NONO ubiquitination is mediated by FBW7 and GSK3 ß via a degron lost upon chromosomal rearrangement in cancer.

NONO is an RNA-binding protein involved in transcription, mRNA splicing, DNA repair, and checkpoint activation in response to UV radiation. NONO expression has been found altered in several tumor types, including prostate, colon, breast, melanoma, and in papillary renal carcinoma, in which an X chromosome inversion generates a NONO-TFE3 fusion protein. Upon such rearrangement, NONO loses its C-terminal domain. Through bioinformatics analysis, we identified a putative degron motif, known to be recognized by the Skp1-Cul1-F-box-protein (SCF) complex. Here, we evaluated how this domain could affect NONO protein biology. We showed that NONO interacts with the nuclear FBW7α isoform and its ubiquitination is regulated following modulation of the GSK3ß kinase. Mutation of T428A/T432A within the degron impaired polyubiquitination upon FBW7α and GSK3ß overexpression. Overall, our data suggest that NONO is likely subjected to proteasome-mediated degradation and add NONO to the list of proteins targeted by FBW7, which is itself often deregulated in cancer.

Enzymatic assay to test diamines produced by vaginal bacteria.

An enzymatic assay was developed to determine the concentration of diamines (DA) in clinical samples of vaginal fluids. Putrescine and cadaverine are DA produced by anaerobic bacteria and are typically present in the vaginal fluids of women with an abnormal microbiota, as occurs in bacterial vaginosis. The vaginal DA (VADA) assay is based on the enzyme diamine oxidase which reacts with putrescine and cadaverine to produce H2O2 in a quantitative manner. H2O2 concentration is measured spectrophotometrically by a chromogenic reaction catalyzed by horseradish peroxidase. The VADA assay proved to be capable of detecting DA concentrations as low as 4 mM and showed a dose-response relationship which was linear over DA concentrations ranging from 4 to 256 mM. Using clinical samples it was possible to show that the VADA assay can be performed on human vaginal swabs and that the mean DA concentration is significantly higher in samples positive for microbial pathogens.

Carbonic anhydrases in development: morphological observations and gene expression profiling in sea urchin embryos exposed to acetazolamide.

Carbonic anhydrases (CANs) are conserved metalloenzymes catalysing the reversible hydration of carbon dioxide into protons and bicarbonate, with important roles in cells physiology. Some CAN-coding genes were found in sea urchin genome, although only one involved in embryonic skeletogenesis was described in Paracentrotus lividus. Here, we investigated gene expression patterns of P. lividus embryos cultured in the presence of acetazolamide (AZ), a CAN inhibitor, to combine morphological defects with their molecular underpinning. CAN inhibition blocked skeletogenesis, affected the spatial/temporal expression of some biomineralization-related genes, inhibited embryos swimming. A comparative analysis on the expression of 127 genes in control and 3 h/24 h AZ-treated embryos, using NanoString technology, showed the differential expression of genes encoding for structural/regulatory proteins, with different embryonic roles: biomineralization, transcriptional regulation, signalling, development and defence response. The study of the differentially expressed genes and the signalling pathways affected, besides in silico analyses and a speculative 'interactomic model', leads to predicting the presence of various CAN isoforms, possibly involved in different physiological processes/activities in sea urchin embryo, and their potential target genes/proteins. Our findings provide new valuable molecular data for further studies in several biological fields: developmental biology (biomineralization, axes patterning), cell differentiation (neural development) and drug toxicology (AZ effects on embryos/tissues).

Intratumor microbiota as a novel potential prognostic indicator in mesothelioma.

