Antagonistic effects of selenium and lipid peroxides on growth control in early hepatocellular carcinoma

Current Trends on the Involvement of Zinc, Copper, and Selenium in the Process of Hepatocarcinogenesis

Numerous nutritional factors increase the risk of hepatocellular carcinoma (HCC) development. The dysregulation of zinc, copper, and selenium homeostasis is associated with the occurrence of HCC. The impairment of the homeostasis of these essential trace elements results in oxidative stress, DNA damage, cell cycle progression, and angiogenesis, finally leading to hepatocarcinogenesis. These essential trace elements can affect the microenvironment in HCC. The carrier proteins for zinc and copper and selenium-containing enzymes play important roles in the prevention or progression of HCC. These trace elements enhance or alleviate the chemosensitivity of anticancer agents in patients with HCC. The zinc, copper, or selenium may affect the homeostasis of other trace elements with each other. Novel types of cell death including ferropotosis and cupropotosis are also associated with hepatocarcinogenesis. Therapeutic strategies for HCC that target these carrier proteins for zinc and copper or selenium-containing enzymes have been developed in in vitro and in vivo studies. The use of zinc-, copper- or selenium-nanoparticles has been considered as novel therapeutic agents for HCC. These results indicate that zinc, copper, and selenium may become promising therapeutic targets in patients with HCC. The clinical application of these agents is an urgent unmet requirement. This review article highlights the correlation between the dysregulation of the homeostasis of these essential trace elements and the development of HCC and summarizes the current trends on the roles of these essential trace elements in the pathogenesis of hepatocarcinogenesis.

Mechanisms and regulations of ferroptosis

Regulation of cell mortality for disease treatment has been the focus of research. Ferroptosis is an iron-dependent regulated cell death whose mechanism has been extensively studied since its discovery. A large number of studies have shown that regulation of ferroptosis brings new strategies for the treatment of various benign and malignant diseases. Iron excess and lipid peroxidation are its primary metabolic features. Therefore, genes involved in iron metabolism and lipid metabolism can regulate iron overload and lipid peroxidation through direct or indirect pathways, thereby regulating ferroptosis. In addition, glutathione (GSH) is the body's primary non-enzymatic antioxidants and plays a pivotal role in the struggle against lipid peroxidation. GSH functions as an auxiliary substance for glutathione peroxidase 4 (GPX4) to convert toxic lipid peroxides to their corresponding alcohols. Here, we reviewed the researches on the mechanism of ferroptosis in recent years, and comprehensively analyzed the mechanism and regulatory process of ferroptosis from iron metabolism and lipid metabolism, and then described in detail the metabolism of GPX4 and the main non-enzymatic antioxidant GSH in vivo.

The Role of Selenium Nanoparticles in the Treatment of Liver Pathologies of Various Natures

The liver is the body's largest gland, and regulates a wide variety of physiological processes. The work of the liver can be disrupted in a variety of pathologies, the number of which is several hundred. It is extremely important to monitor the health of the liver and develop approaches to combat liver diseases. In recent decades, nanomedicine has become increasingly popular in the treatment of various liver pathologies, in which nanosized biomaterials, which are inorganic, polymeric, liposomal, albumin, and other nanoparticles, play an important role. Given the need to develop environmentally safe, inexpensive, simple, and high-performance biomedical agents for theragnostic purposes and showing few side effects, special attention is being paid to nanoparticles based on the important trace element selenium (Se). It is known that the metabolism of the microelement Se occurs in the liver, and its deficiency leads to the development of several serious diseases in this organ. In addition, the liver is the depot for most selenoproteins, which can reduce oxidative stress, inhibit tumor growth, and prevent other liver damage. This review is devoted to the description of the results of recent years, revealing the important role of selenium nanoparticles in the therapy and diagnosis of several liver pathologies, depending on the dose and physicochemical properties. The possibilities of selenium nanoparticles in the treatment of liver diseases, disclosed in the review, will not only reveal the advantages of their hepatoprotective properties but also significantly supplement the data on the role of the trace element selenium in the regulation of these diseases.

GPX4: The hub of lipid oxidation, ferroptosis, disease and treatment

Glutathione peroxidase 4 (GPx4) moonlights as structural protein and antioxidase that powerfully inhibits lipid oxidation. In the past years, it is considered as a key regulator of ferroptosis, which takes role in the lipid and amine acid metabolism and influences the cell aging, oncogenesis, and cell death. More and more evidences show that targeting GPX4-induced ferroptosis is a promising strategy for disease therapy, especially cancer treatment. In view of these, we generalize the function of GPX4 and regulatory mechanism between GPX4 and ferroptosis, discuss its roles in the disease pathology, and focus on the recent advances of disease therapeutic potential.

The effects of selenium supplementation on inflammatory markers in critically ill patients

Abstract

Low serum selenium (Se) levels have been shown in critical illness, which is associated with poor clinical outcomes and a higher mortality rate. Se plays an important role in inflammation and oxidative stress. Since the overproduction of inflammatory cytokines and increased oxidative stress is a major component of critical illnesses, its supplementation has been demonstrated to have promising effects on critically ill patients. This study aims to review the evidence regarding the effects of Se supplementation on inflammatory and oxidative markers in critically ill patients. The literature review highlights alterations of inflammatory markers, including procalcitonin, leukocyte count, albumin, prealbumin, C-reactive protein (CRP), inflammatory cytokines, and cholesterol following Se supplementation in critically ill patients. Besides, the antioxidant properties of Se due to its presence in the structure of several selenoenzymes have been reported.

Article highlights

Low serum Se level have been shown in critical illness, which is associated with poor clinical outcome and higher mortality rate.

Se plays an important role in inflammation and oxidative stress.

Se supplementation can have promising effects by alterations of inflammatory markers and its antioxidant properties for critically ill patients.

Vitamin B6 Metabolic Pathway is Involved in the Pathogenesis of Liver Diseases via Multi-Omics Analysis

Purpose

To clarify the underlying regulatory mechanisms of progression from liver cirrhosis to hepatocellular carcinoma (HCC), we analyzed the microbiomics, metabolomics, and proteomics in plasma and tissues from patients with HCC or decompensated liver cirrhosis (DC).

Patients and Methods

Tissues and plasma from 44 HCC patients and 28 patients with DC were collected for metabolomic analysis. 16S rRNA sequencing was performed in nine HCC tissues (HCCT), four distal noncancerous tissues (HCCN), and 11 DC tissues (DCT). Five HCC tissues had liver cirrhosis (HCCT-LC). Five hepatocellular carcinoma tissues without liver cirrhosis (HCCT-NLC) and five DCT were selected for proteomic sequencing. After combining proteomic and metabolomic analysis, we constructed a mouse model of chronic liver injury using carbon tetrachloride (CCl4) and treated them with vitamin B6 (VB6).

Results

16s rRNA sequence results showed that HCC tissues had higher alpha diversity. The highest LDA scores were detected for Elizabethkingia in HCCT, Subsaxibacter in DCT, and Stenotrophomon in HCCN. Metabolomics results demonstrated some metabolites, including capric acid, L-threonate, choline, alpha-D-Glucose, D-ribose, betaine, 2E-eicosenoic acid, linoleic acid, L-palmitoylcarnitine, taurodeoxycholic acid, L-pyroglutamic acid, androsterone sulfate, and phthalic acid mono-2-ethylhexyl ester (MEHP), had better diagnostic efficacy than AFP (AUC: 0.852; 95% CI: 0.749, 0.954). In a combined analysis of metabolomics and proteomics, we found that HCCT-LC had more obvious disorders of VB6 metabolism and pentose and glucuronate interconversions than DCT, and kynurenine metabolism disorder was more significant in HCCT-LC than in HCCT-NLC. In the CCl4-induced chronic liver injury model, after VB6 supplementation, inflammatory cell infiltration, hepatocyte edema, and degeneration were significantly improved.

Conclusion

We found significant differences in the flora distribution between HCCT and DC; MEHP was a new diagnostic biomarker of HCC, and VB6 ameliorated the inflammatory cell infiltration, hepatocyte edema, and degeneration in chronic liver injury.

