Breast density in NF1 women: a retrospective study.

Neurofibromatosis type 1 (NF1) is an autosomal dominant condition caused by neurofibromin haploinsufficiency due to pathogenic variants in the NF1 gene. Tumor predisposition has long been associated with NF1, and an increased breast cancer (BC) incidence and reduced survival have been reported in recent years for women with NF1. As breast density is another known independent risk factor for BC, this study aims to evaluate the variability of breast density in patients with NF1 compared to the general population. Mammograms from 98 NF1 women affected by NF1, and enrolled onto our monocentric BC screening program, were compared with those from 300 healthy subjects to verify differences in breast density. Mammograms were independently reviewed and scored by a radiologist and using a Computer-Aided Detection (CAD) software. The comparison of breast density between NF1 patients and controls was performed through Chi-squared test and with multivariable ordinal logistic models adjusted for age, body mass index (BMI), number of pregnancies, and menopausal status.breast density was influenced by BMI and menopausal status in both NF1 patients and healthy subjects. No difference in breast density was observed between NF1 patients and the healthy female population, even after considering the potential confounding factors.Although NF1 and a highly fibroglandular breast are known risk factors of BC, in this study, NF1 patients were shown to have comparable breast density to healthy subjects. The presence of pathogenic variants in the NF1 gene does not influence the breast density value.

Prenatal Clinical Findings in RASA1-Related Capillary Malformation-Arteriovenous Malformation Syndrome.

Pathogenic variants in RASA1 are typically associated with a clinical condition called "capillary malformation-arteriovenous malformation" (CM-AVM) syndrome, an autosomal dominant genetic disease characterized by a broad phenotypic variability, even within families. In CM-AVM syndrome, multifocal capillary and arteriovenous malformations are mainly localized in the central nervous system, spine and skin. Although CM-AVM syndrome has been widely described in the literature, only 21 cases with prenatal onset of clinical features have been reported thus far. Here, we report four pediatric cases of molecularly confirmed CM-AVM syndrome which manifested during the prenatal period. Polyhydramnios, non-immune hydrops fetalis and chylothorax are only a few possible aspects of this condition, but a correct interpretation of these prenatal signs is essential due to the possible fatal consequences of unrecognized encephalic and thoracoabdominal deep vascular malformations in newborns and in family members carrying the same RASA1 variant.

Chung-Jansen syndrome can mimic Cornelia de Lange syndrome: Another player among chromatinopathies?

Cornelia de Lange syndrome (CdLS) is a rare multisystem congenital neurodevelopmental disorder (NDD) characterized by distinctive facial anomalies, short stature, developmental delay, hirsutism, gastrointestinal abnormalities and upper limb reduction defects. CdLS syndrome is associated with causative variants in genes encoding for the cohesin complex, a cellular machinery involved in chromatid pairing, DNA repair and gene-expression regulation. In this report, we describe a familial case of a syndromic presentation in a 4-year-old patient (P1) and in his mother (P2). Trio-based Whole Exome Sequencing (WES) performed on P1 was first negative. Since his phenotypic evolution during the follow-up was reminiscent of the CdLS spectrum, a reanalysis of WES data, focused on CdLS-related genes, was requested. Although no alterations in those genes was detected, we identified the likely pathogenetic variant c.40G > A (p.Glu14Lys) in the PHIP gene, in the meanwhile associated with Chung-Jansen syndrome. Reverse phenotyping carried out in both patients confirmed the molecular diagnosis. CHUJANS belongs to NDDs, featuring developmental delay, mild-to-moderate intellectual disability, behavioral problems, obesity and facial dysmorphisms. Moreover, as here described, CHUJANS shows a significant overlap with the CdLS spectrum, with specific regard to facial gestalt. On the basis of our findings, we suggest to include PHIP among genes routinely analyzed in patients belonging to the CdLS spectrum.

Small heterodimer partner 1 directly interacts with NS5A viral protein and has a key role in HCV related liver cell transformation.

HCV life cycle is strictly correlated with the hepatocyte lipid metabolism; moreover, the progression of HCV chronic hepatitis is accelerated by the presence of liver steatosis. Among the steatogenic genes deregulated during the HCV infection one of the most attractive is the Small Heterodimer Protein 1 (SHP1; NR0B2), that is involved in a remarkable number of metabolic functions. HCV NS5A is an essential and integral component of the HCV membranous-web replicon complex (RC) and plays an essential role to transfer the viral genome from the RCs to the surface of the lipid droplets (LDs) that, in turn, play a key function during HCV life cycle.With the help of a HCV infection model, we demonstrate a functional interaction between SHP1 and HCV NS5A protein. SHP1 silencing (siSHP1) reversed the pro-oncogenic effects of HCV infection, inducing a significant decrease in liver lipid accumulation and in NS5A protein expression. Moreover, siSHP1 causes a strong modulation of some genes involved in HCV-related EMT, such as: HNF4, a central regulators of hepatocyte differentiation, E-Cadherin, SNAILs.Our data suggest that SHP1 results not only to be strictly connected to the pathogenesis of HCV-related liver steatosis, but also to its progression towards the liver transformation.

