Extracellular Vesicles from Pancreatic Cancer Stem Cells Lead an Intratumor Communication Network (EVNet) to fuel tumour progression.

OBJECTIVE: Intratumor heterogeneity drives cancer progression and therapy resistance. However, it has yet to be determined whether and how subpopulations of cancer cells interact and how this interaction affects the tumour. DESIGN: We have studied the spontaneous flow of extracellular vesicles (EVs) between subpopulations of cancer cells: cancer stem cells (CSC) and non-stem cancer cells (NSCC). To determine the biological significance of the most frequent communication route, we used pancreatic ductal adenocarcinoma (PDAC) orthotopic models, patient-derived xenografts (PDXs) and genetically engineered mouse models (GEMMs). RESULTS: We demonstrate that PDAC tumours establish an organised communication network between subpopulations of cancer cells using EVs called the EVNet). The EVNet is plastic and reshapes in response to its environment. Communication within the EVNet occurs preferentially from CSC to NSCC. Inhibition of this communication route by impairing Rab27a function in orthotopic xenographs, GEMMs and PDXs is sufficient to hamper tumour growth and phenocopies the inhibition of communication in the whole tumour. Mechanistically, we provide evidence that CSC EVs use agrin protein to promote Yes1 associated transcriptional regulator (YAP) activation via LDL receptor related protein 4 (LRP-4). Ex vivo treatment of PDXs with antiagrin significantly impairs proliferation and decreases the levels of activated YAP.Patients with high levels of agrin and low inactive YAP show worse disease-free survival. In addition, patients with a higher number of circulating agrin+ EVs show a significant increased risk of disease progression. CONCLUSION: PDAC tumours establish a cooperation network mediated by EVs that is led by CSC and agrin, which allows tumours to adapt and thrive. Targeting agrin could make targeted therapy possible for patients with PDAC and has a significant impact on CSC that feeds the tumour and is at the centre of therapy resistance.

Exosomal glypican-1 for risk stratification of pancreatic cystic lesions: A case of pathological progression in the absence of any suspicious imaging finding.

The clinical management of patients with pancreatic cystic lesions is of utmost importance to identify those at high risk for pathological progression. Current recommendations are guided by clinical presentation and radiologic criteria, but the results fall short for a disease that the only curative option is surgical resection. There is an urgent need for the introduction of biomarkers that can help in risk assessment of such lesions. We report a case of a pancreatic cystic lesion without imagiological findings suggestive of advanced disease, and high levels of a circulating biomarker, glypican-1 (GPC-1), which parallel those of patients with pancreatic cancer. One year after, the patient revealed malignant progression at follow-up. Our report is unprecedented in the literature. It describes a clinical case in which a biomarker was positive for a patient that only showed progression one year after its detection. This clinical information goes beyond the current knowledge in the field because it shows that the introduction of liquid biopsy and biomarkers is a highly promising clinical tool for the non-invasive assessment of pancreatic cancer precursor lesions, ultimately increasing the rate of patients eligible for surgical resection.

Exosomes and the Future of Immunotherapy in Pancreatic Cancer.

Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease, associated with a late diagnosis and a five-year survival rate of 8%. Currently available treatments fall short in improving the survival and quality of life of PDAC patients. The only possible curative option is still the surgical resection of the tumor. Exosomes are extracellular vesicles secreted by cells that transport proteins, lipids, and nucleic acids to other cells, triggering phenotypic changes in the recipient cells. Tumor cells often secrete increased amounts of exosomes. Tumor exosomes are now accepted as important players in the remodeling of PDAC tumor stroma, particularly in the establishment of an immunosuppressive microenvironment. This has sparked the interest in their usefulness as mediators of immunomodulatory effects for the treatment of PDAC. In fact, exosomes are now under study to understand their potential as nanocarriers to stimulate an immune response against cancer. This review highlights the latest findings regarding the function of exosomes in tumor-driven immunomodulation, and the challenges and advantages associated with the use of these vesicles to potentiate immunotherapy in PDAC.

