Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 30
Filtrar
1.
Cancers (Basel) ; 16(4)2024 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-38398123

RESUMEN

(1) Background: The sensitivity of head and neck squamous cell carcinoma (HNSCC) to ionizing radiation, among others, is determined by the number of cells with high clonogenic potential and stem-like features. These cellular characteristics are dynamically regulated in response to treatment and may lead to an enrichment of radioresistant cells with a cancer stem cell (CSC) phenotype. Epigenetic mechanisms, particularly DNA and histone methylation, are key regulators of gene-specific transcription and cellular plasticity. Therefore, we hypothesized that specific epigenetic targeting may prevent irradiation-induced plasticity and may sensitize HNSCC cells to radiotherapy. (2) Methods: We compared the DNA methylome and intracellular concentrations of tricarboxylic acid cycle metabolites in radioresistant FaDu and Cal33 cell lines with their parental controls, as well as aldehyde dehydrogenase (ALDH)-positive CSCs with negative controls. Moreover, we conducted a screen of a chemical library targeting enzymes involved in epigenetic regulation in combination with irradiation and analyzed the clonogenic potential, sphere formation, and DNA repair capacity to identify compounds with both radiosensitizing and CSC-targeting potential. (3) Results: We identified the histone demethylase inhibitor GSK-J1, which targets UTX (KDM6A) and JMJD3 (KDM6B), leading to increased H3K27 trimethylation, heterochromatin formation, and gene silencing. The clonogenic survival assay after siRNA-mediated knock-down of both genes radiosensitized Cal33 and SAS cell lines. Moreover, high KDM6A expression in tissue sections of patients with HNSCC was associated with improved locoregional control after primary (n = 137) and post-operative (n = 187) radio/chemotherapy. Conversely, high KDM6B expression was a prognostic factor for reduced overall survival. (4) Conclusions: Within this study, we investigated cellular and molecular mechanisms underlying irradiation-induced cellular plasticity, a key inducer of radioresistance, with a focus on epigenetic alterations. We identified UTX (KDM6A) as a putative prognostic and therapeutic target for HNSCC patients treated with radiotherapy.

2.
Theranostics ; 14(2): 714-737, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38169509

RESUMEN

Rationale: Current therapies for metastatic osseous disease frequently fail to provide a durable treatment response. To date, there are only limited therapeutic options for metastatic prostate cancer, the mechanisms that drive the survival of metastasis-initiating cells are poorly characterized, and reliable prognostic markers are missing. A high aldehyde dehydrogenase (ALDH) activity has been long considered a marker of cancer stem cells (CSC). Our study characterized a differential role of ALDH1A1 and ALDH1A3 genes as regulators of prostate cancer progression and metastatic growth. Methods: By genetic silencing of ALDH1A1 and ALDH1A3 in vitro, in xenografted zebrafish and murine models, and by comparative immunohistochemical analyses of benign, primary tumor, and metastatic specimens from patients with prostate cancer, we demonstrated that ALDH1A1 and ALDH1A3 maintain the CSC phenotype and radioresistance and regulate bone metastasis-initiating cells. We have validated ALDH1A1 and ALDH1A3 as potential biomarkers of clinical outcomes in the independent cohorts of patients with PCa. Furthermore, by RNAseq, chromatin immunoprecipitation (ChIP), and biostatistics analyses, we suggested the molecular mechanisms explaining the role of ALDH1A1 in PCa progression. Results: We found that aldehyde dehydrogenase protein ALDH1A1 positively regulates tumor cell survival in circulation, extravasation, and metastatic dissemination, whereas ALDH1A3 plays the opposite role. ALDH1A1 and ALDH1A3 are differentially expressed in metastatic tumors of patients with prostate cancer, and their expression levels oppositely correlate with clinical outcomes. Prostate cancer progression is associated with the increasing interplay of ALDH1A1 with androgen receptor (AR) and retinoid receptor (RAR) transcriptional programs. Polo-like kinase 3 (PLK3) was identified as a transcriptional target oppositely regulated by ALDH1A1 and ALDH1A3 genes in RAR and AR-dependent manner. PLK3 contributes to the control of prostate cancer cell proliferation, migration, DNA repair, and radioresistance. ALDH1A1 gain in prostate cancer bone metastases is associated with high PLK3 expression. Conclusion: This report provides the first evidence that ALDH1A1 and PLK3 could serve as biomarkers to predict metastatic dissemination and radiotherapy resistance in patients with prostate cancer and could be potential therapeutic targets to eliminate metastasis-initiating and radioresistant tumor cell populations.


