Induction of Oxidative Stress Through Inhibition of Thioredoxin Reductase 1 Is an Effective Therapeutic Approach for Hepatocellular Carcinoma

Auranofin induces urothelial carcinoma cell death via reactive oxygen species production and synergy with cisplatin

Urothelial carcinoma (UC) is one of the most common cancer types of the urinary tract. UC is associated with poor 5-year survival rate, and resistance to cisplatin-based therapy remains a challenge for invasive bladder cancer treatment. Therefore, there is an urgent need to develop new drugs for advanced UC therapy. Auranofin (AF) was developed over 30 years ago for the treatment of rheumatoid arthritis and has been reported to exert an antitumor effect by increasing the level of reactive oxygen species (ROS) in cancer cells. The aim of the present study was to examine the effects of AF on cancer cell proliferation, cell cycle and apoptosis, either alone or in combination with cisplatin. AF induced cell death in two separate cell lines, HT 1376 and BFTC 909, in a concentration- and time-dependent manner by inducing cell cycle arrest. However, the distribution of cells in different phases of the cell cycle differed between the two cell lines, with G₀/G₁ cell cycle arrest in HT 1376 cells and S phase arrest in BFTC 909 cells. In addition, AF induced apoptosis in HT 1376, as well as redox imbalance in both HT 1376 and BFTC 909 cells. Cell viability was rescued following treatment with N-acetyl-L-cysteine, a ROS scavenger. Furthermore, AF treatment synergistically increased the cytotoxicity of HT 1376 and BFTC 909 cells when combined with cisplatin treatment. These findings suggest that AF may represent a potential candidate drug against UC and increase the therapeutic effect of cisplatin.

An Integrated In Silico, In Vitro and Tumor Tissues Study Identified Selenoprotein S (SELENOS) and Valosin-Containing Protein (VCP/p97) as Novel Potential Associated Prognostic Biomarkers in Triple Negative Breast Cancer

Simple Summary

Triple negative breast cancer (TNBC) represents a clinical challenge because its early relapse, poor overall survival and lack of effective treatments. Altered levels selenoproteins have been correlated with development and progression of some cancers, however, no consistent data are available about their involvement in TNBC. Here we analyzed the expression profile of all twenty-five human selenoproteins in TNBC cells and tissues by a systematic approach, integrating in silico and wet lab approaches. We showed that the expression profiles of five selenoproteins are specifically dysregulated in TNBC. Most importantly, by a bioinformatics analysis, we selected selenoprotein S and its interacting protein valosin-containing protein (VCP/p97) as inter-related with the others and whose coordinated over-expression is associated with poor prognosis in TNBC. Overall, we highlighted two mechanistically related novel proteins whose correlated expression could be exploited for a better definition of prognosis as well as suggested as novel therapeutic target in TNBC.

Abstract

Background. Triple negative breast cancer (TNBC) is a heterogeneous group of tumors with early relapse, poor overall survival, and lack of effective treatments. Hence, new prognostic biomarkers and therapeutic targets are needed. Methods. The expression profile of all twenty-five human selenoproteins was analyzed in TNBC by a systematic approach.In silicoanalysis was performed on publicly available mRNA expression datasets (Cancer Cell Line Encyclopedia, CCLE and Library of Integrated Network-based Cellular Signatures, LINCS). Reverse transcription quantitative PCR analysis evaluated selenoprotein mRNA expression in TNBC versus non-TNBC and normal breast cells, and in TNBC tissues versus normal counterparts. Immunohistochemistry was employed to study selenoproteins in TNBC tissues. STRING and Cytoscape tools were used for functional and network analysis. Results.GPX1, GPX4, SELENOS, TXNRD1 and TXNRD3 were specifically overexpressed in TNBC cells, tissues and CCLE/LINCS datasets. Network analysis demonstrated that SELENOS-binding valosin-containing protein (VCP/p97) played a critical hub role in the TNBCselenoproteins sub-network, being directly associated with SELENOS expression. The combined overexpression of SELENOS and VCP/p97 correlated with advanced stages and poor prognosis in TNBC tissues and the TCGA dataset. Conclusion. Combined evaluation of SELENOS and VCP/p97 might represent a novel potential prognostic signature and a therapeutic target to be exploited in TNBC.

A Robust Metabolic Enzyme-Based Prognostic Signature for Head and Neck Squamous Cell Carcinoma

Background

Head and neck squamous cell carcinoma (HNSCC) is still a menace to public wellbeing globally. However, the underlying molecular events influencing the carcinogenesis and prognosis of HNSCC are poorly known.

Methods

Gene expression profiles of The Cancer Genome Atlas (TCGA) HNSCC dataset and GSE37991 were downloaded from the TCGA database and gene expression omnibus, respectively. The common differentially expressed metabolic enzymes (DEMEs) between HNSCC tissues and normal controls were screened out. Then a DEME-based molecular signature and a clinically practical nomogram model were constructed and validated.

Results

A total of 23 commonly upregulated and 9 commonly downregulated DEMEs were identified in TCGA HNSCC and GSE37991. Gene ontology analyses of the common DEMEs revealed that alpha-amino acid metabolic process, glycosyl compound metabolic process, and cellular amino acid metabolic process were enriched. Based on the TCGA HNSCC cohort, we have built up a robust DEME-based prognostic signature including HPRT1, PLOD2, ASNS, TXNRD1, CYP27B1, and FUT6 for predicting the clinical outcome of HNSCC. Furthermore, this prognosis signature was successfully validated in another independent cohort GSE65858. Moreover, a potent prognostic signature-based nomogram model was constructed to provide personalized therapeutic guidance for treating HNSCC. In vitro experiment revealed that the knockdown of TXNRD1 suppressed malignant activities of HNSCC cells.

Conclusion

Our study has successfully developed a robust DEME-based signature for predicting the prognosis of HNSCC. Moreover, the nomogram model might provide useful guidance for the precision treatment of HNSCC.

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.

Upgrade of an old drug: Auranofin in innovative cancer therapies to overcome drug resistance and to increase drug effectiveness

Auranofin is an oral gold(I) compound, initially developed for the treatment of rheumatoid arthritis. Currently, Auranofin is under investigation for oncological application within a drug repurposing plan due to the relevant antineoplastic activity observed both in vitro and in vivo tumor models. In this review, we analysed studies in which Auranofin was used as a single drug or in combination with other molecules to enhance their anticancer activity or to overcome chemoresistance. The analysis of different targets/pathways affected by this drug in different cancer types has allowed us to highlight several interesting targets and effects of Auranofin besides the already well-known inhibition of thioredoxin reductase. Among these targets, inhibitory-κB kinase, deubiquitinates, protein kinase C iota have been frequently suggested. To rationalize the effects of Auranofin by a system biology-like approach, we exploited transcriptomic data obtained from a wide range of cell models, extrapolating the data deposited in the Connectivity Maps website and we attempted to provide a general conclusion and discussed the major points that need further investigation.

Natural diterpenoid eriocalyxin B covalently modifies glutathione and selectively inhibits thioredoxin reductase inducing potent oxidative stress-mediated apoptosis in colorectal carcinoma RKO cells

Increasing evidence suggests the significant contribution of high levels of thioredoxin reductase (TrxR) in various stages of tumorigenesis and resistance to tumor chemotherapy. Thus, inhibition of TrxR with small molecules is an attractive strategy for cancer therapy. Eriocalyxin B (EriB), a naturally occurring diterpenoid extracted from Isodon eriocalyx, has reflected potential anticancer activities through numerous pathways. Here, we describe that EriB covalently modifies GSH and selectively inhibits TrxR activity by targeting the Sec residue of the enzyme. Pharmacological inhibition of TrxR by EriB results in elevated ROS levels, reduced total GSH and thiols content, which ultimately induced potent RKO cell apoptosis mediated by oxidative stress. Importantly, EriB indicates potent synthetic lethality with GSH inhibitors, BSO, in RKO cells. In summary, our results highlight that targeting TrxR by EriB explores a novel mechanism for the biological action of EriB. This opened up a new therapeutic indication for using EriB to combat cancers.

Carminic acid mitigates fructose-triggered hepatic steatosis by inhibition of oxidative stress and inflammatory reaction

Excessive fructose (Fru) consumption has been reported to favor nonalcoholic fatty liver disease (NAFLD). However, the molecular mechanism is still elusive, lacking effective therapeutic strategies. Carminic acid (CA), a glucosylated anthraquinone found in scale insects like Dactylopius coccus, exerts anti-tumor and anti-oxidant activities. Nevertheless, its regulatory role in Fru-induced NAFLD is still obscure. Here, the effects of CA on NAFLD in Fru-challenged mice and the underlying molecular mechanisms were explored. We found that Fru intake significantly led to insulin resistance and dyslipidemia in liver of mice, which were considerably attenuated by CA treatment through repressing endoplasmic reticulum (ER) stress. Additionally, inflammatory response induced by Fru was also attenuated by CA via the blockage of nuclear factor-κB (NF-κB), mitogen-activated protein kinases (MAPKs) and tumor necrosis factor α/TNF-α receptor (TNF-α/TNFRs) signaling pathways. Moreover, Fru-provoked oxidative stress in liver tissues was remarkably attenuated by CA mainly through improving the activation of nuclear factor erythroid 2-related factor 2 (Nrf-2). These anti-dyslipidemias, anti-inflammatory and anti-oxidant activities regulated by CA were confirmed in the isolated primary hepatocytes with Fru stimulation. Importantly, the in vitro experiments demonstrated that Fru-induced lipid accumulation was closely associated with inflammatory response and reactive oxygen species (ROS) production regulated by TNF-α and Nrf-2 signaling pathways, respectively. In conclusion, these results demonstrated that CA could be considered as a potential therapeutic strategy to attenuate metabolic disorder and NAFLD in Fru-challenged mice mainly through suppressing inflammatory response and oxidative stress.