A Functional Screening Identifies a New Organic Selenium Compound Targeting Cancer Stem Cells: Role of c-Myc Transcription Activity Inhibition in Liver Cancer

Cancer stem cells (CSCs) are reported to play essential roles in chemoresistance and metastasis. Pathways regulating CSC self-renewal and proliferation, such as Hedgehog, Notch, Wnt/β-catenin, TGF-β, and Myc, may be potential therapeutic targets. Here, a functional screening from the focused library with 365 compounds is performed by a step-by-step strategy. Among these candidate molecules, phenyl-2-pyrimidinyl ketone 4-allyl-3-amino selenourea (CU27) is chosen for further identification because it proves to be the most effective compound over others on CSC inhibition. Through ingenuity pathway analysis, it is shown CU27 may inhibit CSC through a well-known stemness-related transcription factor c-Myc. Gene set enrichment analysis, dual-luciferase reporter assays, expression levels of typical c-Myc targets, molecular docking, surface plasmon resonance, immunoprecipitation, and chromatin immunoprecipitation are conducted. These results together suggest CU27 binds c-Myc bHLH/LZ domains, inhibits c-Myc-Max complex formation, and prevents its occupancy on target gene promoters. In mouse models, CU27 significantly sensitizes sorafenib-resistant tumor to sorafenib, reduces the primary tumor size, and inhibits CSC generation, showing a dramatic anti-metastasis potential. Taken together, CU27 exerts inhibitory effects on CSC and CSC-associated traits in hepatocellular carcinoma (HCC) via c-Myc transcription activity inhibition. CU27 may be a promising therapeutic to treat sorafenib-resistant HCC.

The Molecular Mechanisms of Ferroptosis and Its Role in Blood-Brain Barrier Dysfunction

The blood-brain barrier (BBB) is a selective, semi-permeable layer of endothelial cells that protects the central nervous system from harmful substances circulating in blood. It is one of the important barriers of the nervous system. BBB dysfunction is an early pathophysiological change observed in nervous system diseases. There are few treatments for BBB dysfunction, so this motivates the review. Ferroptosis is a novel cell death mode caused by iron-mediated lipid peroxidation accumulation, which has recently attracted more attention due to its possible role in nervous system disorders. Studies have shown that lipid peroxidation and iron accumulation are related to the barrier dysfunction, especially the expression of tight junction proteins. Therefore, examination of the relationship between ferroptosis and BBB dysfunction may reveal new targets for the treatment of brain diseases.

The Role and Mechanisms of Selenium Supplementation on Fatty Liver-Associated Disorder

Non-alcoholic fatty liver disease (NAFLD) is the most frequent chronic liver disease without effective therapy. Selenium, as an essential trace element for humans, is notable for its antioxidant properties. The previous study shows that selenium levels in NAFLD patients are lower than normal ones. Selenium supplementation can effectively alleviate metabolic disorders by relieving anti-oxidative stress and anti-inflammatory regulation. However, the correlation between selenium and NAFLD has not been fully clarified. Herein, we review the current studies on selenium in regulating the different stages of NAFLD and summarize relevant clinical trials to highlight the potential roles of selenium in NAFLD treatment.

CRISPR screens uncover protective effect of PSTK as a regulator of chemotherapy-induced ferroptosis in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is among the most common forms of cancer and is associated with poor patient outcomes. The emergence of therapeutic resistance has hampered the efficacy of targeted treatments employed to treat HCC patients to date. In this study, we conducted a series of CRISPR/Cas9 screens to identify genes associated with synthetic lethality capable of improving HCC patient clinical responses.

METHODS

CRISPR-based loss-of-function genetic screens were used to target 18,053 protein-coding genes in HCC cells to identify chemotherapy-related synthetic lethal genes in these cells. Synergistic effects were analyzed through in vitro and in vivo analyses, while related mechanisms were explored through RNA-seq and metabolomics analyses. Potential inhibitors of identified genetic targets were selected through high-throughput virtual screening.

RESULTS

The inhibition of phosphoseryl-tRNA kinase (PSTK) was found to increase HCC cell sensitivity to chemotherapeutic treatment. PSTK was associated with the suppression of chemotherapy-induced ferroptosis in HCC cells, and the depletion of PSTK resulted in the inactivation of glutathione peroxidative 4 (GPX4) and the disruption of glutathione (GSH) metabolism owing to the inhibition of selenocysteine and cysteine synthesis, thus enhancing the induction of ferroptosis upon targeted chemotherapeutic treatment. Punicalin, an agent used to treat hepatitis B virus (HBV), was identified as a possible PSTK inhibitor that exhibited synergistic efficacy when applied together with Sorafenib to treat HCC in vitro and in vivo.

CONCLUSIONS

These results highlight a key role for PSTK as a mediator of resistance to targeted therapeutic treatment in HCC cells that functions by suppressing ferroptotic induction. PSTK inhibitors may thus represent ideal candidates for overcoming drug resistance in HCC.

Molecular alterations that precede the establishment of the hallmarks of cancer: An approach on the prevention of hepatocarcinogenesis

Chronic liver injury promotes the molecular alterations that precede the establishment of cancer. Usually, several decades of chronic insults are needed to develop the most common primary liver tumor known as hepatocellular carcinoma. As other cancer types, liver cancer cells are governed by a common set of rules collectively called the hallmarks of cancer. Although those rules have provided a conceptual framework for understanding the complex pathophysiology of established tumors, therapeutic options are still ineffective in advanced stages. Thus, the molecular alterations that precede the establishment of cancer remain an attractive target for therapeutic interventions. Here, we first summarize the chemopreventive interventions targeting the early liver carcinogenesis stages. After an integrative analysis on the plethora of molecular alterations regulated by anticancer agents, we then underline and discuss that two critical processes namely oxidative stress and genetic alterations, play the role of 'dirty work laborer' in the initial cell damage and drive the transformation of preneoplastic into neoplastic cells, respectively; besides, the activation of cellular senescence works as a key mechanism in attempting to prevent the onset and establishment of liver cancer. Whereas the detrimental effects of the binomial made up of oxidative stress and genetic alterations are either eliminated or reduced, senescence activation is promoted by anticancer agents. We argue that collectively, oxidative stress, genetic alterations, and senescence are key events that influence the fate of initiated cells and the establishment of the hallmarks of cancer.

Increased serum selenium levels are associated with reduced risk of advanced liver fibrosis and all-cause mortality in NAFLD patients: National Health and Nutrition Examination Survey (NHANES) III

INTRODUCTION AND OBJECTIVES

Selenium supplementation has been shown to have therapeutic value in chronic liver disease. We aimed to investigate the association between serum selenium, severity of liver fibrosis, and mortality in patients with Nonalcoholic Fatty Liver Disease (NAFLD).

PATIENTS OR MATERIAL AND METHODS

A total of 33,944 patients were identified from the Third National Health and Nutrition Examination Survey. NAFLD was diagnosed by hepatic ultrasound after the exclusion of other forms of liver diseases. The severity of liver fibrosis was determined by NAFLD Fibrosis Score >0.676. Multivariate logistic regression analysis was used to investigate the relationship between serum selenium level and liver fibrosis. Association between serum selenium and all-cause mortality in NAFLD patients was also evaluated.

RESULTS

Multivariate logistic regression analysis demonstrated odds ratio of advanced liver fibrosis (NFS > 0.676) was significantly reduced with increasing serum selenium levels; OR 0.55, [95% CI 0.32-0.94] in the highest selenium quartile. On stratification analysis, the following populations had a significantly reduced risk of advanced liver fibrosis: non-Hispanic white = OR 0.41 [0.24,0.68]; female = OR 0.32 [0.15-0.66] and age >47 = OR 0.47 [0.28-0.79]. The relationship was significant regardless of BMI as noted by BMI ≤ 30 Kg/m2= OR 0.42 [0.19-0.91] and BMI > 30 Kg/m2=OR 0.52 [0.28-0.97]. Hazard ratio for all-cause mortality was HR 0.72 [0.56-0.95].