Asunto(s)
Neoplasias de la Próstata , Receptores Androgénicos , Masculino , Humanos , Animales , Ratones , Pez Cebra/metabolismo , Línea Celular Tumoral , Aldehído Deshidrogenasa/genética , Aldehído Deshidrogenasa/metabolismo , Neoplasias de la Próstata/genética , Biomarcadores , Familia de Aldehído Deshidrogenasa 1 , Retinal-Deshidrogenasa
3.
Cancers (Basel) ; 15(15)2023 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-37568590

RESUMEN

Overcoming PARPi resistance is a high clinical priority. We established and characterized comparative in vitro models of acquired PARPi resistance, derived from either a BRCA1-proficient or BRCA1-deficient isogenic background by long-term exposure to olaparib. While parental cell lines already exhibited a certain level of intrinsic activity of multidrug resistance (MDR) proteins, resulting PARPi-resistant cells from both models further converted toward MDR. In both models, the PARPi-resistant phenotype was shaped by (i) cross-resistance to other PARPis (ii) impaired susceptibility toward the formation of DNA-platinum adducts upon exposure to cisplatin, which could be reverted by the drug efflux inhibitors verapamil or diphenhydramine, and (iii) reduced PARP-trapping activity. However, the signature and activity of ABC-transporter expression and the cross-resistance spectra to other chemotherapeutic drugs considerably diverged between the BRCA1-proficient vs. BRCA1-deficient models. Using dual-fluorescence co-culture experiments, we observed that PARPi-resistant cells had a competitive disadvantage over PARPi-sensitive cells in a drug-free medium. However, they rapidly gained clonal dominance under olaparib selection pressure, which could be mitigated by the MRP1 inhibitor MK-751. Conclusively, we present a well-characterized in vitro model, which could be instrumental in dissecting mechanisms of PARPi resistance from HR-proficient vs. HR-deficient background and in studying clonal dynamics of PARPi-resistant cells in response to experimental drugs, such as novel olaparib-sensitizers.

4.
Sci Rep ; 13(1): 12859, 2023 08 08.
Artículo en Inglés | MEDLINE | ID: mdl-37553373

RESUMEN

Bats are described as the natural reservoir host for a wide range of viruses. Although an increasing number of bat-associated, potentially human pathogenic viruses were discovered in the past, the full picture of the bat viromes is not explored yet. In this study, the virome composition of Miniopterus phillipsi bats (formerly known as Miniopterus fuliginosus bats in Sri Lanka) inhabiting the Wavul Galge cave, Sri Lanka, was analyzed. To assess different possible excretion routes, oral swabs, feces and urine were collected and analyzed individually by using metagenomic NGS. The data obtained was further evaluated by using phylogenetic reconstructions, whereby a special focus was set on RNA viruses that are typically associated with bats. Two different alphacoronavirus strains were detected in feces and urine samples. Furthermore, a paramyxovirus was detected in urine samples. Sequences related to Picornaviridae, Iflaviridae, unclassified Riboviria and Astroviridae were identified in feces samples and further sequences related to Astroviridae in urine samples. No viruses were detected in oral swab samples. The comparative virome analysis in this study revealed a diversity in the virome composition between the collected sample types which also represent different potential shedding routes for the detected viruses. At the same time, several novel viruses represent first reports of these pathogens from bats in Sri Lanka. The detection of two different coronaviruses in the samples indicates the potential general persistence of this virus species in M. phillipsi bats. Based on phylogenetics, the identified viruses are closely related to bat-associated viruses with comparably low estimation of human pathogenic potential. In further studies, the seasonal variation of the virome will be analyzed to identify possible shedding patterns for particular viruses.