The 1918-1919 Influenza Pandemic in Portugal: A Regional Analysis of Death Impact.

Although the impact of deaths occurring during the 1918-1919 influenza pandemic has been assessed in many archeo-epidemiologic studies, detailed estimates are not available for Portugal. We applied negative binomial models to monthly data on respiratory-related and all-cause deaths at the national and district levels from Portugal for 1916-1922. Influenza-related excess mortality was computed as the difference between observed and expected deaths. Poisson regression was used to estimate the association of geographic and sociodemographic factors with excess mortality. Two waves of pandemic influenza-July 1918 to January 1919 and April to May 1919-were identified, for which the excess all-cause death rate was 195.7 per 10,000 persons. All districts of Portugal were affected. The pandemic hit earlier in southeastern districts and the main cities, but excess mortality was highest in the northeast, in line with the high death burden experienced by northern Spanish provinces. During the period of intense excess mortality (fall/winter 1918-1919), population density was negatively associated with pandemic impact. This pattern changed during the March 1919 to June 1920 wave, when excess mortality increased with population density and in northern and western directions. Portuguese islands were less and later affected. Given the geographic heterogeneity evidenced in our study, subnational sociodemographic characteristics and connectivity should be integrated in pandemic preparedness plans.

Exosomes define a local and systemic communication network in healthy pancreas and pancreatic ductal adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC), a lethal disease, requires a grasp of its biology for effective therapies. Exosomes, implicated in cancer, are poorly understood in living systems. Here we use the genetically engineered mouse model (ExoBow) to map the spatiotemporal distribution of exosomes from healthy and PDAC pancreas in vivo to determine their biological significance. We show that, within the PDAC microenvironment, cancer cells establish preferential communication routes through exosomes with cancer associated fibroblasts and endothelial cells. The latter being a conserved event in the healthy pancreas. Inhibiting exosomes secretion in both scenarios enhances angiogenesis, underscoring their contribution to vascularization and to cancer. Inter-organ communication is significantly increased in PDAC with specific organs as most frequent targets of exosomes communication occurring in health with the thymus, bone-marrow, brain, and intestines, and in PDAC with the kidneys, lungs and thymus. In sum, we find that exosomes mediate an organized intra- and inter- pancreas communication network with modulatory effects in vivo.

Inhibiting SETD7 methyl-transferase activity impairs differentiation, lipid metabolism and lactogenesis in mammary epithelial cells.

SETD7 (SET7/9, KMT7) is a lysine methyltransferase that targets master regulators of cell proliferation and differentiation. Here, the impact of inhibiting SETD7 catalytic activity on mammary epithelial cell differentiation was studied by focusing on genes associated with epithelial differentiation, lactogenesis, and lipid metabolism in HC11 and EpH4 cell lines. Setd7 mRNA and protein levels were induced upon lactogenic differentiation in both cell lines. Inhibition of SETD7 activity by the compound (R)-PFI-2 increased cell proliferation and downregulated E-cadherin, beta-catenin, lactoferrin, insulin-like growth factor binding protein 5, and beta-casein levels. In addition, inhibition of SETD7 activity affected the lipid profile and altered the mRNA expression of the phospholipid biosynthesis-related genes choline phosphotransferase 1, and ethanolamine-phosphate cytidylyltransferase. Altogether, the results suggest that inhibiting SETD7 catalytic activity impairs mammary epithelial and lactogenic differentiation.

Exosomal glypican-1 is elevated in pancreatic cancer precursors and can signal genetic predisposition in the absence of endoscopic ultrasound abnormalities.

