215 research outputs found
Placenta growth factor induces melanoma resistance to temozolomide through a mechanism that involves the activation of the transcription factor NF-κB
Placenta growth factor (PlGF) and its receptor vascular endothelial growth factor receptor-1 (VEGFR-1) are co-expressed in a large number of human melanoma cell lines. Moreover, a correlation between in vivo PlGF production and melanoma progression has been suggested. To investigate whether PlGF might have a role in protecting melanoma cells from the cytotoxic effects of the anticancer agent temozolomide (TMZ), which is used for the treatment of this malignancy, we stably transfected a doxycycline-inducible PlGF antisense mRNA into a human melanoma cell clone that secretes VEGF-A and PlGF and expresses receptors for both growth factors. Induction of PlGF antisense mRNA in the transfected cells (13443/ASP3 subclone) halved TMZ IC(50), and exogenous addition of PlGF to the culture medium 24 h before TMZ treatment, partially restored IC(50) values to that of control cells. The increased sensitivity of 13443/ASP3 cells upon PlGF antisense mRNA expression was not due to down-regulation of O6-methylguanine-DNA methyltransferase, a DNA repair protein that represents the main mechanism of resistance to TMZ. Since the activity of the transcription factor nuclear factor-κB (NF-κB) has been correlated to melanoma chemoresistance, we investigated whether NF-κB was involved in PlGF-induced melanoma cell resistance to TMZ. Induction of PlGF antisense mRNA in 13443/ASP3 cells halved the levels of active NF-κB and the specific inhibition of this transcription factor increased sensitivity of 13443/ASP3 cells to TMZ. In conclusion, our data strongly suggest that PlGF plays a role in melanoma cell resistance to TMZ through a pathway that involves NF-κB activation
NF-κB is activated in response to temozolomide in an AKT-dependent manner and confers protection against the growth suppressive effect of the drug.
BACKGROUND:
Most DNA-damaging chemotherapeutic agents activate the transcription factor nuclear factor κB (NF-κB). However, NF-κB activation can either protect from or contribute to the growth suppressive effects of the agent. We previously showed that the DNA-methylating drug temozolomide (TMZ) activates AKT, a positive modulator of NF-κB, in a mismatch repair (MMR) system-dependent manner. Here we investigated whether NF-κB is activated by TMZ and whether AKT is involved in this molecular event. We also evaluated the functional consequence of inhibiting NF-κB on tumor cell response to TMZ.
METHODS:
AKT phosphorylation, NF-κB transcriptional activity, IκB-α degradation, NF-κB2/p52 generation, and RelA and NF-κB2/p52 nuclear translocation were investigated in TMZ-treated MMR-deficient (HCT116, 293TLα-) and/or MMR-proficient (HCT116/3-6, 293TLα+, M10) cells. AKT involvement in TMZ-induced activation of NF-κB was addressed in HCT116/3-6 and M10 cells transiently transfected with AKT1-targeting siRNA or using the isogenic MMR-proficient cell lines pUSE2 and KD12, expressing wild type or kinase-dead mutant AKT1. The effects of inhibiting NF-κB on sensitivity to TMZ were investigated in HCT116/3-6 and M10 cells using the NF-κB inhibitor NEMO-binding domain (NBD) peptide or an anti-RelA siRNA.
RESULTS:
TMZ enhanced NF-κB transcriptional activity, activated AKT, induced IκB-α degradation and RelA nuclear translocation in HCT116/3-6 and M10 but not in HCT116 cells. In M10 cells, TMZ promoted NF-κB2/p52 generation and nuclear translocation and enhanced the secretion of IL-8 and MCP-1. TMZ induced RelA nuclear translocation also in 293TLα+ but not in 293TLα- cells. AKT1 silencing inhibited TMZ-induced IκB-α degradation and NF-κB2/p52 generation. Up-regulation of NF-κB transcriptional activity and nuclear translocation of RelA and NF-κB2/p52 in response to TMZ were impaired in KD12 cells. RelA silencing in HCT116/3-6 and M10 cells increased TMZ-induced growth suppression. In M10 cells NBD peptide reduced basal NF-κB activity, abrogated TMZ-induced up-regulation of NF-κB activity and increased sensitivity to TMZ. In HCT116/3-6 cells, the combined treatment with NBD peptide and TMZ produced additive growth inhibitory effects.