Asunto(s)
Quirópteros , Coronavirus , Animales , Humanos , Filogenia , Viroma , Sri Lanka , Coronavirus/genética
5.
J Clin Psychol ; 78(10): 2029-2040, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35795899

RESUMEN

Lately, the use of patient-reported outcome measures (PROM) to adapt and improve ongoing psychotherapeutic treatments has become more widespread. Their main purpose is to support data-informed, collaborative treatment decisions which include the patient's point of view on their progress. In case of nonresponse or deterioration, these systems are able to warn clinicians and guide the process "back on track" in treatment. In this case illustration, the Greifswald Psychotherapy Navigator System (GPNS) detected the deterioration of 19-year-old Sarah during the first eight sessions of cognitive-behavioral therapy for social anxiety and depression. Here, the GPNS helped the therapist gain insight as to how Sarah's social anxiety affected their treatment and adjust her strategy accordingly. Using the symptom curves and progress scales of the GPNS, the therapist was able to then address her patient's struggles in detail during their sessions and with her supervisor. After adapting her therapeutic approach, the patient's deterioration could be averted while simultaneously strengthening their communication in the process. Clinical implications and the benefits of using PROM systems for evidence-based personalization of psychotherapy are presented.


Asunto(s)
Terapia Cognitivo-Conductual , Psicoterapia , Adulto , Comunicación , Retroalimentación , Femenino , Humanos , Adulto Joven
6.
Animals (Basel) ; 12(13)2022 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-35804573

RESUMEN

This is the first report on the molecular identification and phylogeny of the Rousettus leschenaultii Desmarest, 1810, Rhinolophus rouxii Temminck, 1835, Hipposideros speoris Schneider, 1800, Hipposideros lankadiva Kelaart, 1850, and Miniopterus fuliginosus Kuhl, 1817, bat species in Sri Lanka, inferred from analyses by mitochondrially encoded cytochrome b gene sequences. Recent research has indicated that bats show enormous cryptic genetic diversity. Moreover, even within the same species, the acoustic properties of echolocation calls and morphological features such as fur color could vary in different populations. Therefore, we have used molecular taxonomy for the accurate identification of five bat species recorded in one of the largest cave populations in Sri Lanka. The bats were caught using a hand net, and saliva samples were collected non-invasively from each bat by using a sterile oral swab. Nucleic acids were extracted from the oral swab samples, and mitochondrial DNA was amplified by using primers targeting the mitochondrially encoded cytochrome b gene. This study reports the first molecular evidence for the identification of five bat species in Sri Lanka. Our findings will contribute to future conservation and systematic studies of bats in Sri Lanka. This study will also provide the basis for a genetic database of Sri Lankan bats which will contribute significantly to the investigation of potentially zoonotic bat viruses.

7.
Pathogens ; 11(4)2022 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-35456109

RESUMEN

Bats are known as typical reservoirs for a number of viruses, including viruses of the family Paramyxoviridae. Representatives of the subfamily Orthoparamyxovirinae are distributed worldwide and can cause mild to fatal diseases when infecting humans. The research on Paramyxoviruses (PMVs) from different bat hosts all over the world aims to understand the diversity, evolution and distribution of these viruses and to assess their zoonotic potential. A high number of yet unclassified PMVs from bats are recorded. In our study, we investigated bat species from the families Rhinolophidae, Hipposiderae, Pteropodidae and Miniopteridae that are roosting sympatrically in the Wavul Galge cave (Koslanda, Sri Lanka). The sampling at three time points (March and July 2018; January 2019) and screening for PMVs with a generic PCR show the presence of different novel PMVs in 10 urine samples collected from Miniopterus fuliginosus. Sequence analysis revealed a high similarity of the novel strains among each other and to other unclassified PMVs collected from Miniopterus bats. In this study, we present the first detection of PMVs in Sri Lanka and the presence of PMVs in the bat species M. fuliginosus for the first time.

