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ERCC excision repair 6 like 2 (ERCC6L2) gene encodes for different helicase-like protein members of the Snf2 family involved in transcription-coupled nucleotide excision repair and in cell proliferation. Germline homozygous mutations in children and adults predispose to a peculiar bone marrow failure phenotype characterized by mild hematological alterations with a high risk of developing acute myeloid leukemia. The outcome for patients with leukemia progression is dismal while patients undergoing hematopoietic stem cell transplantation in the early stage have better outcomes. The ERCC6L2-related hematological disease presents a high penetrance, posing important questions regarding the treatment strategies and possible preemptive approaches. This review describes the biological function of ERCC6L2 and the clinical manifestations of the associated disease, trying to focus on the unsolved clinical questions.

Astolf et al provide the first report of acute promyelocytic leukemia driven by viral insertion into the RARA locus. This represents a clear demonstration of a pathology driven by the member of the anelloviruses, a group of viruses otherwise thought to have minimal or no pathogenic potential.

Clear cell sarcoma of the kidney (CCSK) is a rare pediatric renal tumor with a worse prognosis than Wilms’ tumor. Although recently, BCOR internal tandem duplication (ITD) has been found as a driver mutation in more than 80% of cases, a deep molecular characterization of this tumor is still lacking, as well as its correlation with the clinical course. The aim of this study was to investigate the differential molecular signature between metastatic and localized BCOR-ITD-positive CCSK at diagnosis. Whole-exome sequencing (WES) and whole-transcriptome sequencing (WTS) were performed on six localized and three metastatic BCOR-ITD-positive CCSKs, confirming that this tumor carries a low mutational burden. No significant recurrences of somatic or germline mutations other than BCOR-ITD were identified among the evaluated samples. Supervised analysis of gene expression data showed enrichment of hundreds of genes, with a significant overrepresentation of the MAPK signaling pathway in metastatic cases (p < 0.0001). Within the molecular signature of metastatic CCSK, five genes were highly and significantly over-expressed: FGF3, VEGFA, SPP1, ADM, and JUND. The role of FGF3 in the acquisition of a more aggressive phenotype was investigated in a cell model system obtained by introducing the ITD into the last exon of BCOR by Crispr/Cas9 gene editing of the HEK-293 cell line. Treatment with FGF3 of BCOR-ITD HEK-293 cell line induced a significant increase in cell migration versus both untreated and scramble cell clone. The identification of over-expressed genes in metastatic CCSKs, with a particular focus on FGF3, could offer new prognostic and therapeutic targets in more aggressive cases.

CBL plays a key role in different cell pathways, mainly related to cancer onset and progression, hematopoietic development and T cell receptor regulation. Somatic CBL mutations have been reported in a variety of malignancies, ranging from acute myeloid leukemia to lung cancer. Growing evidence have defined the clinical spectrum of germline CBL mutations configuring the so-called CBL syndrome; a cancer-predisposing condition that also includes multisystemic involvement characterized by variable phenotypic expression and expressivity. This review provides a comprehensive overview of the molecular mechanisms in which CBL exerts its function and describes the clinical manifestation of CBL mutations in humans.

Atopic dermatitis is frequently associated with the onset of other allergic conditions, such as asthma, rhino-conjunctivitis and food allergy. The etiology of atopic dermatitis is marginally understood in spite of the number of predisposing factors, above all, mutations in the Filaggrin gene (FLG). In this study, the association between loss-of-function variants in the FLG gene and other allergic manifestations, in particular food allergy, was evaluated in an Italian pediatric population affected by atopic dermatitis. The 10 more frequently mutated loci in the FLG gene were genotyped in 238 children affected by atopic dermatitis and tested for association with clinical features of allergic disorders by a multivariate logistic regression model. R501X and 2282del4 were the only two mutations identified, 12.2% of children carry one of these variants, corresponding to an allelic frequency of 6.5%. According to multivariate statistical analysis, loss-of-function variants in the FLG gene represent a risk factor for the onset of severe manifestations of food allergy (OR = 8.9, CI: 3.1&ndash, 28.3). Peanut and hazelnut were identified as high-risk foods in patients with FLG mutations. This study demonstrates that atopic children carrying FLG mutations represent a high-risk population due to their predisposition to develop severe food allergy reactions, such as anaphylaxis.