BACKGROUND: Individuals within specific risk groups for pancreatic ductal adenocarcinoma (PDAC) [mucinous cystic lesions (MCLs), hereditary risk (HR), and new-late onset diabetes mellitus (NLOD)] represent an opportunity for early cancer detection. Endoscopic ultrasound (EUS) is a premium image modality for PDAC screening and precursor lesion characterization. While no specific biomarker is currently clinically available for this purpose, glypican-1 (GPC1) is overexpressed in the circulating exosomes (crExos) of patients with PDAC compared with healthy subjects or those harboring benign pancreatic diseases. AIM: To evaluate the capacity of GPC1+ crExos to identify individuals at higher risk within these specific groups, all characterized by EUS. METHODS: This cross-sectional study with a prospective unicentric cohort included 88 subjects: 40 patients with MCL, 20 individuals with HR, and 20 patients with NLOD. A control group (CG) was submitted to EUS for other reasons than pancreatic pathology, with normal pancreas and absence of hereditary risk factors (n = 8). The inclusion period was between October 2016 and January 2019, and the study was approved by the Ethics Committee of Centro Hospitalar Universitário de São João, Porto, Portugal. All patients provided written informed consent. EUS and blood tests for quantification of GPC1+ crExos by flow cytometry and carbohydrate antigen 19-9 (CA 19-9) levels by ELISA were performed in all subjects. EUS-guided tissue acquisition was done whenever necessary. For statistical analysis, SPSS® 27.0 (IBM Corp., Armonk, NY, United States) version was used. All graphs were created using GraphPad Prism 7.00 (GraphPad Software, San Diego, CA, United States). RESULTS: Half of MCLs harbored worrisome features (WF) or high-risk stigmata (HRS). Pancreatic abnormalities were detected by EUS in 10.0% and 35.0% in HR and NLOD individuals, respectively, all considered non-malignant and "harmless." Median levels of GPC1+ crExos were statistically different: MCL [99.4%, interquartile range (IQR): 94.9%-99.8%], HR (82.0%, IQR: 28.9%-98.2%), NLOD (12.6%, IQR: 5.2%-63.4%), and CG (16.2%, IQR: 6.6%-20.1%) (P < 0.0001). Median levels of CA 19-9 were within the normal range in all groups (standard clinical cut-off of 37 U/mL). Within HR, individuals with a positive history of cancer had higher median levels of GPC1+ crExos (97.9%; IQR: 61.7%-99.5%), compared to those without (59.7%; IQR: 26.3%-96.4%), despite no statistical significance (P = 0.21). Pancreatic cysts with WF/HRS were statistically associated with higher median levels of GPC1+ crExos (99.6%; IQR: 97.6%-99.8%) compared to those without (96.5%; IQR: 81.3%-99.5%) (P = 0.011), presenting an area under the receiver operating characteristic curve value of 0.723 (sensitivity 75.0% and specificity 67.7%, using a cut-off of 98.5%; P = 0.012). CONCLUSION: GPC1+ crExos may act as biomarker to support the diagnosis and stratification of PDAC precursor lesions, and in signaling individuals with genetic predisposition in the absence of EUS abnormalities.

The Interplay of Exosomes and NK Cells in Cancer Biology.

Natural killer (NK) cells are innate lymphoid cells involved in tumor surveillance. These immune cells have the potential to fight cancer growth and metastasis, as such, their deregulation can result in tumor immune escape. Recently exosomes were described as mediators of intercellular communication between cancer and NK cells. The exact role of this subclass of extracellular vesicles (EVs), which transport genetic and molecular material to recipient cells, in NK cell biology in the context of cancer, is still an open question. Several reports have demonstrated that tumor-derived exosomes (TDEs) can exert immunomodulatory activities, including immunosuppression, thus promoting cancer progression. Some reports demonstrate that the interplay between cancer exosomes and NK cells allows tumors to escape immune regulation. On the other hand, tumor exosomes were also described to activate NK cells. Additionally, studies show that NK cell exosomes can modulate the immune system, opening up their potential as an immunotherapeutic strategy for cancer treatment. Our review will focus on the reprogramming effect of cancer exosomes on NK cells, and the immunotherapeutic potential of NK cells-derived exosomes.