8.
Mol Cancer Res ; 20(5): 794-809, 2022 05 04.
Artículo en Inglés | MEDLINE | ID: mdl-35135863

RESUMEN

Tumor heterogeneity and cellular plasticity are key determinants of tumor progression, metastatic spread, and therapy response driven by the cancer stem cell (CSC) population. Within the current study, we analyzed irradiation-induced plasticity within the aldehyde dehydrogenase (ALDH)-positive (ALDH+) population in prostate cancer. The radiosensitivity of xenograft tumors derived from ALDH+ and ALDH-negative (ALDH-) cells was determined with local tumor control analyses and demonstrated different dose-response profiles, time to relapse, and focal adhesion signaling. The transcriptional heterogeneity was analyzed in pools of 10 DU145 and PC3 cells with multiplex gene expression analyses and illustrated a higher degree of heterogeneity within the ALDH+ population that even increases upon irradiation in comparison with ALDH- cells. Phenotypic conversion and clonal competition were analyzed with fluorescence protein-labeled cells to distinguish cellular origins in competitive three-dimensional cultures and xenograft tumors. We found that the ALDH+ population outcompetes ALDH- cells and drives tumor growth, in particular upon irradiation. The observed dynamics of the cellular state compositions between ALDH+ and ALDH- cells in vivo before and after tumor irradiation was reproduced by a probabilistic Markov compartment model that incorporates cellular plasticity, clonal competition, and phenotype-specific radiosensitivities. Transcriptional analyses indicate that the cellular conversion from ALDH- into ALDH+ cells within xenograft tumors under therapeutic pressure was partially mediated through induction of the transcriptional repressor SNAI2. In summary, irradiation-induced cellular conversion events are present in xenograft tumors derived from prostate cancer cells and may be responsible for radiotherapy failure. IMPLICATIONS: The increase of ALDH+ cells with stem-like features in prostate xenograft tumors after local irradiation represents a putative cellular escape mechanism inducing tumor radioresistance.


Asunto(s)
Aldehído Deshidrogenasa , Neoplasias de la Próstata , Aldehído Deshidrogenasa/genética , Humanos , Masculino , Recurrencia Local de Neoplasia , Células PC-3 , Neoplasias de la Próstata/genética , Neoplasias de la Próstata/radioterapia , Tolerancia a Radiación
9.
Viruses ; 14(2)2022 02 07.
Artículo en Inglés | MEDLINE | ID: mdl-35215931

RESUMEN

Coronaviruses (CoV) are divided into the genera α-CoVs, ß-CoVs, γ-CoVs and δ-CoVs. Of these, α-CoVs and ß-CoVs are solely capable of causing infections in humans, resulting in mild to severe respiratory symptoms. Bats have been identified as natural reservoir hosts for CoVs belonging to these two genera. Consequently, research on bat populations, CoV prevalence in bats and genetic characterization of bat CoVs is of special interest to investigate the potential transmission risks. We present the genome sequence of a novel α-CoV strain detected in rectal swab samples of Miniopterus fuliginosus bats from a colony in the Wavul Galge cave (Koslanda, Sri Lanka). The novel strain is highly similar to Miniopterus bat coronavirus 1, an α-CoV located in the subgenus of Minunacoviruses. Phylogenetic reconstruction revealed a high identity of the novel strain to other α-CoVs derived from Miniopterus bats, while human-pathogenic α-CoV strains like HCoV-229E and HCoV-NL63 were more distantly related. Comparison with selected bat-related and human-pathogenic strains of the ß-CoV genus showed low identities of ~40%. Analyses of the different genes on nucleotide and amino acid level revealed that the non-structural ORF1a/1b are more conserved among α-CoVs and ß-CoVs, while there are higher variations in the structural proteins known to be important for host specificity. The novel strain was named batCoV/MinFul/2018/SriLanka and had a prevalence of 50% (66/130) in rectal swab samples and 58% (61/104) in feces samples that were collected from Miniopterus bats in Wavul Galge cave. Based on the differences between strain batCoV/MinFul/2018/SriLanka and human-pathogenic α-CoVs and ß-CoVs, we conclude that there is a rather low transmission risk to humans. Further studies in the Wavul Galge cave and at other locations in Sri Lanka will give more detailed information about the prevalence of this virus.


