Patient-Derived Organoid Models of Human Neuroendocrine Carcinoma

Gastroenteropancreatic neuroendocrine carcinoma (GEP-NEC) is a poorly understood disease with limited treatment options. A better understanding of this disease would greatly benefit from the availability of representative preclinical models. Here, we present the potential of tumor organoids, three-dimensional cultures of tumor cells, to model GEP-NEC. We established three GEP-NEC organoid lines, originating from the stomach and colon, and characterized them using DNA sequencing and immunohistochemistry. Organoids largely resembled the original tumor in expression of synaptophysin, chromogranin and Ki-67. Models derived from tumors containing both neuroendocrine and non-neuroendocrine components were at risk of overgrowth by non-neuroendocrine tumor cells. Organoids were derived from patients treated with cisplatin and everolimus and for the three patients studied, organoid chemosensitivity paralleled clinical response. We demonstrate the feasibility of establishing NEC organoid lines and their potential applications. Organoid culture has the potential to greatly extend the repertoire of preclinical models for GEP-NEC, supporting drug development for this difficult-to-treat tumor type

Notas sobre la sostenibilidad de la deuda pública en Venezuela

En el presente trabajo se lleva a cabo una evaluación de la sostenibilidad de la deuda pública en Venezuela. En la primera parte del estudio se presenta un breve bosquejo teórico de los modelos para evaluar la sostenibilidad de la deuda pública que aparece reflejado en la literatura económica. Asimismo, se presenta la evolución de los indicadores de sostenibilidad de la deuda pública, así como una comparación internacional de los niveles de deuda de Venezuela en comparación con otros países de la región. Se observa que aunque los indicadores tradicionales de deuda pública no indican un peso importante de la deuda sobre la economía nacional, al estudiar la trayectoria de endeudamiento actual, se concluye que el endeudamiento público no es sostenible en el tiempo

Gene expression and functional annotation of human choroid plexus epithelium failure in Alzheimer's disease

BACKGROUND: Alzheimer's disease (AD) is the most common form of dementia. AD has a multifactorial disease etiology and is currently untreatable. Multiple genes and molecular mechanisms have been implicated in AD, including ß-amyloid deposition in the brain, neurofibrillary tangle accumulation of hyper-phosphorylated Tau, synaptic failure, oxidative stress and inflammation. Relatively little is known about the role of the blood-brain barriers, especially the blood-cerebrospinal fluid barrier (BCSFB), in AD. The BCSFB is involved in cerebrospinal fluid (CSF) production, maintenance of brain homeostasis and neurodegenerative disorders. RESULTS: Using an Agilent platform with common reference design, we performed a large scale gene expression analysis and functional annotation of the Choroid Plexus Epithelium (CPE), which forms the BCSFB. We obtained 2 groups of freshly frozen Choroid Plexus (CP) of 7 human donor brains each, with and without AD: Braak stages (0-1) and (5-6). We cut CP cryo-sections and isolated RNA from cresyl-violet stained, laser dissected CPE cells. Gene expression results were analysed with T-tests (R) and the knowledge-database Ingenuity. We found statistically significantly altered gene expression data sets, biological functions, canonical pathways, molecular networks and functionalities in AD-affected CPE. We observed specific cellular changes due to increased oxidative stress, such as the unfolded protein response, E1F2 and NRF2 signalling and the protein ubiquitin pathway. Most likely, the AD-affected BCSFB barrier becomes more permeable due to downregulation of CLDN5. Finally, our data also predicted down regulation of the glutathione mediated detoxification pathway and the urea cycle in the AD CPE, which suggest that the CPE sink action may be impaired. Remarkably, the expression of a number of genes known to be involved in AD, such as APP, PSEN1, PSEN2, TTR and CLU is moderate to high and remains stable in both healthy and affected CPE. Literature labelling of our new functional molecular networks confirmed multiple previous (molecular) observations in the AD literature and revealed many new ones. CONCLUSIONS: We conclude that CPE failure in AD exists. Combining our data with those of the literature, we propose the following chronological and overlapping chain of events: increased Aß burden on CPE; increased oxidative stress in CPE; despite continuous high expression of TTR: decreased capability of CPE to process amyloid; (pro-) inflammatory and growth factor signalling by CPE; intracellular ubiquitin involvement, remodelling of CPE tight junctions and, finally, cellular atrophy. Our data corroborates the hypothesis that increased BCSFB permeability, especially loss of selective CLDN5-mediated paracellular transport, altered CSF production and CPE sink action, as well as loss of CPE mediated macrophage recruitment contribute to the pathogenesis of AD