CONCLUSIONS

The risk of advanced liver fibrosis is inversely associated with serum selenium levels, particularly in older patients, Caucasians, and females. All-cause mortality decreased with increased selenium levels. Selenium may play a role in the prevention of liver fibrosis in NAFLD.

Molecular Targets of Ferroptosis in Hepatocellular Carcinoma

Ferroptosis is a special form of regulatory cell death caused by the accumulation of intracellular iron and lipid peroxidation. Here, we summarize the research progress on ferroptosis in hepatocellular carcinoma (HCC), trace the development of the concept of ferroptosis and its key regulatory factors, and discuss the application value of ferroptosis in the treatment of HCC from different perspectives. We believe that exploring the relationship between ferroptosis and HCC and clarifying the metabolism and expression of ferroptosis-specific genes and molecules will accelerate the development of novel ferroptosis-related molecules as HCC markers and therapeutic targets. We hope to provide a theoretical basis for better diagnosis and treatment to effectively improve the prognosis of patients with HCC.

Micronutrient Food Supplements in Patients with Gastro-Intestinal and Hepatic Cancers

Colorectal carcinogenesis is the second most common cause of mortality across all types of malignancies, followed by hepatic and stomach cancers. Chemotherapy and radiotherapy are key approaches to treating cancer patients, but these carry major concerns, such as a high risk of side effects, poor accessibility, and the non-selective nature of chemotherapeutics. A number of natural products have been identified as countering various forms of cancer with fewer side effects. The potential impact of vitamins and minerals on long-term health, cognition, healthy development, bone formation, and aging has been supported by experimental and epidemiological studies. Successful treatment may thus be highly influenced by the nutritional status of patients. An insufficient diet could lead to detrimental effects on immune status and tolerance to treatment, affecting the ability of chemotherapy to destroy cancerous cells. In recent decades, most cancer patients have been taking vitamins and minerals to improve standard therapy and/or to decrease the undesirable side effects of the treatment together with the underlying disease. On the other hand, taking dietary supplements during cancer therapy may affect the effectiveness of chemotherapy. Thus, micronutrients in complementary oncology must be selected appropriately and should be taken at the right time. Here, the potential impact of micronutrients on gastro-intestinal and hepatic cancers is explored and their molecular targets are laid down.

Synthesis and biological evaluation of selenogefitinib for reducing bleomycin-induced pulmonary fibrosis

Selenium has demonstrated effectiveness in the reduction of oxidative stress and inflammation in vitro and in vivo, both of which are key indicators of the pathogenesis of pulmonary fibrosis. Gefitinib, an FDA-approved EGFR inhibitor, effectively reverses the deterioration of bleomycin-induced pulmonary fibrosis. Based on this, we proposed introducing a selenium atom into the structure of gefitinib, resulting in the generation of selenogefitinib. Compared to gefitinib, selenogefitinib was significantly less hepatotoxic and cytotoxic in cells. The results of the H&E staining of lung tissue validated that Selenogefitinib effectively protected the structure of the alveolar tissue and mitigated the infiltration of inflammatory cells in bleomycin-induced pulmonary fibrosis models. The reduction in the deposition of collagen fibers in lung tissue determined by Masson staining and hydroxyproline (HYP) content also corroborated the efficacy of selenogefitinib in the treatment of pulmonary fibrosis. Furthermore, Selenogefitinib decreased the levels of pro-inflammatory markers IL-4, IL-6, and TNF-α more significantly than gefitinib, which indicated that it exhibited a higher anti-inflammatory activity. In addition, the presence of selenium manifested a greater reduction in oxidative stress based on the decrease in the levels of MDA in mice blood. These results suggested that Selenogefitinib may be a potential candidate for the treatment of IPF.

Upregulation of Nogo-B by hypoxia inducible factor-1 and activator protein-1 in hepatocellular carcinoma

Nogo-B is an important regulator of tumor angiogenesis. Expression of Nogo-B is remarkably upregulated in multiple tumor types, especially hepatocellular carcinoma (HCC). Here, we show the transcriptional regulation mechanisms of Nogo-B in liver cancer. In response to hypoxia, expression of Nogo-B significantly increased in HCC tissues and cells. The distal hypoxia-responsive element in the promoter was essential for transcriptional activation of Nogo-B under hypoxic conditions, which is the specific site for hypoxia inducible factor-1α (HIF-1α) binding. In addition, Nogo-B expression was associated with c-Fos expression in HCC tissues. Nogo-B expression was induced by c-Fos, yet inhibited by a dominant negative mutant A-Fos. Deletion and mutation analysis of the predicted activator protein-1 binding sites revealed that functional element mediated the induction of Nogo-B promoter activity, which was confirmed by ChIP. These results indicate that HIF-1α and c-Fos induce the expression of Nogo-B depending on tumor microenvironments, such as hypoxia and low levels of nutrients, and play a role in upregulation of Nogo-B in tumor angiogenesis.

Plasma lipids, tumor parameters and survival in HCC patients with HBV and HCV

INTRODUCTION AND AIMS

Hepatocellular carcinoma (HCC) is a consequence of chronic liver disease, particularly from hepatitis B or C and increasingly from obesity and metabolic syndrome. Since lipids are an important component of cell membranes and are involved in cell signaling and tumor cell growth, we wished to evaluate the relationship between HCC patient plasma lipids and maximum tumor diameter and other indices of HCC human biology.

METHODS

We examined prospectively-collected data from a multi-institutional collaborative Turkish HCC working group, from predominantly HBV-based patients, for plasma lipid profiles, consisting of triglycerides, total cholesterol, LDL-cholesterol (LDL) and HDL-cholesterol (HDL) and compared these with the associated patient maximum tumor diameter (MTD), portal vein thrombosis, alpha-fetoprotein (AFP) and also with patient survival.

RESULTS

We found that both low HDL (p=0.0002) and high LDL (p=0.003) levels were significantly associated with increased MTD, as well as in a final multiple linear regression model on MTD. The combination of low HDL combined with high HDL levels were significant in a regression model on MTD, PVT and an HCC Aggressiveness Index (Odds Ratio 12.91 compared to an Odds Ratio of 1 for the reference). Furthermore, in a Cox regression model on death, the HDL plus LDL combination had a significantly higher Hazard Ratio than the reference category.

CONCLUSIONS

Low plasma HDL, high plasma LDL and especially the combination, were significantly related to more aggressive HCC phenotype and the combination was significantly related to a higher Hazard Ratio for death.

A novel therapeutic strategy for hepatocellular carcinoma: Immunomodulatory mechanisms of selenium and/or selenoproteins on a shift towards anti-cancer

Selenium (Se) is an essential trace chemical element that is widely distributed worldwide. Se exerts its immunomodulatory and nutritional activities in the human body in the form of selenoproteins. Se has increasingly appeared as a potential trace element associated with many human diseases, including hepatocellular carcinoma (HCC). Recently, increasing evidence has suggested that Se and selenoproteins exert their immunomodulatory effects on HCC by regulating the molecules of oxidative stress, inflammation, immune response, cell proliferation and growth, angiogenesis, signaling pathways, apoptosis, and other processes in vitro cell studies and in vivo animal studies. Se concentrations are generally low in tissues of patients with HCC, such as blood, serum, scalp hair, and toenail. However, Se concentrations were higher in HCC patient tissues after Se supplementation than before supplementation. This review summarizes the significant relationship between Se and HCC, and details the role of Se as a novel immunomodulatory or immunotherapeutic approach against HCC.

Trace Elements Status and Metallothioneins DNA Methylation Influence Human Hepatocellular Carcinoma Survival Rate

Background

Mechanisms underlying hepatocellular carcinoma (HCC) development are largely unknown. The role of trace elements and proteins regulating metal ions homeostasis, i.e. metallothioneins (MTs), recently gained an increased interest. Object of the study was to investigate the role of promoter DNA methylation in MTs transcriptional regulation and the possible prognostic significance of serum trace elements in HCC.

Methods

Forty-nine HCC patients were enrolled and clinically characterized. Cu, Se, and Zn contents were measured by Inductively Coupled Plasma Mass Spectrometry in the serum and, for a subset of 27 patients, in HCC and homologous non-neoplastic liver (N) tissues. MT1G and MT1H gene expression in hepatic tissues was assessed by Real-Time RT-PCR and the specific promoter DNA methylation by Bisulfite-Amplicon Sequencing.