Asunto(s)
Alphacoronavirus/genética , Alphacoronavirus/aislamiento & purificación , Quirópteros/virología , Infecciones por Coronavirus/veterinaria , Reservorios de Enfermedades/veterinaria , Reservorios de Enfermedades/virología , Genoma Viral , Alphacoronavirus/clasificación , Animales , Cuevas/virología , Infecciones por Coronavirus/virología , Evolución Molecular , Femenino , Masculino , Filogenia , Análisis de Secuencia de ADN , Sri Lanka
10.
Aging Clin Exp Res ; 34(3): 515-525, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-34533774

RESUMEN

BACKGROUND: The longitudinal association between iron deficiency and inflammatory biomarkers levels has not been fully explored among relatively healthy older adults. AIMS: To assess whether iron deficiency at baseline and at any yearly follow-up time point, with or without anemia, was associated with changes from baseline in high-sensitivity C-reactive protein (hs-CRP) and interleukin-6 (IL-6) levels over 3 years. METHODS: This is a post-hoc observational analysis of DO-HEALTH, a double-blind, randomized controlled trial including 2157 European community-dwelling adults age 70+. The outcomes were changes from baseline in hs-CRP and IL-6 levels, measured at 12, 24, and 36 months of follow-up. Iron deficiency was defined by soluble transferrin receptor levels > 28.1 nmol/L and baseline anemia by hemoglobin levels < 130 g/L for men and < 120 g/L for women. RESULTS: In total, 2141 participants were included in the analyses (mean age: 74.9 years, 61.5% of women, 26.8% with iron deficiency). Baseline iron deficiency was associated with greater increase in IL-6 levels (mean difference in change: 0.52 ng/L, 95%CI 0.03-1.00, P = .04) over 3 years. Iron deficiency at any yearly time point was associated with higher increases in hs-CRP (mean difference in change: 1.62 mg/L, 95%CI 0.98-2.26, P < .001) and IL-6 levels (mean difference in change: 1.33 ng/L, 95%CI 0.87-1.79, P < .001) over 3 years. No significant interaction between iron deficiency and anemia was found, suggesting that the results are independent of the anemic status. CONCLUSIONS: These findings suggest that iron deficiency may play a role in low-grade chronic inflammation among relatively healthy older adults.


Asunto(s)
Anemia Ferropénica , Deficiencias de Hierro , Anciano , Biomarcadores , Proteína C-Reactiva/análisis , Femenino , Hemoglobinas/análisis , Humanos , Inflamación , Masculino
11.
Vaccines (Basel) ; 9(6)2021 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-34203592

RESUMEN

Bats are known to be potential reservoirs of numerous human-pathogenic viruses. They have been identified as natural hosts for coronaviruses, causing Severe Acute Respiratory Syndrome (SARS) in humans. Since the emergence of SARS-CoV-2 in 2019 interest in the prevalence of coronaviruses in bats was newly raised. In this study we investigated different bat species living in a sympatric colony in the Wavul Galge cave (Koslanda, Sri Lanka). In three field sessions (in 2018 and 2019), 395 bats were captured (Miniopterus, Rousettus, Hipposideros and Rhinolophus spp.) and either rectal swabs or fecal samples were collected. From these overall 396 rectal swab and fecal samples, the screening for coronaviruses with nested PCR resulted in 33 positive samples, 31 of which originated from Miniopterus fuliginosus and two from Rousettus leschenaultii. Sanger sequencing and phylogenetic analysis of the obtained 384-nt fragment of the RNA-dependent RNA polymerase revealed that the examined M. fuliginosus bats excrete alphacoronaviruses and the examined R. leschenaultii bats excrete betacoronaviruses. Despite the sympatric roosting habitat, the coronaviruses showed host specificity and seemed to be limited to one species. Our results represent an important basis to better understand the prevalence of coronaviruses in Sri Lankan bats and may provide a basis for pursuing studies on particular bat species of interest.