Liquid Biopsy beyond Circulating Tumor Cells and Cell-Free DNA.

Liquid biopsy represents the analysis of tumor-derived material in the blood and other body fluids of cancer patients. This portrays a minimally invasive detection tool for molecular biomarkers. Liquid biopsy has emerged as a complementary or alternative method to surgical biopsy. This non-invasive detection tool overcomes the recurrent problems in the clinical assessment of tumors that stem from the lack of accessibility to the tumor tissue and its clonal heterogeneity. Moreover, body fluid-derived components have shown to reflect the genetic profile of both primary and metastatic lesions and provide a real-time monitoring of tumor dynamics, representing a great promise for personalized medicine. This review will highlight the latest breakthroughs and the current applications of several tumor-derived biomarkers that can be found in body fluids. The authors will focus on tumor-derived exosomes, tumor-educated platelets, and circulating tumor miRNAs and mRNAs, and how these can be used for tumor detection.

Biological processes and signal transduction pathways regulated by the protein methyltransferase SETD7 and their significance in cancer.

Protein methyltransferases have been shown to methylate histone and non-histone proteins, leading to regulation of several biological processes that control cell homeostasis. Over the past few years, the histone-lysine N-methyltransferase SETD7 (SETD7; also known as SET7/9, KIAA1717, KMT7, SET7, SET9) has emerged as an important regulator of at least 30 non-histone proteins and a potential target for the treatment of several human diseases. This review discusses current knowledge of the structure and subcellular localization of SETD7, as well as its function as a histone and non-histone methyltransferase. This work also underlines the putative contribution of SETD7 to the regulation of gene expression, control of cell proliferation, differentiation and endoplasmic reticulum stress, which indicate that SETD7 is a candidate for novel targeted therapies with the aim of either stimulating or inhibiting its activity, depending on the cell signaling context.

Literacia em saúde mental sobre psicose: Uma intervenção integrada de base comunitária para bombeiros / Psychosis mental health literacy: An integrated community-based intervention for firefighters

Introdução: No decorrer da sua carreira, os Bombeiros experienciam uma vasta gama de situações no que diz respeito a emergências pré-hospitalares. As caraterísticas do plano esquemático de formações da Escola Nacional de Bombeiros e do Instituto Nacional de Emergência Médica, não englobam temáticas direcionadas para a saúde mental. O programa de Primeira Ajuda em Saúde Mental (PASM®), constitui um dos instrumentos educacionais utilizados no contexto da promoção da Literacia em Saúde Mental, que permite capacitar os jovens para agir no que concerne a problemas relacionados com a sua própria saúde mental e dos seus pares. Sendo possível o ajuste do programa a outra população-alvo, adaptou-se o mesmo a outro tipo de participantes, neste caso bombeiros. Objetivo: Este estudo tem como objetivo: avaliar a eficácia de um programa de intervenção psicoeducativa sobre psicose, nos Bombeiros de Arganil. Metodologia: Utilizou-se um desenho pré-experimental, com avaliação antes e após intervenção. A intervenção teve duração de 9 horas, em que o programa foi aplicado a uma amostra de 30 bombeiros com uma média de idades de 32.57±12.07 anos. Para a colheita de dados, utilizou-se o QuALiSMental. Resultados: Os resultados que foram obtidos, permitem verificar a eficácia do programa no que concerne ao incremento da LSM associada à psicose, intenção de procura de ajuda e confiança para prestar ajuda. O programa não foi totalmente eficaz no que concerne às questões referentes ao suicídio, pessoa em crise e confiança para prestar ajuda, admitindo-se que o programa necessita de alguns ajustes, tornando-o mais consistente nestas temáticas. Conclusões: Apesar das limitações que se evidenciam neste estudo, os resultados indicam que o programa contribui para aumentar a literacia em saúde mental dos participantes e consequentemente, capacitá-los para agir em prol da sua saúde mental e daqueles que o rodeiam.