Thioredoxin and thioredoxin-interacting protein as prognostic markers for gastric cancer recurrence

Role of Pyroptosis in Endometrial Cancer and Its Therapeutic Regulation

Pyroptosis is an inflammatory cell death induced by inflammasomes that release several pro-inflammatory mediators such as interleukin-18 (IL-18) and interleukin-1β (IL-1β). Pyroptosis, a type of programmed cell death, has recently received increased interest both as a therapeutic and immunological mechanism. Numerous studies have provided substantial evidence supporting the involvement of inflammasomes and pyroptosis in a variety of pathological conditions including cancers, nerve damage, inflammatory diseases and metabolic conditions. Researchers have demonstrated that dysregulation of pyroptosis and inflammasomes contribute to the progression of endometriosis and gynecological malignancies. Current research also indicates that inflammasome and pyroptosis-dependent signaling pathways may further induce the progression of endometrial cancer (EC). More specifically, dysregulation of NLR family pyrin domain 3 (NLRP3) and caspase-1-dependent pyroptosis play a contributory role in the pathogenesis and development of EC. Therefore, pyroptosis-regulated protein gasdermin D (GSDMD) may be an independent prognostic biomarker for the detection of EC. This review presents the molecular mechanisms of pyroptosis-dependent signaling pathways and their contributory role and function in advancing EC. Moreover, this review offers new insights into potential future applications and innovative approaches in utilizing pyroptosis to develop effective anti-cancer therapies.

Thioredoxin System Protein Expression in Carcinomas of the Pancreas, Distal Bile Duct, and Ampulla in the United Kingdom

Background: Poor survival outcomes in periampullary cancer highlight the need for improvement in biomarkers and the development of novel therapies. Redox proteins, including the thioredoxin system, play vital roles in cellular antioxidant systems. Methods: In this retrospective study, thioredoxin (Trx), thioredoxin-interacting protein (TxNIP), and thioredoxin reductase (TrxR) protein expression was assessed in 85 patients with pancreatic ductal adenocarcinoma (PDAC) and 145 patients with distal bile duct or ampullary carcinoma using conventional immunohistochemistry. Results: In patients with PDAC, high cytoplasmic TrxR expression was significantly associated with lymph node metastasis (p = 0.033). High cytoplasmic and nuclear Trx expression was significantly associated with better overall survival (p = 0.018 and p = 0.006, respectively), and nuclear Trx expression remained significant in multivariate Cox regression analysis (p < 0.0001). In distal bile duct and ampullary carcinomas, high nuclear TrxR expression was associated with vascular (p = 0.001) and perineural (p = 0.021) invasion, and low cytoplasmic TxNIP expression was associated with perineural invasion (p = 0.025). High cytoplasmic TxNIP expression was significantly associated with better overall survival (p = 0.0002), which remained significant in multivariate Cox regression analysis (p = 0.013). Conclusions: These findings demonstrate the prognostic importance of Trx system protein expression in periampullary cancers.

Exploring the Thioredoxin System as a Therapeutic Target in Cancer: Mechanisms and Implications

Cells constantly face the challenge of managing oxidants. In aerobic organisms, oxygen (O2) is used for energy production, generating reactive oxygen species (ROS) as byproducts of enzymatic reactions. To protect against oxidative damage, cells possess an intricate system of redox scavengers and antioxidant enzymes, collectively forming the antioxidant defense system. This system maintains the redox equilibrium and enables the generation of localized oxidative signals that regulate essential cellular functions. One key component of this defense is the thioredoxin (Trx) system, which includes Trx, thioredoxin reductase (TrxR), and NADPH. The Trx system reverses oxidation of macromolecules and indirectly neutralizes ROS via peroxiredoxin (Prx). This dual function protects cells from damage accumulation and supports physiological cell signaling. However, the Trx system also shields tumors from oxidative damage, aiding their survival. Due to elevated ROS levels from their metabolism, tumors often rely on the Trx system. In addition, the Trx system regulates critical pathways such as proliferation and neoangiogenesis, which tumors exploit to enhance growth and optimize nutrient and oxygen supply. Consequently, the Trx system is a potential target for cancer therapy. The challenge lies in selectively targeting malignant cells without disrupting the redox equilibrium in healthy cells. The aim of this review article is threefold: first, to elucidate the function of the Trx system; second, to discuss the Trx system as a potential target for cancer therapies; and third, to present the possibilities for inhibiting key components of the Trx system, along with an overview of the latest clinical studies on these inhibitors.

Strategies for the design of analogs of auranofin endowed with anticancer potential

INTRODUCTION

Auranofin (AF) is a well-established, FDA-approved, antiarthritic gold drug that is currently being reevaluated for a variety of therapeutic indications through drug repurposing. AF has shown great promise as a potential anticancer agent and has been approved for a few clinical trials in cancer. The renewed interest in AF has led to extensive research into the design, preparation and biological evaluation of auranofin analogs, which may have an even better pharmacological profile than the parent drug.

AREAS COVERED

This article reviews the strategies for chemical modification of the AF scaffold. Several auranofin analogs have been prepared and characterized for medical application in the field of cancer treatment over the last 20 years. Some emerging structure-function relationships are proposed and discussed.

EXPERT OPINION

The chemical modification of the AF scaffold has been the subject of intense activity in recent years and this strategy has led to the preparation and evaluation of several AF analogs. The case of iodauranofin is a particularly promising example. The availability of homogeneous biological data for a group of AF derivatives allows some initial structure-function relationships to be proposed, which may inspire the design and synthesis of new and better AF analogs for cancer treatment.

LncRNA STARD7-AS1 suppresses cervical cancer cell proliferation while promoting autophagy by regulating miR-31-5p/TXNIP axis to inactivate the mTOR signaling

OBJECTIVE

Cervical cancer (CC) is a serious gynecologic health issue for women worldwide. Long non-coding RNA (lncRNA) has been well-documented in controlling malignant behavior of various cancer cells. The role of lncRNA STARD7-AS1 in regulating CC cell proliferation and autophagy and its possible mechanism were investigated in this work.

METHODS

RNA expression and protein levels were quantified by reverse transcription quantitative polymerase chain reaction and western blotting. The location of STARD7-AS1 in CC cells was examined using subcellular fraction assays. Cell Counting Kit-8 assays and colony forming assays were performed to measure CC cell viability and proliferation. Autophagy in CC cells was evaluated using macrophage-derived chemokine (MDC) staining and transmission electron microscopy. The binding between microRNA (miR)-31-5p and STARD7-AS1 (or thioredoxin-interacting protein [TXNIP]) was determined by performing luciferase reporter, RNA pull-down or RNA immunoprecipitation assays.

RESULTS

STARD7-AS1 overexpression significantly suppressed CC cell viability and proliferation while notably inducing autophagy. STARD7-AS1 upregulated TXNIP expression via interaction with miR-31-5p. In addition, the effects of STARD7-AS1 on CC cell proliferation and autophagy were reversed by TXNIP silencing. The suppressive effect of STARD7-AS1 overexpression on phosphorylated levels of mTOR and S6K1 was countervailed by TXNIP deficiency.

CONCLUSION

In conclusion, lncRNA STARD7-AS1 inhibits CC cell proliferation and promotes cell autophagy by targeting the miR-31-5p/TXNIP axis to inactivate the mTOR signaling.

Circulating tumor cells reveal early predictors of disease progression in patients with stage III NSCLC undergoing chemoradiation and immunotherapy

Circulating tumor cells (CTCs) are early signs of metastasis and can be used to monitor disease progression well before radiological detection by imaging. Using an ultrasensitive graphene oxide microfluidic chip nanotechnology built with graphene oxide sheets, we were able to demonstrate that CTCs can be specifically isolated and molecularly characterized to predict future progression in patients with stage III non-small cell lung cancer (NSCLC). We analyzed CTCs from 26 patients at six time points throughout the treatment course of chemoradiation followed by immune checkpoint inhibitor immunotherapy. We observed that CTCs decreased significantly during treatment, where a larger decrease in CTCs predicted a significantly longer progression-free survival time. Durvalumab-treated patients who have future progression were observed to have sustained higher programmed death ligand 1+ CTCs compared to stable patients. Gene expression profiling revealed phenotypically aggressive CTCs during chemoradiation. By using emerging innovative bioengineering approaches, we successfully show that CTCs are potential biomarkers to monitor and predict patient outcomes in patients with stage III NSCLC.