Introduction: Despite increased attention on immunotherapy, primarily immune checkpoint blockade, as a therapeutic approach for mesothelioma (MMe), its efficacy and tolerability remain questioned. One potential explanation for different responses to immunotherapy is the gut and intratumor microbiota; however, these remain an underexplored facet of MMe. This article highlights the cancer intratumor microbiota as a novel potential prognostic indicator in MMe. Methods: TCGA data on 86 MMe patients from cBioPortal underwent bespoke analysis. Median overall survival was used to divide patients into "Low Survivors" and "High Survivors". Comparison of these groups generated Kaplan-Meier survival analysis, differentially expressed genes (DEGs), and identification of differentially abundant microbiome signatures. Decontamination analysis refined the list of signatures, which were validated as an independent prognostic indicator through multiple linear regression modelling and Cox proportional hazards modelling. Finally, functional annotation analysis on the list of DEGs was performed to link the data together. Results: 107 genera signatures were significantly associated with patient survival (positively or negatively), whilst clinical characteristic comparison between the two groups demonstrated that epithelioid histology was more common in "High Survivors" versus biphasic in "Low Survivors". Of the 107 genera, 27 had published articles related to cancer, whilst only one (Klebsiella) had MMe-related published articles. Functional annotation analysis of the DEGs between the two groups highlighted fatty acid metabolism as the most enriched term in "High Survivors", whilst for "Low Survivors" the enriched terms primarily related to cell cycle/division. Linking these ideas and findings together is that the microbiome influences, and is influenced by, lipid metabolism. Finally, to validate the independent prognostic value of the microbiome, multiple linear regression modelling as well as Cox proportional hazards modelling were employed, with both approaches demonstrating that the microbiome was a better prognostic indicator than patient age or stage of the cancer. Discussion: The findings presented herein, alongside the very limited literature from scoping searches to validate the genera, highlight the microbiome and microbiota as a potentially rich source of fundamental analysis and prognostic value. Further in vitro studies are needed to elucidate the molecular mechanisms and functional links that may lead to altered survival.

Analysis of the P. lividus sea urchin genome highlights contrasting trends of genomic and regulatory evolution in deuterostomes.

Sea urchins are emblematic models in developmental biology and display several characteristics that set them apart from other deuterostomes. To uncover the genomic cues that may underlie these specificities, we generated a chromosome-scale genome assembly for the sea urchin Paracentrotus lividus and an extensive gene expression and epigenetic profiles of its embryonic development. We found that, unlike vertebrates, sea urchins retained ancestral chromosomal linkages but underwent very fast intrachromosomal gene order mixing. We identified a burst of gene duplication in the echinoid lineage and showed that some of these expanded genes have been recruited in novel structures (water vascular system, Aristotle's lantern, and skeletogenic micromere lineage). Finally, we identified gene-regulatory modules conserved between sea urchins and chordates. Our results suggest that gene-regulatory networks controlling development can be conserved despite extensive gene order rearrangement.

Tracking the 2009 H1N1 influenza virus in the Italian region Campania.

A novel swine-origin influenza A (H1N1) virus affecting humans was detected in April 2009 in Mexico, Canada, and USA. The S-OIV infection caused a mild to severe febrile respiratory disease throughout the world. Here, we briefly review the main features of influenza A viruses, which caused also other pandemics in the past, and focus in particular on the epidemiology data of the H1N1 influenza in the Italian region Campania, which resulted the most affected by the S-OIV and the one with more lethal cases. In Campania, the peak of influenza preceded of about 2 weeks the incidence peak at the national level. Moreover, the percentage of H1N1-positive patients was much higher in the main town Naples, compared to the other Campania provinces. The age group from 7 months to 17 years was the most affected by the H1N1 infection (43.45%), similarly to what reported at the national level. Here, we discuss the possible reasons of the high H1N1 incidence in Campania and the implications that these findings could have on the future prevention campaigns.

Phylogenetic analysis and expression patterns of p16 and p19 in Paracentrotus lividus embryos.