12.
Virol J ; 18(1): 110, 2021 06 02.
Artículo en Inglés | MEDLINE | ID: mdl-34078394

RESUMEN

BACKGROUND: The reliable detection of SARS-CoV-2 has become one of the most important contributions to COVID-19 crisis management. With the publication of the first sequences of SARS-CoV-2, several diagnostic PCR assays have been developed and published. In addition to in-house assays the market was flooded with numerous commercially available ready-to-use PCR kits, with both approaches showing alarming shortages in reagent supply. AIM: Here we present a resource-efficient in-house protocol for the PCR detection of SARS-CoV-2 RNA in patient specimens (RKI/ZBS1 SARS-CoV-2 protocol). METHODS: Two duplex one-step real-time RT-PCR assays are run simultaneously and provide information on two different SARS-CoV-2 genomic regions. Each one is duplexed with a control that either indicates potential PCR inhibition or proves the successful extraction of nucleic acid from the clinical specimen. RESULTS: Limit of RNA detection for both SARS-CoV-2 assays is below 10 genomes per reaction. The protocol enables testing specimens in duplicate across the two different SARS-CoV-2 PCR assays, saving reagents by increasing testing capacity. The protocol can be run on various PCR cyclers with several PCR master mix kits. CONCLUSION: The presented RKI/ZBS1 SARS-CoV-2 protocol represents a cost-effective alternative in times of shortages when commercially available ready-to-use kits may not be available or affordable.


Asunto(s)
Prueba de Ácido Nucleico para COVID-19/métodos , COVID-19/diagnóstico , ARN Viral/análisis , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , SARS-CoV-2/genética , Proteínas de la Envoltura de Coronavirus/genética , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Humanos , Límite de Detección , Poliproteínas/genética , ARN Viral/genética , SARS-CoV-2/aislamiento & purificación , Sensibilidad y Especificidad , Proteínas Virales/genética
13.
Viruses ; 12(11)2020 11 12.
Artículo en Inglés | MEDLINE | ID: mdl-33198291

RESUMEN

Studies of virus-host interactions in vitro may be hindered by biological characteristics of conventional monolayer cell cultures that differ from in vivo infection. Three-dimensional (3D) cell cultures show more in vivo-like characteristics and may represent a promising alternative for characterisation of infections. In this study, we established easy-to-handle cell culture platforms based on bioprinted 3D matrices for virus detection and characterisation. Different cell types were cultivated on these matrices and characterised for tissue-like growth characteristics regarding cell morphology and polarisation. Cells developed an in vivo-like morphology and long-term cultivation was possible on the matrices. Cell cultures were infected with viruses which differed in host range, tissue tropism, cytopathogenicity, and genomic organisation and virus morphology. Infections were characterised on molecular and imaging level. The transparent matrix substance allowed easy optical monitoring of cells and infection even via live-cell microscopy. In conclusion, we established an enhanced, standardised, easy-to-handle bioprinted 3D-cell culture system. The infection models are suitable for sensitive monitoring and characterisation of virus-host interactions and replication of different viruses under physiologically relevant conditions. Individual cell culture models can further be combined to a multicellular array. This generates a potent diagnostic tool for propagation and characterisation of viruses from diagnostic samples.


Asunto(s)
Bioimpresión/métodos , Técnicas de Cultivo de Célula , Interacciones Huésped-Patógeno , Virosis/diagnóstico , Virosis/virología , Animales , Biomarcadores , Supervivencia Celular , Chlorocebus aethiops , Humanos , Imagen Molecular , Esferoides Celulares , Células Vero
14.
PLoS Biol ; 17(10): e3000463, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-31613875

RESUMEN

The Animal Study Registry (ASR; www.animalstudyregistry.org) was launched in January 2019 for preregistration of animal studies in order to increase transparency and reproducibility of bioscience research and to promote animal welfare. The registry is free of charge and is designed for exploratory and confirmatory studies within applied science as well as basic and preclinical research. The registration form helps scientists plan their study thoroughly by asking detailed questions concerning study design, methods, and statistics. With registration, the study automatically receives a digital object identifier (DOI) that marks it as intellectual property of the researcher. To accommodate the researchers concerns about theft of ideas, users can restrict the visibility of their registered studies for up to 5 years. The full content of the study becomes publicly accessible at the end of the embargo period. Because the platform is embedded in the infrastructure of the German Federal Government, continuity and data security are provided. By registering a study in the ASR, researchers can show their commitment to transparency and data quality to reviewers and editors, to third-party donors, and to the general public.