Gaucher disease is a lysosomal storage disorder characterized by β-glucosidase enzyme deficiency and substrate accumulation, especially in cells of the reticuloendothelial system. Typical features of the disease are the unrestrained activation of inflammatory mechanisms, whose molecular pathways are still unclear. To investigate biological mechanisms underlying the macrophage activation in GD, we derived iPSCs from a healthy donor and a GD patient line and differentiated them into hematopoietic progenitors. While GD iPSCs are able to efficiently give rise to CD33+/CD45+ myeloid progenitors, the maturation towards the CD14+/CD163+ monocyte/macrophages fate resulted enhanced in the GD lines, that in addition displayed a decreased growth potential compared to control cells either in semisolid or in liquid culture. The GD lines growth impairment was associated with a significant upregulation of RIPK3 and MLKL, two key effectors of necroptosis, the inflammation related cell death pathway. The activation of necroptosis, which has already been linked to neuronopathic GD, may play a role in the disease proinflammatory condition and in the identified cell growth defects. Understanding the GD macrophage role in the alteration of mechanisms linked to cellular metabolism imbalance, cell death and inflammation are crucial in identifying new ways to approach the disease.

Background: About 20–40% of gastrointestinal stromal tumors (GISTs) lacking KIT/PDGFRA mutations show defects in succinate dehydrogenase (SDH) complex. This study uncovers the gene expression profile (GEP) of SDH-deficient GIST in order to identify new signaling pathways or molecular events actionable for a tailored therapy. Methods: We analyzed 36 GIST tumor samples, either from formalin-fixed, paraffin-embedded by microarray or from fresh frozen tissue by RNA-seq, retrospectively collected among KIT-mutant and SDH-deficient GISTs. Pathway analysis was performed to highlight enriched and depleted transcriptional signatures. Tumor microenvironment and immune profile were also evaluated. Results: SDH-deficient GISTs showed a distinct GEP with respect to KIT-mutant GISTs. In particular, SDH-deficient GISTs were characterized by an increased expression of neural markers and by the activation of fibroblast growth factor receptor signaling and several biological pathways related to invasion and tumor progression. Among them, hypoxia and epithelial-to-mesenchymal transition emerged as features shared with SDH-deficient pheochromocytoma/paraganglioma. In addition, the study of immune landscape revealed the depletion of tumor microenvironment and inflammation gene signatures. Conclusions: This study provides an update of GEP in SDH-deficient GISTs, highlighting differences and similarities compared to KIT-mutant GISTs and to other neoplasm carrying the SDH loss of function. Our findings add a piece of knowledge in SDH-deficient GISTs, shedding light on their putative histology and on the dysregulated biological processes as targets of new therapeutic strategies.

Asthma is a complex and heterogeneous disease, caused by the interaction between genetic and environmental factors with a predominant allergic background in children. The role of specific genes in asthmatic bronchial reactivity is still not clear, probably because of the many common pathways shared with other allergic disorders. This study is focused on 11 SNPs possibly related to asthma that were previously identified in a GWAS study. The genetic variability of these SNPs has been analysed in a population of 773 Italian healthy controls, and the presence of an association between the polymorphisms and the asthma onset was evaluated performing genotyping analysis on 108 children affected with asthma compared with the controls. Moreover, a pool of 171 patients with only allergic rhinoconjunctivitis has been included in the case–control analysis. The comparison of allele frequencies in asthmatic patients versus healthy controls identified two SNPs—rs1162394 (p = 0.019) and rs25681 (p = 0.044)—associated with the asthmatic condition, which were not differentially distributed in the rhinoconjunctivitis group. The rs25681 SNP, together with three other SNPs, also resulted in not being homogenously distributed in the Italian population. The significantly higher frequency of the rs25681 and rs1162394 SNPs (located, respectively, in the C5 and SRGAP3 genes) in the asthmatic population suggests an involvement of these genes in the asthmatic context, playing a role in increasing the inflammatory condition that may influence asthma onset and clinical course.

Gaucher disease (GD) is a monogenic disorder characterized byβ-glucocerebrosidase enzyme deficiency. Typical features of the diseaseare the unrestrained activation of inflammatory mechanisms andneuronal cell death in neuronopathic conditions, whose molecularpathways are still not fully understood. Recent evidences show thatupregulation of the Hippo pathway is associated with neuroinflamma-tion and neuronal cell death. We analyzed the Hippo pathway activitytaking advantage of a Drosophila Gaucher-like model characterized bydGBA1b knock-out (GBA1bKO).WefoundderegulationofCycE,dIAPandMYC, direct targets of the pathway both in Drosophila and mammals,which were severely reduced at transcript and protein level,suggestingacell growth impairment. Analyzing upstream components we foundthat Fat, an atypical cadherin upstream of the kinase complex, wasupregulated. Moreover the glypicans Dally and Dally-like, known to benegatively regulated by Fat and involved in glial and synapsedevelopment, were found downregulated in the GBA1bKObackground,supporting a role in neurological damage. On the other hand, theaberrant inflammatory condition of the hematological compartmentwas investigated in the human model of induced Pluripotent Stem Cells(iPSC), differentiated into hematopoietic progenitors. While GD iPSCswere able to differentiate into CD34+/CD43+/CD45+ progenitors, theyshowed a decreased proliferative potential compared to healthy donoriPSC either in semisolid and liquid culture, therefore exhibiting a growthimpairment. This effect was coupled with the activation of necroptosispathway with a significant upregulation of RIPK3 and MLKL both in thepluripotent and differentiated state. Correction of the mutation to rescuethe phenotype is ongoing, taking advantage of AAVS1 editing approachin order to develop a fully comparable cell model useful in a cell therapyperspective. These data obtained with suitable GD models support therole of Hippo and necroptosis effectors in GD, amenable of furtherconsideration as potential therapeutic targets.