Results

Patients with Cu serum concentration above the 80^th percentile had a significantly decreased survival rate (P < 0.001) with a marked increased hazard ratio for mortality (HR 6.88 with 95% CI 2.60-18.23, P < 0.001). Se and Zn levels were significantly lower in HCC as compared to N tissues (P < 0.0001). MT1G and MT1H gene expression was significantly down-regulated in HCC as compared to N tissues (P < 0.05). MTs promoter was hypermethylated in 9 out of the 19 HCC tissues showing MTs down-regulation and methylation levels of three specific CpGs paralleled to an increased mortality rate among the 23 patients analyzed (P = 0.015).

Conclusions

MT1G and MT1H act as potential tumor suppressor genes regulated through promoter DNA methylation and, together with serum Cu concentrations, be related to survival rate in HCC.

Selenoprotein P inhibits cell proliferation and ROX production in HCC cells

Selenoprotein P (SEPP1) is a kind of secretory glycoproteins with an antioxidant effect during the development of some diseases. In this study, we attempted to observe the expression of SEPP1 in livers from the patients with hepatocellular carcinoma (HCC) and explore its effect on HCC cells. All the tissues from patients with HCC were obtained from Affiliated Hospital of Nantong University. Western blot and immunohistochemical results showed that SEPP1 was reduced in HCC liver tissues. Its expression was negatively correlated with Ki67 expression in tissues. The expression of SEPP1 in normal liver cell line was significantly higher than those in the liver cancer cell lines. Serum starvation and release experiment demonstrated that SEPP1 expression was reduced and PCNA expression was increased, when the serum was re-added into cell culture system and the cells were on a proliferation state. After SEPP1 over-expression plasmid was transfected into HepG2 cells, cell proliferation of HepG2 cells and PCNA expression level were all inhibited by SEPP1. Results obtained via 8-isoprostane ELISA further indicated that inhibited ROS level was found in HepG2 cells transfected with SEPP1 over-expression plasmid. In addition, RT-qPCR results demonstrated that GPX1 expression levels increased in HepG2 cells transfected with SEPP1 over-expression plasmid. In conclusion, SEPP1 may inhibit the proliferation of HCC cells, accompanied by the reduction of ROS production and the increasing of GPX1 expression.

Hepatic copper and other trace mineral concentrations in dogs with hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) is the most common primary liver tumor in dogs. Abnormalities in hepatic copper, iron, zinc, and selenium concentrations increase risk for HCC development in other species, but trace mineral concentrations have not been evaluated in dogs with HCC.

Objectives

To investigate hepatic trace mineral concentrations in dogs with HCC.

Animals

Archived liver specimens from 85 dogs with HCC and 85 control dogs.

Methods

Retrospective case‐control study. A histopathology database was searched to identify dogs with HCC (test population) and an age‐matched control population. Demographic information was retrieved, and H&E and rhodanine stained slides were reviewed for all cases. Copper, iron, zinc, and selenium concentrations were determined in noncancerous liver tissues (test and control population) and in HCC tissues (test population) using inductively coupled plasma mass spectrometry.

Results

Hepatic copper concentrations (non‐neoplastic hepatic tissue) were greater in test population dogs (median, IQR; 294.9 μg/g, 233.5‐475.9 μg/g) than in control dogs (202.8 μg/g, 135.0‐295.3 μg/g; P < .001). Hepatic zinc concentrations in test (132.1 μg/g,108.6‐163.2 μg/g) and control dogs (151.5 μg/g, 117.1‐184.5 μg/g) also were different (P = .03). Within test population dogs, all trace mineral concentrations were decreased in the HCC tissue as compared to the non‐neoplastic hepatic tissue (all P < .001).

Conclusions and Clinical Importance

Hepatic copper accumulation and other abnormalities in hepatic trace mineral concentrations could be involved in the pathogenesis of HCC in some dogs.

Association between Serum Selenium Level and the Presence of Diabetes Mellitus: A Meta-Analysis of Observational Studies

BACKGROUND

Epidemiological studies have suggested an association between selenium (Se) and diabetes mellitus (DM). However, different studies have reported conflicting results. Therefore, we performed a comprehensive meta-analysis to clarify the impact of Se on DM.

METHODS

We searched the PubMed database for studies on the association between Se and DM from inception to June 2018.

RESULTS

Twenty articles evaluating 47,930 participants were included in the analysis. The meta-analysis found that high levels of Se were significantly associated with the presence of DM (pooled odds ratios [ORs], 1.88; 95% confidence interval [CI], 1.44 to 2.45). However, significant heterogeneity was found (I²=82%). Subgroup analyses were performed based on the Se measurement methods used in each study. A significant association was found between high Se levels and the presence of DM in the studies that used blood (OR, 2.17; 95% CI, 1.60 to 2.93; I²=77%), diet (OR, 1.61; 95% CI, 1.10 to 2.36; I²=0%), and urine (OR, 1.49; 95% CI, 1.02 to 2.17; I²=0%) as samples to estimate Se levels, but not in studies on nails (OR, 1.24; 95% CI, 0.52 to 2.98; I²=91%). Because of significant heterogeneity in the studies with blood, we conducted a sensitivity analysis and tested the publication bias. The results were consistent after adjustment based on the sensitivity analysis as well as the trim and fill analysis for publication bias.

CONCLUSION

This meta-analysis demonstrates that high levels of Se are associated with the presence of DM. Further prospective and randomized controlled trials are warranted to elucidate the link better.

Hepatic accumulation of S-adenosylmethionine in hamsters with non-alcoholic fatty liver disease associated with metabolic syndrome under selenium and vitamin E deficiency

Progression of non-alcoholic fatty liver disease (NAFLD) in the context of metabolic syndrome (MetS) is only partially explored due to the lack of preclinical models. In order to study the alterations in hepatic metabolism that accompany this condition, we developed a model of MetS accompanied by the onset of steatohepatitis (NASH) by challenging golden hamsters with a high-fat diet low in vitamin E and selenium (HFD), since combined deficiency results in hepatic necroinflammation in rodents. Metabolomics and transcriptomics integrated analyses of livers revealed an unexpected accumulation of hepatic S-Adenosylmethionine (SAM) when compared with healthy livers likely due to diminished methylation reactions and repression of GNMT. SAM plays a key role in the maintenance of cellular homeostasis and cell cycle control. In agreement, analysis of over-represented transcription factors revealed a central role of c-myc and c-Jun pathways accompanied by negative correlations between SAM concentration, MYC expression and AMPK phosphorylation. These findings point to a drift of cell cycle control toward senescence in livers of HFD animals, which could explain the onset of NASH in this model. In contrast, hamsters with NAFLD induced by a conventional high-fat diet did not show SAM accumulation, suggesting a key role of selenium and vitamin E in SAM homeostasis. In conclusion, our results suggest that progression of NAFLD in the context of MetS can take place even in a situation of hepatic SAM excess and that selenium and vitamin E status might be considered in current therapies against NASH based on SAM supplementation.

Selenium, Selenoproteins, and Immunity

Selenium is an essential micronutrient that plays a crucial role in development and a wide variety of physiological processes including effect immune responses. The immune system relies on adequate dietary selenium intake and this nutrient exerts its biological effects mostly through its incorporation into selenoproteins. The selenoproteome contains 25 members in humans that exhibit a wide variety of functions. The development of high-throughput omic approaches and novel bioinformatics tools has led to new insights regarding the effects of selenium and selenoproteins in human immuno-biology. Equally important are the innovative experimental systems that have emerged to interrogate molecular mechanisms underlying those effects. This review presents a summary of the current understanding of the role of selenium and selenoproteins in regulating immune cell functions and how dysregulation of these processes may lead to inflammation or immune-related diseases.

Plasma cholesterol and lipoprotein levels in relation to tumor aggressiveness and survival in HCC patients

BACKGROUND AND AIMS:

Hepatocellular carcinoma is associated with several chronic liver diseases, especially chronic hepatitis B virus, hepatitis C virus, and alcoholism. It is increasingly appreciated that obesity/metabolic syndrome is also associated with chronic liver disease and subsequent hepatocellular carcinoma.