P16 and P19 are two small acidic proteins involved in the formation of the biomineralized skeleton of sea urchin embryos and adults. Here, we describe the cloning and the embryonic temporal and spatial expression profiles of p16 and p19 mRNAs, identified for the first time in Paracentrotus lividus. Phylogenetic analysis showed a high degree of similarity of the deduced Pl-P16 and Pl-P19 sequences with the Lytechinus variegatus and Strongylocentrotus purpuratus orthologs. While only a reduced similarity with other phyla, including mammals, was detected, their implication in biomineralized tissues calls for their conservation in evolution. By comparative quantitative PCR and in situ hybridization, we found that Pl-p16 and Pl-p19 expression was restricted to skeletogenic cells throughout embryogenesis, with transcript levels peaking at the late gastrula stage. Dissimilar Pl-p16 and Pl-p19 spatial expression within the primary mesenchyme cell syncytium at the gastrula and pluteus stages suggests the occurrence of a different regulation of gene transcription.

Paroxysmal non-epileptic motor events in childhood: a clinical and video-EEG-polymyographic study.

AIM: The aim of this article was to describe the phenomenology and polymyographic features of paroxysmal non-epileptic motor events (PNMEs) observed in a series of typically developing and children with neurological impairment. METHOD: We conducted a retrospective evaluation of 63 individuals (29 females; 34 males) affected by PNMEs at the National Neurological Institute 'C. Besta' between 2006 and 2008. Individuals were included in the study if they had PNMEs documented by a video-electroencephalography-polymyographic study and were aged between 1 month and 18 years (mean age at the time of video-electroencephalography-polymyography: 5y 10mo). RESULTS: In 45 of the 63 participants (71%), PNMEs were associated with other neurological conditions (secondary) including epilepsy, whereas in 18 participants PNME was the only neurological symptom (primary). Clinical features allowed classification of the motor disturbance into usual movement disorder categories in 31 individuals (49%); in the remaining 32 (51%), the movement disorder was characterized on the basis of polymyographic pattern of 'jerks' or 'sustained contraction'. The most frequent PNMEs were paroxysmal dyskinesias, followed by startle, stereotypies, shuddering, sleep myoclonus, psychogenic movement disorders, and benign myoclonus of early infancy; the last syndrome was also observed in children with neurological impairment. In eight participants, PNMEs remained unclassified. INTERPRETATION: PNMEs may occur in both healthy and children with neurological impairment and are caused by a wide range of static and progressive conditions. In the majority of children with neurological impairment with associated epilepsy, the PNMEs do not fit into the usual movement disorders categories. A video-electroencephalography-polymyography is therefore useful for characterizing them.

Gene Expression Analysis of the Stress Response to Lithium, Nickel, and Zinc in Paracentrotus lividus Embryos.

Many anthropogenic pollutants such as metals are discharged into the marine environment through modern sources. Among these, lithium (Li), nickel (Ni), and zinc (Zn) can interfere with biological processes in many organisms when their concentration rises. These metals are toxic to sea urchin embryos, affecting their development. Indeed, animal/vegetal and dorso/ventral embryonic axes are differently perturbed: Li is a vegetalizing agent, Ni can disrupt dorso-ventral axis, Zn can be animalizing. To address the molecular response adopted by embryos to cope with these metals or involved in the gene networks regulating embryogenesis, and to detect new biomarkers for evaluating hazards in polluted environments in a well-known in vivo model, we applied a high-throughput screening approach to sea urchin embryos. After fertilization, Paracentrotus lividus embryos were exposed to Li, Ni, and Zn for 24/48 h. At both endpoints, RNAs were analyzed by NanoString nCounter technology. By in silico analyses, we selected a panel of 127 transcripts encoding for regulatory and structural proteins, ranked in categories: Apoptosis, Defense, Immune, Nervous, Development, and Biomineralization. The data analysis highlighted the dysregulation of many genes in a metal-dependent manner. A functional annotation analysis was performed by the KEEG Orthology database. This study provides a platform for research on metals biomarkers in sea urchins.

Echinoderms as blueprints for biocalcification: regulation of skeletogenic genes and matrices.