Transcriptome Analyses Identify a Metabolic Gene Signature Indicative of Antitumor Immunosuppression of EGFR Wild Type Lung Cancers With Low PD-L1 Expression

Purpose

With the development and application of targeted therapies like tyrosine kinase inhibitors (TKIs) and immune checkpoint inhibitors (ICIs), non-small cell lung cancer (NSCLC) patients have achieved remarkable survival benefits in recent years. However, epidermal growth factor receptor (EGFR) wild-type and low expression of programmed death-ligand 1 (PD-L1) NSCLCs remain unmanageable. Few treatments for these patients exist, and more side effects with combination therapies have been observed. We intended to generate a metabolic gene signature that could successfully identify high-risk patients and reveal its underlying molecular immunology characteristics.

Methods

By identifying the bottom 50% PD-L1 expression level as PD-L1 low expression and removing EGFR mutant samples, a total of 640 lung adenocarcinoma (LUAD) and lung squamous carcinoma (LUSC) tumor samples and 93 adjacent non-tumor samples were finally extracted from The Cancer Genome Atlas (TCGA). We identified differentially expressed metabolic genes (DEMGs) by R package limma and the prognostic genes by Univariate Cox proportional hazards regression analyses. The intersect genes between DEMGs and prognostic genes were put into the least absolute shrinkage and selection operator (LASSO) penalty Cox regression analysis. The metabolic gene signature contained 18 metabolic genes generated and successfully stratified LUAD and LUSC patients into the high-risk and low-risk groups, which was also validated by the Gene Expression Omnibus (GEO) database. Its accuracy was proved by the time-dependent Receiver Operating Characteristic (ROC) curve, Principal Components Analysis (PCA), and nomogram. Furthermore, the Single-sample Gene Set Enrichment Analysis (ssGSEA) and diverse acknowledged methods include XCELL, TIMER, QUANTISEQ, MCPcounter, EPIC, CIBERSORT-ABS, and CIBERSORT revealed its underlying antitumor immunosuppressive status. Besides, its relationship with somatic copy number alterations (SCNAs) and tumor mutational burden (TMB) was also discussed.

Results

It is noteworthy that metabolism reprogramming is associated with the survival of the double-negative LUAD and LUSC patients. The SCNAs and TMB of critical metabolic genes can inhibit the antitumor immune process, which might be a promising therapeutic target.

Prognostic Role and Potential Mechanisms of the Ferroptosis-Related Metabolic Gene Signature in Hepatocellular Carcinoma

Purpose

Ferroptosis, as a novel regulated cell death form, has a close interaction with metabolism, which is largely unknown in cancer. In the present study, we conducted a comprehensive analysis of ferroptosis-related metabolic genes to delineate the metabolic signatures induced by ferroptosis and evaluate its prognostic significance in hepatocellular carcinoma (HCC).

Methods

The ferroptosis-related metabolic genes (Fer-MRGs) were identified by correlation analyses with transcriptome data from The Cancer Genome Atlas and Gene Expression Omnibus. Then, univariate and the least absolute shrinkage and selection operator Cox regression analysis was used to establish a novel risk score model. Univariate and multivariate COX analyses were used to identify independent prognostic factors for overall survival (OS) of HCC, and a nomogram was developed. The Fer-MRGs’ expression was further evaluated by quantitative real-time polymerase chain reaction in HCC.

Results

A total of 77 metabolic genes were identified as Fer-MRGs, and 26 were found with prognostic values for OS of HCC. Then, a novel nine-gene (AKR1C3, ATIC, G6PD, GMPS, GNPDA1, IMPDH1, PRIM1, RRM2, and TXNRD1) risk score model was constructed. Survival analyses showed worse OS in high-risk patients both in the training and validation groups. The model was also identified as an independent prognostic factor for HCC, and a prognostic nomogram for OS was further established with superior discriminative capacity and prediction accuracy. Notably, close correlations were also identified between the risk score and the expression of immune checkpoint genes, immune subtypes of tumor, and susceptibility of HCC to chemotherapeutic agents. Finally, elevated expression of eight Fer-MRGs (except for IMPDH1) was further verified in 16 pairs of HCC tumor and adjacent tissues.

Conclusion

These results indicated the intense interaction between ferroptosis and metabolism, the significant role of ferroptosis-related MRGs, and the great potential of the novel risk score model for prognosis prediction in HCC.

Adaptive and Constitutive Activations of Malic Enzymes Confer Liver Cancer Multilayered Protection Against Reactive Oxygen Species

BACKGROUND AND AIMS

HCC undergoes active metabolic reprogramming. Reactive oxygen species (ROS) are excessively generated in cancer cells and are neutralized by NADPH. Malic enzymes (MEs) are the less studied NADPH producers in cancer.

APPROACH AND RESULTS

We found that ME1, but not ME3, was regulated by the typical oxidative stress response pathway mediated by kelch-like ECH associated protein 1/nuclear factor erythroid 2-related factor (NRF2). Surprisingly, ME3 was constitutively induced by superenhancers. Disruption of any ME regulatory pathways decelerated HCC progression and sensitized HCC to sorafenib. Therapeutically, simultaneous blockade of NRF2 and a superenhancer complex completely impeded HCC growth. We show that superenhancers allow cancer cells to counteract the intrinsically high level of ROS through constitutively activating ME3 expression. When HCC cells encounter further episodes of ROS insult, NRF2 allows cancer cells to adapt by transcriptionally activating ME1.

CONCLUSIONS

Our study reveals the complementary regulatory mechanisms which control MEs and provide cancer cells multiple layers of defense against oxidative stress. Targeting both regulatory mechanisms represents a potential therapeutic approach for HCC treatment.

Auranofin prevents liver fibrosis by system Xc-mediated inhibition of NLRP3 inflammasome

Demand for a cure of liver fibrosis is rising with its increasing morbidity and mortality. Therefore, it is an urgent issue to investigate its therapeutic candidates. Liver fibrosis progresses following 'multi-hit' processes involving hepatic stellate cells, macrophages, and hepatocytes. The NOD-like receptor protein 3 (NLRP3) inflammasome is emerging as a therapeutic target in liver fibrosis. Previous studies showed that the anti-rheumatic agent auranofin inhibits the NLRP3 inflammasome; thus, this study evaluates the antifibrotic effect of auranofin in vivo and explores the underlying molecular mechanism. The antifibrotic effect of auranofin is assessed in thioacetamide- and carbon tetrachloride-induced liver fibrosis models. Moreover, hepatic stellate cell (HSC), bone marrow-derived macrophage (BMDM), kupffer cell, and hepatocyte are used to examine the underlying mechanism of auranofin. Auranofin potently inhibits activation of the NLRP3 inflammasome in BMDM and kupffer cell. It also reduces the migration of HSC. The underlying molecular mechanism was inhibition of cystine-glutamate antiporter, system Xc. Auranofin inhibits system Xc activity and instantly induced oxidative burst, which mediated inhibition of the NLRP3 inflammasome in macrophages and HSCs. Therefore, to the best of our knowledge, we propose the use of auranofin as an anti-liver fibrotic agent.

Auranofin prevents liver fibrosis by system Xc-mediated inhibition of NLRP3 inflammasome

Demand for a cure of liver fibrosis is rising with its increasing morbidity and mortality. Therefore, it is an urgent issue to investigate its therapeutic candidates. Liver fibrosis progresses following 'multi-hit' processes involving hepatic stellate cells, macrophages, and hepatocytes. The NOD-like receptor protein 3 (NLRP3) inflammasome is emerging as a therapeutic target in liver fibrosis. Previous studies showed that the anti-rheumatic agent auranofin inhibits the NLRP3 inflammasome; thus, this study evaluates the antifibrotic effect of auranofin in vivo and explores the underlying molecular mechanism. The antifibrotic effect of auranofin is assessed in thioacetamide- and carbon tetrachloride-induced liver fibrosis models. Moreover, hepatic stellate cell (HSC), bone marrow-derived macrophage (BMDM), kupffer cell, and hepatocyte are used to examine the underlying mechanism of auranofin. Auranofin potently inhibits activation of the NLRP3 inflammasome in BMDM and kupffer cell. It also reduces the migration of HSC. The underlying molecular mechanism was inhibition of cystine-glutamate antiporter, system Xc. Auranofin inhibits system Xc activity and instantly induced oxidative burst, which mediated inhibition of the NLRP3 inflammasome in macrophages and HSCs. Therefore, to the best of our knowledge, we propose the use of auranofin as an anti-liver fibrotic agent.

