Focal adhesion kinase: Insight into molecular roles and functions in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related death worldwide. Due to the high incidence of post-operative recurrence after current treatments, the identification of new and more effective drugs is required. In previous years, new targetable genes/pathways involved in HCC pathogenesis have been discovered through the help of high-throughput sequencing technologies. Mutations in TP53 and β-catenin genes are the most frequent aberrations in HCC. However, approaches able to reverse the effect of these mutations might be unpredictable. In fact, if the reactivation of proteins, such as p53 in tumours, holds great promise as anticancer therapy, there are studies arguing that chronic activation of these types of molecules may be deleterious. Thus, recently the efforts on potential targets have focused on actionable mutations, such as those occurring in the gene encoding for focal adhesion kinase (FAK). This tyrosine kinase, localized to cellular focal contacts, is over-expressed in a variety of human tumours, including HCC. Moreover, several lines of evidence demonstrated that FAK depletion or inhibition impair in vitro and in vivo HCC growth and metastasis. Here, we provide an overview of FAK expression and activity in the context of tumour biology, discussing the current evidence of its connection with HCC development and progression

Intrauterine Growth Retardation and Nonalcoholic Fatty Liver Disease in Children

Intrauterine growth retardation (IUGR), the most important cause of perinatal mortality and morbidity, is defined as a foetal growth less than normal for the population, often used as synonym of small for gestational age (SGA). Studies demonstrated the relationships between metabolic syndrome (MS) and birthweight. This study suggested that, in children, adolescents, and adults born SGA, insulin resistance could lead to other metabolic disorders: type 2 diabetes (DM2), dyslipidemia, and nonalcoholic fatty liver disease (NAFLD). NAFLD may evolve to nonalcoholic steatohepatitis (NASH), and it is related to the development of MS. Lifestyle intervention, physical activity, and weight reduction represent the mainstay of NAFLD therapy. In particular, a catch-up growth reduction could decrease the risk to develop MS and NAFLD. In this paper, we outline clinical and experimental evidences of the association between IUGR, metabolic syndrome, insulin resistance, and NAFLD and discuss on a possible management to avoid the risk of MS in adulthood

Lipid-induced hepatocyte-derived extracellular vesicles regulate hepatic stellate cell via microRNAs targeting PPAR-γ.

Background&aimsHepatic stellate cells (HSCs) play a key role in liver fibrosis in various chronic liver disorders including nonalcoholic fatty liver disease (NAFLD). The development of liver fibrosis requires a phenotypic switch from quiescent to activated HSCs. The triggers for HSCs activation in NAFLD remain poorly understood. We investigated the role and molecular mechanism of extracellular vesicles (EVs) released by hepatocytes during lipotoxicity in modulation of HSC phenotype.MethodsEVs were isolated from fat-laden hepatocytes by differential centrifugation and incubated with HSCs. EV internalization and HSCs activation, migration and proliferation were assessed. Loss- and gain-of-functions studies were performed to explore the potential role of PPAR-γ-targeting miRNAs carried by EVs into HSC.ResultsHepatocyte-derived EVs released during lipotoxicity are efficiently internalized by HSCs resulting in their activation, as shown by marked up-regulation of pro-fibrogenic genes (Collagen-I, α-SMA and TIMP-2), proliferation, chemotaxis and wound healing responses. These changes were associated with miRNAs shuttled by EVs and suppression of PPAR-γ expression in HSC. Hepatocyte-derived EVs miRNA content included various miRNAs that are known inhibitors of PPAR-γ expression with miR-128-3p being the most effectively transferred. Furthermore loss- and gain-of-function studies identified miR-128-3p as a central modulator of the effects of EVs on PPAR-γ inhibition and HSC activation.ConclusionOur findings demonstrate a link between fat-laden hepatocyte-derived EVs and liver fibrosis and have potential implications for the development of novel anti-fibrotic targets for NAFLD and other fibrotic diseases

Activation of an endothelial Notch1-Jagged1 circuit induces VCAM1 expression, an effect amplified by interleukin-1β

The Notch1 and Notch4 signaling pathways regulate endothelial cell homeostasis. Inflammatory cytokines induce the expression of endothelial adhesion molecules, including VCAM1, partly by downregulating Notch4 signaling. We investigated the role of endothelial Notch1 in this IL-1β-mediated process. Brief treatment with IL-1β upregulated endothelial VCAM1 and Notch ligand Jagged1. IL-1β decreased Notch1 mRNA levels, but levels of the active Notch1ICD protein remained constant. IL-1β-mediated VCAM1 induction was downregulated in endothelial cells subjected to pretreatment with a pharmacological inhibitor of the γ-secretase, which activates Notch receptors, producing NotchICD. It was also downregulated in cells in which Notch1 and/or Jagged1 were silenced.Conversely, the forced expression of Notch1ICD in naïve endothelial cells upregulated VCAM1 per se and amplified IL-1β-mediated VCAM1 induction. Jagged1 levels increased and Notch4 signaling was downregulated in parallel. Finally, Notch1ICD and Jagged1 expression was upregulated in the endothelium of the liver in a model of chronic liver inflammation.In conclusion, we describe here a cell-autonomous, pro-inflammatory endothelial Notch1-Jagged1 circuit (i) triggering the expression of VCAM1 even in the absence of inflammatory cytokines and (ii) enhancing the effects of IL-1β. Thus, IL-1β regulates Notch1 and Notch4 activity in opposite directions, consistent with a selective targeting of Notch1 in inflamed endothelium