Echinoderms have an extensive endoskeleton composed of magnesian calcite, a form of calcium carbonate that contains small amounts of magnesium carbonate and occluded matrix proteins. Adult sea urchins have several calcified structures, including test, teeth, and spines, composed of numerous ossicles which form a three-dimensional meshwork of mineral trabeculae, the stereom. The biomineral development begins in 24-hour-old embryos within the primary mesenchyme cells (PMCs), the only cells producing a set of necessary matrix proteins. The deposition of the biomineral occurs in a privileged extracellular space produced by the fused filopodial processes of the PMCs. We showed for the first time that signals from ectoderm cells overlying PMCs play an important role in the regulation of biomineralization-related genes. It is believed that growth factors are produced by ectoderm cells and released into the blastocoel where they interact with cognate receptor tyrosine kinases restricted to PMCs, which activate signaling cascades regulating the expression of biomineralization-related genes. We demonstrated the implication of a TGF-beta family factor by a perturbation model in which skeleton elongation was indirectly blocked by monoclonal antibodies to an extracellular matrix (ECM) protein located on the apical surface of ectoderm. Thus, it was inferred that interfering with the binding of the ECM ligand, a member of the discoidin family, to its cell surface receptor, a ßC integrin, disrupts the ectodermal cell signaling cascade, resulting in reduced or aberrant skeletons. During the last few years, we analyzed the expression of biomineralization-related genes in other examples of experimentally induced skeleton malformations, produced by the exposure to toxic metals, such as Cd and Mn or ionizing radiations, such as UV-B and X-rays. Besides the obvious toxicological implication, since the mis-expression of spicule matrix genes paralleled skeleton defects, we believe that by means of these studies we can dissect the molecular steps taking place and possibly understand the physiological events regulating embryonic biomineralization.

A preliminary gene expression analysis on Paracentrotus lividus embryos exposed to UVB, Cadmium and their combination.

Paracentrotus lividus is a Mediterranean and Eastern Atlantic sea urchin species, very sensitive to chemical and physical environmental changes and widely used in eco-toxicological studies. Here, we applied a high throughput screening approach on P. lividus embryos exposed to UVB radiation (UV), Cadmium Chloride (Cd) and their combination (Cd/UV), to deeply characterize the molecular responses adopted by embryos to cope with these stressors. in vitro eco-toxicological assays were performed by exposing embryos to Cd (10-4 M) soon after fertilization, to UV (200 and 400J/m2) at early stage of development, while in co-exposure experiments, Cd-exposed embryos were irradiated with UV at 200 J/m2. By NanoString nCounter technology, custom-made probes were developed and hybridized on total RNA extracted from exposed embryos at 51h after fertilization. By in silico analyses, we selected and retrieved at the NCBI nucleotide database a panel of P. lividus transcripts encoding for many regulatory and structural proteins that we ranked in categories, i.e., Apoptosis, Biomineralization, Defense, Development, Immunity, Signaling and Transcription Factors. The analysis of 127 transcripts highlighted the dysregulation of many genes, some specifically activated to cope with stress agents, others involved in the complex molecular network of genes that regulate embryo development. We revealed the downregulation of Biomineralization and Development genes and the upregulation of Defensive genes in Cd and Cd/UV embryos. Our approach, using sea urchin embryo as an in vivomodel, contributes to advance our knowledge about cellular responses to UV, Cd and their combination.

Neurotoxicity in Marine Invertebrates: An Update.