Mortalin/glucose-regulated protein 75 promotes the cisplatin-resistance of gastric cancer via regulating anti-oxidation/apoptosis and metabolic reprogramming

Platinum drug treatment is one of the most predominant chemotherapeutic strategies for patients with gastric cancer (GC). However, the therapeutic effect is less than satisfactory, largely due to the acquired resistance to platinum drugs. Therefore, a better understanding of the underlying mechanisms can greatly improve the therapeutic efficacy of GC. In this study, we aimed to investigate the chemo-resistance related functions/mechanisms and clinical significance of glucose-regulated protein 75 (GRP75) in GC. Here, our data showed that compared with SGC7901 cells, the expression of GRP75 was markedly higher in cisplatin-resistance cells (SGC7901^CR). Knockdown of GRP75 abolished the maintenance of mitochondrial membrane potential (MMP) and inhibited the nuclear factor erythroid-2-related factor 2 (NRF2), phosphatidylinositol 3 kinase/protein kinase B (PI3K/AKT), hypoxia-inducible factor 1α (HIF-1α), and c-myc, which resulted in blocking the activation of their downstream targets. These processes attenuated the anti-oxidation/apoptosis abilities and altered the metabolic reprogramming in SGC7901^CR cells, leading to re-sensitizing these cells to cisplatin. However, overexpression of GRP75 in SGC7901 cells caused the opposite effects. A xenografts model confirmed the abovementioned results. In GC patients receiving platinum chemotherapy and a meta-analysis, a high level of GRP75 was positively associated with aggressive characteristics and poor prognosis including but not limited to gastrointestinal cancers, and was an independent predictor for overall survival. Collectively, our study indicated that GRP75 was involved in the cisplatin-resistance of GC and that GRP75 could be a potential therapeutic target for restoring the drug response in platinum-resistance cells and a useful additive prognostic tool in guiding clinical management of GC patients.

Investigation of the Mechanism of Traditional Chinese Medicines in Angiogenesis through Network Pharmacology and Data Mining

Although traditional Chinese medicine is effective and safe for the treatment of angiogenesis, the in vivo intervention mechanism is diverse, complex, and largely unknown. Therefore, we aimed to explore the active ingredients of traditional Chinese medicine and their mechanisms of action against angiogenesis. Data on angiogenesis-related targets were collected from GeneCards, Therapeutic Target Database, Online Mendelian Inheritance in Man, DrugBank, and DisGeNET. These were matched to related molecular compounds and ingredients in the traditional Chinese medicine system pharmacology platform. The data were integrated and based on the condition of degree > 1, and relevant literature, target-compound, compound-medicine, and target-compound-medicine networks were constructed using Cytoscape. Molecular docking was used to predict the predominant binding combination of core targets and components. We obtained 79 targets for angiogenesis; 41 targets were matched to 3839 compounds, of which 110 compounds were selected owing to their high correlation with angiogenesis. Fifty-five combinations in the network were obtained by molecular docking, among which PTGS2-astragalin (-9.18 kcal/mol), KDR-astragalin (-7.94 kcal/mol), PTGS2-quercetin (-7.41 kcal/mol), and PTGS2-myricetin (-7.21 kcal/mol) were top. These results indicated that the selected potential core compounds have good binding activity with the core targets. Eighty new combinations were obtained from the network, and the top combinations based on affinity were KDR-beta-carotene (-10.13 kcal/mol), MMP9-beta-sitosterol (-8.04 kcal/mol), MMP9-astragalin (-7.82 kcal/mol), and MMP9-diosgenin (-7.51 kcal/mol). The core targets included PTGS2, KDR, VEGFA, and MMP9. The essential components identified were astragalin, kaempferol, myricetin, quercetin, and β-sitosterol. The crucial Chinese medicines identified included Polygoni Cuspidati Rhizoma et Radix, Morus alba Root Bark, and Forsythiae Fructus. By systematically analysing the ingredients of traditional Chinese medicine and their targets, it is possible to determine their potential mechanisms of action against pathological angiogenesis. Our study provides a basis for further research and the development of new therapeutics for angiogenesis.

Development and Validation of a Metabolic-related Prognostic Model for Hepatocellular Carcinoma

BACKGROUND AND AIMS

Growing evidence suggests that metabolic-related genes have a significant impact on the occurrence and development of hepatocellular carcinoma (HCC). However, the prognostic value of metabolic-related genes for HCC has not been fully revealed.

METHODS

mRNA sequencing and clinical data were obtained from The Cancer Genome Atlas and the GTEx Genotype-Tissue Expression comprehensive database. Differentially expressed metabolic-related genes in tumor tissues (n=374) and normal tissues (n=160) were identified by the Wilcoxon test. Time-dependent receiver operating characteristic curve analysis, univariate multivariate Cox regression analysis and Kaplan-Meier survival analysis were used to evaluate the predictive effectiveness and independence of the prognostic model. Two independent cohorts (International Cancer Genome Consortiums and GSE14520) were applied to verify the prognostic model.

RESULTS

Our study included a total of 793 patients with HCC. We constructed a risk score consisting of five metabolic-genes (BDH1, RRM2, CYP2C9, PLA2G7, and TXNRD1). For the overall survival rate, the low-risk group had a considerably higher rate than the high-risk group. Univariate and multivariate Cox regression analyses indicated that the risk score was an independent predictor for the prognosis of HCC.

CONCLUSIONS

We constructed and validated a novel prognostic model, which may provide support for the precise treatment of HCC.

Transcriptome profiles associated with selenium-deficiency-dependent oxidative stress identify potential diagnostic and therapeutic targets in liver cancer cells

Hepatocellular carcinoma (HCC) is one of the most common cancer types with high mortality rates and displays increased resistance to various stress conditions such as oxidative stress. Conventional therapies have low efficacies due to resistance and off-target effects in HCC. Here we aimed to analyze oxidative stress-related gene expression profiles of HCC cells and identify genes that could be crucial for novel diagnostic and therapeutic strategies. To identify important genes that cause resistance to reactive oxygen species (ROS), a model of oxidative stress upon selenium (Se) deficiency was utilized. The results of transcriptome-wide gene expression data were analyzed in which the differentially expressed genes (DEGs) were identified between HCC cell lines that are either resistant or sensitive to Se-deficiency-dependent oxidative stress. These DEGs were further investigated for their importance in oxidative stress resistance by network analysis methods, and 27 genes were defined to have key roles; 16 of which were previously shown to have impact on liver cancer patient survival. These genes might have Se-deficiency-dependent roles in hepatocarcinogenesis and could be further exploited for their potentials as novel targets for diagnostic and therapeutic approaches.

Development and Validation of a Metabolic Gene-Based Prognostic Signature for Hepatocellular Carcinoma

Background

Hepatocellular carcinoma (HCC) is a malignant tumor with great variation in prognosis among individuals. Changes in metabolism influence disease progression and clinical outcomes. The objective of this study was to determine the overall survival (OS) risk of HCC patients from a metabolic perspective.

Patients and Methods

The model was constructed using the least absolute shrinkage and selection operator (LASSO) COX regression based on The Cancer Genome Atlas (TCGA, n=342) dataset. The International Cancer Genome Consortium (ICGC, n=232), GSE14520 (n=242) datasets, and a clinical cohort (n=64) were then used to assess the prognostic value of the signature.

Results

A 10 metabolic gene-based signature was constructed and verified as a robust and independent prognostic classifier in public and real-world validation cohorts. Meanwhile, the signature enabled the identification of HCC molecular subtypes, yielding an AUC value of 0.678 [95% CI: 0.592–0.763]. Besides, the signature was associated with metabolic processes like glycolysis, supported by a clear correlation between the risk score and expression of rate-limiting enzymes. Furthermore, high-risk tumor was likely to have a high tumor infiltration status of immunosuppressive cells, as well as elevated expression of some immune checkpoint molecules. For final clinical translation, a nomogram integrating the signature and tumor stage was established, and showed improved predictive accuracy of 3- and 5-year OS and brought more net benefit to patients.

Conclusion

We developed a prognostic signature based on 10 metabolic genes, which has proven to be an independent and reliable prognostic predictor for HCC and reflects the metabolic and immune characteristics of tumors.

Quiescin sulfhydryl oxidase 1 promotes sorafenib-induced ferroptosis in hepatocellular carcinoma by driving EGFR endosomal trafficking and inhibiting NRF2 activation

Sorafenib is a first-line molecular-target drug for advanced hepatocellular carcinoma (HCC), but its clinical effects are still limited. In this study we identify Quiescin sulfhydryl oxidase 1 (QSOX1) acting as a cellular pro-oxidant, specifically in the context of sorafenib treatment of HCC. QSOX1 disrupts redox homoeostasis and sensitizes HCC cells to oxidative stress by inhibiting activation of the master antioxidant transcription factor NRF2. A negative correlation between QSOX1 and NRF2 expression was validated in tumor tissues from 151 HCC patients. Mechanistically, QSOX1 restrains EGF-induced EGFR activation by promoting ubiquitination-mediated degradation of EGFR and accelerating its intracellular endosomal trafficking, leading to suppression of NRF2 activity. Additionally, QSOX1 potentiates sorafenib-induced ferroptosis by suppressing NRF2 in vitro and in vivo. In conclusion, the data presented identify QSOX1 as a novel candidate target for sorafenib-based combination therapeutic strategies in HCC or other EGFR-dependent tumor types.

A pan-cancer study of selenoprotein genes as promising targets for cancer therapy

Background

The most important health benefit of selenium (Se) is in the prevention and control of cancer. Glutathione peroxidases (GPXs) and thioredoxin reductases (TXNRDs) are selenoenzymes that are thought to play a role in oxidative stress. The differential expression of genes of the TXNRD and GPX families is closely related to carcinogenesis and the occurrence of cancer. This study comprehensively analyzed the expression profiles of seven genes in the TXNRD and GPX families, in terms of their correlations with patient survival and immune-cell subtypes, tumor microenvironment, and drug sensitivity.