Recent Insights into Notch Signaling in Embryonal Rhabdomyosarcoma.

The Notch signaling pathway is an evolutionarily conserved developmental network critical for embryonic and postnatal regulation of tissue growth, homeostasis, and repair. Signaling is initiated when transmembrane Notch ligands bind to transmembrane Notch receptors on nearby cells. Sequential proteolytic steps generate an activated Notch fragment that translocates to the nucleus, where it drives activation of canonical Notch target genes. In skeletal muscle, Notch signaling governs myogenic cell fate and stem cell maintenance. In the human soft tissue sarcoma rhabdomyosarcoma, which bears markers of skeletal muscle commitment and so is thought to be related to the skeletal muscle lineage, Notch signaling is also found to be upregulated and dysregulated. This review provides an overview of Notch signaling during normal embryonic and postnatal myogenesis, information on the recently discovered aberrant Notch signaling occurring in muscular dystrophies, the upregulation and mechanism of Notch signaling in the embryonal variant of rhabdomyosarcoma and related soft tissue sarcomas, and Notch cross-talk with other metazoan developmental pathways including Hippo, Hedgehog, Wnt, and TGF-β. The review concludes with updates on current promising efforts to target and inhibit Notch signaling in human sarcomas including rhabdomyosarcoma.

MicroRNA-101 is repressed by EZH2 and its restoration inhibits tumorigenic features in embryonal rhabdomyosarcoma.

BACKGROUND: Rhabdomyosarcoma (RMS) is a pediatric soft tissue sarcoma arising from myogenic precursors that have lost their capability to differentiate into skeletal muscle. The polycomb-group protein EZH2 is a Lys27 histone H3 methyltransferase that regulates the balance between cell proliferation and differentiation by epigenetically silencing muscle-specific genes. EZH2 is often over-expressed in several human cancers acting as an oncogene. We previously reported that EZH2 inhibition induces cell cycle arrest followed by myogenic differentiation of RMS cells of the embryonal subtype (eRMS). MiR-101 is a microRNA involved in a negative feedback circuit with EZH2 in different normal and tumor tissues. To that, miR-101 can behave as a tumor suppressor in several cancers by repressing EZH2 expression. We, therefore, evaluated whether miR-101 is de-regulated in eRMS and investigated its interplaying with EZH2 as well as its role in the in vitro tumorigenic potential of these tumor cells. RESULTS: Herein, we report that miR-101 is down-regulated in eRMS patients and in tumor cell lines compared to their controls showing an inverse pattern of expression with EZH2. We also show that miR-101 is up-regulated in eRMS cells following both genetic and pharmacological inhibition of EZH2. In turn, miR-101 forced expression reduces EZH2 levels as well as restrains the migratory potential of eRMS cells and impairs their clonogenic and anchorage-independent growth capabilities. Finally, EZH2 recruitment to regulatory region of miR-101-2 gene decreases in EZH2-silenced eRMS cells. This phenomenon is associated to reduced H3K27me3 levels at the same regulatory locus, indicating that EZH2 directly targets miR-101 for repression in eRMS cells. CONCLUSIONS: Altogether, our data show that, in human eRMS, miR-101 is involved in a negative feedback loop with EZH2, whose targeting has been previously shown to halt eRMS tumorigenicity. They also demonstrate that the re-induction of miR-101 hampers the tumor features of eRMS cells. In this scenario, epigenetic dysregulations confirm their crucial role in the pathogenesis of this soft tissue sarcoma.

Lymphocytes as liver damage mirror of HCV related adipogenesis deregulation.

Hepatitis C virus infection leads to a wide spectrum of liver diseases ranging from mild chronic hepatitis to end-stage cirrhosis and hepatocellular carcinoma. An intriguing aspect of the HCV infection is its close connection with lipid metabolism playing an important role in the HCV life cycle and in its pathogenesis. HCV is known to be a hepatotropic virus; however, it can also infect peripheral blood mononuclear cells (PBMCs). The goal of the current investigation is to compare the adipogenesis profile of liver tissues to lymphocytes of HCV infected patients, in order to understand if PBMCs may reflect the alterations of intracellular pathways occurring during HCV-related liver steatosis. Using the Human Adipogenesis PCR Array, gene expression was analyzed in liver samples and PBMCs of chronic HCV+, HBV+ and Healthy Donors (HDs) patients. We observed a similar modulation of lipid metabolism in HCV+ and HBV+liver tissues and lymphoid, cells suggesting that PBMCs reflect the liver adipogenesis deregulation related to infection, even if the two viruses have a different impact in the regulation of the adipogenesis mechanisms. In particular, some genes involved in lipid metabolism and inflammation, as well as in cell transformation, were up-regulated, in a similar way, in both HCV models analyzed. Interestingly, these genes were positively correlated to virological and hepatic functional parameters of HCV+ patients. On the contrary, HBV+ patients displayed a completely different profile. PBMCs of HCV+ patients seem to be useful model to study how HCV-related lipid metabolism deregulation occurs in liver. The obtained data suggest some molecules as new possible biomarkers of HCV-related liver damage progression.