Gaucher disease (GD) is an autosomic recessive genetic disorder, known as the most common lysosomal storage disease. The causative genetic alteration involves mutation of the GBA gene, encoding for the β-glucocerebrosidase enzyme, whose loss-of-function causes the accumulation of glucosylceramide and glucosylsphingosine especially in cells primarily of the reticulo-endothelial system. More than 90% of patients show a systemic disorder and only fewer has an impairment of the central nervous system. The aggressiveness of the disorder is not tightly correlated with the genotype indeed there are many cases reported in literature of patients carrying the same mutation but different pathological symptoms. Typical features of the disease are the unrestrained activation of inflammatory mechanisms and neuronal cell death in neuronopathic conditions, whose molecular pathways are still not fully understood. Recent evidences show that upregulation of the Hippo pathway is associated with neuroinflammation and neuronal cell death, while the necroptosis pathway was found involved in a murine model of Gaucher Disease.

The Gaucher Disease (GD) is a lysosomal disorder associated with mutations in the GBA1 gene, encoding the acidic β-glucocerebrosidase. GD is characterized by a wide spectrum of phenotypic manifestations, the most severe of which involve the nervous system, with massive neuronal loss and microglial proliferation. Different symptoms are also observed in individuals bearing identical GBA1 mutations, suggesting that additional players are involved in the disease. Our hypothesis is that hyper-activation of the Hippo pathway, recently found involved in some neurodegenerative syndromes, may contribute to the dramatic outcome of the neuronopathic GD. We thus started an expression analysis of upstream and downstream Hippo pathway components in Drosophila GBA1-deficient larval and adult organs. While some Hippo downstream targets resulted down-regulated in GBA1-deficient tissues, both in terms of transcript and protein content, Fat, an atypical cadherin upstream of the kinase complex involved in the regulation of glial and synapse development, was found up-regulated. In the light of this latter result, we are currently performing behavioural assays in flies where GBA1 expression has been silenced in glial or neuronal cells, to find out possible cross-effects. Preliminary data will be presented about the implication of the Hippo pathway in the pathogenesis of the neuronopathic GD.

La malattia di Gaucher è un disordine monogenico caratterizzato dal deficit dell’enzima β-glucocerebrosidasi. Dal momento che l’innesco aberrante di meccanismi infiammatori cellulari è un aspetto peculiare della malattia, ci siamo concentrati sullo studio del pathway della necroptosi, forma di morte cellulare programmata dettata dall’infiammazione. Dall’analisi dell’espressione genica e dalla valutazione dei livelli proteici in modelli cellulari Gaucher-like, ottenuti tramite inibizione enzimatica, abbiamo evidenziato come la chinasi RIP1, primo effettore della via di segnalazione sia iperattivato nello stato patologico. Per disporre di un sistema d’analisi più accurato stiamo mettendo a punto modelli che sfruttano cellule staminali pluripotenti indotte (iPSCs) derivate da paziente e donatore sano. Tramite gene editing la più comune mutazione puntiforme causante la malattia (N370S), è stata inserita in iPSCs derivate da donatore sano. Le cellule sono state trasfettate, tramite nucleofezione, con il plasmide pSpCas9(BB)-2A-Puro codificante per la Cas9 e per una guida a RNA in grado di indirizzarne il taglio sito-specifico. La sequenza stampo per l’inserimento della mutazione è stata introdotta sotto forma di DNA a singolo filamento. La presenza della mutazione è stata verificata tramite PCR effettuata con primer specifici su pool di cellule trasfettate. Parallelamente, da cellule mononucleate del sangue periferico di un paziente Gaucher con mutazione N370S/L444P sono state ottenute iPSCs grazie a trasduzione con i vettori virali Sendai codificanti per i fattori di riprogrammazione: Klf4, cMyc e KOS. Il monitoraggio del differenziamento verso destino ematopoietico sarà portato avanti concentrandosi nello specifico sul tipo cellulare macrofagico in quanto maggior target dell’accumulo sfingolipidico caratterizzante la malattia.