Results

The expression profiles of genes in the TXNRD and GPX families differ between different types of cancer, and also between and within individual cancer cases. The expression levels of the seven analyzed genes are related to the overall survival of patients. The TXNRD1 and TXNRD3 genes are mainly related to poor prognoses, while other genes are related to good or poor prognoses depending on the type of cancer. All of the genes were found to be correlated to varying degrees with immune-cell subtypes, level of mechanistic cell infiltration, and tumor cell stemness. The TXNRD1, GPX1, and GPX2 genes may exert dual effects in tumor mutagenesis and development, while the TXNRD1, GPX1, GPX2, and GPX3 genes were found to be related to drug sensitivity or the formation of drug resistance.

Conclusions

The results will greatly help in identifying the association between genes and tumorigenesis, especially in the immune response, tumor microenvironment, and drug resistance, and very important when attempting to identify new therapeutic targets.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12920-021-00930-1.

Six Metabolism Related mRNAs Predict the Prognosis of Patients With Hepatocellular Carcinoma

Background: Hepatocellular carcinoma (HCC) is one of the most common aggressive solid malignant tumors and current research regards HCC as a type of metabolic disease. This study aims to establish a metabolism-related mRNA signature model for risk assessment and prognosis prediction in HCC patients. Methods: HCC data were obtained from The Cancer Genome Atlas (TCGA), International Cancer Genome Consortium (ICGC) and Gene Enrichment Analysis (GSEA) website. Least absolute shrinkage and selection operator (LASSO) was used to screen out the candidate mRNAs and calculate the risk coefficient to establish the prognosis model. A high-risk group and low-risk group were separated for further study depending on their median risk score. The reliability of the prediction was evaluated in the validation cohort and the whole cohort. Results: A total of 548 differential mRNAs were identified from HCC samples (n = 374) and normal controls (n = 50), 45 of which were correlated with prognosis. A total of 373 samples met the screening criteria and there were randomly divided into the training cohort (n = 186) and the validation cohort (n = 187). In the training cohort, six metabolism-related mRNAs were used to construct a prognostic model with a LASSO regression model. Based on the risk model, the overall survival rate of the high-risk cohort was significantly lower than that of the low-risk cohort. The results of a time-ROC curve proved that the risk score (AUC = 0.849) had a higher prognostic value than the pathological grade, clinical stage, age or gender. Conclusion: The model constructed by the six metabolism-related mRNAs has a significant value for survival prediction and can be applied to guide the evaluation of HCC and the designation of clinical therapy.

The Molecular Mechanisms of Regulating Oxidative Stress-Induced Ferroptosis and Therapeutic Strategy in Tumors

Ferroptosis is an atypical form of regulated cell death, which is different from apoptosis, necrosis, pyroptosis, and autophagy. Ferroptosis is characterized by iron-dependent oxidative destruction of cellular membranes following the antioxidant system's failure. The sensitivity of ferroptosis is tightly regulated by a series of biological processes, the metabolism of iron, amino acids, and polyunsaturated fatty acids, and the interaction of glutathione (GSH), NADPH, coenzyme Q10 (CoQ10), and phospholipids. Elevated oxidative stress (ROS) level is a hallmark of cancer, and ferroptosis serves as a link between nutrition metabolism and redox biology. Targeting ferroptosis may be an effective and selective way for cancer therapy. The underlying molecular mechanism of ferroptosis occurrence is still not enough. This review will briefly summarize the process of ferroptosis and introduce critical molecules in the ferroptotic cascade. Furthermore, we reviewed the occurrence and regulation of reduction-oxidation (redox) for ferroptosis in cancer metabolism. The role of the tumor suppressor and the epigenetic regulator in tumor cell ferroptosis will also be described. Finally, old drugs that can be repurposed to induce ferroptosis will be characterized, aiming for drug repurposing and novel drug combinations for cancer therapy more efficiently and economically.

Prognostic roles of metabolic reprogramming-associated genes in patients with hepatocellular carcinoma

Metabolic reprogramming for adaptation to the tumor microenvironment is recognized as a hallmark of cancer. Although many altered metabolic genes have been reported to be associated with tumor pathological processes, systematic analysis of metabolic genes implicated in hepatocellular carcinoma prognosis remains rare. The aim of this study was to identify key metabolic genes related to hepatocellular carcinoma, and to explore their clinical significance. We downloaded mRNA expression profiles and clinical hepatocellular carcinoma data from The Cancer Genome Atlas database to explore the prognostic roles of metabolic genes. Five prognosis-associated metabolic genes, including POLA1, UCK2, ACYP1, ENTPD2, and TXNRD1, were screened via univariate Cox regression analysis and a LASSO Cox regression model, which divided patients into high- and low-risk groups. Furthermore, gene set enrichment analysis revealed that significantly-enriched gene ontology terms and pathways involving high-risk patients were focused on regulation of nucleic and fatty acid metabolism. Taken together, our study identified five metabolic genes related to survival, which can be used to predict the prognosis of patients with hepatocellular carcinoma. These genes may play essential roles in metabolic microenvironment regulation, and represent potentially important candidate targets in metabolic therapy.

Regulation of redox processes in biological systems with the participation of the Keap1/Nrf2/ARE signaling pathway, biogenic selenium nanoparticles as Nrf2 activators

The article is devoted to the mechanisms of regulation of redox processes in cells, a review of the Keap1 / Nrf2 / ARE redox-sensitive signaling system as a fundamental pathway that plays a key role in maintaining cellular redox homeostasis under stressful, inflammatory, carcinogenic and proapoptotic conditions. The structure of the cysteine-rich repressor protein Keap1, which is responsible for sensory perception of electrophiles and reactive oxygen species, the structure and functions of the transcription factor Nrf2, mechanisms of Nrf2 activation through the Keap1 / Nrf2 / ARE signaling system, which regulates the transcription and expression of cellular cytoprotective and antioxidant proteins, are described. Published data on the specificity of the interaction of the components of this cellular signaling pathway, the mechanisms of Keap1 dependent and independent adaptive response to the action of inductors, the role of biogenic selenium nanoparticles synthesized by green chemistry with the participation of bacteria in these processes are analyzed; features of Nrf2 induction depending on the type of bacteria and the stabilizing shell. It has been shown that biogenic selenium nanoparticles (BNSe), synthesized by different types of bacteria, activate the transcription factor Nrf2 using the Keap1-independent activation pathway through mitogen-protein kinases (MAPK): p38, ERK1 / 2 and AKT-mediated phosphorylation of Nrf2, protect the intestinal epithelial barrier function from the effects of oxidative damage, normalize mitochondrial function. A detailed understanding of thiol-dependent and independent redox signaling mechanisms under physiological and pathological conditions will lead to a deeper understanding of the redox component in human and animal diseases. The use of biogenic nanoselen, synthesized with the participation of various bacterial species, has been demonstrated to activate the Keap1 / Nrf2 / ARE signaling pathway, which may be of practical interest as a therapeutic target for many redox-mediated diseases.

Circ0120816 acts as an oncogene of esophageal squamous cell carcinoma by inhibiting miR-1305 and releasing TXNRD1

BACKGROUND

Circular RNAs (circRNAs) have been discovered to participate in the carcinogenesis of multiple cancers. However, the role of circRNAs in esophageal squamous cell carcinoma (ESCC) progression is yet to be properly understood. This research aimed to investigate and understand the mechanism used by circRNAs to regulate ESCC progression.

METHODS

Bioinformatics analysis was first performed to screen dysregulated circRNAs and differentially expressed genes in ESCC. The ESCC tissue samples and adjacent normal tissue samples utilized in this study were obtained from 36 ESCC patients. All the samples were subjected to qRT-PCR analysis to identify the expression of TXNRD1, circRNAs, and miR-1305. Luciferase reporter assay, RNA immunoprecipitation assay and RNA pull-down assay were later conducted to verify the existing relationship among circ0120816, miR-1305 and TXNRD1. CCK-8, BrdU, cell adhesion, cell cycle, western blot and caspase 3 activity assays were also employed to evaluate the regulation of these three biological molecules in ESCC carcinogenesis. To evaluate the effect of circ0120816 on ESCC tumor growth and metastasis, the xenograft mice model was constructed.

RESULTS

Experimental investigations revealed that circ0120816 was the highest upregulated circRNA in ESCC tissues and that this non-coding RNA acted as a miR-1305 sponge in enhancing cell viability, cell proliferation, and cell adhesion as well as repressing cell apoptosis in ESCC cell lines. Moreover, miR-1305 was observed to exert a tumor-suppressive effect in ESCC cells by directly targeting and repressing TXNRD1. It was also noticed that TXNRD1 could regulate cyclin, cell adhesion molecule, and apoptosis-related proteins. Furthermore, silencing circ0120816 was found to repress ESCC tumor growth and metastasis in vivo.

CONCLUSIONS

This research confirmed that circ0120816 played an active role in promoting ESCC development by targeting miR-1305 and upregulating oncogene TXNRD1.