Intratumoral microbiome is associated with gastric cancer prognosis and therapy efficacy

The role of the intratumoral microbiome in gastric cancer (GC) has not been comprehensively assessed. Here, we explored the relationship between the microbial community and GC prognosis and therapy efficacy. Several cancer-associated microbial characteristics were identified, including increased α-diversity, differential β-diversity, and decreased Helicobacter pylori abundance. After adjusting for clinical features, prognostic analysis revealed 2 phyla, 14 genera, and 5 species associated with the overall survival of patients with GC. Additionally, 2 phyla, 14 genera, and 6 species were associated with adjuvant chemotherapy (ACT) efficacy in patients with stage II - III GC. Furthermore, we classified GC microbiome structures into three microbial subtypes (MS1, MS2 and MS3) with distinguishing features. The MS1 subtype exhibited high immune activity and enrichment of microbiota related to immunotherapy and butyric acid-producing, as well as potential benefits in immunotherapy. MS2 featured the highest α-diversity and activation of the TFF pathway, MS3 was characterized by epithelial-mesenchymal transition and was associated with poor prognosis and reduced ACT efficacy. Collectively, the results of this study provide valuable insights into the microbial characteristics associated with GC prognosis and therapy efficacy.

Comprehensive analysis of single-cell and bulk RNA-sequencing data identifies B cell marker genes signature that predicts prognosis and analysis of immune checkpoints expression in head and neck squamous cell carcinoma

Recent studies have shown that B cells and the associated tertiary lymphoid structures (TLS) correlate with the response of patients to immune checkpoint inhibitors (ICIs) and predict overall survival (OS) in cancer patients. We screened 145 B cell marker genes (BCMG) by a comprehensive analysis of single-cell RNA-sequencing (scRNA-seq) data of head and neck squamous cell carcinoma (HNSC) from the Gene Expression Omnibus (GEO) database. The BCMG signature (BCMGS) was established using The Cancer Genome Atlas (TCGA) dataset of HNSC and verified in four independent datasets. The multivariate Cox regression analysis identified the signature as an independent prognostic factor. A prognostic nomogram was constructed with independent prognostic factors using the TCGA dataset. GO and KEGG analysis revealed the underlying signaling pathways related to this signature. Study of immune profiles showed that patients in the low-risk group presented discriminative immune-cell infiltrations. Furthermore, the low-risk group was featured by higher TCR and BCR diversity, which suggested that low-risk patients may be more sensitive to ICIs. Immunohistochemistry was performed, and we found that high expression of FTH1 was significantly correlated with poor OS (P = 0.025). The expression of TIM-3, LAG-3 and PD-1 was positively correlated and associated with better OS in HNSC. However, there was no statistically significant difference between PD-L1, PD-L2, CTLA-4, TIGIT and prognosis. The BCMGS was a promising prognostic biomarker in HNSC, which may help to interpret the responses to immunotherapy and provide a new perspective for future research on the treatment in HNSC.

microRNA-301b-3p from mesenchymal stem cells-derived extracellular vesicles inhibits TXNIP to promote multidrug resistance of gastric cancer cells

OBJECTIVE

MicroRNAs (miRNAs) from mesenchymal stem cells (MSC)-derived extracellular vesicles (MSCs-EVs), including exosomes, are known to participate in different diseases. However, the function of miR-301b-3p from MSCs-EVs on the chemoresistance of gastric cancer (GC) cells remains poorly characterized. Thus, we aim to explore the role of MSCs-EVs-derived miR-301b-3p in multidrug resistance of GC cells.

METHODS

Cisplatin (DDP)/vincristine (VCR)-resistant and sensitive GC clinical samples were harvested to detect expression of miR-301b-3p and thioredoxin interacting protein (TXNIP). MSCs were respectively transfected with miR-301b-3p oligonucleotides and/or TXNIP plasmids to extract the EVs, which were then co-cultured with multidrug-resistant GC cells. Then, P-glycoprotein (P-gp) and multidrug resistance-associated protein (MRP), IC50, proliferation, migration, and apoptosis of resistant GC cells were determined. The tumor growth was observed in nude mice. Targeting relationship between miR-301b-3p and TXNIP was confirmed.

RESULTS

miR-301b-3p was upregulated, and TXNIP was downregulated in DDP/VCR-resistant GC tissues and cells. MSC-EVs induced drug resistance, proliferation, and migration and inhibited apoptosis of DDP/VCR-resistant GC cells in vitro, as well as facilitated tumor growth in vivo. Inhibition of miR-301b-3p or upregulation of TXNIP reversed the promoting effect of MSC-EVs on DDP/VCR resistant GC cells to DDP/VCR resistance and malignant behaviors. The effects of MSC-EVs carrying miR-301b-3p inhibition on DDP/VCR-resistant GC cells were reversed by TXNIP downregulation. TXNIP was confirmed as a target gene of miR-301b-3p.

CONCLUSION

miR-301b-3p from MSCs-EVs inhibits TXNIP to promote multidrug resistance of GC cells, providing a novel insight for chemotherapy in GC.

FLED: a full-length eccDNA detector for long-reads sequencing data

Reconstructing the full-length sequence of extrachromosomal circular DNA (eccDNA) from short sequencing reads has proved challenging given the similarity of eccDNAs and their corresponding linear DNAs. Previous sequencing methods were unable to achieve high-throughput detection of full-length eccDNAs. Herein, a novel algorithm was developed, called Full-Length eccDNA Detection (FLED), to reconstruct the sequence of eccDNAs based on the strategy that combined rolling circle amplification and nanopore long-reads sequencing technology. Seven human epithelial and cancer cell line samples were analyzed by FLED and over 5000 full-length eccDNAs were identified per sample. The structures of identified eccDNAs were validated by both Polymerase Chain Reaction (PCR) and Sanger sequencing. Compared to other published nanopore-based eccDNA detectors, FLED exhibited higher sensitivity. In cancer cell lines, the genes overlapped with eccDNA regions were enriched in cancer-related pathways and cis-regulatory elements can be predicted in the upstream or downstream of intact genes on eccDNA molecules, and the expressions of these cancer-related genes were dysregulated in tumor cell lines, indicating the regulatory potency of eccDNAs in biological processes. The proposed method takes advantage of nanopore long reads and enables unbiased reconstruction of full-length eccDNA sequences. FLED is implemented using Python3 which is freely available on GitHub (https://github.com/FuyuLi/FLED).

The Importance of Thioredoxin-1 in Health and Disease

Thioredoxin-1 (Trx-1) is a multifunctional protein ubiquitously found in the human body. Trx-1 plays an important role in various cellular functions such as maintenance of redox homeostasis, proliferation, and DNA synthesis, but also modulation of transcription factors and control of cell death. Thus, Trx-1 is one of the most important proteins for proper cell and organ function. Therefore, modulation of Trx gene expression or modulation of Trx activity by various mechanisms, including post-translational modifications or protein-protein interactions, could cause a transition from the physiological state of cells and organs to various pathologies such as cancer, and neurodegenerative and cardiovascular diseases. In this review, we not only discuss the current knowledge of Trx in health and disease, but also highlight its potential function as a biomarker.