CONCLUSION:
NF-κB is activated in response to TMZ in a MMR- and AKT-dependent manner and confers protection against drug-induced cell growth inhibition. Our findings suggest that a clinical benefit could be obtained by combining TMZ with NF-κB inhibitors
Switched Spatial Impulse Response Convolution as an Ambisonic Distance-Panning Function
Ambisonics offers a robust and effective approach to the recording, processing and delivery of Spatial Audio. The Ambisonic system is often considered to provide a perceptually and computationally advantageous Spatial Audio experience in comparison to typical Binaural systems. This is true even when an end-step Binaural render is required, as is typical in Virtual or Augmented Reality systems which naturally imply audio delivery via headphones. Standard Ambisonic processing allows for the rotation of a sound field around an origin position. There is not, however, a strongly established means of modulating the radial distance of a virtual sound source from the origin. This paper presents a potential solution to an Ambisonic distance-panning function for both static and dynamic virtual sources in the form of a FOA (First Order Ambisonics) Switched-SIR (Spatial Impulse Response) Convolution Reverberator. This includes a presentation of the framework for such a function, and an analysis of audio rendered using prototype scripts
Early molecular diagnosis of aspergillosis in a patient with acute myeloid leukaemia
Diagnosis of invasive fungal infection remains challenging. Here we report a case of early diagnosis of invasive aspergillosis in a neutropenic patient affected by acute myeloid leukaemia, achieved through the detection of Aspergillus fumigatus species-specific ribonucleic acid sequences by a sensitive multiplex real-time polymerase chain reaction-based molecular assay. Thanks to the early diagnosis, targeted therapy was promptly established and the severe fungal infection controlled, allowing the patient to subsequently receive allogeneic hematopoietic stem cell transplantation from a haploidentical donor, her only curative option. Also in this instance, targeted secondary antifungal prophylaxis with voriconazole avoided any other fungal infection afterwards. This report suggests how the implementation of molecular assays in combination with routine diagnostic procedures, can improve microbiological diagnosis in sepsis, particularly in case of fungal infection, difficult to detect with standard microbiological culture methods
hMYH and hMTH1 cooperate for survival in mismatch repair defective T-cell acute lymphoblastic leukemia
hMTH1 is an 8-oxodGTPase that prevents mis-incorporation of free oxidized nucleotides into genomic DNA. Base excision and mismatch repair pathways also restrict the accumulation of oxidized lesions in DNA by removing the mis-inserted 8-oxo-7,8-dihydro-2'-deoxyguanosines (8-oxodGs). In this study, we aimed to investigate the interplay between hMYH DNA glycosylase and hMTH1 for cancer cell survival by using mismatch repair defective T-cell acute lymphoblastic leukemia (T-ALL) cells. To this end, MYH and MTH1 were silenced individually or simultaneously using small hairpin RNAs. Increased sub-G1 population and apoptotic cells were observed upon concurrent depletion of both enzymes. Elevated cell death was consistent with cleaved caspase 3 accumulation in double knockdown cells. Importantly, overexpression of the nuclear isoform of hMYH could remove the G1 arrest and partially rescue the toxicity observed in hMTH1-depleted cells. In addition, expression profiles of human DNA glycosylases were generated using quantitative reverse transcriptase–PCR in MTH1 and/or MYH knockdown cells. NEIL1 DNA glycosylase, involved in repair of oxidized nucleosides, was found to be significantly downregulated as a cellular response to MTH1–MYH co-suppression. Overall, the results suggest that hMYH and hMTH1 functionally cooperate for effective repair and survival in mismatch repair defective T-ALL Jurkat A3 cells
Researching Complex Interventions in Health: The State of the Art : Exeter, UK. 14-15 October 2015.