Potential relationship between the selenoproteome and cancer

The role of the selenoproteome, which is the collection of all proteins containing selenium in an organism, in cancer development, growth and progression requires further investigation, due to the importance of selenium in both cancer and immune system function. Data about the selenoproteome, including its differential expression, single nucleotide variations, copy number variations, methylation, pathways and overall survival (OS) in five leading types of cancer are available from the GSCALite website. Subsequent to the analysis of these datasets, it was revealed that there was increased expression of GPX3 in stomach adenocarcinoma and lung squamous cell carcinoma, SELENOV in oesophageal carcinoma, GPX8 and GPX4 in colon adenocarcinoma, TXNRD1 and SEPHS1 in hepatocellular carcinoma and GPX8 in lung adenocarcinoma were associated with poor survival. Decreased gene expression of SELENOP was indicated in liver hepatocellular carcinoma and GPX3, and SELENOW, SELENOK, SELENBP1 and SECISBP2 in lung adenocarcinoma were associated with a poor prognosis. OS data suggested that hypermethylation of GPX4 in colon adenocarcinoma, GPX8 in lung squamous cell carcinoma, GPX1 in stomach adenocarcinoma and GPX3 in lung adenocarcinoma was associated with low survival, as is hypomethylation of GPX5 in lung adenocarcinoma. The selenoproteome is heterogeneous, especially in its effect on the OS of patients with cancer. The present study demonstrated that the roles of GPX4 in colon adenocarcinoma, SCLY and SELENOV in oesophageal carcinoma, SEPHS1 in liver hepatocellular carcinoma, SELENOK in lung cancer, as well as SELENOM and SELENOW in stomach adenocarcinoma requires further research. The present study may lead to the identification of novel biomarkers or potential therapeutic targets for use in the treatment of cancers, such as colon adenocarcinoma, oesophageal carcinoma, liver hepatocellular carcinoma, lung cancer and stomach adenocarcinoma.

Sulfiredoxin-1 is a promising novel prognostic biomarker for hepatocellular carcinoma

Identifying novel prognostic biomarkers for hepatocellular carcinoma (HCC) and then, develop an effective individualized treatment strategy remain extremely warranted. The prognostic role of sulfiredoxin-1(SRXN1), an antioxidant enzyme, remains unknown in HCC. This study aimed to explore the prognostic implications of SRXN1 in HCC patients after partial hepatectomy. The expression of SRXN1 in HCC and normal tissue were analyzed using the patients from the public databases and Zhongshan Hospital. The Cox regression, Kaplan-Meier survival analysis, and time-dependent receiver operating characteristic curves were performed to identify the predictive role of SRXN1 expression on HCC patients. A prognostic nomogram based on SRXN1 expression was constructed and validated to further confirm the predictive power of SRXN1 as a prognostic biomarker. Finally, functional enrichment analysis and protein-protein interaction network analysis of SRXN1 and its associated genes were conducted. The results showed that SRXN1 was upregulated in HCC samples compared with the normal liver tissues. Patients with SRXN1 upregulation had shorter survival time. SRXN1 overexpression was significantly correlated with advanced clinicopathological parameters. The prognostic nomogram based on SRXN1 expression was proved to be more accurate than routine staging systems for the prediction of overall survival. Protein-protein interaction network analysis demonstrated the first neighbor genes of SRXN1 mainly participated in response to oxidative stress. In brief, SRXN1 could be a prognostic biomarker for the management of HCC.

Microbial and metabolic impacts of trehalose and trehalose analogues

Trehalose is a disaccharide and fasting-mimetic that has been both canonized and vilified for its putative cardiometabolic and microbial effects. Trehalose analogues are currently under development to extend the key metabolic therapeutic actions of trehalose without adversely affecting host microbial communities. In the current study, we contrast the extent to which trehalose and its degradation-resistant analogue, lactotrehalose (LT), modulate microbial communities and host transcriptomic profiles. We demonstrate that trehalose and LT each exert adaptive metabolic and microbial effects that both overlap and diverge. We postulate that these effects depend both upon compound stability and bioavailability, and on stereospecific signal transduction. In context, the data suggest that trehalose is unlikely to be harmful, and yet it harbors unique effects that are not yet fully replicated by its analogues. These compounds are thus valuable probes to better define trehalose structure-function, and to offer as therapeutic metabolic agents.

Identification of a prognostic signature of nine metabolism-related genes for hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) is the fifth most common cancer. Since changes in liver metabolism contribute to liver disease development, it is necessary to build a metabolism-related prognostic model for HCC.

Methods

We constructed a metabolism-related-gene (MRG) signature comprising nine genes, which segregated HCC patients into high- and low-risk groups.

Results

The survival rate (overall survival: OS; relapse-free survival; and progression-free survival) of patients in the low-risk group of The Cancer Genome Atlas (TCGA) cohort was significantly higher than that of patients in the high-risk group. The OS prognostic signature was validated in the International Cancer Genome Consortium independent cohort. The corresponding receiver operating characteristic curves of the model indicated that the signature had good diagnostic efficiency, in terms of improving OS over 1, 3, and 5 years. Hierarchical analysis demonstrated that the MRG signature was significantly associated with better prognosis in male patients, patients aged ≤ 65 years, and patients carrying the wild-type TP53 or CTNNB1 genes. A nomogram was established, and good performance and clinical practicability were confirmed. Additionally, using the GSE109211 dataset from the Gene Expression Omnibus database, we were able to verify that the nine genes in this MRG signature had different responses to sorafenib, suggesting that some of these MRGs may act as therapeutic targets for HCC.

Conclusions

We believe that these findings will add value in terms of the diagnosis, treatment, and prognosis of HCC.

SRXN1 stimulates hepatocellular carcinoma tumorigenesis and metastasis through modulating ROS/p65/BTG2 signalling

Sulfiredoxin 1 (SRXN1) is a pivotal regulator of the antioxidant response in eukaryotic cells. However, the role of SRXN1 in hepatocellular carcinoma (HCC) is far from clear. The present study aims to elucidate whether SRXN1 participates in tumorigenesis and metastasis of HCC and to determine the molecular mechanisms. We found that SRXN1 expression was up-regulated in HCC tissue samples and correlated with poor prognosis in HCC patients. We also observed that SRXN1 knockdown by transient siRNA transfection inhibited HCC cell proliferation, migration and invasion. Overexpression of SRXN1 increased HCC cell migration and invasion. B-cell translocation gene 2 (BTG2) was identified as a downstream target of SRXN1. Mechanistic studies revealed that SRXN1-depleted reactive oxygen species (ROS) modulated migration and invasion of HCC cells. In addition, the ROS/p65/BTG2 signalling hub was found to regulate the epithelial-mesenchymal transition (EMT), which mediates the pro-metastasis role of SRXN1 in HCC cells. In vivo experiments showed SRXN1 promotes HCC tumour growth and metastasis in mouse subcutaneous xenograft and metastasis models. Collectively, our results revealed a novel pro-tumorigenic and pro-metastatic function of SRXN1 in HCC. These findings demonstrate a rationale to exploit SRXN1 as a therapeutic target effectively preventing metastasis of HCC.

Halo and Pseudohalo Gold(I)-NHC Complexes Derived from 4,5-Diarylimidazoles with Excellent In Vitro and In Vivo Anticancer Activities Against HCC

A series of halo and pseudohalo gold(I)-NHC complexes (NHC-Au-X) (X = Cl, Br, I, NCO, and OAc) derived from 4,5-diarylimidazoles were synthesized, structurally characterized, and analyzed for their biological activities. The most active complex was iodo(1,3-diethyl-4,5-bis(4-methoxyphenyl)imidazol-2-ylidene)gold(I) (6), which was at least 2-fold more cytotoxic than cisplatin and auranofin against hepatocellular carcinoma (HCC) cells. In vivo studies indicated that complex 6 exhibited a considerably higher anticancer efficacy (IRT = 75.7%) than cisplatin (IRT = 44.4%) in a HepG2 xenograft mouse model and ameliorated liver injury caused by CCl₄ in chronic HCC. Further studies revealed that complex 6 can inhibit the expression of the thioredoxin reductase (TrxR) both in vitro and in vivo, block the HepG2 cells in the G2/M phase, induce reactive oxygen species (ROS) production, damage mitochondrial membrane potential (MMP), and promote HepG2 cell apoptosis.

Genetic variants in xenobiotic detoxification enzymes, antioxidant defenses and hormonal pathways as biomarkers of susceptibility to prostate cancer

Cancer is considered a complex disease that in many cases results from the interaction between chemical exposures, either from environmental or dietary sources, and genetic polymorphisms of xenobiotic-metabolizing enzymes (XME) or antioxidant enzymatic defenses. This study explored associations and interactions between genetic and environmental risk factors on the risk of prostate cancer (PCa) in 323 subjects that underwent prostate biopsy due to prostate specific antigen (PSA) levels above 4 ng/ml (161 PCa and 162 non-PCa). Eleven genes involved directly or indirectly in xenobiotic detoxification, oxidative stress and estrogen signaling were studied (GSTM1, GPX1 (rs1050450 and rs17650792), NAT2 (rs1801280), TXNRD1 (rs7310505), PRDX3 (rs3740562), CYP17A1 (rs743572), PON1 (rs662), SOD1 (rs10432782), SOD2 (rs4880), CAT (rs1001179), and ESR1 (rs746432)). A structured questionnaire was administered to all individuals to assess environmental and dietary chemical exposures. Medical data was collected by urologists. GPX1 rs17650792 polymorphism was the only one showing a significant inverse association with PCa risk. PRDX3 and GPX1 (rs17650792) genetic polymorphisms were significantly associated with Gleason score and PSA levels, respectively. The intake of nuts and soya products was associated with a reduced risk of PCa, as well as the performance of physical activity. Moreover, a number of gene-environmental interactions were found to increase the risk of PCa, particularly exposure to pesticides and rs1801280 (NAT2) and tobacco smoking and rs1050450 (GPX1). These findings suggest that the association of genetic and environmental risk factors with PCa risk should be assessed jointly for a better understanding of this complex disease.