TGFß overrides HNF4α tumor suppressing activity through GSK3ß inactivation: implication for hepatocellular carcinoma gene therapy.

BACKGROUND & AIMS: The tumor fate derives from cell autonomous properties and niche microenvironmental cues. The transforming growth factor ß (TGFß) is a major microenvironmental factor for hepatocellular carcinoma (HCC) influencing tumor dedifferentiation, induction of epithelial-to-mesenchymal transition (EMT) and acquisition of metastatic properties. The loss of the transcriptional factor HNF4α is a predominant mechanism through which HCCs progress to a more aggressive phenotype; its re-expression, reducing tumor formation and repressing EMT program, has been suggested as a therapeutic tool for HCC gene therapy. We investigated the influence of TGFß on the anti-EMT and tumor suppressor HNF4α activity. METHODS: Cell motility and invasion were analyzed by wound healing and invasion assays. EMT was evaluated by RT-qPCR and immunofluorescence. ChIP and EMSA assays were utilized for investigation of the HNF4α DNA binding activity. HNF4α post-translational modifications (PTMs) were assessed by 2-DE analysis. GSK3ß activity was modulated by chemical inhibition and constitutive active mutant expression. RESULTS: We demonstrated that the presence of TGFß impairs the efficiency of HNF4α as tumor suppressor. We found that TGFß induces HNF4α PTMs that correlate with the early loss of HNF4α DNA binding activity on target gene promoters. Furthermore, we identified the GSK3ß kinase as one of the TGFß targets mediating HNF4α functional inactivation: GSK3ß chemical inhibition results in HNF4α DNA binding impairment while a constitutively active GSK3ß mutant impairs the TGFß-induced inhibitory effect on HNF4α tumor suppressor activity. CONCLUSIONS: Our data identify in the dominance of TGFß a limit for the HNF4α-mediated gene therapy of HCC.

Focal adhesion kinase (FAK) mediates the induction of pro-oncogenic and fibrogenic phenotypes in hepatitis C virus (HCV)-infected cells.

Hepatitis C Virus (HCV) infection is one of the most common etiological factors involved in fibrosis development and its progression to hepatocellular carcinoma (HCC). The pivotal role of hepatic stellate cells (HCSs) and extracellular matrix (ECM) in fibrogenesis is now certainly accepted, while the network of molecular interactions connecting HCV is emerging as a master regulator of several biological processes including proliferation, inflammation, cytoskeleton and ECM remodeling. In this study, the effects of HCV proteins expression on liver cancer cells, both pro-invasive and pro-fibrogenic phenotypes were explored. As a model of HCV infection, we used permissive Huh7.5.1 hepatoma cells infected with JFH1-derived ccHCV. Conditioned medium from these cells was used to stimulate LX-2 cells, a line of HSCs. We found that the HCV infection of Huh7.5.1 cells decreased adhesion, increased migration and caused the delocalization of alpha-actinin from plasma membrane to cytoplasm and increased expression levels of paxillin. The treatment of LX-2 cells, with conditioned medium from HCV-infected Huh7.5.1 cells, caused an increase in cell proliferation, expression of alpha-smooth muscle actin, hyaluronic acid release and apoptosis rate measured as cleaved poly ADP-ribose polymerase (PARP). These effects were accompanied in Huh7.5.1 cells by an HCV-dependent increasing of FAK activation that physically interacts with phosphorylated paxillin and alpha-actinin, and a rising of tumor necrosis factor alpha production/release. Silencing of FAK by siRNA reverted all effects of HCV infection, both those directed on Huh7.5.1 cells, and those indirect effects on the LX-2 cells. Moreover and interestingly, FAK inhibition enhances apoptosis in HCV-conditioned LX-2 cells. In conclusion, our findings demonstrate that HCV, through FAK activation, may promote cytoskeletal reorganization and a pro-oncogenic phenotype in hepatocyte-like cells, and a fibrogenic phenotype in HSCs.

The stable repression of mesenchymal program is required for hepatocyte identity: a novel role for hepatocyte nuclear factor 4α.