METHODS:

We retrospectively investigated the serum lipid profiles in a large hepatocellular carcinoma cohort, associated predominantly with the hepatitis B virus, hepatitis C virus, alcohol or nonalcoholic steatohepatitis. The cohort was examined both as a whole, as well as stratified by etiology.

RESULTS:

We found significant associations between parameters of hepatocellular carcinoma biology such as maximum tumor diameter, portal vein thrombosis, tumor multifocality or alpha-fetoprotein levels and individual lipid components, including total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides and body mass index. In a final multiple linear regression model considering all lipid variables together, only high-density lipoprotein cholesterol was significantly associated with the tumor Tumor Aggressiveness Index. High-density lipoprotein cholesterol was found to have a statistically higher hazard ratio for death than low high-density lipoprotein cholesterol levels (Cox). On examination by etiological group, alpha-fetoprotein levels were significantly higher in patients with hepatitis C virus compared to those with alcohol or nonalcoholic steatohepatitis, but maximum tumor diameter, tumor multifocality and portal vein thrombosis were similar across etiological groups. Nonalcoholic steatohepatitis patients had significantly less cirrhosis than other groups and hepatitis B virus patients had significantly higher cholesterol and low-density lipoprotein cholesterol levels than hepatitis C virus patients.

CONCLUSIONS:

This is the first report, to our knowledge, of a relationship between serum lipid parameters and indices of hepatocellular carcinoma growth, invasion and aggressiveness, as well as with survival.

The Effects of Selenium Supplementation on Gene Expression Related to Insulin and Lipid in Infertile Polycystic Ovary Syndrome Women Candidate for In Vitro Fertilization: a Randomized, Double-Blind, Placebo-Controlled Trial

This study was conducted to evaluate the effects of selenium supplementation on gene expression related to insulin and lipid in infertile women with polycystic ovary syndrome (PCOS) candidate for in vitro fertilization (IVF). This randomized double-blind, placebo-controlled trial was conducted among 40 infertile women with PCOS candidate for IVF. Subjects were randomly allocated into two groups to intake either 200-μg selenium (n = 20) or placebo (n = 20) per day for 8 weeks. Gene expression levels related to insulin and lipid were quantified in lymphocytes of women with PCOS candidate for IVF with RT-PCR method. Results of RT-PCR demonstrated that after the 8-week intervention, compared with the placebo, selenium supplementation upregulated gene expression of peroxisome proliferator-activated receptor gamma (PPAR-γ) (1.06 ± 0.15-fold increase vs. 0.94 ± 0.18-fold reduction, P = 0.02) and glucose transporter 1 (GLUT-1) (1.07 ± 0.20-fold increase vs. 0.87 ± 0.18-fold reduction, P = 0.003) in lymphocytes of women with PCOS candidate for IVF. In addition, compared with the placebo, selenium supplementation downregulated gene expression of low-density lipoprotein receptor (LDLR) (0.88 ± 0.17-fold reduction vs. 1.05 ± 0.22-fold increase, P = 0.01) in lymphocytes of women with PCOS candidate for IVF. We did not observe any significant effect of selenium supplementation on gene expression levels of lipoprotein(a) [LP(a)] in lymphocytes of women with PCOS candidate for IVF. Overall, selenium supplementation for 8 weeks in lymphocytes of women with infertile PCOS candidate for IVF significantly increased gene expression levels of PPAR-γ and GLUT-1 and significantly decreased gene expression levels of LDLR, but did not affect LP(a).

CLINICAL TRIAL REGISTRATION NUMBER

http://www.irct.ir : IRCT201704245623N113.

Oxidative stress is bane in chronic liver diseases: Clinical and experimental perspective

Oxidative stress plays an important role in the pathogenesis of various chronic liver diseases (CLD) and increasing evidence have confirmed the contributory role of oxidative stress in the pathogenesis of drugs and chemical-induced CLD. Chronic liver injury is manifested as necrosis, cholestasis, fibrosis, and cirrhosis. Chronic administration of anti-tubercular, anti-retroviral, immunosuppressive drugs is reported to induce free radical generation during their biotransformation in the liver. Further, these reactive intermediates are said to induce profibrogenic cytokines, several inflammatory markers, collagen synthesis during the progression of hepatic fibrosis. Oxidative stress and free radicals are reported to induce activation and proliferation of hepatic stellate cells in the injured liver leading to the progression of CLD. Hence, to counteract or to scavenge these reactive intermediates, several plant-derived antioxidant principles have been effectively employed against oxidative stress and came out with promising results in human and experimental models of CLD. This review summarizes the relationships between oxidative stress and different liver pathogenesis induced by drugs and xenobiotics, focusing upon different chronic liver injury induced by alcohol, antitubercular drugs and hyperactivity of antiretroviral drugs in HIV patients, viral hepatitis infection induced oxidative stress.

Model Prediction and Validation of an Order Mechanism Controlling the Spatiotemporal Phenotype of Early Hepatocellular Carcinoma

Recently, hepatocyte-sinusoid alignment (HSA) has been identified as a mechanism that supports the coordination of hepatocytes during liver regeneration to reestablish a functional micro-architecture (Hoehme et al. in Proc Natl Acad Sci 107(23):10371-10376, 2010). HSA means that hepatocytes preferentially align along the closest micro-vessels. Here, we studied whether this mechanism is still active in early hepatocellular tumors. The same agent-based spatiotemporal model that previously correctly predicted HSA in liver regeneration was further developed to simulate scenarios in early tumor development, when individual initiated hepatocytes gain increased proliferation capacity. The model simulations were performed under conditions of realistic liver micro-architectures obtained from 3D reconstructions of confocal laser scanning micrographs. Interestingly, the established model predicted that initiated hepatocytes at first arrange in elongated patterns. Only when the tumor progresses to cell numbers of approximately 4000, does it adopt spherical structures. This prediction may have relevant consequences, since elongated tumors may reach critical structures faster, such as larger vessels, compared to a spherical tumor of similar cell number. Interestingly, this model prediction was confirmed by analysis of the spatial organization of initiated hepatocytes in a rat liver tumor initiation study using single doses of 250 mg/kg of the genotoxic carcinogen N-nitrosomorpholine (NNM). Indeed, small clusters of GST-P positive cells induced by NNM were elongated, almost columnar, while larger GDT-P positive foci of approximately the size of liver lobuli adopted spherical shapes. From simulations testing numerous possible mechanisms, only HSA could explain the experimentally observed initial deviation from spherical shape. The present study demonstrates that the architecture of small cell clusters of hepatocytes early after initiation is still controlled by physiological mechanisms. However, this coordinating influence is lost when the tumor grows to approximately 4000 cells, leading to further growth in spherical shape. Our findings stress the potential importance of organ micro-architecture in understanding tumor phenotypes.

Meta-analysis of the correlation between selenium and incidence of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common cancer type. There is a correlation between selenium (Se) deficiency and the incidence of HCC. To clarify the effects of Se level on the risk of HCC patients, a meta-analysis was performed. A total of 9 articles published between 1994 and 2016 worldwide were selected through searching PubMed, EMBASE, web of science, Cochrane Library, Springer Link, Chinese National Knowledge Infrastructure (CNKI), and Chinese Biology Medicine (CBM), and the information were analyzed using a meta-analysis method. Heterogeneity was assessed by using the I² index. Publication bias was evaluated by Begg's Test analysis. Pooled analysis indicated that patients with HCC had lower Se levels than the healthy controls [standardized mean difference (SMD)= −1.08, 95% confidence intercal (CI) = (−0.136, −0.08), P < 0.001]. Further subgroup analysis showed this effect to be independent of the study design, race or sample collection. In conclusion, this meta-analysis suggested an inverse correlation between Se level and the risk of HCC in humans patients.

