885 research outputs found
Targeting Notch Trafficking and Processing in Cancers
The Notch family comprises a group of four ligand-dependent receptors that control evolutionarily conserved developmental and homeostatic processes and transmit signals to the microenvironment. NOTCH undergoes remodeling, maturation, and trafficking in a series of post-translational events, including glycosylation, ubiquitination, and endocytosis. The regulatory modifications occurring in the endoplasmic reticulum/Golgi precede the intramembrane γ-secretase proteolysis and the transfer of active NOTCH to the nucleus. Hence, NOTCH proteins coexist in different subcellular compartments and undergo continuous relocation. Various factors, including ion concentration, enzymatic activity, and co-regulatory elements control Notch trafficking. Interfering with these regulatory mechanisms represents an innovative therapeutic way to bar oncogenic Notch signaling. In this review, we briefly summarize the role of Notch signaling in cancer and describe the protein modifications required for NOTCH to relocate across different subcellular compartments. We focus on the functional relationship between these modifications and the corresponding therapeutic options, and our findings could support the development of trafficking modulators as a potential alternative to the well-known γ-secretase inhibitors
Role of CD73 - A2A/A2B receptors axis in cancer
2016 - 2017The adenosinergic pathway plays a critical role in cancer development and progression, as well as
in drug resistance to chemotherapy and/or targeted-therapy.
The goal of this PhD thesis was to investigate and fully characterize the role of CD73/adenosine
A2A-A2B receptors axis in cancer, highlighting the therapeutic potential of inhibitors of the
adenosinergic pathway.
We firstly characterized the mechanism/s by which A2BR promotes immunosuppression and
angiogenesis in tumor-bearing hosts, focusing on the role of myeloid-derived suppressor cells
(MDSCs) and cancer-associated fibroblasts (CAFs). The results revealed that treatment of
melanoma-bearing mice with Bay60-6583, a selective A2BR agonist, is associated with 1. increased
tumor VEGF-A expression and vessel density, and 2. increased accumulation of tumor-infiltrating
CD11b+Gr1+cells (MDSCs). MDSCs strongly contribute to the immunosuppressive and
angiogenic effects of Bay60-6583. Melanoma-bearing mice treated with a selective A2BR antagonist
PSB1115 showed reduced tumor growth compared to controls and this effect was associated with
reduced tumor angiogenesis, low levels of MDSCs and increased number of tumor-infiltrating
CD8+ T cells. Furthermore, blockade of A2BR increased the anti-tumor effects of VEGF-A
inhibitors. Next, we verified that A2BR activation also drives fibroblasts activation within melanoma
tissues, by increasing the number of FAP positive cells within tumor lesions. FAP is a common
marker of activated fibroblasts also named cancer-associated fibroblasts. These cells produce and
secrete various tumor-promoting factors, including fibroblast growth factor (FGF)-2 and CXCL12
or stromal-derived factor 1 α (SDF1α), that were increased both in melanoma tissue and fibroblasts
isolated from melanoma tissue or from skin upon Bay60-6583 treatment. Bay60-6583-induced
FGF-2 from fibroblasts contributed to melanoma cells proliferation. The CXCL12/CXCR4
pathway, instead, was involved in the pro-angiogenic effects of A2BR agonist, but not in its
immunosuppressive effects. These effects were significantly blocked by the A2BR antagonists
PSB1115. Taken together, these data elucidate the pivotal role of A2BR in establishing a positive
cross-talk between tumor-infiltrating immune cells, fibroblasts and endothelial cells that sustain
tumor growth, reinforcing the therapeutic potential of A2BR blockers for cancer therapy. ... [edited by Author]XXX cicl
Direito fundamental de Acesso à Justiça: uma análise à luz da necessidade de autonomia da Defensoria Pública da União
