43 research outputs found

    The mutant p53-driven secretome has oncogenic functions in pancreatic ductal adenocarcinoma cells

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    The cancer secretome is a rich repository of useful information for both cancer biology and clinical oncology. A better understanding of cancer secretome is particularly relevant for pancreatic ductal adenocarcinoma (PDAC), whose extremely high mortality rate is mainly due to early metastasis, resistance to conventional treatments, lack of recognizable symptoms, and assays for early detection. TP53 gene is a master transcriptional regulator controlling several key cellular pathways and it is mutated in ~75% of PDACs. We report the functional effect of the hot-spot p53 mutant isoforms R175H and R273H on cancer cell secretome, showing their influence on proliferation, chemoresistance, apoptosis, and autophagy, as well as cell migration and epithelial-mesenchymal transition. We compared the secretome of p53-null AsPC-1 PDAC cells after ectopic over-expression of R175H-mutp53 or R273H-mutp53 to identify the differentially secreted proteins by mutant p53. By using high-resolution SWATH-MS technology, we found a great number of differentially secreted proteins by the two p53 mutants, 15 of which are common to both mutants. Most of these secreted proteins are reported to promote cancer progression and epithelial-mesenchymal transition and might constitute a biomarker secreted signature that is driven by the hot-spot p53 mutants in PDAC

    Tumor Suppressor Role of Wild-Type P53-Dependent Secretome and Its Proteomic Identification in PDAC

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    : The study of the cancer secretome is gaining even more importance in cancers such as pancreatic ductal adenocarcinoma (PDAC), whose lack of recognizable symptoms and early detection assays make this type of cancer highly lethal. The wild-type p53 protein, frequently mutated in PDAC, prevents tumorigenesis by regulating a plethora of signaling pathways. The importance of the p53 tumor suppressive activity is not only primarily involved within cells to limit tumor cell proliferation but also in the extracellular space. Thus, loss of p53 has a profound impact on the secretome composition of cancer cells and marks the transition to invasiveness. Here, we demonstrate the tumor suppressive role of wild-type p53 on cancer cell secretome, showing the anti-proliferative, apoptotic and chemosensitivity effects of wild-type p53 driven conditioned medium. By using high-resolution SWATH-MS technology, we characterized the secretomes of p53-deficient and p53-expressing PDAC cells. We found a great number of secreted proteins that have known roles in cancer-related processes, 30 of which showed enhanced and 17 reduced secretion in response to p53 silencing. These results are important to advance our understanding on the link between wt-p53 and cancer microenvironment. In conclusion, this approach may detect a secreted signature specifically driven by wild-type p53 in PDAC

    Excellent Response to OnabotulinumtoxinA : Different Definitions, Different Predictors

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    The identification of patients who can benefit the most from the available preventive treatments is important in chronic migraine. We explored the rate of excellent responders to onabotulinumtoxinA in a multicenter European study and explored the predictors of such response, according to different definitions. A pooled analysis on chronic migraineurs treated with onabotulinumtoxinA and followed-up for, at least, 9 months was performed. Excellent responders were defined either as patients with a ≥75% decrease in monthly headache days (percent-based excellent responders) or as patients with <4 monthly headache days (frequency-based excellent responders). The characteristics of excellent responders at the baseline were compared with the ones of patients with a <30% decrease in monthly headache days. Percent-based excellent responders represented about 10% of the sample, whilst frequency-based excellent responders were about 5% of the sample. Compared with non-responders, percent-based excellent responders had a higher prevalence of medication overuse and a higher excellent response rate even after the 1st and the 2nd injection. Females were less like to be frequency-based excellent responders. Chronic migraine sufferers without medication overuse and of female sex may find fewer benefits with onabotulinumtoxinA. Additionally, the excellent response status is identifiable after the first cycle

    The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

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    INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

