functional characterization of a GI network in these latter organisms is consequently of high interest. In this study, we present an in-depth characterization of ~1.5K GIs in the nematode Caenorhabditis elegans. We identify and characterize six distinct classes of GIs by examining a wide-range of structural and functional properties of genes and network, including co-expression, phenotypical manifestations, relationship with protein-protein interaction dense subnetworks (PDS) and pathways, molecular and biological functions, gene essentiality and pleiotropy. Our study shows that GI classes link genes within pathways and display distinctive properties, specifically towards PDS. It suggests a model in which pathways are composed of PDS-centric and PDS-independent GIs coordinating molecular machines through two specific classes of GIs involving pleiotropic and non-pleiotropic connectors. Our study provides the first in-depth characterization of a GI network within pathways of a multicellular organism. It also suggests a model to understand better how GIs control system robustness and evolution.
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Proteínas de Caenorhabditis elegans/genética , Caenorhabditis elegans/genética , Redes Reguladoras de Genes/genética , Mapas de Interacción de Proteínas/genética , Animales , Proteínas de Caenorhabditis elegans/metabolismo , Biología Computacional , Modelos BiológicosRESUMEN
Immunosurveillance constitutes the first step of cancer immunoediting in which developing malignant lesions are eliminated by antitumorigenic immune cells. However, the mechanisms by which neoplastic cells induce an immunosuppressive state to evade the immune response are still unclear. The transcription factor STAT3 has been implicated in breast carcinogenesis and tumor immunosuppression in advanced disease, but its involvement in early disease development has not been established. Here, we genetically ablated Stat3 in the tumor epithelia of the inducible PyVmT mammary tumor model and found that Stat3-deficient mice recapitulated the three phases of immunoediting: elimination, equilibrium, and escape. Pathologic analyses revealed that Stat3-deficient mice initially formed hyperplastic and early adenoma-like lesions that later completely regressed, thereby preventing the emergence of mammary tumors in the majority of animals. Furthermore, tumor regression was correlated with massive immune infiltration into the Stat3-deficient lesions, leading to their elimination. In a minority of animals, focal, nonmetastatic Stat3-deficient mammary tumors escaped immune surveillance after a long latency or equilibrium period. Taken together, our findings suggest that tumor epithelial expression of Stat3 plays a critical role in promoting an immunosuppressive tumor microenvironment during breast tumor initiation and progression, and prompt further investigation of Stat3-inhibitory strategies that may reactivate the immunosurveillance program.
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Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Tolerancia Inmunológica/fisiología , Vigilancia Inmunológica/fisiología , Metástasis de la Neoplasia/patología , Factor de Transcripción STAT3/metabolismo , Microambiente Tumoral/fisiología , Animales , Carcinogénesis/metabolismo , Carcinogénesis/patología , Femenino , Neoplasias Mamarias Animales/metabolismo , Neoplasias Mamarias Animales/patología , RatonesRESUMEN
A father's lifetime experiences can be transmitted to his offspring to affect health and development. However, the mechanisms underlying paternal epigenetic transmission are unclear. Unlike in somatic cells, there are few nucleosomes in sperm, and their function in epigenetic inheritance is unknown. We generated transgenic mice in which overexpression of the histone H3 lysine 4 (H3K4) demethylase KDM1A (also known as LSD1) during spermatogenesis reduced H3K4 dimethylation in sperm. KDM1A overexpression in one generation severely impaired development and survivability of offspring. These defects persisted transgenerationally in the absence of KDM1A germline expression and were associated with altered RNA profiles in sperm and offspring. We show that epigenetic inheritance of aberrant development can be initiated by histone demethylase activity in developing sperm, without changes to DNA methylation at CpG-rich regions.
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Anomalías Congénitas/genética , Epigénesis Genética , Regulación del Desarrollo de la Expresión Génica , Histona Demetilasas/metabolismo , Histonas/metabolismo , Espermatogénesis/genética , Espermatozoides/crecimiento & desarrollo , Animales , Islas de CpG , Metilación de ADN , Femenino , Histona Demetilasas/genética , Masculino , Metilación , Ratones , Ratones Transgénicos , ARN Mensajero/metabolismo , Espermatozoides/enzimologíaRESUMEN
OBJECTIVES: There have been multiple calls for explicit integration of ethical, legal, and social issues (ELSI) in health technology assessment (HTA) and addressing ELSI has been highlighted as key in optimizing benefits in the Omics/Personalized Medicine field. This study examines HTAs of an early clinical example of Personalized Medicine (gene expression profile tests [GEP] for breast cancer prognosis) aiming to: (i) identify ELSI; (ii) assess whether ELSIs are implicitly or explicitly addressed; and (iii) report methodology used for ELSI integration. METHODS: A systematic search for HTAs (January 2004 to September 2012), followed by descriptive and qualitative content analysis. RESULTS: Seventeen HTAs for GEP were retrieved. Only three (18%) explicitly presented ELSI, and only one reported methodology. However, all of the HTAs included implicit ELSI. Eight themes of implicit and explicit ELSI were identified. "Classical" ELSI including privacy, informed consent, and concerns about limited patient/clinician genetic literacy were always presented explicitly. Some ELSI, including the need to understand how individual patients' risk tolerances affect clinical decision-making after reception of GEP results, were presented both explicitly and implicitly in HTAs. Others, such as concern about evidentiary deficiencies for clinical utility of GEP tests, occurred only implicitly. CONCLUSIONS: Despite a wide variety of important ELSI raised, these were rarely explicitly addressed in HTAs. Explicit treatment would increase their accessibility to decision-makers, and may augment HTA efficiency maximizing their utility. This is particularly important where complex Personalized Medicine applications are rapidly expanding choices for patients, clinicians and healthcare systems.
Asunto(s)
Neoplasias de la Mama/genética , Perfilación de la Expresión Génica/ética , Medicina de Precisión/ética , Evaluación de la Tecnología Biomédica/ética , Evaluación de la Tecnología Biomédica/legislación & jurisprudencia , Toma de Decisiones , HumanosRESUMEN
One of the major challenges of cocaine addiction is the high rate of relapse to drug use after periods of withdrawal. During the first few weeks of withdrawal, cue-induced cocaine craving intensifies, or "incubates," and persists over extended periods of time. Although several brain regions and molecular mechanisms were found to be involved in this process, the underlying epigenetic mechanisms are still unknown. Herein, we used a rat model of incubation of cocaine craving, in which rats were trained to self-administer cocaine (0.75 mg/kg, 6 h/d, 10 d), and cue-induced cocaine-seeking was examined in an extinction test after 1 or 30 d of withdrawal. We show that the withdrawal periods, as well as cue-induced cocaine seeking, are associated with broad, time-dependent enhancement of DNA methylation alterations in the nucleus accumbens (NAc). These gene methylation alterations were partly negatively correlated with gene expression changes. Furthermore, intra-NAc injections of a DNA methyltransferase inhibitor (RG108, 100 µm) abolished cue-induced cocaine seeking on day 30, an effect that persisted 1 month, whereas the methyl donor S-adenosylmethionine (500 µm) had an opposite effect on cocaine seeking. We then targeted two proteins whose genes were demethylated by RG108-estrogen receptor 1 (ESR1) and cyclin-dependent kinase 5 (CDK5). Treatment with an intra-NAc injection of the ESR1 agonist propyl pyrazole triol (10 nm) or the CDK5 inhibitor roscovitine (28 µm) on day 30 of withdrawal significantly decreased cue-induced cocaine seeking. These results demonstrate a role for NAc DNA methylation, and downstream targets of DNA demethylation, in incubation of cocaine craving.