Hepatocellular Carcinoma Cells Up-regulate PVRL1, Stabilizing PVR and Inhibiting the Cytotoxic T-Cell Response via TIGIT to Mediate Tumor Resistance to PD1 Inhibitors in Mice

BACKGROUND & AIMS

Immune checkpoint inhibitors are effective in the treatment of some hepatocellular carcinomas (HCCs), but these tumors do not always respond to inhibitors of programmed cell death 1 (PDCD1, also called PD1). We investigated mechanisms of resistance of liver tumors in mice to infiltrating T cells.

METHODS

Mice were given hydrodynamic tail vein injections of clustered regularly interspaced short palindromic repeats-Cas9 (CRISPR-Cas9) and transposon vectors to disrupt Trp53 and overexpress C-Myc (Trp53^KO/C-Myc^OE mice). Pvrl1 and Pvrl3 were knocked down in Hepa1-6 cells by using short hairpin RNAs. Hepa1-6 cells were injected into livers of C57BL/6 mice; some mice were given intraperitoneal injections of antibodies against PD1, T-cell immunoreceptor with Ig and ITIM domains (TIGIT), or CD8 before the cancer cells were injected. Liver tissues were collected from mice and analyzed by histology, immunohistochemistry, and quantitative real-time polymerase chain reaction; tumors were analyzed by mass cytometry using markers to detect T cells and other lymphocytes. We obtained HCC and nontumorous liver tissues and clinical data from patients who underwent surgery in Hong Kong and analyzed the tissues by immunohistochemistry.

RESULTS

Trp53^KO/C-Myc^OE mice developed liver tumors in 3-5 weeks; injections of anti-PD1 did not slow tumor development. Tumors from mice given anti-PD1 had larger numbers of memory CD8⁺ T cells (CD44⁺CD62L^-KLRG1^int) and T cells that expressed PD1, lymphocyte activating 3 (LAG3), and TIGIT compared with mice not given the antibody. HCC tissues from patients had higher levels of PVRL1 messenger RNA and protein than nontumorous tissues. Increased PVRL1 was associated with shorter times of disease-free survival. Knockdown of Pvrl1 in Hepa1-6 cells caused them to form smaller tumors in mice, infiltrated by higher numbers of CD8⁺ T cells that expressed the inhibitory protein TIGIT; these effects were not observed in mice with depletion of CD8⁺ T cells. In Hepa1-6 cells, PVRL1 stabilized cell surface PVR, which interacted with TIGIT on CD8⁺ T cells; knockdown of Pvrl1 reduced cell-surface levels of PVR but not levels of Pvr messenger RNA. In Trp53^KO/C-Myc^OE mice and mice with tumors grown from Hepa1-6 cells, injection of the combination of anti-PD1 and anti-TIGIT significantly reduced tumor growth, increased the ratio of cytotoxic to regulatory T cells in tumors, and prolonged survival.

CONCLUSIONS

PVRL1, which is up-regulated by HCC cells, stabilizes cell surface PVR, which interacts with TIGIT, an inhibitory molecule on CD8⁺ effector memory T cells. This suppresses the ant-tumor immune response. Inhibitors of PVRL1/TIGIT, along with anti-PD1 might be developed for treatment of HCC.

Auranofin mitigates systemic iron overload and induces ferroptosis via distinct mechanisms

Iron homeostasis is essential for health; moreover, hepcidin-deficiency results in iron overload in both hereditary hemochromatosis and iron-loading anemia. Here, we identified iron modulators by functionally screening hepcidin agonists using a library of 640 FDA-approved drugs in human hepatic Huh7 cells. We validated the results in C57BL/6J mice and a mouse model of hemochromatosis (Hfe^−/− mice). Our screen revealed that the anti-rheumatoid arthritis drug auranofin (AUR) potently upregulates hepcidin expression. Interestingly, we found that canonical signaling pathways that regulate iron, including the Bmp/Smad and IL-6/Jak2/Stat3 pathways, play indispensable roles in mediating AUR’s effects. In addition, AUR induces IL-6 via the NF-κB pathway. In C57BL/6J mice, acute treatment with 5 mg/kg AUR activated hepatic IL-6/hepcidin signaling and decreased serum iron and transferrin saturation. Whereas chronically treating male Hfe^−/− mice with 5 mg/kg AUR activated hepatic IL-6/hepcidin signaling, decreasing systemic iron overload, but less effective in females. Further analyses revealed that estrogen reduced the ability of AUR to induce IL-6/hepcidin signaling in Huh7 cells, providing a mechanistic explanation for ineffectiveness of AUR in female Hfe^−/− mice. Notably, high-dose AUR (25 mg/kg) induces ferroptosis and causes lipid peroxidation through inhibition of thioredoxin reductase (TXNRD) activity. We demonstrate the ferroptosis inhibitor ferrostatin significantly protects liver toxicity induced by high-dose AUR without comprising its beneficial effect on iron metabolism. In conclusion, our findings provide compelling evidence that TXNRD is a key regulator of ferroptosis, and AUR is a novel activator of hepcidin and ferroptosis via distinct mechanisms, suggesting a promising approach for treating hemochromatosis and hepcidin-deficiency related disorders.

Identification and targeting of selective vulnerability rendered by tamoxifen resistance

BACKGROUND

The estrogen receptor (ER)-positive breast cancer represents over 80% of all breast cancer cases. Even though adjuvant hormone therapy with tamoxifen (TMX) is saving lives of patients with ER-positive breast cancer, the acquired resistance to TMX anti-estrogen therapy is the main hurdle for successful TMX therapy. Here we address the mechanism for TMX resistance and explore the ways to eradicate TMX-resistant breast cancer in both in vitro and ex vivo experiments.

EXPERIMENTAL DESIGN

To identify compounds able to overcome TMX resistance, we used short-term and long-term viability assays in cancer cells in vitro and in patient samples in 3D ex vivo, analysis of gene expression profiles and cell line pharmacology database, shRNA screen, CRISPR-Cas9 genome editing, real-time PCR, immunofluorescent analysis, western blot, measurement of oxidative stress using flow cytometry, and thioredoxin reductase 1 enzymatic activity.

RESULTS

Here, for the first time, we provide an ample evidence that a high level of the detoxifying enzyme SULT1A1 confers resistance to TMX therapy in both in vitro and ex vivo models and correlates with TMX resistance in metastatic samples in relapsed patients. Based on the data from different approaches, we identified three anticancer compounds, RITA (Reactivation of p53 and Induction of Tumor cell Apoptosis), aminoflavone (AF), and oncrasin-1 (ONC-1), whose tumor cell inhibition activity is dependent on SULT1A1. We discovered thioredoxin reductase 1 (TrxR1, encoded by TXNRD1) as a target of bio-activated RITA, AF, and ONC-1. SULT1A1 depletion prevented the inhibition of TrxR1, induction of oxidative stress, DNA damage signaling, and apoptosis triggered by the compounds. Notably, RITA efficiently suppressed TMX-unresponsive patient-derived breast cancer cells ex vivo.

CONCLUSION

We have identified a mechanism of resistance to TMX via hyperactivated SULT1A1, which renders selective vulnerability to anticancer compounds RITA, AF, and ONC-1, and provide a rationale for a new combination therapy to overcome TMX resistance in breast cancer patients. Our novel findings may provide a strategy to circumvent TMX resistance and suggest that this approach could be developed further for the benefit of relapsed breast cancer patients.

Mitochondrial TXNRD3 confers drug resistance via redox-mediated mechanism and is a potential therapeutic target in vivo

Alterations in ROS metabolism and redox signaling are often observed in cancer cells and play a significant role in tumor development and drug resistance. However, the mechanisms by which redox alterations impact cellular sensitivity to anticancer drugs remain elusive. Here we have identified the mitochondrial isoform of thioredoxin reductase 3 (mtTXNRD3), through RT-PCR microarray screen, as a key molecule that confers drug resistance to sorafenib and other clinical anticancer agents. High expression of mtTXNRD3 is detected in drug-resistant leukemia and hepatocellular carcinoma cells associated with significant metabolic alterations manifested by low mitochondrial respiration and high glycolysis. Mechanistically, high mtTXNRD3 activity keeps the mitochondrial thioredoxin2 (Trx2) in a reduced stage that in turn stabilizes several key survival molecules including HK2, Bcl-XL, Bcl-2, and MCL-1, leading to increased cell survival and drug resistance. Pharmacological inhibition of thioredoxin reductase by auranofin effectively overcomes such drug resistance in vitro and in vivo, suggesting that targeting this redox mechanism may be a feasible strategy to treat drug-resistant cancer.