Invertebrates represent about 95% of existing species, and most of them belong to aquatic ecosystems. Marine invertebrates are found at intermediate levels of the food chain and, therefore, they play a central role in the biodiversity of ecosystems. Furthermore, these organisms have a short life cycle, easy laboratory manipulation, and high sensitivity to marine pollution and, therefore, they are considered to be optimal bioindicators for assessing detrimental chemical agents that are related to the marine environment and with potential toxicity to human health, including neurotoxicity. In general, albeit simple, the nervous system of marine invertebrates is composed of neuronal and glial cells, and it exhibits biochemical and functional similarities with the vertebrate nervous system, including humans. In recent decades, new genetic and transcriptomic technologies have made the identification of many neural genes and transcription factors homologous to those in humans possible. Neuroinflammation, oxidative stress, and altered levels of neurotransmitters are some of the aspects of neurotoxic effects that can also occur in marine invertebrate organisms. The purpose of this review is to provide an overview of major marine pollutants, such as heavy metals, pesticides, and micro and nano-plastics, with a focus on their neurotoxic effects in marine invertebrate organisms. This review could be a stimulus to bio-research towards the use of invertebrate model systems other than traditional, ethically questionable, time-consuming, and highly expensive mammalian models.

Potential Approaches Versus Approved or Developing Chronic Myeloid Leukemia Therapy.

Tyrosine kinase inhibitors (TKIs) have revolutionized the treatment of patients with chronic myeloid leukemia (CML). However, continued use of these inhibitors has contributed to the increase in clinical resistance and the persistence of resistant leukemic stem cells (LSCs). So, there is an urgent need to introduce additional targeted and selective therapies to eradicate quiescent LSCs, and to avoid the relapse and disease progression. Here, we focused on emerging BCR-ABL targeted and non-BCR-ABL targeted drugs employed in clinical trials and on alternative CML treatments, including antioxidants, oncolytic virus, engineered exosomes, and natural products obtained from marine organisms that could pave the way for new therapeutic approaches for CML patients.

Phylogenetic analysis and homology modelling of Paracentrotus lividus nectin.

The extracellular matrix protein Pl-nectin, a 210-kDa homodimer originally purified from sea urchin eggs, plays a crucial role in cell adhesion and embryonic morphogenesis. The compiled cDNA sequence, obtained by RT-PCR primer walking and 3' RACE, identified a 984aa product containing a 23aa signal peptide and including all six internal peptides identified by protein microsequencing. The protein is a new member of the galactose-binding protein superfamily as it consists of six 151-156aa-long tandemly repeated domains (D1-D6), homologous to the discoidin-like domains, also known as F5/8-type C domains. Based on homology modelling, we present a three-dimensional structure (3D) for D5, identified as the prototype domain. The molecular modelling of the assembled Pl-nectin homodimer accounts for a Pl-nectin quaternary structure composed of two 105-kDa C-shaped monomers linked by a S-S bridge. The presence of an LDT motif between the first and the second exposed loops of the D2 domain suggests the binding of Pl-nectin to an integrin receptor. Altogether, the in silico analysis described here is consistent with previous biochemical reports and offers a basis for predictions to be experimentally tested.

Embryonic development and skeletogenic gene expression affected by X-rays in the Mediterranean sea urchin Paracentrotus lividus.

International concern over environmental nuclear contamination of salt water fisheries and coastal resources has attracted the interests of ecologists, marine biologists and stakeholders. There are not many studies on the effects of X-rays, a component of radionuclides emissions, on embryonic development and gene expression. The sea urchin embryo is emerging as a useful model system for environmental and eco-toxicological studies. Here, we describe how X-rays affect development and gene expression in embryos of the Mediterranean sea urchin Paracentrotus lividus. Cleavage embryos were exposed to doses from 0.1 to 5 Gy, using an Ag source of X radiation. We found a dose-dependent increase in developmental delays and severe morphological defects in embryos microscopically inspected at two endpoints, 24 and 48 h after irradiation. By analogy with classical toxicity tests parameters we defined the No Observed Effect Dose at 0.1 Gy, the Lowest Observed Effect Dose at 0.5 Gy and ED50 at 1.0 Gy. Major perturbations concerned primitive intestine and skeleton differentiation and development: X-rays exposed embryos had both no gut and arms or poorly and abnormally developed ones. We found a dose-dependent reduction in the mRNA levels of two skeleton-specific genes, Pl-SM30 (spicule matrix 30) and Pl-msp130 (matrix spicule protein 130), as measured by semi-quantitative RT-PCR and whole mount in situ hybridization, respectively. These findings indicate the sea urchin embryo as a sensible bioindicator of X-radiation and propose its use as an alternative model, emphasizing the need for further investigation aimed to protect ecosystem health.