Impact of glutathione peroxidase 4 on cell proliferation, angiogenesis and cytokine production in hepatocellular carcinoma

Insufficient supplementation with the micronutrient selenium and persistent hepatic inflammation predispose to hepatocellular carcinoma (HCC). Inflammation-associated reactive oxygen species attack membrane lipids and form lipid hydroperoxides able to propagate oxidative hepatic damage. Selenium-containing enzyme glutathione peroxidase 4 (GPx4) antagonizes this damage by reducing lipid hydroperoxides to respective hydroxides. However, the role of GPx4 in HCC remains elusive. We generated two human HCC cell lines with stable overexpression of GPx4, performed xenotransplantation into NOD.Cg-Prkdc^scidIl2rg^tm1Wjl/SzJ (NSG) host mice and characterized the tumors formed. The experimental data were verified using gene expression data from two independent HCC patient cohorts. GPx4 overexpression protected from oxidative stress and reduced intracellular free radical level. GPx4-overexpressing cells displayed impaired tumor growth, reduced proliferation, altered angiogenesis and decreased expression of clinically relevant cytokine interleukin-8 and C-reactive protein. Moreover, GPx4 overexpression impaired migration of endothelial cells in vitro, and enhanced expression of thrombospondin 1, an endogenous inhibitor of angiogenesis. In patients, GPx4 expression in tumors positively correlated with survival and was linked to pathways which regulate cell proliferation, motility, tissue remodelling, immune response and M1 macrophage polarization. The patient data largely confirmed experimental findings especially in a subclass of poor prognosis tumors with high proliferation. GPx4 suppresses formation and progression of HCC by inhibition of angiogenesis and tumor cell proliferation as well as by immune-mediated mechanisms. Modification of GPx4 expression may represent a novel tool for HCC prevention or treatment.

Oxidative stress mediates an increased formation of vascular endothelial growth factor in human hepatocarcinoma cells exposed to erlotinib

The tyrosine kinase inhibitor erlotinib targets the receptor of epidermal growth factor (EGFR) involved in development of hepatocellular carcinoma (HCC).

Although inefficient in established HCC, erlotinib has been recently proposed for HCC chemoprevention. Since Cyp3A4 and Cyp1A2 enzymes metabolize erlotinib in the liver, the insights into the mechanisms of erlotinib effects on liver cells with maintained drug metabolizing activity are needed.

We applied erlotinib to both commercially available (SNU398, Huh7) and established in Austria HCC cell lines (HCC-1.2, HCC-3). Cyp3A4 and Cyp1A2, microarray gene expression, cell viability, LDH release, DHFC fluorescence were assessed. VEGF expression was analysed by real-time RT-PCR and ELISA.

Higher cumulative expression of erlotinib metabolizing enzymes was observed in HCC-1.2 and HCC-3 cells. Gene expression microarray analysis showed upregulation of VEGF signalling by erlotinib. VEGF was increased up to 134 ± 14% (n = 5, p = 0.002) in HCC-1.2, HCC-3 and Huh7 cells. Interventions by Cyp1A2 and Mek2siRNA, MEK inhibitor UO126, diphenylene iodonium, as well as a combination of N-acetylcysteine with selenium all inhibited VEGF upregulation caused by erlotinib.

Thus, erlotinib increases VEGF production by mechanisms involving Cyp1A2, oxidative stress and MEK1/2. VEGF may favour angiogenesis and growth of early HCC tumours limiting the therapeutic and chemopreventive effects of erlotinib.

Prediagnostic selenium status and hepatobiliary cancer risk in the European Prospective Investigation into Cancer and Nutrition cohort

BACKGROUND

Selenium status is suboptimal in many Europeans and may be a risk factor for the development of various cancers, including those of the liver and biliary tract.

OBJECTIVE

We wished to examine whether selenium status in advance of cancer onset is associated with hepatobiliary cancers in the EPIC (European Prospective Investigation into Cancer and Nutrition) study.

DESIGN

We assessed prediagnostic selenium status by measuring serum concentrations of selenium and selenoprotein P (SePP; the major circulating selenium transfer protein) and examined the association with hepatocellular carcinoma (HCC; n = 121), gallbladder and biliary tract cancers (GBTCs; n = 100), and intrahepatic bile duct cancer (IHBC; n = 40) risk in a nested case-control design within the EPIC study. Selenium was measured by total reflection X-ray fluorescence, and SePP was determined by a colorimetric sandwich ELISA. Multivariable ORs and 95% CIs were calculated by using conditional logistic regression.

RESULTS

HCC and GBTC cases, but not IHBC cases, showed significantly lower circulating selenium and SePP concentrations than their matched controls. Higher circulating selenium was associated with a significantly lower HCC risk (OR per 20-μg/L increase: 0.41; 95% CI: 0.23, 0.72) but not with the risk of GBTC or IHBC. Similarly, higher SePP concentrations were associated with lowered HCC risk only in both the categorical and continuous analyses (HCC: P-trend ≤ 0.0001; OR per 1.5-mg/L increase: 0.37; 95% CI: 0.21, 0.63).

CONCLUSION

These findings from a large prospective cohort provide evidence that suboptimal selenium status in Europeans may be associated with an appreciably increased risk of HCC development.

Selenium Supplementation Affects Insulin Resistance and Serum hs-CRP in Patients with Type 2 Diabetes and Coronary Heart Disease

To our knowledge, this study is the first indicating the effects of selenium supplementation on metabolic status of patients with type 2 diabetes mellitus (T2DM) and coronary heart disease (CHD). This study was conducted to evaluate the effects of selenium supplementation on metabolic profiles, biomarkers of inflammation, and oxidative stress of patients with T2DM and CHD. This randomized, double-blind, placebo-controlled trial was performed among 60 patients with T2DM and CHD aged 40-85 years. Participants were randomly divided into 2 groups. Group A received 200 μg selenium supplements (n=30) and group B received placebo per day (n=30) for 8 weeks. Fasting blood samples were taken at the beginning of the study and after 8-week intervention to quantify metabolic profiles. After 8 weeks, compared with the placebo, selenium supplementation resulted in a significant decrease in serum insulin levels (- 2.2±4.6 vs. + 3.6±8.4 μIU/ml, p=0.001), homeostasis model of assessment-insulin resistance (HOMA-IR) (- 0.7±1.3 vs. + 0.9±2.4, p=0.004), homeostatic model assessment-beta cell function (HOMA-B) (- 7.5±17.2 vs. + 15.1±34.5, p=0.002) and a significant increase in quantitative insulin sensitivity check index (QUICKI) (+0.01±0.03 vs. - 0.01±0.03, p=0.02). In addition, patients who received selenium supplements had a significant reduction in serum high-sensitivity C-reactive protein (hs-CRP) (- 1 372.3±2 318.8 vs. - 99.8±1 453.6 ng/ml, p=0.01) and a significant rise in plasma total antioxidant capacity (TAC) concentrations (+ 301.3±400.6 vs. - 127.2±428.0 mmol/l, p<0.001) compared with the placebo. A 200 μg/day selenium supplementation among patients with T2DM and CHD resulted in a significant decrease in insulin, HOMA-IR, HOMA-B, serum hs-CRP, and a significant increase in QUICKI score and TAC concentrations.

Selenium Supplementation and the Effects on Reproductive Outcomes, Biomarkers of Inflammation, and Oxidative Stress in Women with Polycystic Ovary Syndrome

Selenium supplementation could be effective on reproductive outcomes, biomarkers of inflammation, and oxidative stress among women with polycystic ovary syndrome (PCOS). The aim of the study was to determine the effects of selenium supplementation on reproductive outcomes, biomarkers of inflammation, and oxidative stress in PCOS patients. The present randomized double-blind, placebo-controlled trial was conducted on 64 women aged 18-40 years old with PCOS at the clinic affiliated to Ardabil University of Medical Sciences, Ardabil, Iran. The participants were randomly assigned to 2 groups receiving either 200 μg selenium daily (n=32) or placebo (n=32) for 8 weeks. Hormonal profiles, biomarkers of inflammation, and oxidative stress were measured and compared both before and after the treatment. After 8 weeks of intervention, pregnancy rate in the selenium group was higher than in the placebo group: 18.8 (6/32) vs. 3.1% (1/32), p=0.04. In addition, alopecia (40.6 vs. 9.4%, p=0.004) and acne (46.9 vs. 12.5 %, p=0.003) decreased following the consumption of selenium supplements compared with placebo. Additionally, patients who received selenium supplements had significantly decreased serum dehydroepiandrosterone (DHEA) levels (p=0.02), hirsutism (modified Ferriman-Gallwey scores) (p<0.001), serum high sensitivity C-reactive protein (hs-CRP) (p=0.02), and plasma malondialdehyde (MDA) levels (p=0.01) compared with placebo. We did not observe any significant effects of taking selenium supplements on other hormonal profiles, nitric oxide (NO), and other biomarkers of oxidative stress. Taken together, selenium supplementation for 8 weeks among PCOS women had beneficial effects on reproductive outcomes, DHEA, hs-CRP, and MDA levels. Supporting Information for this article is available online at http://www.thieme-connect.de/products.