Asunto(s)
Experimentación Animal/legislación & jurisprudencia , Bienestar del Animal/legislación & jurisprudencia , Sistema de Registros , Proyectos de Investigación/legislación & jurisprudencia , Experimentación Animal/ética , Bienestar del Animal/ética , Seguridad Computacional , Exactitud de los Datos , Alemania , Regulación Gubernamental , Humanos , Propiedad Intelectual
15.
Environ Sci Technol ; 53(21): 12725-12733, 2019 Nov 05.
Artículo en Inglés | MEDLINE | ID: mdl-31536708

RESUMEN

A key challenge of mixture toxicity testing is that a multitude of substances with even more combinations need to be tested in a broad dose range. Consequently testing in rodent bioassays, the current gold standard of toxicity testing, is hardly feasible. High-throughput compatible cell culture systems, however, suffer from limitations with respect to toxicokinetics, tissue interactions, and compensatory mechanisms. Therefore, simple organisms like the nematode Caenorhabditis elegans, combining relevant advantages of complex in vivo and fast in vitro assays might prove highly valuable within a testing strategy for mixtures. To investigate the comparability between results obtained with C. elegans and traditional rodent assays, we used five azole fungicides as well investigated model substances. Our findings suggest that azoles act additively in C. elegans which is in line with previous results in rats. Additionally, we show that toxicokinetics are one important factor for the differences in the relative toxicity of the azoles in both species. Importantly, we also demonstrate that in contrast to most rodent in vivo studies, C. elegans assays provide well-defined concentration-response relationships which are a very good basis for the prediction of mixture effects. We conclude that C. elegans may be an appropriate model for mixture toxicity testing at least within a first step to identify and prioritize relevant mixtures for further testing.


Asunto(s)
Fungicidas Industriales , Nematodos , Animales , Azoles , Caenorhabditis elegans , Ratas , Pruebas de Toxicidad
16.
Stem Cell Res ; 38: 101474, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-31176917

RESUMEN

Von Hippel-Lindau (VHL) syndrome is a familial cancer syndrome caused by mutations in the tumor suppressor gene VHL. We generated human iPSC lines from primary dermal fibroblasts of three VHL syndrome patients carrying distinct VHL germ line mutations (c.194C>G, c.194C>T and nt440delTCT, respectively). Characterization of the iPSC lines confirmed expression of pluripotency markers, trilineage differentiation potential and absence of exogenous vector expression. The three hiPSC lines were genetically stable and retained the VHL mutation of each donor. These iPSC lines, the first derived from VHL syndrome patients, offer a useful resource to study disease pathophysiology and for anti-cancer drug development.


Asunto(s)
Mutación de Línea Germinal , Células Madre Pluripotentes Inducidas , Proteína Supresora de Tumores del Síndrome de Von Hippel-Lindau , Enfermedad de von Hippel-Lindau , Línea Celular , Femenino , Humanos , Células Madre Pluripotentes Inducidas/metabolismo , Células Madre Pluripotentes Inducidas/patología , Proteína Supresora de Tumores del Síndrome de Von Hippel-Lindau/genética , Proteína Supresora de Tumores del Síndrome de Von Hippel-Lindau/metabolismo , Enfermedad de von Hippel-Lindau/genética , Enfermedad de von Hippel-Lindau/metabolismo , Enfermedad de von Hippel-Lindau/patología
17.
Cancers (Basel) ; 11(5)2019 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-31052565

RESUMEN

Head and neck squamous cell carcinoma (HNSCC) is the sixth most commonly diagnosed cancer worldwide. Despite advances in the treatment management, locally advanced disease has a poor prognosis, with a 5-year survival rate of approximately 50%. The growth of HNSCC is maintained by a population of cancer stem cells (CSCs) which possess unlimited self-renewal potential and induce tumor regrowth if not completely eliminated by therapy. The population of CSCs is not only a promising target for tumor treatment, but also an important biomarker to identify the patients at risk for therapeutic failure and disease progression. This review aims to provide an overview of the recent pre-clinical and clinical studies on the biology and potential therapeutic implications of HNSCC stem cells.