UNLABELLED: The concept that cellular terminal differentiation is stably maintained once development is complete has been questioned by numerous observations showing that differentiated epithelium may undergo an epithelial-to-mesenchymal transition (EMT) program. EMT and the reverse process, mesenchymal-to-epithelial transition (MET), are typical events of development, tissue repair, and tumor progression. In this study, we aimed to clarify the molecular mechanisms underlying these phenotypic conversions in hepatocytes. Hepatocyte nuclear factor 4α (HNF4α) was overexpressed in different hepatocyte cell lines and the resulting gene expression profile was determined by real-time quantitative polymerase chain reaction. HNF4α recruitment on promoters of both mesenchymal and EMT regulator genes was determined by way of electrophoretic mobility shift assay and chromatin immunoprecipitation. The effect of HNF4α depletion was assessed in silenced cells and in the context of the whole liver of HNF4 knockout animals. Our results identified key EMT regulators and mesenchymal genes as new targets of HNF4α. HNF4α, in cooperation with its target HNF1α, directly inhibits transcription of the EMT master regulatory genes Snail, Slug, and HMGA2 and of several mesenchymal markers. HNF4α-mediated repression of EMT genes induces MET in hepatomas, and its silencing triggers the mesenchymal program in differentiated hepatocytes both in cell culture and in the whole liver. CONCLUSION: The pivotal role of HNF4α in the induction and maintenance of hepatocyte differentiation should also be ascribed to its capacity to continuously repress the mesenchymal program; thus, both HNF4α activator and repressor functions are necessary for the identity of hepatocytes.

Proteomic analysis reveals a major role for contact inhibition in the terminal differentiation of hepatocytes.

BACKGROUND & AIMS: Hepatocytes are considered an exception of the paradigmatic inverse correlation between cell proliferation and terminal differentiation. In fact, hepatic vital functions are guaranteed by proliferating parenchymal cells during liver regeneration. However, a fine molecular characterization of the relationship between proliferation and differentiation in hepatocytes has been hampered by the lack of reliable in vivo or in vitro models. METHODS: The hepatocyte terminal differentiation program was characterized in the immortalized, untransformed and differentiated hepatocytic cell line MMH, using several techniques. Particularly, two-dimensional difference gel electrophoresis combined to tandem mass spectrometry proteomic approach was used. Cell cycle and cell adhesion properties of MMH have been altered using either myc-overexpression and MEK1/2 inhibition or a constitutive active beta-catenin mutant, respectively. RESULTS: The hepatocyte terminal differentiation program is stimulated by the exit from the cell cycle induced by cell-cell contact. Comparative proteomic analysis of proliferating versus quiescent hepatocytes validated the importance of contact inhibition, identifying 68 differently expressed gene products, representing 49 unique proteins. Notably, enzymes involved in important liver functions such as detoxification processes, lipid metabolism, iron and vitamin A storage and secretion, anti-inflammatory response and exocytosis were found significantly up-regulated in quiescent hepatocytes. Finally, we found that: (i) cell cycle arrest induced by MEK1/2 inhibition is not sufficient to induce hepatic product expression; (ii) constitutive activation of beta-catenin counteracts the contact inhibition-induced terminal differentiation. CONCLUSION: The hepatocyte terminal differentiation program requires a quiescent state maintained by cell-cell contact through the E-cadherin/beta-catenin pathway, rather than the inhibition of proliferation.

C242T polymorphism of NADPH oxidase p22phox and recurrence of cardiovascular events in coronary artery disease.

OBJECTIVE: The common C242T polymorphism in the gene for the p22phox subunit of NADPH oxidase has been reported to be negatively associated with oxidative stress, but whether it confers prognostic information is not yet clear. METHODS AND RESULTS: The incidence of major adverse cardiovascular events (MACE) were determined in 237 patients with coronary stenosis during a median follow-up of 7.8 years. The p22phox genotypes were evaluated in 213 patients (89.9%) by polymerase chain reaction and RsaI. digestion. Plasma levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG), a marker of oxidative stress, were also measured. In the univariate analysis, patients with CT/TT genotypes showed reduced recurrence of cardiovascular deaths, nonfatal MI, and revascularization procedures compared with homozygous carriers of the C allele. After controlling for confounders, a significantly lower risk of new revascularization procedures (HR=0.31, 95% CI 0.12 to 0.70; P=0.014) remained associated with the T allele. The Kaplan-Meier analysis showed a longer survival free from fatal and nonfatal MI in carriers of T allele (P<0.001). The presence of the 242T allele was associated with significantly reduced plasma concentrations of 8-OHdG. CONCLUSIONS: The 242T allele was a predictor of lower risk of recurrence of cardiovascular events in high-risk patients and was associated with reduced systemic oxidative stress.