The Role of Glucose and Lipid Metabolism in Growth and Survival of Cancer Cells

One of the prerequisites for cell growth and proliferation is the synthesis of macromolecules, including proteins, nucleic acids and lipids. Cells have to alter their metabolism to allow the production of metabolic intermediates that are the precursors for biomass production. It is now evident that oncogenic signalling pathways target metabolic processes on several levels and metabolic reprogramming has emerged as a hallmark of cancer. The increased metabolic demand of cancer cells also produces selective dependencies that could be targeted for therapeutic intervention. Understanding the role of glucose and lipid metabolism in supporting cancer cell growth and survival is crucial to identify essential processes that could provide therapeutic windows for cancer therapy.

Whole genome and transcriptome sequencing of matched primary and peritoneal metastatic gastric carcinoma

Gastric cancer is one of the most aggressive cancers and is the second leading cause of cancer death worldwide. Approximately 40% of global gastric cancer cases occur in China, with peritoneal metastasis being the prevalent form of recurrence and metastasis in advanced disease. Currently, there are limited clinical approaches for predicting and treatment of peritoneal metastasis, resulting in a 6-month average survival time. By comprehensive genome analysis will uncover the pathogenesis of peritoneal metastasis. Here we describe a comprehensive whole-genome and transcriptome sequencing analysis of one advanced gastric cancer case, including non-cancerous mucosa, primary cancer and matched peritoneal metastatic cancer. The peripheral blood is used as normal control. We identified 27 mutated genes, of which 19 genes are reported in COSMIC database (ZNF208, CRNN, ATXN3, DCTN1, RP1L1, PRB4, PRB1, MUC4, HS6ST3, MUC17, JAM2, ITGAD, IREB2, IQUB, CORO1B, CCDC121, AKAP2, ACAN and ACADL), and eight genes have not previously been described in gastric cancer (CCDC178, ARMC4, TUBB6, PLIN4, PKLR, PDZD2, DMBT1and DAB1).Additionally,GPX4 and MPND in 19q13.3-13.4 region, is characterized as a novel fusion-gene. This study disclosed novel biological markers and tumorigenic pathways that would predict gastric cancer occurring peritoneal metastasis.

Characterization of TLR2, NOD2, and related cytokines in mammary glands infected by Staphylococcus aureus in a rat model

Background

Staphylococcus aureus causes subclinical mastitis as well as persistent and chronic infections in cattle. Bovine mastitis induced by S. aureus is often refractory to antibiotic treatment. Local innate immune defenses play an important role in eliminating the invading bacteria. TLR2 and NOD2 are important pathogen recognition receptors, but their functions have not been investigated in the context of early stages of mastitis. The present study examined TLR2, NOD2, and related cytokines in mammary glands infection induced by S. aureus at early stages in a rat mastitis model.

Findings

All inoculated mammary glands developed mastitis. Acute changes were induced in mammary tissues infected with S. aureus at early stages and then chronic infections persisted until the end of the experiment. TLR2 and NOD2 mRNA expression increased significantly after inoculation with S. aureus. The expression levels of cytokine mRNAs, including TNF-α, IL-1β, IL-6, IL-10, and CXCL1, also increased. TGF-β1 expression was suppressed at early phase and IFN-γ mRNA expression increased significantly at a later stage.

Conclusions

Mammary innate immune responses were activated after S. aureus inoculation. TLR2, NOD2, and inflammatory cytokines (TNF-α, IL-1β, IL-6, CXCL1, IL-10, TGF-β1, and IFN-γ) are involved in the response to mastitis induced by S. aureus.

Electronic supplementary material

The online version of this article (doi:10.1186/s13028-015-0116-0) contains supplementary material, which is available to authorized users.

Effects of selenium supplementation on glucose homeostasis, inflammation, and oxidative stress in gestational diabetes: Randomized, double-blind, placebo-controlled trial

OBJECTIVE

To our knowledge, no reports are available indicating the effects of selenium supplementation on metabolic parameters, inflammatory factors, and oxidative stress in gestational diabetes mellitus (GDM). The aim of this study was to assess the effects of selenium supplementation on metabolic status in pregnant women with GDM who were not on oral hypoglycemic agents.

METHODS

This randomized, double-blind, placebo-controlled clinical trial was performed with 70 women with GDM. Patients were randomly assigned to receive either 200 μg selenium supplements as tablet (n = 35) or placebo (n = 35) for 6 wk from weeks 24 to 28 of gestation. Fasting plasma samples were taken at study baseline and after 6 wk of intervention to quantify related variables.

RESULTS

Selenium supplementation, compared with placebo, resulted in a significant reduction in fasting plasma glucose (-10.5 ± 11.9 versus +4.5 ± 12.9 mg/dL; P < 0.001), serum insulin levels (-1.98 ± 11.25 versus +5.26 ± 9.33 μIU/mL; P = 0.005), homeostasis model of assessment (HOMA)-insulin resistance (-0.84 ± 2.76 versus +1.47 ± 2.46; P < 0.001) and a significant increase in quantitative insulin sensitivity check index (+0.008 ± 0.03 versus -0.01 ± 0.01; P = 0.009). Additionally, a significant decrease in serum high-sensitivity C-reactive protein (hs-CRP) levels (-791.8 ± 2271.8 versus +500.5 ± 2563.3 ng/mL; P = 0.02) was seen after the administration of selenium supplements compared with placebo. Additionally, we observed a significant elevation in plasma glutathione (+52.14 ± 58.31 versus -39.93 ± 153.52 μmol/L; P = 0.002) and a significant reduction in plasma malondialdehyde levels (-0.01 ± 0.36 versus +0.67 ± 1.90 μmol/L; P = 0.04) after consumption of selenium supplements compared with placebo. We did not find any significant effect of taking selenium supplements on HOMA β-cell function, lipid profiles, plasma nitric oxide, or total antioxidant capacity concentrations.

CONCLUSION

Selenium supplementation in pregnant women with GDM demonstrated beneficial effects on glucose metabolism, hs-CRP levels, and biomarkers of oxidative stress.

VEGF-A inhibition ameliorates podocyte apoptosis via repression of activating protein 1 in diabetes

BACKGROUND/AIMS

Vascular endothelial growth factor-A (VEGF-A) upregulation and podocyte apoptosis have been documented in diabetes. This study was designed to investigate whether inhibiting VEGF-A could ameliorate podocyte apoptosis in diabetes and the underlying mechanisms.

METHODS

In vitro, small interfering RNAs (siRNAs) of VEGF-A and activator protein 1 (AP-1, c-fos and c-jun), bevacizumab (VEGF-A inhibitor) and SP600125 (AP-1 inhibitor) were added to high glucose (30 mM) induced podocytes. Luciferase reporter assay was used to investigate whether AP-1 was a direct target of VEGF-A. In vivo, bevacizumab and SP600125 were administered to 12-week-old streptozotocin-induced male Sprague Dawley rats. The level of VEGF-A, c-fos, c-jun and bcl-2 were examined using immunostaining and Western blot analysis. Podocyte apoptosis was detected using the terminal deoxynucleotidyl transferase-mediated uridine 5'-triphosphate-biotin nick end labeling (TUNEL) assay, electron microscopy and flow cytometry.