    The immunological implications of the new Vitamin D metabolism

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    Vitamin D is actually a neurohormone whose pleiotropic activities encompass regulation of calcium-phosphate metabolism, cell proliferation and immunomodulation. Starting from a cutaneous compound, 2 hydroxylation steps are required to produce the active form of vitamin D3, named calcitriol [1, 25-(OH)2-cholecalciferol]. The second hydroxylation step may occur at different tis- sues and cell types, including kidney, lung, prostate, brain, immune cells and placenta. Based on the advancing knowledge of Cytochrome P450 functions, a new conception of Vitamin D metabolism emerged. It implies that, depending on the site where the second hydroxylation step occurs, the active hormone can act as a calcium-phosphorus-homeostasis regulator, or an immune system modulator, or a cell proliferation and differentiation regulator. A detailed description of new Vitamin D metabolism and Vitamin D regulation of immune response is provided in this review

    FiberWire tension band for patellar fractures

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    Symptomatic hardware represents the most frequent complication reported following surgical treatment of patellar fracture. For this reason, some authors suggested using nonabsorbable sutures to fix the fracture with various techniques. The aim of this study was to evaluate clinical and radiological results of patients treated following a modified Pyriford technique using a FiberWire suture (Arthrex, Naples, FL, USA).We retrospectively evaluated a case series of seventeen patients with displaced patellar fractures treated by open reduction and internal fixation with a modified tension band using FiberWire sutures. Clinical and radiological outcome were evaluated. Union time, complications, and reoperation rate were observed and recorded.All fractures healed (time to union 9.2 +/- 2 weeks), and no fixation failure was observed. Slight losses of reduction (&lt; 4 mm) were noted in two patients at 4 weeks postoperatively. The average Lysholm and Bostman scores at the final follow-up were 91 +/- 5.7 (range 83-100) and 28.3 +/- 1.6 (range 26-30), respectively.Modified tension band using FiberWire sutures showed satisfactory clinical results, with a low incidence of complications and reoperations. FiberWire tension bands could be used in place of metal-wire tension bands to treat patellar fracture, reducing the rate of symptomatic hardware.4

    Clinical utility of HFABP in myocardial infarction

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    Assessing chest pain patients presenting to the emergency area (EA) is still a clinical challenge, as acute myocardial infarction (AMI) diagnosis is not adjudicated in the majority of patients. New generation high sensitivity troponin assays (hs-cTn) still present some limitations, thus, novel biomarkers to early rule-in and rule- out myocardial infarction in chest pain patients presenting to the EA are sought after. Among all, heart- type fatty acid binding protein (h-FABP) has been largely investigated. Studies performed on HFABP in these patients present marked heterogeneity. However, it can be stated that HFABP is clearly not a reliable marker for AMI diagnosis, neither as a stand-alone test nor in combination with hs- cTn. More interventional trials are needed and more homogeneous studies are required to understand whether HFABP can add incremental value in rule- out AMI and risk stratify chest pain patients, however, available data may not encourage going on investigating

    Vitamin D in malaria: more hypotheses than clues

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    Vitamin D is a secosteroid hormone regulating calcium and phosphate metabolism, immune response and brain development. Low blood 25(OH)D levels have been reported in patients affected by infectious diseases caused by parasites, including malaria. Despite the high effectiveness of antimalarials, malaria is burdened with high morbidity and mortality, and the search for additional therapies is rapidly growing. Furthermore, available preventive measures have proved to be barely effective so far. Finding new prevention and therapy tools is a matter of urgency. Studies on animal models and humans have hypothesized some mechanisms by which the hormone can influence malaria pathogenesis, and the role of Vitamin D supplementation in preventing and treating this disease has been suggested. Few studies on the association between Vitamin D and malaria are available and disagreeing results have been reported. Studies in humans reporting an association between low 25(OH)D circulating levels and Malaria have a small sample size and observational study-set. Randomized controlled trials are needed in order to understand if Vitamin D administration might play a role in preventing and treating malaria
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