Erratum to this paper available at http://hdl.handle.net/10871/23087
Changes in socioeconomic resources and mental health after the second COVID-19 wave (2020-2021): a longitudinal study in Switzerland
BACKGROUND: During the 2020/2021 winter, the labour market was under the impact of the COVID-19 pandemic. Changes in socioeconomic resources during this period could have influenced individual mental health. This association may have been mitigated or exacerbated by subjective risk perceptions, such as perceived risk of getting infected with SARS-CoV-2 or perception of the national economic situation. Therefore, we aimed to determine if changes in financial resources and employment situation during and after the second COVID-19 wave were prospectively associated with depression, anxiety and stress, and whether perceptions of the national economic situation and of the risk of getting infected modified this association. METHODS: One thousand seven hundred fifty nine participants from a nation-wide population-based eCohort in Switzerland were followed between November 2020 and September 2021. Financial resources and employment status were assessed twice (Nov2020-Mar2021, May-Jul 2021). Mental health was assessed after the second measurement of financial resources and employment status, using the Depression, Anxiety and Stress Scale (DASS-21). We modelled DASS-21 scores with linear regression, adjusting for demographics, health status, social relationships and changes in workload, and tested interactions with subjective risk perceptions. RESULTS: We observed scores above thresholds for normal levels for 16% (95%CI = 15-18) of participants for depression, 8% (95%CI = 7-10) for anxiety, and 10% (95%CI = 9-12) for stress. Compared to continuously comfortable or sufficient financial resources, continuously precarious or insufficient resources were associated with worse scores for all outcomes. Increased financial resources were associated with higher anxiety. In the working-age group, shifting from full to part-time employment was associated with higher stress and anxiety. Perceiving the Swiss economic situation as worrisome was associated with higher anxiety in participants who lost financial resources or had continuously precarious or insufficient resources. CONCLUSION: This study confirms the association of economic stressors and mental health during the COVID-19 pandemic and highlights the exacerbating role of subjective risk perception on this association
Observing galaxy clusters and the cosmic web through the Sunyaev Zel'dovich effect with MISTRAL
Galaxy clusters and surrounding medium, can be studied using X-ray
bremsstrahlung emission and Sunyaev Zel'dovich (SZ) effect. Both astrophysical
probes, sample the same environment with different parameters dependance. The
SZ effect is relatively more sensitive in low density environments and thus is
useful to study the filamentary structures of the cosmic web. In addition,
observations of the matter distribution require high angular resolution in
order to be able to map the matter distribution within and around galaxy
clusters. MISTRAL is a camera working at 90GHz which, once coupled to the
Sardinia Radio Telescope, can reach angular resolution over field
of view (f.o.v.). The forecasted sensitivity is
and the mapping speed is . MISTRAL was recently
installed at the focus of the SRT and soon will take its first photons.Comment: To appear in Proc. of the mm Universe 2023 conference, Grenoble
(France), June 2023, published by F. Mayet et al. (Eds), EPJ Web of
conferences, EDP Science
The development of an occupational therapy intervention for adults with a diagnosed psychotic disorder following discharge from hospital
Background: A deterioration in mental health and admission to an acute mental health unit can result in skill loss and decreased participation in daily life. Furthermore, discharge from hospital is associated with high risks of social isolation and suicide. This intervention development study aims to describe the rationale, methods and processes of developing an intervention for adults with a diagnosed psychotic disorder following discharge from hospital. The intervention aims to increase participation in self-care and leisure, wellbeing and quality of life and reduce crisis service use.
Methods: The United Kingdom Medical Research Council framework for the development of complex interventions was used to guide the process of developing the intervention to ensure the developed intervention is empirically justifiable and evidence based. The development involved a systematic and literature reviews and focus groups with people with psychosis and clinical staff to understand the problems the intervention should address and approaches to resolving these.
Results: A manualised four-month intervention named Graduating Living skills Outside the Ward (GLOW) was developed for use by occupational therapists for people with a diagnosed psychotic disorder following discharge from hospital. The one-to-one stepped intensity intervention is of four months in duration and takes place in the person’s home and in community locations. The intervention aims to increase occupational performance of domestic and personal self-care, leisure and some productive roles.
Conclusions: The intervention developed in this study has potential to improve the efficiency of community mental health services following discharge from hospital as it is evidence-based, time-limited and manualised and aims to reduce hospital admissions and crisis service use. The intervention will be tested to assess its clinical 41 and cost effectiveness in a randomised controlled trial
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