O presente trabalho cuidará do direito fundamental de Acesso à Justiça preconizado no artigo 5°, LXXIV, da Constituição Federal de 1988, com enfoque para o direito à autonomia da Defensoria Pública da União. A pesquisa se justifica pela ineficácia apresentada por essa instituição na prestação de assistência jurídica integral e gratuita aos hipossuficientes em razão da precariedade estrutural que se encontra, e tem como objetivo mediato apresentar o descompasso existente entre a importância social da instituição e o valor que a ela é conferido pelo Poder Executivo Federal, em flagrante descumprimento dos preceitos constitucionais, para ao final, defender a sua autonomia institucional, tal qual fora conferida às defensorias Estaduais por meio da EC 45/2004. Para tanto, a questão será enfrentada a partir de uma análise estatística, doutrinária e embasada na lei acerca do conceito de Acesso à Justiça, perpassada pelos princípios da liberdade e igualdade e do conceito de garantias institucionais, ressaltada a importância da instituição Defensoria Pública, e apresentados todos os problemas enfrentados pela Defensoria Pública da União na tutela dos interesses dos economicamente necessitados. Para isso serão tratadas todas as peculiaridades institucionais da DPU, bem como apresentados diversos dados estatísticos que embasam a necessidade de mudança. Como solução para os problemas relatados, foi apresentada a Proposta de Emenda à Constituição - PEC 207-B, convertida na Emenda Constitucional - EC 74 que incluiu o § 3º ao artigo 134 da Constituição Federal de 1988, que confere à Defensoria Pública da União autonomia funcional, administrativa e financeira
Activation of human endogenous retrovirus K (HERV-K) and cellular modifications in human melanoma cell line: transcriptional profiling analysis
Evaluation of the Siemens HIV Antigen-Antibody Immunoassay
Fourth-generation assays for the simultaneous detection of human immunodeficiency virus (HIV) antigen and antibodies are available on the international market and are currently used for blood donor screening and for HIV diagnosis. In this study we evaluated the performance of the novel automated fourth-generation ADVIA Centaur® HIV Ag/Ab Combo assay. The assay detected seroconversion at the same bleed or at least one bleed earlier in panels with respect to other assays and showed a detection efficacy equal to those of other assays in a low-titer panel. Samples obtained from blood donors (n = 2,778) or from HIV-positive patients (HIV-1 B subtype, n = 82; non-B subtype, n = 71) were also tested, showing a good correlation with other fourth-generation assays. We assessed the performance of 3 fourth-generation assays for detecting in utero transmitted anti-HIV antibodies and found a more specific detection efficiency with the ADVIA Centaur HIV Ag/Ab Combo assay compared to the other fourth-generation assays
Evolution of nonspecific duodenal lymphocytosis over 2 years of follow-up
AIM: To assess the evolution of duodenal lymphocytosis (DL), a condition characterized by increased intraepithelial lymphocytes (IELs), over 2 years of follow-up. METHODS: Consecutive patients undergoing upper endoscopy/histology for abdominal pain, diarrhea, weight loss, weakness or other extraintestinal features compatible with celiac disease (CD) were included. Evaluation of IELs infiltrate in duodenal biopsy samples was carried out by CD3-immunohistochemistry and expressed as number of positive cells/100 enterocytes. Diagnostic agreement on the IELs count was tested by calculating the weighted k coefficient. All patients underwent serological detection of autoantibodies associated with CD: IgG and IgA anti-tissue transglutaminase and endomysium. Each patient underwent further investigations to clarify the origin of DL at baseline and/or in the course of 2 years of follow-up every six months. Autoimmune thyroiditis, intestinal infections, parasitic diseases, bacterial intestinal overgrowth, hypolactasia and wheat allergy were detected. Colonoscopy and enteric magnetic resonance imaging were performed when necessary. Risk factors affecting the final diagnosis were detected by multinomial logistic regression and expressed as OR. RESULTS: Eighty-five patients (16 males, 69 females, aged 34.1 ± 12.5 years) were