Prognostic biomarkers and molecular pathways mediating Helicobacter pylori–induced gastric cancer: a network-biology approach

Cancer of the stomach is the second most frequent cancer-related death worldwide. The survival rate of patients with gastric cancer (GC) remains fragile. There is a requirement to discover biomarkers for prognosis approaches. Helicobacter pylori in the stomach is closely associated with the progression of GC. We identified the genes associated with poor/favorable prognosis in H. pylori–induced GC. Multivariate statistical analysis was applied on the Gene Expression Omnibus (GEO) dataset GSE54397 to identify differentially expressed miRNAs (DEMs) in gastric tissues with H. pylori–induced cancer compared with the H. pylori–positive with non-cancerous tissue. A protein interaction map (PIM) was built and subjected to DEMs targets. The enriched pathways and biological processes within the PIM were identified based on substantial clusters. Thereafter, the most critical genes in the PIM were illustrated, and their prognostic impact in GC was investigated. Considering p-value less than 0.01 and |Log2 fold change| as >1, five microRNAs demonstrated significant changes among the two groups. Gene functional analysis revealed that the ubiquitination system, neddylation pathway, and ciliary process are primarily involved in H. pylori–induced GC. Survival analysis illustrated that the overexpression of DOCK4, GNAS, CTGF, TGF-b1, ESR1, SELE, TIMP3, SMARCE1, and TXNIP was associated with poor prognosis, while increased MRPS5 expression was related to a favorable prognosis in GC patients. DOCK4, GNAS, CTGF, TGF-b1, ESR1, SELE, TIMP3, SMARCE1, TXNIP, and MRPS5 may be considered prognostic biomarkers for H. pylori–induced GC. However, experimental validation is necessary in the future.

Peroxiredoxins and Hypoxia-Inducible Factor-1α in Duodenal Tissue: Emerging Factors in the Pathophysiology of Pediatric Celiac Disease Patients

Celiac disease (CD) is an autoimmune enteropathy. Peroxiredoxins (PRDXs) are powerful antioxidant enzymes having an important role in significant cellular pathways including cell survival, apoptosis, and inflammation. This study aimed at investigating the expression levels of all PRDX isoforms (1-6) and their possible relationships with a transcription factor, HIF-1α, in the small intestinal tissue samples of pediatric CD patients. The study groups consisted of first-diagnosed CD patients (n = 7) and non-CD patients with functional gastrointestinal tract disorders as the controls (n = 7). The PRDXs and HIF-1α expression levels were determined by using real-time PCR and Western blotting in duodenal biopsy samples. It was observed that the mRNA and protein expression levels of PRDX 5 were significantly higher in the CD patients, whereas the PRDX 1, -2, and -4 expressions were decreased in each case compared to the control group. No significant differences were detected in the PRDX 3 and PRDX 6 expressions. The expression of HIF-1α was also significantly elevated in CD patients. These findings indicate, for the first time, that PRDXs, particularly PRDX 5, may play a significant role in the pathogenesis of CD. Furthermore, our results suggest that HIF-1α may upregulate PRDX-5 transcription in the duodenal tissue of CD.

The thioredoxin system: Balancing redox responses in immune cells and tumors

The thioredoxin (TRX) system is an important contributor to cellular redox balance and regulates cell growth, apoptosis, gene expression, and antioxidant defense in nearly all living cells. Oxidative stress, the imbalance between reactive oxygen species (ROS) and antioxidants, can lead to cell death and tissue damage, thereby contributing to aging and to the development of several diseases, including cardiovascular and allergic diseases, diabetes, and neurological disorders. Targeting its activity is also considered as a promising strategy in the treatment of cancer. Over the past years, immunologists have established an essential function of TRX for activation, proliferation, and responses in T cells, B cells, and macrophages. Upon activation, immune cells rearrange their redox system and activate the TRX pathway to promote proliferation through sustainment of nucleotide biosynthesis, and to support inflammatory responses in myeloid cells by allowing NF-κB and NLRP3 inflammasome responses. Consequently, targeting the TRX system may therapeutically be exploited to inhibit immune responses in inflammatory conditions. In this review, we summarize recent insights revealing key roles of the TRX pathway in immune cells in health and disease, and lessons learnt for cancer therapy.

Evaluation of Auranofin Loading within Ferritin Nanocages

Auranofin (AF), a gold(I) compound that is currently used for the treatment of rheumatoid arthritis and is in clinical trials for its promising anticancer activity, was encapsulated within the human H-chain and the horse spleen ferritin nanocages using the alkaline disassembly/reassembly protocol. The aim of the work was to highlight possible differences in their drug loading capacity and efficacy. The drug-loaded ferritins were characterized via UV-vis absorption spectroscopy and inductively coupled plasma-atomic emission spectroscopy to assess AF encapsulation and to define the exact amount of gold atoms trapped in the Ft cavity. The crystal structures allowed us to define the nature of AF interaction with both ferritins and to identify the gold binding sites. Moreover, the biological characterization let us to obtain preliminary information on the cytotoxic effect of AF when bound to the human H-chain.

Anti-Cancer Effects of Auranofin in Human Lung Cancer Cells by Increasing Intracellular ROS Levels and Depleting GSH Levels

Auranofin, as a thioredoxin reductase (TrxR) inhibitor, has promising anti-cancer activity in several cancer types. However, little is known about the inhibitory effect of auranofin on lung cancer cell growth. We, therefore, investigated the antigrowth effects of auranofin in various lung cancer cells with respect to cell death, reactive oxygen species (ROS), and glutathione (GSH) levels. Treatment with 0~5 µM auranofin decreased cell proliferation and induced cell death in Calu-6, A549, SK-LU-1, NCI-H460, and NCI-H1299 lung cancer cells at 24 h. In addition, 0~5 µM auranofin increased ROS levels, including O2•−, and depleted GSH levels in these cells. N-acetyl cysteine (NAC) prevented growth inhibition and mitochondrial membrane potential (MMP, ∆Ψm) loss in 3 and 5 µM auranofin-treated Calu-6 and A549 cells at 24 h, respectively, and decreased ROS levels and GSH depletion in these cells. In contrast, L-buthionine sulfoximine (BSO) enhanced cell death, MMP (∆Ψm) loss, ROS levels, and GSH depletion in auranofin-treated Calu-6 and A549 cells. Treatment with 3 and 5 µM auranofin induced caspase-3 activation and poly (ADP ribose) polymerase (PARP) cleavage in Calu-6 and A549 cells, respectively. Both were prevented by NAC, but enhanced by BSO. Moreover, TrxR activity was reduced in auranofin-treated Calu-6 and A549 cells. That activity was decreased by BSO, but increased by NAC. In conclusion, these findings demonstrate that auranofin-induced cell death is closely related to oxidative stress resulted from increased ROS levels and GSH depletion in lung cancer cells.

ITCH facilitates proteasomal degradation of TXNIP in hypoxia- induced lung cancer cells

Background

Lung cancer (LC) is one of the most common cancers and a leading cause of cancer‐related deaths worldwide. In many pathological conditions, particularly in the tumor microenvironment, cells and tissues frequently exist in a hypoxic state.

Here, we evaluated Itchy E3 ubiquitin protein ligase (ITCH) expression in LC cells following hypoxia treatment.

Methods

LC cell lines were treated with hypoxic condition. Cell migration, invasion, inflammation, reactive oxygen species (ROS) production, and apoptosis of LC cells were determined by wound healing assay, Transwell invasive assay, ELISA, DCFH‐DA staining, and flow cytometry, respectively. qPCR and WB were used to determine the expression of ITCH and TXNIP. Co‐IP was performed to assess the interaction between ITCH and TXNIP.

Results

ITCH expression was downregulated in LC cells under hypoxic conditions. Next, LC cells were subjected to hypoxic conditions and changes in cell viability and metastasis were determined. Hypoxic conditions resulted in increased migration and invasion abilities of LC cells. Intracellular reactive oxygen species (ROS) production, inflammation, and apoptosis were also promoted by hypoxia. We found that ITCH overexpression led to the proteasomal degradation of thioredoxin‐interacting protein (TXNIP), whereas the expression of the ITCH C830A mutant did not affect TXNIP levels in LC cells. The gain‐of‐function experiment demonstrated that migration, invasion, ROS generation, inflammation, and apoptosis of hypoxia‐conditioned LC cells were ameliorated by ITCH overexpression, whereas the ITCH C830A mutant did not cause any changes in these phenotypes. Furthermore, the contribution of TXNIP knockdown and ITCH overexpression to the hypoxia‐induced features in LC cells with ITCH C830A was found to be similar.

Conclusion

Our results suggest a novel mechanism underlying the changes in ITCH‐mediated malignant phenotypes of hypoxia‐conditioned LC cells via TXNIP.