PI3K inhibition highlights new molecular interactions involved in the skeletogenesis of Paracentrotus lividus embryos.

The sea urchin embryo develops a well-defined biomineralized endoskeleton, synthesized exclusively by the skeletogenic cells, supported by ectodermal cues for the correct skeleton patterning. The biomineralization process is tightly regulated via a hierarchical order of gene expression, including transcription and growth factors, biomineralization proteins. Recently, the role of kinases and intracellular signaling pathways in sea urchin skeletogenesis has been addressed, although the downstream components still remain unknown. In this study, we investigated the role of phosphatidylinositide 3-kinase (PI3K)-mediated signaling pathway in Paracentrotus lividus, to identify its genes/proteins targets. The effects of LY294002 (LY), a PI3K-specific inhibitor, were evaluated at morphological and molecular levels. Treatment with 40 µM LY from the blastula stage completely blocked skeleton deposition, which was reversed by wash out experiments. Besides, LY caused a slight delay in the tripartite gut development. Despite the skeleton absence, a few skeleton-specific proteins/mRNAs were regularly expressed and localized in LY-treated embryos, as shown for MSP130 and SM50 by immunofluorescence and in situ hybridization experiments. QPCR analyses showed that LY differently affected the expression of genes coding for other biomineralization proteins, transcription and growth factors. SM30 and carbonic anhydrase expression was severely downregulated, while almost all the transcription factors analyzed were upregulated. Based on the present results and in silico analyses, we propose an "interactomic" model simulating PI3K connections in P. lividus embryos. Our findings define a novel regulatory step in the embryonic skeletogenesis, and provide valuable molecular data for further studies on the role of PI3K signaling in invertebrate biomineralization.

Do Animals Play a Role in the Transmission of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2)? A Commentary.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) belongs to the Beta-coronavirus genus. It is 96.2% homologous to bat CoV RaTG13 and 88% homologous to two bat SARS-like coronaviruses. SARS-CoV-2 is the infectious agent responsible for the coronavirus disease (COVID-19), which was first reported in the Hubei province of Wuhan, China, at the beginning of December 2019. Human transmission from COVID-19 patients or incubation carriers occurs via coughing, sneezing, speaking, discharge from the nose, or fecal contamination. Various strains of the virus have been reported around the world, with different virulence and behavior. In addition, SARS-CoV-2 shares certain epitopes with some taxonomically related viruses, with tropism for the most common synanthropic animals. By elucidating the immunological properties of the circulating SARS-CoV-2, a partial protection due to human-animal interactions could be supposed in some situations. In addition, differential epitopes could be used for the differential diagnosis of SARS-CoV-2 infection. There have been cases of transmission from people with COVID-19 to pets such as cats and dogs. In addition, wild felines were infected. All These animals were either asymptomatic or mildly symptomatic and recovered spontaneously. Experimental studies showed cats and ferrets to be more susceptible to COVID-19. COVID-19 positive dogs and felines do not transmit the infection to humans. In contrast, minks at farms were severely infected from people with COVID-19. A SARS-Cov-2 variant in the Danish farmed mink that had been previously infected by COVID-19 positive workers, spread to mink workers causing the first case of animal-to-human infection transmission that causes a moderate decreased sensitivity to neutralizing antibodies. Thus, more investigations are necessary. It remains important to understand the risk that people with COVID-19 pose to their pets, as well as wild or farm animals so effective recommendations and risk management measures against COVID-19 can be made. A One Health unit that facilitates collaboration between public health and veterinary services is recommended.

