Extracellular vesicle microRNAs contribute to Notch signaling pathway in T-cell acute lymphoblastic leukemia

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive T-cell malignancy characterized by genotypically-defined and phenotypically divergent cell populations, governed by adaptive landscapes. Clonal expansions are associated to genetic and epigenetic events, and modulation of external stimuli that affect the hierarchical structure of subclones and support the dynamics of leukemic subsets. Recently, small extracellular vesicles (sEV) such as exosomes were also shown to play a role in leukemia. Here, by coupling miRNome, bulk and single cell transcriptome profiling, we found that T-ALL-secreted sEV contain NOTCH1-dependent microRNAs (EV-miRs), which control oncogenic pathways acting as autocrine stimuli and ultimately promoting the expansion/survival of highly proliferative cell subsets of human T-cell leukemias. Of interest, we found that NOTCH1-dependent EV-miRs mostly comprised members of miR-17-92a cluster and paralogues, which rescued in vitro the proliferation of T-ALL cells blocked by γ-secretase inhibitors (GSI) an regulated a network of genes characterizing patients with relapsed/refractory early T-cell progenitor (ETP) ALLs. All these findings suggest that NOTCH1 dependent EV-miRs may sustain the growth/survival of immunophenotypically defined cell populations, altering the cell heterogeneity and the dynamics of T-cell leukemias in response to conventional therapies

Gut microbiota composition in COVID-19 hospitalized patients with mild or severe symptoms

Background and aimCOVID-19, the infectious disease caused by SARS-CoV-2 virus that has been causing a severe pandemic worldwide for more than 2 years, is characterized by a high heterogeneity of clinical presentations and evolution and, particularly, by a varying severity of respiratory involvement. This study aimed to analyze the diversity and taxonomic composition of the gut microbiota at hospital admission, in order to evaluate its association with COVID-19 outcome. In particular, the association between gut microbiota and a combination of several clinical covariates was analyzed in order to characterize the bacterial signature associate to mild or severe symptoms during the SARS-CoV-2 infection.Materials and methodsV3–V4 hypervariable region of 16S rRNA gene sequencing of 97 rectal swabs from a retrospective cohort of COVID-19 hospitalized patients was employed to study the gut microbiota composition. Patients were divided in two groups according to their outcome considering the respiratory supports they needed during hospital stay: (i) group “mild,” including 47 patients with a good prognosis and (ii) group “severe,” including 50 patients who experienced a more severe disease due to severe respiratory distress that required non-invasive or invasive ventilation. Identification of the clusters of bacterial population between patients with mild or severe outcome was assessed by PEnalized LOgistic Regression Analysis (PELORA).ResultsAlthough no changes for Chao1 and Shannon index were observed between the two groups a significant greater proportion of Campylobacterota and Actinobacteriota at phylum level was found in patients affected by SARS-CoV-2 infection who developed a more severe disease characterized by respiratory distress requiring invasive or non-invasive ventilation. Clusters have been identified with a useful early potential prognostic marker of the disease evolution.DiscussionMicroorganisms residing within the gut of the patients at hospital admission, were able to significantly discriminate the clinical evolution of COVID-19 patients, in particular who will develop mild or severe respiratory involvement. Our data show that patients affected by SARS-CoV-2 with mild or severe symptoms display different gut microbiota profiles which can be exploited as potential prognostic biomarkers paving also the way to new integrative therapeutic approaches

In-depth characterization of a novel aggressive subtype of lung cancer and dissection of exosomal-miRNAs as key-players for early identification