LPS-induced TNF-α factor mediates pro-inflammatory and pro-fibrogenic pattern in non-alcoholic fatty liver disease

Lipopolysaccharide (LPS) is currently considered one of the major players in non-alcoholic fatty liver disease (NAFLD) pathogenesis and progression. Here, we aim to investigate the possible role of LPS-induced TNF-α factor (LITAF) in inducing a pro-inflammatory and pro-fibrogenic phenotype of non-alcoholic steatohepatitis (NASH).We found that children with NAFLD displayed, in different liver-resident cells, an increased expression of LITAF which correlated with histological traits of hepatic inflammation and fibrosis. Total and nuclear LITAF expression increased in mouse and human hepatic stellate cells (HSCs). Moreover, LPS induced LITAF-dependent transcription of IL-1β, IL-6 and TNF-α in the clonal myofibroblastic HSC LX-2 cell line, and this effect was hampered by LITAF silencing. We showed, for the first time in HSCs, that LITAF recruitment to these cytokine promoters is LPS dependent. However, preventing LITAF nuclear translocation by p38MAPK inhibitor, the expression of IL-6 and TNF-α was significantly reduced with the aid of p65NF-ĸB, while IL-1β transcription exclusively required LITAF expression/activity. Finally, IL-1β levels in plasma mirrored those in the liver and correlated with LPS levels and LITAF-positive HSCs in children with NASH.In conclusion, a more severe histological profile in paediatric NAFLD is associated with LITAF over-expression in HSCs, which in turn correlates with hepatic and circulating IL-1β levels outlining a panel of potential biomarkers of NASH-related liver damage. The in vitro study highlights the role of LITAF as a key regulator of the LPS-induced pro-inflammatory pattern in HSCs and suggests p38MAPK inhibitors as a possible therapeutic approach against hepatic inflammation in NASH

Association between Serum Atypical Fibroblast Growth Factors 21 and 19 and Pediatric Nonalcoholic Fatty Liver Disease

Atypical fibroblast growth factors (FGF) 21 and 19 play a central role in energy metabolism through the mediation of Klotho coreceptor. Contradictory findings are available about the association of FGF21 and FGF19 with nonalcoholic fatty liver disease (NAFLD) in humans. We investigated the association of serum FGF21, FGF19 and liver Klotho coreceptor with non-alcoholic steatohepatitis (NASH) and fibrosis in children with NAFLD. Serum FGF21 and FGF19 were measured in 84 children with biopsy-proven NAFLD and 23 controls (CTRL). The hepatic expression of Klotho coreceptor was measured in 7 CTRL, 9 patients with NASH (NASH+) and 11 patients without NASH (NASH-). FGF21 and FGF19 showed a tendency to decrease from CTRL (median FGF21 = 196 pg/mL; median FGF19 = 201 pg/mL) to NASH- (FGF21 = 89 pg/mL; FGF19 = 81 pg/mL) to NASH+ patients (FGF21 = 54 pg/mL; FGF19 = 41 pg/mL) (p<0.001 for all comparisons) and were inversely associated with the probability of NASH and fibrosis in children with NAFLD. The hepatic expression of Klotho coreceptor was inversely associated with NASH (R2 = 0.87, p<0.0001) and directly associated with serum FGF21 (R2 = 0.57, p<0.0001) and FGF19 (R2 = 0.67, p<0.0001). In conclusion, serum FGF19 and FGF21 and hepatic Klotho expression are inversely associated with hepatic damage in children with NAFLD and these findings may have important implications for understanding the mechanisms of NAFLD progression. © 2013 Alisi et al

Perturbation of specific transcripts in peripheral blood mononuclear cells in breast cancer: a case control pilot study