Titanium dioxide nanoparticles temporarily influence the sea urchin immunological state suppressing inflammatory-relate gene transcription and boosting antioxidant metabolic activity.

Titanium dioxide nanoparticles (TiO2NPs) are revolutionizing biomedicine due to their potential application as diagnostic and therapeutic agents. However, the TiO2NP immune-compatibility remains an open issue, even for ethical reasons. In this work, we investigated the immunomodulatory effects of TiO2NPs in an emergent proxy to human non-mammalian model for in vitro basic and translational immunology: the sea urchin Paracentrotus lividus. To highlight on the new insights into the evolutionarily conserved intracellular signaling and metabolism pathways involved in immune-TiO2NP recognition/interaction we applied a wide-ranging approach, including electron microscopy, biochemistry, transcriptomics and metabolomics. Findings highlight that TiO2NPs interact with immune cells suppressing the expression of genes encoding for proteins involved in immune response and apoptosis (e.g. NF-κB, FGFR2, JUN, MAPK14, FAS, VEGFR, Casp8), and boosting the immune cell antioxidant metabolic activity (e.g. pentose phosphate, cysteine-methionine, glycine-serine metabolism pathways). TiO2NP uptake was circumscribed to phagosomes/phagolysosomes, depicting harmless vesicular internalization. Our findings underlined that under TiO2NP-exposure sea urchin innate immune system is able to control inflammatory signaling, excite antioxidant metabolic activity and acquire immunological tolerance, providing a new level of understanding of the TiO2NP immune-compatibility that could be useful for the development in Nano medicines.

P53-regulated miR-320a targets PDL1 and is downregulated in malignant mesothelioma.

Malignant pleural mesothelioma (MPM) is an aggressive cancer, related to asbestos exposure, which has a dismal prognosis. MPM diagnosis is late and often challenging, suggesting the need to identify more reliable molecular biomarkers. Here, we set out to identify differentially expressed miRNAs in epithelioid, biphasic, and sarcomatoid MPMs versus normal mesothelium and explored specific miRNA contribution to mesothelial tumorigenesis. We screened an LNA™-based miRNA-microrray with 14 formalin-fixed paraffin-embedded (FFPE) MPMs and 6 normal controls. Through real-time qRT-PCR we extended the analysis of a miRNA subset and further investigated miR-320a role through state-of-the-art techniques. We identified 16 upregulated and 32 downregulated miRNAs in MPMs versus normal tissue, including the previously identified potential biomarkers miR-21, miR-126, miR-143, miR-145. We showed in an extended series that miR-145, miR-10b, and miR-320a levels can discriminate tumor versus controls with high specificity and sensitivity. We focused on miR-320a because other family members were found downregulated in MPMs. However, stable miR-320a ectopic expression induced higher proliferation and migration ability, whereas miR-320a silencing reduced these processes, not supporting a classic tumor-suppressor role in MPM cell lines. Among putative targets, we found that miR-320a binds the 3'-UTR of the immune inhibitory receptor ligand PDL1 and, consistently, miR-320a modulation affects PDL1 levels in MPM cells. Finally, we showed that p53 over-expression induces the upregulation of miR-320a, along with miR-200a and miR-34a, both known to target PDL1, and reduces PDL1 levels in MPM cells. Our data suggest that PDL1 expression might be due to a defective p53-regulated miRNA response, which could contribute to MPM immune evasion or tumorigenesis through tumor-intrinsic roles.

Correction: P53-regulated miR-320a targets PDL1 and is downregulated in malignant mesothelioma.

Author Francesca Pentimalli was incorrectly associated with Histopathological Unit, IRCCS-Istituto Tumori "Giovanni Paolo II", Viale Orazio Flacco 65, 70124 Bari, Italy. The author's actual affiliation is Cell Biology and Biotherapy Unit, Istituto Nazionale Tumori-IRCCS-Fondazione G. Pascale, I-80131 Napoli, Italy.