Additional file 7: Figure S4. of Gene expression and functional annotation of human choroid plexus epithelium failure in Alzheimer’s disease

In this file a standard output of the most established and most simple (linear) representation of biology (canonical pathways) are given on the basis of input data (in this case statistically significant BH corrected upregulated genes in AD; Additional file 6: Table S3). The knowledge database recognizes enriched biological themes (for example: unfolded protein response etc.) in the input data compared to a random distribution of genes over all relevant biological themes. In the figure, the y-axis denotes statistical significance levels, the horizontal axis contains biological themes. The bars indicate the statistical significance for that particular theme. The orange horizontal line gives the significance level P = 0.05. The orange irregular line follows the ratio (number of molecules in particular theme/relevant number of genes under consideration). For further details, see www.ingenuity.com . (JPEG 76 kb

Boletín de Segovia: Número 68 - 1871 junio 7

Copia digital. Madrid : Ministerio de Cultura. Subdirección General de Coordinación Bibliotecaria, 200

Additional file 3: Table S2. of Gene expression and functional annotation of human choroid plexus epithelium failure in Alzheimer’s disease

Contains compilations of lists of (disease) genes previously implicated in relevant disease. The entries are used to label the molecular network in Additional file 4: Figure S2 and Additional file 5: Figure S3. (XLS 190 kb

Additional file 4: Figure S2. of Gene expression and functional annotation of human choroid plexus epithelium failure in Alzheimer’s disease

Upregulated genes in AD (Br5–6). Molecular networks are presented which were generated by the core analysis of the Ingenuity knowledge database (see also Methods section and www.ingenuity.com for explanation and details). The symbols (with Genbank Gene name) in the network come from: input genes (Additional file 6: Table S3: upregulated genes in AD Br5–6) see also description below (Additional file 5: Figure S3). (PDF 17491 kb

Additional file 9: Figure S5. of Gene expression and functional annotation of human choroid plexus epithelium failure in Alzheimer’s disease

See description for Additional file 7: Figure S4, but now the input used are the down-regulated genes in CPE AD (5–6) Additional file 8: Table S4). (JPEG 56 kb

Patient-derived organoids can predict response to chemotherapy in metastatic colorectal cancer patients

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Dysregulation of the Wnt pathway inhibits timely myelination and remyelination in the mammalian CNS

The progressive loss of CNS myelin in patients with multiple sclerosis (MS) has been proposed to result from the combined effects of damage to oligodendrocytes and failure of remyelination. A common feature of demyelinated lesions is the presence of oligodendrocyte precursors (OLPs) blocked at a premyelinating stage. However, the mechanistic basis for inhibition of myelin repair is incompletely understood. To identify novel regulators of OLP differentiation, potentially dysregulated during repair, we performed a genome-wide screen of 1040 transcription factor-encoding genes expressed in remyelinating rodent lesions. We report that ∼50 transcription factor-encoding genes show dynamic expression during repair and that expression of the Wnt pathway mediator Tcf4 (aka Tcf7l2) within OLPs is specific to lesioned—but not normal—adult white matter. We report that β-catenin signaling is active during oligodendrocyte development and remyelination in vivo. Moreover, we observed similar regulation of Tcf4 in the developing human CNS and lesions of MS. Data mining revealed elevated levels of Wnt pathway mRNA transcripts and proteins within MS lesions, indicating activation of the pathway in this pathological context. We show that dysregulation of Wnt–β-catenin signaling in OLPs results in profound delay of both developmental myelination and remyelination, based on (1) conditional activation of β-catenin in the oligodendrocyte lineage in vivo and (2) findings from APCMin mice, which lack one functional copy of the endogenous Wnt pathway inhibitor APC. Together, our findings indicate that dysregulated Wnt–β-catenin signaling inhibits myelination/remyelination in the mammalian CNS. Evidence of Wnt pathway activity in human MS lesions suggests that its dysregulation might contribute to inefficient myelin repair in human neurological disorders