Thioredoxin-Interacting Protein in Cancer and Diabetes

Significance: Thioredoxin-interacting protein (Txnip) is an α-arrestin protein that acts as a cancer suppressor. Txnip is simultaneously a critical regulator of energy metabolism. Other alpha-arrestin proteins also play key roles in cell biology and cancer. Recent Advances: Txnip expression is regulated by multilayered mechanisms, including transcriptional regulation, microRNA, messenger RNA (mRNA) stabilization, and protein degradation. The Txnip-based connection between cancer and metabolism has been widely recognized. Meanwhile, new aspects are proposed for the mechanism of action of Txnip, including the regulation of RNA expression and autophagy. Arrestin domain containing 3 (ARRDC3), another α-arrestin protein, regulates endocytosis and signaling, whereas ARRDC1 and ARRDC4 regulate extracellular vesicle formation. Critical Issues: The mechanism of action of Txnip is yet to be elucidated. The regulation of intracellular protein trafficking by arrestin family proteins has opened an emerging field of biology and medical research, which needs to be examined further. Future Directions: A fundamental understanding of the mechanism of action of Txnip and other arrestin family members needs to be explored in the future to combat diseases such as cancer and diabetes. Antioxid. Redox Signal. 36, 1001-1022.

TXNIP: A Double-Edged Sword in Disease and Therapeutic Outlook

Thioredoxin-interacting protein (TXNIP) was originally named vitamin D₃ upregulated protein-1 (VDUP1) because of its ability to bind to thioredoxin (TRX) and inhibit TRX function and expression. TXNIP is an alpha-arrestin protein that is essential for redox homeostasis in the human body. TXNIP may act as a double-edged sword in the cell. The balance of TXNIP is crucial. A study has shown that TXNIP can travel between diverse intracellular locations and bind to different proteins to play different roles under oxidative stress. The primary function of TXNIP is to induce apoptosis or pyroptosis under oxidative stress. TXNIP also inhibits proliferation and migration in cancer cells, although TXNIP levels decrease, and function diminishes in various cancers. In this review, we summarized the main structure, binding proteins, pathways, and the role of TXNIP in diseases, aiming to explore the double-edged sword role of TXNIP, and expect it to be helpful for future treatment using TXNIP as a therapeutic target.

Au-24 as a Potential Thioredoxin Reductase Inhibitor in Hepatocellular Carcinoma Cells

A novel TrxR inhibitor Au-24 and its inhibitory ability to hepatocellular carcinoma in vitro and in vivo is reported herein. Au-24 can suppress HepG2 cells from proliferating by lowering mitochondrial membrane potential (MMP) and increasing reactive oxygen species (ROS) levels, resulting in oxidative stress, which causes DNA damage, autophagy, cell cycle arrest, and apoptosis. This compound can also affect the normal function of apoptosis, MAPK, PI3K/AKT/mTOR, NF-κB, STAT3 signaling pathways. In vivo experiments revealed that Au-24 inhibited HepG2 tumor growth more effectively than AA1 (chloro(triethylphosphine)gold(I)) by decreasing Ki67 and CD31 protein expression and promoting tumor cell apoptosis and necrosis lesions. As a result, Au-24 was found to be a promising candidate as a TrxR inhibitor for the treatment of hepatocellular carcinoma (HCC) in both in vivo and in vitro experiments.

Imbalanced GSH/ROS and sequential cell death

Reactive oxygen species (ROS) are produced in cells during metabolic processes. Excessive intracellular ROS may react with large biomolecules, such as DNA, RNA, proteins, and small biomolecules, that is, glutathione (GSH) and unsaturated fatty acids. GSH has physiological functions, including free radical scavenging, anti-oxidation, and electrophile elimination. The disruption of ROS/GSH balance results in the deleterious oxidation and chemical modification of biomacromolecules, which eventually leads to cell-cycle arrest and proliferation inhibition, and even induces cell death. Imbalanced ROS/GSH may result from a direct increase of ROS, consumption of GSH, intracellular oxidoreductase interference, or thioredoxin activity reduction. Some chemicals including arsenic trioxide (ATO), pyrogallol (PG), and carbobenzoxy-Leu-Leu-leucinal (MG132) could also disrupt the balance of GSH and ROS. This article reviews the occurrence and consequences of the imbalance between GSH and ROS and introduces factors responsible for the disruption of cellular ROS and GSH balance, resulting in cell death. "GSH" and "ROS" were used as keywords to search the relevant literaturess.

The gold complex auranofin: new perspectives for cancer therapy

Advanced stages of cancer are highly associated with short overall survival in patients due to the lack of long-term treatment options following the standard form of care. New options for cancer therapy are needed to improve the survival of cancer patients without disease recurrence. Auranofin is a clinically approved agent against rheumatoid arthritis that is currently enrolled in clinical trials for potential repurposing against cancer. Auranofin mainly targets the anti-oxidative system catalyzed by thioredoxin reductase (TrxR), which protects the cell from oxidative stress and death in the cytoplasm and the mitochondria. TrxR is over-expressed in many cancers as an adaptive mechanism for cancer cell proliferation, rendering it an attractive target for cancer therapy, and auranofin as a potential therapeutic agent for cancer. Inhibiting TrxR dysregulates the intracellular redox state causing increased intracellular reactive oxygen species levels, and stimulates cellular demise. An alternate mechanism of action of auranofin is to mimic proteasomal inhibition by blocking the ubiquitin-proteasome system (UPS), which is critically important in cancer cells to prevent cell death when compared to non-cancer cells, because of its role on cell cycle regulation, protein degradation, gene expression, and DNA repair. This article provides new perspectives on the potential mechanisms used by auranofin alone, in combination with diverse other compounds, or in combination with platinating agents and/or immune checkpoint inhibitors to combat cancer cells, while assessing the feasibility for its repurposing in the clinical setting.

One Century of Study: What We Learned about Paracoccidioides and How This Pathogen Contributed to Advances in Antifungal Therapy

Paracoccidioidomycosis (PCM) is a notable fungal infection restricted to Latin America. Since the first description of the disease by Lutz up to the present day, Brazilian researchers have contributed to the understanding of the life cycle of this pathogen and provided the possibility of new targets for antifungal therapy based on the structural and functional genomics of Paracoccidioides. In this context, in silico approaches have selected molecules that act on specific targets, such as the thioredoxin system, with promising antifungal activity against Paracoccidioides. Some of these are already in advanced development stages. In addition, the application of nanostructured systems has addressed issues related to the high toxicity of conventional PCM therapy. Thus, the contribution of molecular biology and biotechnology to the advances achieved is unquestionable. However, it is still necessary to transcend the boundaries of synthetic chemistry, pharmaco-technics, and pharmacodynamics, aiming to turn promising molecules into newly available drugs for the treatment of fungal diseases.

Expression of JWA and XRCC1 as prognostic markers for gastric cancer recurrence

Gastric cancer is one of the common gastrointestinal tumors. Tumor recurrence leads to a high death rate of gastric cancer. It is very important to find markers to effectively predict gastric cancer recurrence. We constructed a gastric cancer tissue microarray containing 89 tumors and corresponding normal tissues to explore the relationship between some proteins' expression and gastric cancer recurrence. The expression of JWA, Cullin1, p53, XRCC1, CHIP, FAK, MMP-2, MDM2 and p21 was determined on the microarray by immunohistochemistry. The relationship between the expression of these proteins and gastric cancer recurrence was analyzed. Tumor diameter, lymph node metastasis, and TNM stage were closely related with gastric cancer recurrence by Fisher's exact test (P<0.05). We used the univariate Cox regression analysis to find that JWA, XRCC1 were related to gastric cancer recurrence (P<0.05); Lymph node metastasis and TNM stage were closely related to gastric cancer recurrence (P<0.05). Multivariate Cox regression analysis revealed that XRCC1 or lymph node metastasis were independent risk factors of gastric cancer recurrence (P<0.05). Kaplan-Meier survival curve assay indicated that patients with low JWA or XRCC1 expression in gastric cancer had significantly shorter DFS than those with high-expressed proteins (P<0.05). JWA or XRCC1 may be effective markers to predict gastric cancer recurrence.