Lung adenocarcinoma (LUAD) is the most common type of non-small-cell lung cancer, and a subset of patients with early-stage LUAD experience relapses and adverse prognosis. Here we identified by a 10-gene prognostic signature an aggressive LUAD subtype, named C1, that is characterized by loss of lung cell lineage and gain of stem cell-like characteristics, along with mutator and immune evasion phenotypes. In addition, with a multi-tiered approach using coupled RNA-seq and miRNA-seq data analysis of a large cohort of lung cancer patients, we found high accuracy in scoring aggressive disease and identified a minimal signature of 7-miRNAs, which we validated in a cohort of FFPE lung adenocarcinoma samples. The results demonstrate the reliability of miRNA-based biomarkers for lung cancer prognostication and make a step forward to the application of miRNA biomarkers in the clinical routine. In line with this, we finally identified a 6-exo-miRNA signature derived from LUAD patients exosomes that is a reliable biomarker to identify the C1-LUAD subtype. Moreover, we also showed that miR-223-3p was significantly enriched in exosomes derived from C1-like cells and acted as a modulator of immune response. Overall, we provide new insights into the molecular and biological features of aggressive C1-LUAD, providing new biomarkers for the early identification of aggressive subtypes of lung cancer

MicroRNAs and the Mediterranean diet: a nutri-omics perspective for lung cancer

Abstract Lung cancer is the deadliest cancer type worldwide with ~ 1.8 million deaths per-year. Smoking accounts for ~ 85% of all cases, with a described joint effect with unhealthy diet in lung cancer risk increase. Public health policies to prevent carcinogens exposure, promote smoking cessation and advocacy for healthy nutrition, are therefore highly recommended. Here we have examined the benefits of the Mediterranean Diet (MedDiet) in protecting against some non-communicable diseases including lung cancer, highlighting the epidemiological and biomolecular aspects of MedDiet anti-inflammatory effect and its interaction with smoking habits closely linked to risk of lung cancer. Considering the high incidence and mortality rates of lung cancer, we discussed also about the global impact that a Planeterranean extension of the benefits of MedDiet could have on controlling lung cancer risk. We also debated the impact of personalized nutrition on lung cancer prevention, considering individual heterogeneity in response to diet plans as well as recent advancements on nutri-omics in lung cancer research, with a specific focus on the role of microRNAs (miRNAs) as a promising nutritional molecular hub for lung cancer prevention. We strongly believe that a deep understanding of the molecular link between food components and genetic/epigenetics factors can expand effective intervention strategies

Strength of Composite Pressure Insulators for High Voltage Circuit Breakers: An Experimental and Numerical Investigation

Glass fiber-reinforced composite cylinders, capable of withstanding internal pressure generated during service, are increasingly utilized as insulators in high voltage circuit breakers. Different testing procedures have been suggested by various standards to assess the pressure resistance of these components. Due to its simplicity and cost-effectiveness, the split-disk testing method is the most widely used for evaluating the hoop strength of pressure cylinders during the development and verification phases. However, the method presents several aspects, such as those related to the influence of specimen geometry and friction, which require further examination since they may impact the outcome of the experimental tests. The investigation, carried out by a combination of experimental testing and finite element analyses, shows that the friction between the specimen and the semi-disks has a noteworthy effect on the hoop load applied to the specimen. Almost constant load distributions along the hoop direction, representative of the real operating conditions in a pressurized cylinder, can be achieved via proper lubrication of the contact surfaces. Furthermore, FE analyses demonstrate that the notch geometry suggested by specific standards (short notch) is not capable of inducing a uniform strain distribution in the notched region. A different notch geometry (long notch) is proposed in the study to attain a more uniform strain field over the reduced area region. The experimental results indicate that the strength measured on the short notch specimens is higher than that determined on the long notch specimens, thus confirming the significant influence of strain distribution on the strength properties measured with the split-disk method

Abstract 2582: Investigating the origin and function of circulating miRNA in lung cancer