Glucometabolic Reprogramming in the Hepatocellular Carcinoma Microenvironment: Cause and Effect

Hepatocellular carcinoma (HCC) is a tumor that exhibits glucometabolic reprogramming, with a high incidence and poor prognosis. Usually, HCC is not discovered until an advanced stage. Sorafenib is almost the only drug that is effective at treating advanced HCC, and promising metabolism-related therapeutic targets of HCC are urgently needed. The “Warburg effect” illustrates that tumor cells tend to choose aerobic glycolysis over oxidative phosphorylation (OXPHOS), which is closely related to the features of the tumor microenvironment (TME). The HCC microenvironment consists of hypoxia, acidosis and immune suppression, and contributes to tumor glycolysis. In turn, the glycolysis of the tumor aggravates hypoxia, acidosis and immune suppression, and leads to tumor proliferation, angiogenesis, epithelial–mesenchymal transition (EMT), invasion and metastasis. In 2017, a mechanism underlying the effects of gluconeogenesis on inhibiting glycolysis and blockading HCC progression was proposed. Treating HCC by increasing gluconeogenesis has attracted increasing attention from scientists, but few articles have summarized it. In this review, we discuss the mechanisms associated with the TME, glycolysis and gluconeogenesis and the current treatments for HCC. We believe that a treatment combination of sorafenib with TME improvement and/or anti-Warburg therapies will set the trend of advanced HCC therapy in the future.

Diurnal and day-to-day variation of urinary oxidative stress marker 8-hydroxy-2'-deoxyguanosine

The urinary 8-hydroxy-2'-deoxyguanosine levels have been widely used as a biomarker of oxidative stress. The purpose of this study is to investigate the diurnal and day-to-day variations of urinary 8-hydroxy-2'-deoxyguanosine levels. For the diurnal variation, the urine samples were collected at the time of awakening and every 2 h, from 10:00 to 22:00, from 6 healthy participants. For the day-to-day variation, the urine samples were collected at the time of awakening for 35 consecutive days, from 27 healthy participants. As a result, no differences were observed in the diurnal urinary 8-hydroxy-2'-deoxyguanosine levels, and each subject had a characteristic 8-hydroxy-2'-deoxyguanosine level. On the other hand, the daily 8-hydroxy-2'-deoxyguanosine values showed a certain range of variation reflecting lifestyle factors, such as stress status, exercise, sleep time, drinking and diet. In conclusion, urinary 8-hydroxy-2'-deoxyguanosine may be a useful biomarker to control and prevent oxidative stress-related diseases, if the certain range of day-to-day variations of urinary 8-hydroxy-2'-deoxyguanosine is known. Even with only one measurement per year, the baseline urinary 8-hydroxy-2'-deoxyguanosine level could be achieved in a few years by incorporating the 8-hydroxy-2'-deoxyguanosine measurement as part of an annual health check. As the number of subjects was limited, further studies are needed for practical applications.

Comprehensive analysis reveals a metabolic ten-gene signature in hepatocellular carcinoma

Background

Due to the complicated molecular and cellular heterogeneity in hepatocellular carcinoma (HCC), the morbidity and mortality still remains high level in the world. However, the number of novel metabolic biomarkers and prognostic models could be applied to predict the survival of HCC patients is still small. In this study, we constructed a metabolic gene signature by systematically analyzing the data from The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO) and International Cancer Genome Consortium (ICGC).

Methods

Differentially expressed genes (DEGs) between tumors and paired non-tumor samples of 50 patients from TCGA dataset were calculated for subsequent analysis. Univariate cox proportional hazard regression and LASSO analysis were performed to construct a gene signature. The Kaplan–Meier analysis, time-dependent receiver operating characteristic (ROC), Univariate and Multivariate Cox regression analysis, stratification analysis were used to assess the prognostic value of the gene signature. Furthermore, the reliability and validity were validated in four types of testing cohorts. Moreover, the diagnostic capability of the gene signature was investigated to further explore the clinical significance. Finally, Go enrichment analysis and Gene Set Enrichment Analysis (GSEA) have been performed to reveal the different biological processes and signaling pathways which were active in high risk or low risk group.

Results

Ten prognostic genes were identified and a gene signature were constructed to predict overall survival (OS). The gene signature has demonstrated an excellent ability for predicting survival prognosis. Univariate and Multivariate analysis revealed the gene signature was an independent prognostic factor. Furthermore, stratification analysis indicated the model was a clinically and statistically significant for all subgroups. Moreover, the gene signature demonstrated a high diagnostic capability in differentiating normal tissue and HCC. Finally, several significant biological processes and pathways have been identified to provide new insights into the development of HCC.

Conclusion

The study have identified ten metabolic prognostic genes and developed a prognostic gene signature to provide more powerful prognostic information and improve the survival prediction for HCC.

Redox Modulation and Induction of Ferroptosis as a New Therapeutic Strategy in Hepatocellular Carcinoma

Ferroptosis, a newly discovered form of cell death mediated by reactive oxygen species (ROS) and lipid peroxidation, has recently been shown to have an impact on various cancer types; however, so far there are only few studies about its role in hepatocellular carcinoma (HCC). The delicate equilibrium of ROS in cancer cells has found to be crucial for cell survival, thus increased levels may trigger ferroptosis in HCC. In our study, we investigated the effect of different ROS modulators and ferroptosis inducers on a human HCC cell line and a human hepatoblastoma cell line. We identified a novel synergistic cell death induction by the combination of Auranofin and buthionine sulfoxime (BSO) or by Erastin and BSO at subtoxic concentrations. We found a caspase-independent, redox-regulated cell death, which could be rescued by different inhibitors of ferroptosis. Both cotreatments stimulated lipid peroxidation. All these findings indicated ferroptotic cell death. Both cotreatments affected the canonical ferroptosis pathway through GPX4 downregulation. We also found an accumulation of Nrf2 and HO-1, indicating an additional effect on the non-canonical pathway. Our results implicate that targeting these two main ferroptotic pathways simultaneously can overcome chemotherapy resistance in HCC.

Preclinical Gold Complexes as Oral Drug Candidates to Treat Leishmaniasis Are Potent Trypanothione Reductase Inhibitors

The drugs currently used to treat leishmaniases have limitations concerning cost, efficacy, and safety, making the search for new therapeutic approaches urgent. We found that the gold(I)-derived complexes were active against L. infantum and L. braziliensis intracellular amastigotes with IC₅₀ values ranging from 0.5 to 5.5 μM. All gold(I) complexes were potent inhibitors of trypanothione reductase (TR), with enzyme IC₅₀ values ranging from 1 to 7.8 μM. Triethylphosphine-derived complexes enhanced reactive oxygen species (ROS) production and decreased mitochondrial respiration after 2 h of exposure, indicating that gold(I) complexes cause oxidative stress by direct ROS production, by causing mitochondrial damage or by impairing TR activity and thus accumulating ROS. There was no cross-resistance to antimony; in fact, SbR (antimony-resistant mutants) strains were hypersensitive to some of the complexes. BALB/c mice infected with luciferase-expressing L. braziliensis or L. amazonensis and treated orally with 12.5 mg/kg/day of AdT Et (3) or AdO Et (4) presented reduced lesion size and parasite burden, as revealed by bioimaging. The combination of (3) and miltefosine allowed for a 50% reduction in miltefosine treatment time. Complexes 3 and 4 presented favorable pharmacokinetic and toxicity profiles that encourage further drug development studies. Gold(I) complexes are promising antileishmanial agents, with a potential for therapeutic use, including in leishmaniasis caused by antimony-resistant parasites.

Hypomethylation of the cyclin D1 promoter in hepatitis B virus-associated hepatocellular carcinoma

The hypomethylation of the Cyclin D1 (CCND1) promoter induced by excess oxidative stress likely promotes the development of hepatitis B virus-associated hepatocellular carcinoma (HBV-HCC). We aimed to evaluate methylation status of the CCND1 promoter as a new plasma marker for the detection of HBV-HCC.We consecutively recruited 191 participants, including 105 patients with HBV-HCC, 54 patients with chronic hepatitis B (CHB), and 32 healthy controls (HCs). Using methylation-specific polymerase chain reaction, we identified the methylation status of the CCND1 promoter in plasma samples. We analyzed the expression levels of the CCND1 mRNA in peripheral blood mononuclear cells by using quantitative real-time PCR. We assessed the plasma levels of superoxide dismutase, 8-hydroxydeoxyguanosine and malondialdehyde by using enzyme-linked immunosorbent assays.Patients with HBV-HCC (23.81%) presented a reduced methylation frequency compared with patients with CHB (64.81%) or HCs (78.13%) (P < .001). When receiver operating characteristic curves were plotted for patients with HBV-HCC versus CHB, the methylation status of the CCND1 promoter yielded diagnostic parameter values for the area under the curve of 0.705, sensitivity of 76.19%, and specificity of 64.81%, thus outperforming serum alpha-fetoprotein (AFP), which had an area under the curve of 0.531, sensitivity of 36.19%, and specificity of 90.74%. Methylation of the CCND1 promoter represents a prospective diagnostic marker for patients with AFP-negative HBV-HCC and AFP-positive CHB. The expression levels of CCND1 mRNA was increased in patients with HBV-HCC compared with patients with CHB (Z = -4.946, P < .001) and HCs (Z = -6.819, P < .001). Both the extent of oxidative injury and antioxidant capacity indicated by the superoxide dismutase, 8-hydroxydeoxyguanosine and malondialdehyde levels were increased in patients with HBV-HCC. Clinical follow up of patients with HBV-HCC revealed a worse overall survival (P = .012, log-rank test) and a decreased progression-free survival (HR = 0.109, 95%CI: 0.031-0.384) for the unmethylated CCND1 group than methylated CCND1 group.Our study confirms that oxidative stress appears to correlate with plasma levels of CCND1 promoter methylation, and the methylation status of the CCND1 promoter represents a prospective biomarker with better diagnostic performance than serum AFP levels.