The NRF2, Thioredoxin, and Glutathione System in Tumorigenesis and Anticancer Therapies

Cancer remains an elusive, highly complex disease and a global burden. Constant change by acquired mutations and metabolic reprogramming contribute to the high inter- and intratumor heterogeneity of malignant cells, their selective growth advantage, and their resistance to anticancer therapies. In the modern era of integrative biomedicine, realizing that a personalized approach could benefit therapy treatments and patients' prognosis, we should focus on cancer-driving advantageous modifications. Namely, reactive oxygen species (ROS), known to act as regulators of cellular metabolism and growth, exhibit both negative and positive activities, as do antioxidants with potential anticancer effects. Such complexity of oxidative homeostasis is sometimes overseen in the case of studies evaluating the effects of potential anticancer antioxidants. While cancer cells often produce more ROS due to their increased growth-favoring demands, numerous conventional anticancer therapies exploit this feature to ensure selective cancer cell death triggered by excessive ROS levels, also causing serious side effects. The activation of the cellular NRF2 (nuclear factor erythroid 2 like 2) pathway and induction of cytoprotective genes accompanies an increase in ROS levels. A plethora of specific targets, including those involved in thioredoxin (TRX) and glutathione (GSH) systems, are activated by NRF2. In this paper, we briefly review preclinical research findings on the interrelated roles of the NRF2 pathway and TRX and GSH systems, with focus given to clinical findings and their relevance in carcinogenesis and anticancer treatments.

Research Progress of TXNIP as a Tumor Suppressor Gene Participating in the Metabolic Reprogramming and Oxidative Stress of Cancer Cells in Various Cancers

Thioredoxin-interacting protein (TXNIP) is a thioredoxin-binding protein that can mediate oxidative stress, inhibit cell proliferation, and induce apoptosis by inhibiting the function of the thioredoxin system. TXNIP is important because of its wide range of functions in cardiovascular diseases, neurodegenerative diseases, cancer, diabetes, and other diseases. Increasing evidence has shown that TXNIP expression is low in tumors and that it may act as a tumor suppressor in various cancer types such as hepatocarcinoma, breast cancer, and lung cancer. TXNIP is known to inhibit the proliferation of breast cancer cells by affecting metabolic reprogramming and can affect the invasion and migration of breast cancer cells through the TXNIP-HIF1α-TWIST signaling axis. TXNIP can also prevent the occurrence of bladder cancer by inhibiting the activation of ERK, which inhibits apoptosis in bladder cancer cells. In this review, we find that TXNIP can be regulated by binding to transcription factors or other binding proteins and can also be downregulated by epigenetic changes or miRNA. In addition, we also summarize emerging insights on TXNIP expression and its functional role in different kinds of cancers, as well as clarify its participation in metabolic reprogramming and oxidative stress in cancer cells, wherein it acts as a putative tumor suppressor gene to inhibit the proliferation, invasion, and migration of different tumor cells as well as promote apoptosis in these cells. TXNIP may therefore be of basic and clinical significance for finding novel molecular targets that can facilitate the diagnosis and treatment of malignant tumors.

Thioredoxin Interacting Protein (TXNIP) Is Differentially Expressed in Human Tumor Samples but Is Absent in Human Tumor Cell Line Xenografts: Implications for Its Use as an Immunosurveillance Marker

Simple Summary

The metabolic protein TXNIP plays a crucial role in various cellular processes. Abnormal TXNIP levels are notable, e.g., in type II diabetes, cardiovascular diseases, and tumors. Using immunohistochemical staining for TXNIP in different tumor entities, we give new insights of TXNIP expression on the protein level. In human tumors, staining intensity inversely correlated with aggressiveness of the tumor entity. In contrast, human tumor cell lines grown in mice (xenografts), consistently revealed no staining. Hence, loss of TXNIP suggests a critical role for the development of tumors in xenografts. Furthermore, we investigated TXNIP staining of immunocompetent cells in the proximity of the xenograft tumor tissue. Our findings demonstrate that TXNIP downregulation is a common feature in human tumor xenograft models. Subsequently, TXNIP expression might be used to monitor the functional state of tumor-infiltrating leukocytes in tissue sections and may help to predict response to modern immune therapy.

Abstract

Thioredoxin interacting protein (TXNIP) is a metabolic protein critically involved in redox homeostasis and has been proposed as a tumor suppressor gene in a variety of malignancies. Accordingly, TXNIP is downregulated in breast, bladder, and gastric cancer and in tumor transplant models TXNIP overexpression inhibits growth and metastasis. As TXNIP protein expression has only been investigated in few malignancies, we employed immunohistochemical detection in a large multi-tumor tissue microarray consisting of 2,824 samples from 94 different tumor entities. In general, TXNIP protein was present only in a small proportion of primary tumor samples and in these cases was differently expressed depending on tumor stage and subtype (e.g., renal cell carcinoma, thyroid cancer, breast cancer, and ductal pancreatic cancer). Further, TXNIP protein expression was determined in primary mouse xenograft tumors derived from human cancer cell lines and was immunohistochemically absent in all xenograft tumors investigated. Intriguingly, TXNIP expression became gradually lower in the proximity of the primary tumor tissue and was absent in leukocytes directly adjacent to tumor tissue. In conclusion, these findings suggest that TXNIP downregulation is as a common feature in human tumor xenograft models and that intra-tumoral leukocytes down-regulate TXNIP. Hence TXNIP expression might be used to monitor the functional state of tumor-infiltrating leukocytes in tissue sections.

TXNIP induces growth arrest and enhances ABT263-induced apoptosis in mixed-lineage leukemia-rearranged acute myeloid leukemia cells

Thioredoxin‐interacting protein (TXNIP) has been widely recognized as a tumor suppressor in various cancers, including liver, breast, and thyroid cancers. Although TXNIP is epigenetically silenced in acute myeloid leukemia (AML) cells, as in many cancer cells, its role in leukemogenesis remains elusive. Mixed‐lineage leukemia (MLL) gene rearrangements in AML are associated with poor prognosis, and the development of a new treatment method is eagerly anticipated. In this study, we first reveal that lower expression of TXNIP is correlated with shortened overall survival periods in AML patients. Moreover, we demonstrated that TXNIP overexpression significantly suppresses proliferation in AML cells harboring MLL fusion genes. TXNIP promotes autophagy by increasing expression of the autophagy protein, Beclin 1, and lipidation of LC3B. We also show that TXNIP overexpression combined with ABT263, a potent inhibitor of Bcl‐2 and Bcl‐xL, is highly effective at inducing cell death in MLL‐rearranged (MLL‐r) AML cells. In summary, this study provides insights into the molecular mechanism of TXNIP‐mediated tumor suppression and furthermore underscores the potential of TXNIP as a promising therapeutic target for MLL‐r AML.

ROS-mediated inactivation of the PI3K/AKT pathway is involved in the antigastric cancer effects of thioredoxin reductase-1 inhibitor chaetocin

Novel drugs are urgently needed for gastric cancer (GC) treatment. The thioredoxin-thioredoxin reductase (TRX-TRXR) system has been found to play a critical role in GC tumorigenesis and progression. Thus, agents that target the TRX-TRXR system may be highly efficacious as GC treatments. In this study, we showed that chaetocin, a natural product isolated from the Chaetomium species of fungi, inhibited proliferation, induced G₂/M phase arrest and caspase-dependent apoptosis in both in vitro and in vivo models (cell xenografts and patient-derived xenografts) of GC. Chaetocin inactivated TRXR-1, resulting in the accumulation of reactive oxygen species (ROS) in GC cells; overexpression of TRX-1 as well as cotreatment of GC cells with the ROS scavenger N-acetyl-L-cysteine attenuated chaetocin-induced apoptosis; chaetocin-induced apoptosis was significantly increased when GC cells were cotreated with auranofin. Moreover, chaetocin was shown to inactivate the PI3K/AKT pathway by inducing ROS generation; AKT-1 overexpression also attenuated chaetocin-induced apoptosis. Taken together, these results reveal that chaetocin induces the excessive accumulation of ROS via inhibition of TRXR-1. This is followed by PI3K/AKT pathway inactivation, which ultimately inhibits proliferation and induces caspase-dependent apoptosis in GC cells. Chaetocin therefore may be a potential agent for GC treatment.