followed up for a mean period of 21.7 ± 11.7 mo. At baseline, endoscopy/duodenal biopsy, CD3 immunohistochemistry revealed: > 25 IELs/100 enterocytes in 22 subjects, 15-25 IELs in 37 and < 15 IELs in 26. They all had negative serum anti-transglutaminase and anti-endomysium, whilst 5 showed IgG anti-gliadin positivity. In the course of follow-up, 23 developed CD seropositivity and gluten sensitivity (GS) was identified in 19. Other diagnoses were: 5 Helicobacter pylori infections, 4 jejunal Crohn's disease, 1 lymphocytic colitis and 1 systemic sclerosis. The disease in the remaining 32 patients was classified as irritable bowel syndrome because of the lack of diagnostic evidence. At multivariate analysis, the evolution towards CD was associated with an IELs infiltrate > 25 (OR = 1640.4) or 15-25 (OR = 16.95), human leukocyte antigen (HLA) DQ2/8 (OR = 140.85) or DQA1∗0501 (OR = 15.36), diarrhea (OR = 5.56) and weakness (OR = 11.57). GS was associated with IELs 15-25 (OR = 28.59), autoimmune thyroiditis (OR = 87.63), folate deficiency (OR = 48.53) and diarrhea (OR = 54.87). CONCLUSION: DL may have a multifactorial origin but the IELs infiltrate and HLA are strong predictive factors for CD development and a clinical diagnosis of GS
Helical surface magnetization in nanowires: the role of chirality
Nanomagnetism is nowadays expanding into three dimensions, triggered by the discovery of new magnetic phenomena and their potential use in applications. This shift towards 3D structures should be accompanied by strategies and methodologies to map the tridimensional spin textures associated. We present here a combination of dichroic X-ray transmission microscopy at different angles and micromagnetic simulations allowing to determine the magnetic configuration of cylindrical nanowires. We have applied it to permalloy nanowires with equispaced chemical barriers that can act as pinning sites for domain walls. The magnetization at the core is longitudinal and generates at the surface of the wire helical magnetization. Different types of domain walls are found at the pinning sites, which respond differently to applied fields depending on the relative chirality of the adjacent domains
Clinical longevity of direct and indirect posterior resin composite restorations: an updated systematic review and meta-analysis.
Objectives: To answer the PICO(S) question: Is there a difference in clinical longevity between direct and indirect resin composite restorations placed on permanent posterior teeth?
Data: Randomized controlled clinical trials (RCTs) investigating direct and indirect resin composite restorations in posterior permanent teeth were considered.
Sources: Several electronic databases were searched, with no language or date restrictions. The revised Cochrane Collaboration’s tool for assessing risk of bias (RoB-2) was used to analyze the studies; meta-analyses were run and the certainty of evidence was assessed by the GRADE tool. A subgroup meta-analysis was performed for resin composite restorations placed on posterior worn dentition.
Study selection: Twenty-three articles were included in qualitative synthesis, while 8 studies were used for meta- analyses. According to the RoB-2 tool, 5 studies were ranked as “low risk”, 7 had “some concerns”, while 11 papers were rated as “high risk” of bias. There were no statistically significant differences in short-term (p = 0.27; RR=1.54, 95% CI [0.72, 3.33]), medium-term (p = 0.27; RR=1.87, 95% CI [0.61, 5.72]) and long-term longevity (p = 0.86; RR=0.95, 95% CI [0.57, 1.59]). The choice of restorative technique had no influence on short-term survival of resin composite restorations placed on worn dentition (p = 0.13; RR=0.46, 95% CI [0.17, 1.25]). The certainty of evidence was rated as “very low”.
Conclusions: Direct and indirect resin composite restorations may show similar clinical longevity in posterior region, regardless of the observation period or substrate (wear-affected and non-affected dentition). The very low quality of evidence suggests that more long-term RCTs are needed to confirm our results
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