Introduction: Breast cancer (BC) is the most common type of diagnosed cancer worldwide and the leading cause of cancer death in women and it is the second most frequent cancer-causing mortality for women worldwide. Peripheral blood-based biopsy for BC could be a promising tool for risk prediction and diagnosis. In this study, we aimed to evaluate the gene expression profile of PBMCs in Italian patients with BC. Methods: In this case-control pilot study, we isolated PBMCs from 22 BC patients and 21 healthy controls and evaluated the expression of a panel of 52 target genes related to BC or circadian rhythm by a customized TaqMan Open Array Real-Time PCR panel. Results: Among the differentially expressed genes, 22 remained unchanged. These unchanged genes are mainly involved in cellular processes, including the circadian clock, cellular responses to stress/stimuli, the immune system, signal transduction, and metabolism. We found a total of 30 significantly de-regulated genes. In particular, 8 genes, including PARP6, IGFR1, EZH2, VEGFA, NOTCH1, CD44, BCAR1, and CD24A, resulted significantly down-regulated in patients with BC compared to Controls, while 22 genes were significantly up-regulated in BCs patients compared to Controls. We found several already reported BC-associated genes up-regulated in PBMCs of our BC patients, but FOXO3, ARNTL, and ADAM17 emerged as the most strongly up-regulated. The enrichment pathways analysis highlight that de-regulated genes are mainly involved in the regulation of gene expression and transcription, signal transduction, and immune system response. Discussion: The results of our pilot study demonstrated that the evaluation of PBMC gene signature could be a valuable tool for primary prevention and early diagnosis of BC in several high-risk settings, thus reducing the global mortality associated with this tumour. Take-home message: Non-invasive screening programs, particularly those adopted in workplaces, may have a great impact on early diagnosis and good prognosis for BC. Our study provided proof of concept that the development of a screening test based on PBMC-derived gene expression biomarkers could be a viable route

Blood cell gene expression profiles: A narrative review of biomarkers and effects of low-dose ionizing radiation exposure

Ionizing radiation (IR) is a ubiquitous environmental agent whose effects on organisms are well known. This review provides a summary about definitions and man-made low-dose ionizing radiation (LDIR) sources and dosimeters used in radiation protection. Moreover, the main purpose of this article was to overview the pro-oncogenic effects of LDIR, and to provide experimental evidence that reinforce the use of gene expression data as biomarkers of LDIR effects. Our review showed that basic studies on biological response to LDIR are considered priority. Further, understanding occupational exposure to LDIR may provide valuable information to organize the prevention and prevent from the onset of long-term health effects in radiation workers. Currently, the biodosimetry-based assessment in certain high risk occupational groups may be performed by using peripheral blood cells as samples for testing and validation of biomarkers specificity and sensitivity. Most of the studies on this topic are aimed at establishing new biomarkers and approaches to biological dosimetry, for allowing non-invasive monitoring of long-term health effects of LDIR. Analysis on changes in gene-expression, which is an early specific biological response to LDIR, could provide rapid estimates of individual dose in occupational cohorts, improving the management of periodical medical examination in subjects exposed to LDIR sources

Emodin Prevents Intrahepatic Fat Accumulation, Inflammation and Redox Status Imbalance During Diet-Induced Hepatosteatosis in Rats

High-fat and/or high-carbohydrate diets may predispose to several metabolic disturbances including liver fatty infiltration (hepatosteatosis) or be associated with necro-inflammation and fibrosis (steatohepatitis). Several studies have emphasized the hepatoprotective effect of some natural agents. In this study, we investigated the potential therapeutic effects of the treatment with emodin, an anthraquinone derivative with anti-oxidant and anti-cancer abilities, in rats developing diet-induced hepatosteatosis and steatohepatitis. Sprague-Dawley rats were fed a standard diet (SD) for 15 weeks, or a high-fat/high-fructose diet (HFD/HF). After 5 weeks, emodin was added to the drinking water of some of the SD and HFD/HF rats. The experiment ended after an additional 10 weeks. Emodin-treated HFD/HF rats were protected from hepatosteatosis and metabolic derangements usually observed in HFD/HF animals. Furthermore, emodin exerted anti-inflammatory activity by inhibiting the HFD/HF-induced increase of tumor necrosis factor (TNF)-α. Emodin also affected the hepatocytes glutathione homeostasis and levels of the HFD/HF-induced increase of glutathionylated/phosphorylated phosphatase and tensin homolog (PTEN). In conclusion, we demonstrated that a natural agent such as emodin can prevent hepatosteatosis, preserving liver from pro-inflammatory and pro-oxidant damage caused by HFD/HF diet. These findings are promising, proposing emodin as a possible hindrance to progression of hepatosteatosis into steatohepatitis

Focal Adhesion Kinase: Insight into Molecular Roles and Functions in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related death worldwide. Due to the high incidence of post-operative recurrence after current treatments, the identification of new and more effective drugs is required. In previous years, new targetable genes/pathways involved in HCC pathogenesis have been discovered through the help of high-throughput sequencing technologies. Mutations in TP53 and β-catenin genes are the most frequent aberrations in HCC. However, approaches able to reverse the effect of these mutations might be unpredictable. In fact, if the reactivation of proteins, such as p53 in tumours, holds great promise as anticancer therapy, there are studies arguing that chronic activation of these types of molecules may be deleterious. Thus, recently the efforts on potential targets have focused on actionable mutations, such as those occurring in the gene encoding for focal adhesion kinase (FAK). This tyrosine kinase, localized to cellular focal contacts, is over-expressed in a variety of human tumours, including HCC. Moreover, several lines of evidence demonstrated that FAK depletion or inhibition impair in vitro and in vivo HCC growth and metastasis. Here, we provide an overview of FAK expression and activity in the context of tumour biology, discussing the current evidence of its connection with HCC development and progression