The thioredoxin system and cancer therapy: a review

Thioredoxin (Trx), thioredoxin reductase (TrxR), and NADPH are key members of the Trx system that is involved in redox regulation and antioxidant defense. In recent years, several researchers have provided information about the roles of the Trx system in cancer development and progression. These reports indicated that many tumor cells express high levels of Trx and TrxR, which can be responsible for drug resistance in tumorigenesis. Inhibition of the Trx system may thus contribute to cancer therapy and improving chemotherapeutic agents. There are now a number of effective natural and synthetic inhibitors with chemotherapy applications possessing antitumor activity ranging from oxidative stress induction to apoptosis. In this article, we first described the features and functions of the Trx system and then reviewed briefly its correlations with cancer. Finally, we summarized the present knowledge about the Trx/TrxR inhibitors as anticancer drugs.

Upregulated thioredoxin and its reductase prevent H2O2-induced growth inhibition and death in human pulmonary artery smooth muscle cells

The thioredoxin (Trx) system controls cellular redox in vascular smooth muscle cells. The present study investigated the roles of Trx1 and Trx reductase1 (TrxR1) proteins in regulation of cell growth, death, reactive oxygen species (ROS) and glutathione (GSH) levels in hydrogen peroxide (H₂O₂)-treated human pulmonary artery smooth muscle (HPASM) cells. H₂O₂ induced growth inhibition and cell death in HPASM cells over 24 h. Overexpression of Trx1 and TrxR1 using adenoviruses significantly weakened cell growth inhibition and cell death caused by H₂O₂. Increases in ROS levels including mitochondrial superoxide anion (O₂^•-) were observed as early as 5-30 min after H₂O₂ addition. Administration of adTrxR1 attenuated H₂O₂-induced increases in ROS levels at 30-180 min. adTrx1 and adTrxR1 significantly reduced the increases in O₂^•- level in H₂O₂-treated HPASM cells at 24 h. Furthermore, HPASM cells transfected with Trx1 or TrxR1 siRNA showed increases in ROS levels with or without H₂O₂ at 5 min. While H₂O₂ transiently decreased GSH level at 5 min, Trx1 and TrxR1 siRNA intensified the decrease in GSH level. In conclusion, upregulation of Trx1 and TrxR1 significantly attenuated cell growth inhibition and death in H₂O₂-treated HPASM cells. As a whole, Trx-related adenoviruses diminished H₂O₂-induced ROS level in HPASM cells whereas Trx-related siRNAs increased ROS levels and decreased GSH level in these cells.

Increased Thioredoxin-1 Expression Promotes Cancer Progression and Predicts Poor Prognosis in Patients with Gastric Cancer

Background

Thioredoxin-1 (Trx-1) is a small redox protein, which plays an important role in many biological processes. Although increased expression of Trx-1 in various solid tumors has been reported, the prognostic significance and function of Trx-1 in human gastric cancer (GC) are still unclear. Here, we investigated the clinical and prognostic significance of Trx-1 expression and the function and mechanism of Trx-1 in human GC.

Methods

We analyzed Trx-1 mRNA expression from the GEO database and Trx-1 protein expression in 144 GC tissues using immunohistochemistry. Effects of Trx-1 on GC cell were assessed in vitro and in vivo through Trx-1 knockdown or overexpression. The antitumor effects of the Trx-1 inhibitor, PX-12, on GC cells were investigated. PTEN and p-AKT expressions were evaluated by Western blotting.

Results

Increased Trx-1 expression was found in GC tissues and associated with poor prognosis and aggressive clinicopathological characteristics in patients with GC. High Trx-1 expression predicted poor prognosis, and its expression was an independent prognostic factor for overall survival of GC patients. Knockdown of Trx-1 expression inhibited GC cell growth, migration, and invasion in vitro and tumor growth and lung metastasis in vivo. Conversely, overexpression of Trx-1 promoted GC cell growth, migration, and invasion. We also found that PX-12 inhibited GC cell growth, migration, and invasion. Overexpression of Trx-1 caused a decrease in PTEN and increase in p-AKT levels whereas silencing Trx-1 caused an increase in PTEN and decrease in p-AKT levels in GC cells. Inhibition of AKT signaling pathway by MK2206 also inhibited GC cell growth, migration, and invasion.

Conclusion

Our results indicate that Trx-1 may be a promising prognostic indicator and therapeutic target for GC patients.

Cellular acidosis triggers human MondoA transcriptional activity by driving mitochondrial ATP production

Human MondoA requires glucose as well as other modulatory signals to function in transcription. One such signal is acidosis, which increases MondoA activity and also drives a protective gene signature in breast cancer. How low pH controls MondoA transcriptional activity is unknown. We found that low pH medium increases mitochondrial ATP (mtATP), which is subsequently exported from the mitochondrial matrix. Mitochondria-bound hexokinase transfers a phosphate from mtATP to cytoplasmic glucose to generate glucose-6-phosphate (G6P), which is an established MondoA activator. The outer mitochondrial membrane localization of MondoA suggests that it is positioned to coordinate the adaptive transcriptional response to a cell’s most abundant energy sources, cytoplasmic glucose and mtATP. In response to acidosis, MondoA shows preferential binding to just two targets, TXNIP and its paralog ARRDC4. Because these transcriptional targets are suppressors of glucose uptake, we propose that MondoA is critical for restoring metabolic homeostasis in response to high energy charge.

Analysis of cancer gene attributes using electrical sensor

Prediction of cancer gene attributes by their primary structure (long amino acid sequence) is instrumental in large-scale genomics projects, especially in the field of genomics. Various methods are proposed to predict gene characteristics from its primary structure, but accurate prediction of it is still very challenging task. Here we introduce an electrical network based sensor or detector to discriminate cancer and non-cancer cells based on two features i.e. amino acid sequence length, and hydrophilic/hydrophobic property. The electrical circuit consists of resistors, capacitors and inductors, is used for modeling individual amino acid and cascaded to form gene system. Corresponding electrical responses are judged using Bode and Nyquist analyzers and achieve 89.55% accuracy with 87.06% True Positive rate and 95.42% True Negative rate, demonstrate that proposed electrical sensor model is very promising for predicting the cancer gene attributes as well as non-cancer gene in the field of large-scale genomics study.

Chemosensitizing effect of Alpinia officinarum rhizome extract in cisplatin-treated rats with hepatocellular carcinoma

This study was conducted to estimate the preventing and sensitizing efficiency of Alpinia officinarum rhizome extract (AORE) in an experimental model of hepatocellular carcinoma (HCC) +/- cisplatin. HCC was induced by a single intraperitoneal (i.p) dose of diethylnitrosamine (DENA, 200mg/kg). After 14 days, phenobarbitone (PB, 0.05%) was added to drinking water for 14 weeks to promote hepatocarcinogenesis. Cisplatin (CP) was given in a dose of 1.5 mg/kg (i.p), twice a week, alone or with AORE (400 mg/kg daily, orally) for 21 days. AORE was tried as a protective before the induction of HCC for three weeks as well. Results revealed that DENA/PB elevated hepatic indices as ALT and AST and total bilirubin with declining serum total protein. It increased oxidative stress, as hepatic malondialdehyde (MDA) with depressed hepatic reduced glutathione (GSH) contents, superoxide dismutase (SOD) and catalase activities. This was accompanied by an increase in hepatic expression of antioxidant genes (thioredoxin and glutaredoxin). Hepatocarcinogenesis was detected by histopathological changes in liver sections and the elevation of serum alpha-fetoprotein (AFP) level. Treatment with CP partially restored altered hepatic functions and oxidative stress markers. It also showed a partial decrease in the expression of antioxidant genes, improving histopathological changes in the liver and AFP level in serum. The treatment with AORE alone or AORE+CP enhanced hepatic function and oxidative stress markers. It also caused a decrease in the expression of antioxidant genes and improved histopathological changes in liver and serum AFP level. This effect is more potent than the treatment with CP alone. Our study suggested that AORE can be used as a promising natural chemoprevention or a chemosensitizing agent against hepatocarcinogenesis.

Comparative study of gastric cancer and chronic gastritis via network analysis

AIM

In this study the significant differentially expressed genes (DEGs) related to gastric cancer (GC) and chronic gastritis were screened to introduce common and distinctive genes between the two diseases.