RESULTS

Silencing VEGF-A or AP-1 upregulated bcl-2 and ameliorated podocyte apoptosis. Silencing VEGF-A decreased the level of c-fos and c-jun and bevacizumab and SP600125 treatment attenuated podocyte apoptosis. Luciferase reporter activity of VEGF-A-3'-UTR constructs was significantly provoked when stimulated with TGF-β1. In diabetic rat kidneys, VEGF-A co-localized with bcl-2 in podocytes. With bevacizumab and SP600125 treatment, the level of VEGF-A and AP-1 decreased while bcl-2 increased. Podocyte apoptotic rate was reduced with condensed podocyte nuclei less frequently observed. The urine albumin excretion rate (UAER) and albumin/creatinine were improved.

CONCLUSION

This study demonstrates VEGF-A inhibition ameliorates podocyte apoptosis by regulating AP-1 and bcl-2 signaling. AP-1 is a direct target of VEGF-A and a novel player in podocyte apoptosis.

A novel AP-1/miR-101 regulatory feedback loop and its implication in the migration and invasion of hepatoma cells

MicroRNA-101 (miR-101) is frequently downregulated in various cancers. To date, the regulatory networks of miR-101 remain obscure. In this study, we demonstrated that miR-101 was mainly transcribed from human miR-101-2 and mouse miR-101bgene loci. Subsequent analyses revealed that activator protein-1 (AP-1) directly binded to the −17.4 to −16.4 k region upstream of pre-miR-101-2 and activated the expression of miR-101. On the other hand, miR-101 could inhibit the expression of ERK2 and c-Fos, two key factors of the AP-1 pathway, by binding to their 3′-UTRs. Furthermore, reintroduction of miR-101 efficiently suppressed the AP-1 activity and pri-miR-101-2 transcription. These data thus suggest a novel AP-1/miR-101 regulatory circuitry, that is, AP-1 promotes the transcription of miR-101, whereas the expression of miR-101 reduces the level of ERK2 and c-Fos and thereby attenuates the AP-1 signaling. Further investigation disclosed that the AP-1 activator TPA-induced MMP9 activity and the TPA-promoted migration and invasion of hepatoma cells were significantly attenuated by miR-101 but were enhanced by miR-101 inhibitor. Our results suggest that the AP-1/miR-101 feedback loop may prevent the excessive activation of metastatic signals imposed by ERK2/AP-1 and highlight the biological significance of miR-101 downregulation in cancer metastasis.

The effects of di(2-ethylhexyl)phthalate on rat liver in relation to selenium status

This study was performed to determine the hepatotoxicity of di(2-ethylhexyl)phthalate (DEHP) in relation to selenium status. In 3-week-old Sprague-Dawley rats, selenium deficiency was induced by a ≤0.05 selenium mg/kg. A selenium supplementation group was given 1 mg selenium/kg diet for 5 weeks. Di(2-ethylhexyl)phthalate-treated groups received 1000 mg/kg dose by gavage during the last 10 days of the experiment. Histopathology, peroxisome proliferation, catalase (CAT) immunoreactivity and activity and apoptosis were assessed. Activities of antioxidant selenoenzymes [glutathione peroxidase 1 (GPx1), glutathione peroxidase 4 (GPx4), thioredoxin reductase (TrxR1)], superoxide dismutase (SOD), and glutathione S-transferase (GST); aminotransferase, total glutathione (tGSH), and lipid peroxidation (LP) levels were measured. Di(2-ethylhexyl)phthalate caused cellular disorganization while necrosis and inflammatory cell infiltration were observed in Se-deficient DEHP group (DEHP/SeD). Catalase activity and immunoreactivity were increased in all DEHP-treated groups. Glutathione peroxidase 1 and GPx4 activities decreased significantly in DEHP and DEHP/SeD groups, while GST activities decreased in all DEHP-exposed groups. Thioredoxin reductase activity increased in DEHP and DEHP/SeS, while total SOD activities increased in all DEHP-treated groups. Lipid peroxidation levels increased significantly in SeD (26%), DEHP (38%) and DEHP/SeD (71%) groups. Selenium supplementation partially ameliorated DEHP-induced hepatotoxicity; while in DEHP/SeD group, drastic changes in hepatic histopathology and oxidative stress parameters were observed.

Effects of supplementation with selenium, as selenized yeast, in a healthy male population from New Zealand

Selenium (Se) supplementation was tested in a group of healthy men from Auckland, New Zealnd with selenized yeast (Selplex, 200 μg/day) as the supplementation mode. A set of biomarkers, including DNA damage levels and seleno-antioxidant enzyme levels, were evaluated at pre- and postsupplementation time points. Supplementation produced significant increases in serum Se levels, red blood cell (RBC) thioredoxin reductase (TR) activity and peroxide-induced DNA damage, when the mean baseline serum Se level was 110 ng/ml. Those with higher baseline serum Se levels gained less serum Se and showed a significant reduction of RBC glutathione peroxidase (GPx) activity by supplementation. The optimum benefits of supplementation on DNA stability are observed when the serum Se level reaches between >120 and <160 ng/ml. However, the most significant observation was that those with highest baseline DNA damage benefit the most from Se supplementation, whereas those having lower baseline DNA damage are disadvantaged. A dose of 200 μg/day selenized yeast was also shown to be a safer supplementation option compared to a similar dose of selenomethionine (SeMet). This study highlights the requirement for prestratification of a population by standing serum Se level and baseline DNA damage level, before any Se supplementation is carried out.

Circadian rhythm connections to oxidative stress: implications for human health

SIGNIFICANCE

Oxygen and circadian rhythmicity are essential in a myriad of physiological processes to maintain homeostasis, from blood pressure and sleep/wake cycles, down to cellular signaling pathways that play critical roles in health and disease. If the human body or cells experience significant stress, their ability to regulate internal systems, including redox levels and circadian rhythms, may become impaired. At cellular as well as organismal levels, impairment in redox regulation and circadian rhythms may lead to a number of adverse effects, including the manifestation of a variety of diseases such as heart diseases, neurodegenerative conditions, and cancer.

RECENT ADVANCES

Researchers have come to an understanding as to the basics of the circadian rhythm mechanism, as well as the importance of the numerous species of oxidative stress components. The effects of oxidative stress and dysregulated circadian rhythms have been a subject of intense investigations since they were first discovered, and recent investigations into the molecular mechanisms linking the two have started to elucidate the bases of their connection.

CRITICAL ISSUES

While much is known about the mechanics and importance of oxidative stress systems and circadian rhythms, the front where they interact has had very little research focused on it. This review discusses the idea that these two systems are together intricately involved in the healthy body, as well as in disease.

FUTURE DIRECTIONS

We believe that for a more efficacious management of diseases that have both circadian rhythm and oxidative stress components in their pathogenesis, targeting both systems in tandem would be far more successful.

Distribution of selenium and oxidative stress in breast tumor-bearing mice

The present study investigated the effects of breast tumors on the blood and tissue distribution of essential trace mineral selenium (Se), and oxidative stress status of mice. Female 10-week-old BALB/cByJNarl mice were randomly assigned into control (CNL) and breast tumor-bearing (TB) groups. TB mice were injected subcutaneously into the right hind thigh with 5 × 10(6) EMT6 mouse mammary tumor cells. After 22 days, we measured Se concentrations, Se-dependent glutathione peroxidase (GPx) activities, and malondialdehyde (MDA) products (indicator of oxidative stress) in plasma, various tissues, and plasma vascular endothelial growth factor (VEGF) concentrations. There were no significant differences in body weights and daily intake between both groups. Compared with the CNL group, TB mice have decreases in plasma Se concentrations and GPx activities, as well as higher plasma VEGF and MDA concentrations. Plasma Se concentrations were also negatively correlated with plasma MDA and VEGF concentrations. Furthermore, tissue Se concentrations and GPx activities in TB animals were lower; whereas the MDA concentrations higher in various tissues including liver, kidney, brain, lung, spleen, and thymic tissues. In conclusion, disruption of Se homeostasis critically reflects oxidative stress in target tissues, thus may increase the risk for progression of breast cancer and metastasis.