Synthesis and biological evaluation of gold(III) Schiff base complexes for the treatment of hepatocellular carcinoma through attenuating TrxR activity

Hepatocellular carcinoma (HCC) is one of the most common cancers and a leading cause of death worldwide. Increased thioredoxin reductase (TrxR) levels were recently identified as possible prognostic markers for HCC. Here, four gold(III) complexes 1b-4b bearing Schiff base ligands were synthesized, characterized, and screened for antitumor activity against HCC. All complexes triggered significant antiproliferative effects against HCC cells, especially the most active complex 1b induced HepG2 cells apoptosis by activating the endoplasmic reticulum stress (ERS). 1b could clearly inhibit the TrxR activity to elevate reactive oxygen species (ROS), mediate ERS and lead to mitochondrial dysfunction. Notably, treatment of 1b improved the CCl₄-induced liver damage in vivo by down-regulation of TrxR expression and inflammation level.

Correlation between the expressions of circular RNAs in peripheral venous blood and clinicopathological features in hepatocellular carcinoma

Background

Recent studies have reported that circular RNAs (circRNAs) are involved in the development of hepatocellular carcinoma (HCC). This study evaluated the expression of preoperative peripheral venous blood circRNAs in HCC patients and their predictive ability for microvascular invasion (MVI).

Methods

Seven circRNAs (circMTO1, circ-10720, circZKSCAN1, cSMARCA5, circHIPK3, circSETD3 and ciRS-7) were screened from the literature as circRNAs with reported biological functions in HCC. The expression levels of seven circRNAs in preoperative blood samples and HCC tissues were detected by quantitative reverse transcription polymerase chain reaction. The correlations between the circRNA expressions in blood and the clinicopathological factors of HCC patients were analyzed. The risk factors of MVI were analyzed by univariate and multivariate logistic regression. The functional role of circSETD3 in cell migration and invasion was evaluated by wound healing and Transwell assays in vitro.

Results

The expressions of all seven circRNAs were measured in peripheral venous blood samples. The venous expression levels of circHIPK3 and circMTO1 were significantly associated with gender, while circ-10720 and circMTO1 levels were significantly correlated with gross vascular invasion. Furthermore, circMTO1 and cSMARCA5 levels were significantly associated with alpha-fetoprotein level and ciRS-7 was significantly associated with satellite nodules. Importantly, low venous circSETD3 expression was significantly associated with prothrombin induced by vitamin K absence or antagonist-II (PIVKA-II) level, MVI, gross vascular invasion, and liver capsule. Furthermore, venous circSETD3 expression had predictive ability for MVI. Knockdown of circSETD3 promoted cell invasion and metastasis in vitro.

Conclusions

CircRNAs were stably present in peripheral venous blood and associated with multiple clinicopathological characteristics of HCC patients. Venous circSETD3 was an independent risk factor of MVI and shows ability to predict MVI in HCC patients before surgery.

ZNF143 Suppresses Cell Apoptosis and Promotes Proliferation in Gastric Cancer via ROS/p53 Axis

Aim

This study was aimed at identifying the role of zinc finger protein 143 (ZNF143) in gastric cancer (GC) progression.

Methods

The impact of ZNF143 on the proliferation ability and apoptosis of GC cells was detected. The expression of ZNF143 and related targeted genes was determined using Western blot analysis. The reactive oxygen species (ROS) level of GC cells was examined using the ROS generation assay. The role of ZNF143 in the proliferation of GC cells in vivo was examined using tumor xenograft assay.

Results

The ectopic overexpression of ZNF143 promoted the proliferation of GC cells, while its knockdown reduced the effect in vitro. The downregulation of ZNF143 facilitated cell apoptosis. ZNF143 decreased the ROS level in GC cells, resulting in the reduction of cell apoptosis. Transfection with p53 reversed the antiapoptotic effect of ZNF143, while pifithrin-α, a specific inhibitor of p53, reduced the apoptosis in ZNF143-knockdown GC cells. However, p53 had no influence on the ROS level in GC cells. p53 played a key role in inhibiting ROS generation in GC cells, thereby inhibiting apoptosis. The transplanted tumor weight and volume were higher in the ZNF143-overexpressed group than in the ZNF143-knockdown group in vivo was examined using tumor xenograft assay.

Conclusion

ZNF143, as a tumor oncogene, promoted the proliferation of GC cells both in vitro and in vivo, indicating that ZNF143 might function as a novel target for GC therapy.in vitro. The downregulation of ZNF143 facilitated cell apoptosis. ZNF143 decreased the ROS level in GC cells, resulting in the reduction of cell apoptosis. Transfection with p53 reversed the antiapoptotic effect of ZNF143, while pifithrin-in vivo was examined using tumor xenograft assay.

The microenvironmental and metabolic aspects of sorafenib resistance in hepatocellular carcinoma

In most cases, sorafenib-resistant HCC cells exhibit significant mesenchymal phenotype and stemness features. In this context, tumor cells might undergo cell fate transition in response to sorafenib or other targeted drugs in the presence or absence of genetic mutations. Therefore, understanding the major characteristics of drug-resistant cells state helps to discover new treatments that overcome drug resistance. To note, little is known about the metabolic or microenvironmental aspects of the certain tumor cell states beyond the genome. This review mainly focuses on the underlying mechanisms of acquired sorafenib resistance based on CSCs and EMT models, which explain tumor heterogeneity and have been considered the major cause of secondary sorafenib resistance. In particular, it discusses how the tumor microenvironment and tumor metabolism regulate cell stemness, mesenchymal state, and sorafenib resistance through epigenetic regulations, and provides reliable targets that might have synergetic effect with sorafenib.

Hypoxia regulates the mitochondrial activity of hepatocellular carcinoma cells through HIF/HEY1/PINK1 pathway

Hypoxia is commonly found in cancers. Hypoxia, due to the lack of oxygen (O₂) as the electron recipient, causes inefficient electron transfer through the electron transport chain at the mitochondria leading to accumulation of reactive oxygen species (ROS) which could create irreversible cellular damages. Through hypoxia-inducible factor 1 (HIF-1) which elicits various molecular events, cells are able to overcome low O₂. Knowledge about the new molecular mechanisms governed by HIF-1 is important for new therapeutic interventions targeting hypoxic tumors. Using hepatocellular carcinoma (HCC) as a model, we revealed that the HIF-1 and the Notch signaling pathways cross-talk to control mitochondrial biogenesis of cancer cells to maintain REDOX balance. From transcriptome sequencing, we found that HEY1, a transcriptional repressor, in the NOTCH pathway was consistently induced by hypoxia in HCC cell lines. We identified a strong hypoxia response element (HRE) in HEY1 by chromatin immunoprecipitation (ChIP) and luciferase reporter assays. Transcriptome and ChIP sequencing further identified PINK1, a gene essential for mitochondrial biogenesis, as a novel transcriptional target of HEY1. HCC cells with HEY1 knockdown re-expressed PINK1. HEY1 and PINK1 expressions inversely correlated in human HCC samples. Overexpression of HEY1 and under-expression of PINK1 were detected in human HCC and associated with poor clinical outcomes. Functionally, we found that overexpression of HEY1 or knockdown of PINK1 consistently reduced mitochondrial cristae, mitochondrial mass, oxidative stress level, and increased HCC growth.

Large-scale analyses identify a cluster of novel long noncoding RNAs as potential competitive endogenous RNAs in progression of hepatocellular carcinoma

The abnormal expression of noncoding RNAs has attracted increasing interest in the field of hepatocellular carcinoma progression. However, the underlying molecular mechanisms mediated by noncoding RNAs in these processes are unclear. Here, we obtained the expression profiles of long noncoding RNAs, microRNAs, and mRNAs from the Gene Expression Omnibus database and identified hepatocarcinogenesis-specific differentially expressed transcripts. Next, we identified significant Gene Ontology and pathway terms that the differentially expressed transcripts involved in. Using functional analysis and target prediction, we constructed a hepatocellular carcinoma-associated deregulated competitive endogenous RNA network to reveal the potential mechanisms underlying tumor progression. By analyzing The Cancer Genome Atlas dataset, six key long noncoding RNAs showed significant association with overall survival as well as strong correlation with some microRNAs and mRNAs in the competitive endogenous RNA network. We further validated the above results and determined their diagnostic and prognostic value in clinical samples. Importantly, by large-scale analyses, we identified a cluster of long noncoding RNAs, GBAP1, MCM3AP-AS1, SLC16A1-AS1, C3P1, DIO3OS, and HNF4A-AS1 as candidate biomarkers for the diagnosis and prognosis of hepatocellular carcinoma, which will improve our understanding of competitive endogenous RNA-mediated regulatory mechanisms underlying hepatocellular carcinoma development and will provide novel therapeutic targets in the future.

The Crosstalk of miRNA and Oxidative Stress in the Liver: From Physiology to Pathology and Clinical Implications

The liver is the central metabolic organ of mammals. In humans, most diseases of the liver are primarily caused by an unhealthy lifestyle-high fat diet, drug and alcohol consumption- or due to infections and exposure to toxic substances like aflatoxin or other environmental factors. All these noxae cause changes in the metabolism of functional cells in the liver. In this literature review we focus on the changes at the miRNA level, the formation and impact of reactive oxygen species and the crosstalk between those factors. Both, miRNAs and oxidative stress are involved in the multifactorial development and progression of acute and chronic liver diseases, as well as in viral hepatitis and carcinogenesis, by influencing numerous signaling and metabolic pathways. Furthermore, expression patterns of miRNAs and antioxidants can be used for biomonitoring the course of disease and show potential to serve as possible therapeutic targets.