BACKGROUND

Diagnosis of gastric cancer as a mortal disease and chronic gastritis the stomach disorder which can be considered as risk factor of GCs required safe and effective molecular biomarkers.

METHODS

Microarray profiles were downloaded from Gene Expression Omnibus (GEO) and analyzed via GEO2R. The candidate DEGs plus relevant genes from STRING database were interacted by Cytoscape software version 3.6.0 the central nodes were determined and analyzed.

RESULTS

JUN, GAPDH, FOS, TP53, PRDM10, VEGFA, and CREB1 as central nodes and TFF1 and ERG1 as the top changed expressed genes were determined as critical nodes related to gastric cancer. GAPDH, PRDM10, TP53, JUN, AKT1, EGFR, MAPK1, EGF, DECR1, and MYC were identified as common remarkable genes between GC and chronic gastritis.

CONCLUSION

Identification of distinctive and common genes between GC and chronic gastritis can be useful in the early stage detection of disease and reducing risk of GCs.

Thioredoxin-Interact ing-Pro t e in [TXNIP] and Transglutaminase 2 [TGM2] Expression in Meningiomas of Different Grades and the Role of Their Expression in Meningioma Recurrence and Prognosis

Background: Meningiomas are common central nervous system (CNS) tumors that account for thirty percent of primary intracranial tumors.. The accuracy of predicting meningioma recurrence and progression is not enough. So, there is a real need for discovering recent factors for identification of the relapse risk, progression rates, which patients will need aggressive treatment and predicting and improving patients’ survival. Thioredoxin-interacting-protein [TXNIP] is an alpha-arrestin-protein family member that is mapped on chromosome 1-q21–22 and is found to participate in cellular redox reactions regulations and control. Transglutaminase 2 (TGM2) is a transglutaminase enzyme family member that is found in many human cells, it may act as an enzyme, a structural protein and also has multiple roles in many cellular activities. Aim of our study: It was to explore the expression of TXNIP, TGM2 and Ki-67 using immunohistochemistry in different pathological grades of meningiomas, and to investigate the relevance between their expressions, clinicopathological criteria, disease recurrence and prognosis of meningioma patients. Methods: we included 50 cases of meningioma of different pathological grades; all patients were managed according to their grade by surgery alone, with radiotherapy or combined modalities. Sections from paraffin blocks prepared from samples of all patients stained by TXNIP, TGM2 and Ki-67 using immunohistochemistry. Results: high expression of TXNIP in 28 out of 50 (56%) cases of meningioma of different pathological grades and was positively correlated with meningioma lower grade, low KI labeling index (p=0.000), adequacy of resection, negatively correlated with high incidence of recurrence after surgery and it was negatively correlated with meningioma higher pathological grades (p=0.000). We detected high expression of TGM2 in 21 out of 50 (42%) cases of meningioma and it was positively correlated with meningioma higher grade (p= 0.002), high KI labeling index (p=0.000), high incidence of recurrence after surgery, progression to higher pathological grades and was negatively correlated with adequacy of resection of meningioma (p=0.000). Conclusion: There is inverse relation between both [TXNIP and TGM2 expression in meningiomas and the combination of decreased expression of TXNIP and increased expression of TGM2 could predict risk of meningioma recurrence and progression in to higher pathological grades.

BEclear: Batch Effect Detection and Adjustment in DNA Methylation Data

Batch effects describe non-natural variations of, for example, large-scale genomic data sets. If not corrected by suitable numerical algorithms, batch effects may seriously affect the analysis of these datasets. The novel array platform independent software tool BEclear enables researchers to identify those portions of the data that deviate statistically significant from the remaining data and to replace these portions by typical values reconstructed from neighboring data entries based on latent factor models. In contrast to other comparable methods that often use some sort of global normalization of the data, BEclear avoids changing the apparently unaffected parts of the data. We tested the performance of this approach on DNA methylation data for various tumor data sets taken from The Cancer Genome Atlas and compared the results to those obtained with the existing algorithms ComBat, Surrogate Variable Analysis, RUVm and Functional normalization. BEclear constantly performed at par with or better than these methods. BEclear is available as an R package at the Bioconductor project http://bioconductor.org/packages/release/bioc/html/BEclear.html.

Response of esophageal cancer cells to epigenetic inhibitors is mediated via altered thioredoxin activity

We previously showed that histone deacetylase inhibitor (HDACi) and 5-azacytidine (AZA) treatment selectively induced cell death of esophageal cancer cells. The mechanisms of cancer selectivity, however, remained unclear. Here we examined whether the cancer selectivity of HDACi/AZA treatment is mediated by the thioredoxin (Trx) system and reactive oxygen species (ROS) in esophageal cancer cells. For this, we first analyzed human tissue specimens of 37 esophageal cancer patients by immunohistochemistry for Trx, Trx-interacting protein (TXNIP) and Trx reductase (TXNRD). This revealed a loss or at least reduction of nuclear Trx in esophageal cancer cells, compared with normal epithelial cells (P<0.001). Although no differences were observed for TXNIP, TXNRD was more frequently expressed in cancer cells (P<0.001). In the two main histotypes of esophageal squamous cell carcinomas (ESCCs, n=19) and esophageal adenomcarcinomas (EAC, n=16), similar Trx, TXNIP and TXNRD expression patterns were observed. Also in vitro, nuclear Trx was only detectable in non-neoplastic Het-1A cells, but not in OE21/ESCC or OE33/EAC cell lines. Moreover, the two cancer cell lines showed an increased Trx activity, being significant for OE21 (P=0.0237). After treatment with HDACi and/or AZA, ROS were exclusively increased in both cancer cell lines (P=0.048-0.017), with parallel decrease of Trx activity. This was variably accompanied by increased TXNIP levels upon AZA, MS-275 or MS-275/AZA treatment for 6 or 24 h in OE21, but not in Het-1A or OE33 cells. In summary, this study evaluated Trx and its associated proteins TXNIP and TXNRD for the first time in esophageal cancers. The analyses revealed an altered subcellular localization of Trx and strong upregulation of TXNRD in esophageal cancer cells. Moreover, HDACi and AZA disrupted Trx function and induced accumulation of ROS with subsequent apoptosis in esophageal cancer cells exclusively. Trx function is hence an important cellular mediator conferring non-neoplastic cell resistance for HDACi and/or AZA.

Upregulation of connexin43 contributes to PX-12-induced oxidative cell death

Thioredoxin (Trx) is a small redox protein that underlies aggressive tumor growth and resistance to chemotherapy. Inhibition of Trx with the chemical inhibitor PX-12 suppresses tumor growth and induces cell apoptosis. Currently, the mechanism underlying the therapeutic actions of PX-12 and the molecules influencing cell susceptibility to PX-12 are incompletely understood. Given that connexin43 (Cx43), a tumor suppressor, regulates tumor cell susceptibility to chemotherapy, we examined the possible involvement of Cx43 in PX-12-induced cell death. Exposure of cells to PX-12 led to a loss of cell viability, which was associated with the activation of oxidative sensitive c-Jun N-terminal kinase (JNK). Inhibition of JNK or supplement of cells with anti-oxidants prevented the cell-killing action of PX-12. The forced expression of Cx43 in normal and tumor cells increased cell sensitivity to PX-12-induced JNK activation and cell death. In contrast, the downregulation of Cx43 with siRNA or the suppression of gap junctions with chemical inhibitors attenuated JNK activation and enhanced cell resistance to PX-12. Further analysis revealed that PX-12 at low concentrations induced a JNK-dependent elevation in the Cx43 protein, which was also preventable by supplementing the cells with anti-oxidants. Our results thus indicate that Cx43 is a determinant in the regulation of cell susceptibility to PX-12 and that the upregulation of Cx43 may be an additional mechanism by which PX-12 exerts its anti-tumor actions.