MicroRNAs (miRNAs) are small, highly conserved noncoding RNA molecules involved in the regulation of gene expression. MicroRNAs are resistant to harsh conditions and stably exist in body fluids (e.g. saliva, urine, breast milk, blood). Circulating cell-free miRNAs (cf-miRNA) were shown to be effective biomarkers for the early diagnosis of cancer. Furthermore, cf-miRNA were also found in exosomes that are nano-sized extracellular vesicles which exchange molecular information among cells. However, the understanding of origin of cf-miRNAs and of biological function still remains elusive. We recently identified a signature of cf-miRNAs diagnostic for lung cancer which we now hypothesize being released by lung cancer cells (EP-cf-miRNA) and by tumor microenvironment (TME-cf-miRNA). In particular, two cf-miRNAs, miR-29a and 223-3p, were selected as prototypes of EP- and TME-cf-miRNAs for further investigations.We found that the expression of miR-223-3p was higher in TME than in cancer cells of a cohort of 19 lung adenocarcinoma. In contrast, miR-29a-3p was frequently overexpressed (≥2 fold) in cancer cells. Interestingly, the serum concentration of cf-miR-29a was lower than miR-223-3p and this also in exosomes.We next investigated the expression profile of miR-29a/223-3p in a panel of lung normal and adenocarcinoma cell lines (N=14). miR-29a/223-3p were both expressed intracellularly and in exosomes. Of note, the miR-29a expression level resembles that observed in lung cancer cells from FFPE samples. Conversely, miR-223-3p expression was lower in the adenocarcinoma cell lines which further confirm a more TME origin. We are now expanding our analysis by screening the whole set of cf-miRNAs by high-throughput qPCR profile (OpenArray technology) and by applying laser capture microdissection to investigate single cancer epithelial cells and TME. Our work provides proof of principle demonstration of an effective approach to investigate cf-miRNA origin to unravel the role of cf-miRNA in lung adenocarcinoma

Analysis of extracellular-vesicle miRNAs in a new aggressive molecular subtype of lung cancer

Non-Small Cell Lung cancer is the most frequently diagnosed lung cancer type (80-90%) and lung adenocarcinoma (LUAD) is the major subtype. Early diagnosis by low-dose computed tomography was shown to be effective in reducing mortality (~20% at 5 years). However, the management of lung cancer patients can be difficult due to pathological and genetic heterogeneity of the disease. We discovered a new molecular subtype namely C1-LUAD using a 10-genes signature, which correlates with the worst prognosis and has peculiar features of mesenchymal and stem-like cells. Of note, analyzing intracellular differentially expressed miRNAs in C1 patients, we found a targeted network of genes as hubs of mechanisms for lung cancer progression. Moreover, we discovered 5 miRNAs up-regulated and 6 miRNAs down-regulated in C1 exosomes extracted from serum, which pave the way to make an early diagnosis for this aggressive subtype of LUAD. Finally, we highlighted that C1-like cells are more prone to internalized labeled-exosomes in a time and dose dependent manner, suggesting a role of these extracellular-vesicles in the maintenance of the metastatic features

Epidemiological and Molecular Investigation of the Heater–Cooler Unit (HCU)-Related Outbreak of Invasive <i>Mycobacterium chimaera</i> Infection Occurred in Italy

Background: From 2013 onwards, a large outbreak of Mycobacterium chimaera (MC) invasive infection, which was correlated with the use of contaminated heater–cooler units (HCUs) during open chest surgery, was reported from all over the world. Here, we report the results of the epidemiological and molecular investigations conducted in Italy after the alarm raised about this epidemic event. Methods: MC strains isolated from patients or from HCU devices were characterized by genomic sequencing and molecular epidemiological analysis. Results: Through retrospective epidemiological analysis conducted between January 2010 and December 2022, 40 possible cases of patients infected with MC were identified. Thirty-six strains isolated from these patients were analysed by whole genome sequencing (WGS) and were found to belong to the genotypes 1.1 or 1.8, which are the genotypes correlated with the outbreak. Most of the cases presented with prosthetic valve endocarditis, vascular graft infection or disseminated infection. Among the cases found, there were 21 deaths. The same analysis was carried out on HCU devices. A total of 251 HCUs were found to be contaminated by MC; genotypes 1.1 or 1.8 were identified in 28 of those HCUs. Conclusions: To ensure patients’ safety and adequate follow-up, clinicians and general practitioners were made aware of the results and public health measures, and recommendations were issued to prevent further cases in the healthcare settings. The Italian Society of Cardiac Surgery performed a national survey to assess the incidence of HCU-related MC prosthetic infections in cardiac surgery. No cases were reported after HCU replacement or structural modification and disinfection and possibly safe allocation outside surgical rooms