18.
Am J Hum Genet ; 103(6): 1045-1052, 2018 12 06.
Artículo en Inglés | MEDLINE | ID: mdl-30526862

RESUMEN

We describe six persons from three families with three homozygous protein truncating variants in PUS7: c.89_90del (p.Thr30Lysfs∗20), c.1348C>T (p.Arg450∗), and a deletion of the penultimate exon 15. All these individuals have intellectual disability with speech delay, short stature, microcephaly, and aggressive behavior. PUS7 encodes the RNA-independent pseudouridylate synthase 7. Pseudouridylation is the most abundant post-transcriptional modification in RNA, which is primarily thought to stabilize secondary structures of RNA. We show that the disease-related variants lead to abolishment of PUS7 activity on both tRNA and mRNA substrates. Moreover, pus7 knockout in Drosophila melanogaster results in a number of behavioral defects, including increased activity, disorientation, and aggressiveness supporting that neurological defects are caused by PUS7 variants. Our findings demonstrate that RNA pseudouridylation by PUS7 is essential for proper neuronal development and function.


Asunto(s)
Agresión/fisiología , Enanismo/genética , Variación Genética/genética , Discapacidad Intelectual/genética , Trastornos del Desarrollo del Lenguaje/genética , Microcefalia/genética , Adolescente , Animales , Niño , Drosophila melanogaster/genética , Exones/genética , Femenino , Técnicas de Inactivación de Genes/métodos , Homocigoto , Humanos , Masculino , Linaje , Fenotipo , ARN Mensajero/genética , ARN de Transferencia/genética
19.
PLoS One ; 13(9): e0202762, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30208060

RESUMEN

We developed a new probabilistic model to assess the impact of recommendations rectifying the reproducibility crisis (by publishing both positive and 'negative' results and increasing statistical power) on competing objectives, such as discovering causal relationships, avoiding publishing false positive results, and reducing resource consumption. In contrast to recent publications our model quantifies the impact of each single suggestion not only for an individual study but especially their relation and consequences for the overall scientific process. We can prove that higher-powered experiments can save resources in the overall research process without generating excess false positives. The better the quality of the pre-study information and its exploitation, the more likely this beneficial effect is to occur. Additionally, we quantify the adverse effects of both neglecting good practices in the design and conduct of hypotheses-based research, and the omission of the publication of 'negative' findings. Our contribution is a plea for adherence to or reinforcement of the good scientific practice and publication of 'negative' findings.


Asunto(s)
Investigación Biomédica , Modelos Teóricos , Edición , Reproducibilidad de los Resultados
20.
Horm Metab Res ; 50(8): 602-608, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-30081408

RESUMEN

Circulating tumor cells (CTCs) have been shown to be a valuable prognostic marker for different solid cancers. Within the present study we quantified CTCs in thyroid cancer (TC) patients. Special focus was given to disease-free PTC patients with undetectable serum thyroglobulin (Tg) levels. Altogether, 67 TC patients (33 papillary, 20 follicular, 14 medullary) were included in the study. CTC numbers, which were normalized to 3.3×105 peripheral blood mononuclear cells, were correlated with clinical outcome. TC patients had significantly higher CTC numbers compared to controls. The number of CTCs correlated to the initial tumor stage. Importantly, in comparison to controls, differentiated TC patients with serum Tg levels<0.3 ng/ml (no evidence of tumor recurrence) revealed a significantly higher amount of CTCs, also associated to their former tumor stage. Regarding the tumor-free papillary TC (PTC) patients the number of CTCs additionally correlated to the time point of radioiodine (RI) therapy: PTC patients with RI therapies>8 years before CTC measurement had significantly higher CTC numbers compared to those with RI therapy<8 years ago. We found a clear correlation between the number of CTCs and the tumor stage. Importantly, PTC patients who are in remission may still have increased numbers of CTCs. Follow-up analyses in these patients will reveal whether these data will have a clinical impact.


Asunto(s)
Células Neoplásicas Circulantes/patología , Neoplasias de la Tiroides/sangre , Adulto , Anciano , Anciano de 80 o más Años , Carcinoma Papilar/sangre , Carcinoma Papilar/patología , Recuento de Células , Femenino , Humanos , Masculino , Persona de Mediana Edad , Cáncer Papilar Tiroideo , Neoplasias de la Tiroides/patología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...