2-Deoxyglucose induces the expression of thioredoxin interacting protein (TXNIP) by increasing O-GlcNAcylation - Implications for targeting the Warburg effect in cancer cells

The high proliferation rate of cancer cells and the microenvironment in the tumor tissue require the reprogramming of tumor cell metabolism. The major mechanism of metabolic reprogramming in cancer cells is the Warburg effect, defined as the preferential utilization of glucose via glycolysis even in the presence of oxygen. Targeting the Warburg effect is considered as a promising therapeutic strategy in cancer therapy. In this regard, the glycolytic inhibitor 2-deoxyglucose (2DG) has been evaluated clinically. 2DG exerts its effect by directly inhibiting glycolysis at the level of hexokinase and phosphoglucoisomerase. In addition, 2DG is also known to induce the expression of thioredoxin interacting protein (TXNIP), a tumor suppressor protein and an important negative regulator of cellular glucose uptake. Hence, characterization of the mechanism through which 2DG regulates TXNIP expression may reveal novel approaches to target the Warburg effect in cancer cells. Therefore, in this study we sought to test various hypotheses for the mechanistic basis of the 2DG dependent TXNIP regulation. We have shown that 2DG induced TXNIP expression is independent of carbohydrate response element mediated transcription. Furthermore, the induction of TXNIP is neither dependent on the ability of 2DG to deplete cellular ATP nor to cause endoplasmic reticulum stress. We found that the 2DG induced TXNIP expression is at least in part dependent on the inhibition of the O-GlcNAcase enzyme and the accumulation of O-GlcNAc modified proteins. These results have implications for the identification of therapeutic targets to increase TXNIP expression in cancer.

Oxidative stress associates with aggressiveness in lung large-cell carcinoma

Oxidative stress is involved in many cancer-related processes; however, current therapeutics are unable to benefit from this approach. The lungs have a very exquisite redox environment that may contribute to the frequent and deadly nature of lung cancer. Very few studies specifically address lung large-cell carcinoma (LCC), even though this is one of the major subtypes. Using bioinformatic (in silico) tools, we demonstrated that a more aggressive lung LCC cell line (HOP-92) has an overall increase activity of the human antioxidant gene (HAG) network (P = 0.0046) when compared to the less aggressive cell line H-460. Gene set enrichment analysis (GSEA) showed that the expression of metallothioneins (MT), glutathione peroxidase 1 (GPx-1), and catalase (CAT) are responsible for this difference in gene signature. This was validated in vitro, where HOP-92 showed a pro-oxidative imbalance, presenting higher antioxidant enzymes (superoxide dismutase (SOD), CAT, and GPx) activities, lower reduced sulfhydryl groups and antioxidant potential, and higher lipoperoxidation and reactive species production. Also, HAG network is upregulated in lung LCC patients with worst outcome. Finally, the prognostic value of genes enriched in the most aggressive cell line was assessed in this cohort. Isoforms of metallothioneins are associated with bad prognosis, while the thioredoxin-interacting protein (TXNIP) is associated with good prognosis. Thus, redox metabolism can be an important aspect in lung LCC aggressiveness and a possible therapeutic target.

Thioredoxin-1 inhibitor, 1-methylpropyl 2-imidazolyl disulfide, inhibits the growth, migration and invasion of colorectal cancer cell lines

1-Methylpropyl 2-imidazolyl disulfide (PX-12) has been proposed as an inhibitor of thioredoxin-1 (Trx-1) with antitumor activity. However, the antitumor activity of the Trx-1 redox signaling inhibitor PX-12 on colorectal cancer is still obscure. In the present study, we showed that PX-12 inhibited the growth of colorectal cancer DLD-1 and SW620 cells in a dose- and time-dependent manner. Further analysis demonstrated that PX-12 reduced cell colony formation and induced a G2/M phase arrest of the cell cycle. In addition, PX-12 treatment induced apoptosis, as observed by the increased number of Annexin V-positive cells and increased activation of caspase-3. Notably, a low dose of PX-12 inhibited colorectal cancer cell migration and invasion. Treatment of cancer cells with PX-12 reduced NOX1, CDH17 and S100A4 mRNA expression, and increased KLF17 mRNA expression. Moreover, PX-12 decreased S100A4 protein expression in the colorectal cancer cells. Collectively, the present study demonstrates the antitumor effects and therapeutic potential of PX-12 in colorectal cancer.

PX-12 induces apoptosis in Calu-6 cells in an oxidative stress-dependent manner

PX-12 (1-methylpropyl 2-imidazolyl disulfide) as a thioredoxin (Trx) inhibitor has an anti-tumor effect. However, there is no report about the toxicological effect of PX-12 on lung cancer cells. Here, we investigated the anti-growth effects of PX-12 on Calu-6 lung cancer cells in relation to reactive oxygen species (ROS) and glutathione (GSH) levels. PX-12 induced the growth inhibition of Calu-6 cells with IC50 of nearly 3 μM at 72 h. In contrast, PX-12 did not affect the growth of human small airway epithelial cells (HSAECs). Cell cycle distribution analysis indicated that PX-12 significantly induced a G2/M phase arrest in Calu-6 cells. PX-12 also increased the number of annexin V-FITC-positive cells in Calu-6 cells. All the tested caspase inhibitors markedly prevented Calu-6 cell death induced by PX-12. With regard to ROS and GSH levels, PX-12 increased ROS levels containing O2(·-) in Calu-6 cells and induced the depletion of GSH. N-acetyl cysteine (NAC), which is a well-known antioxidant, significantly reduced O2(·-) level in PX-12-treated Calu-6 cells and prevented apoptosis and GSH depletion in these cells. In conclusion, it is the first report that PX-12 inhibited the growth of Calu-6 cells via a G2/M phase arrest as well as apoptosis, which effect was related to the intracellular increases in ROS levels.

Anti-oxidative stress response genes: bioinformatic analysis of their expression and relevance in multiple cancers

Cells mount a transcriptional anti-oxidative stress (AOS) response program to scavenge reactive oxygen species (ROS) that arise from chemical, physical, and metabolic challenges. This protective program has been shown to reduce carcinogenesis triggered by chemical and physical insults. However, it is also hijacked by established cancers to thrive and proliferate within the hostile tumor microenvironment and to gain resistance against chemo- and radiotherapies. Therefore, targeting the AOS response proteins that are exploited by cancer cells is an attractive therapeutic strategy. In order to identify the AOS genes that are suspected to support cancer progression and resistance, we analyzed the expression patterns of 285 genes annotated for being involved in oxidative stress in 994 tumors and 353 normal tissues. Thereby we identified a signature of 116 genes that are highly overexpressed in multiple carcinomas while being only minimally expressed in normal tissues. To establish which of these genes are more likely to functionally drive cancer resistance and progression, we further identified those whose overexpression correlates with negative patient outcome in breast and lung carcinoma. Gene-set enrichment, GO, network, and pathway analyses revealed that members of the thioredoxin and glutathione pathways are prominent components of this oncogenic signature and that activation of these pathways is common feature of many cancer entities. Interestingly, a large fraction of these AOS genes are downstream targets of the transcription factors NRF2, NF-kappaB and FOXM1, and relay on NADPH for their enzymatic activities highlighting promising drug targets. We discuss these findings and propose therapeutic strategies that may be applied to overcome cancer resistance.

Expression of Thioredoxins and Glutaredoxins in Human Hepatocellular Carcinoma: Correlation to Cell Proliferation, Tumor Size and Metabolic Syndrome

Thioredoxins (Trx) and glutaredoxins (Grx) are thiol oxidoreductases that are ubiquitously expressed, and are involved in several biological processes. The expression of thioredoxins and glutaredoxins is induced in many neoplasms, and correlates with prognosis in gallbladder and colorectal carcinoma. The aim of the present study was to examine the expression pattern of these proteins (redoxins) in hepatocellular carcinoma (HCC) and to correlate their levels with clinical features. Paraffin-embedded tissues from 25 patients resected for HCC and 15 patients resected for colorectal carcinoma (CRC) liver metastases were analyzed with immunohistochemistry. Our results showed that Trx1, Trx2 and Grx5 were upregulated in HCCs as compared to the respective surrounding liver. In comparison, almost all redoxins were upregulated in CRC liver metastases, with Trx1 and Grx3 being significantly more increased in the CRC liver metastases than in the primary HCC tumors. In HCC, Trx1 correlated significantly with cell proliferation, and with a trend towards increased levels with micro-vascular invasion, while expression of Trx2 decreased with tumor size. Trx1 levels were lower in tumors of males, smokers, and patients with high alcohol consumption. Grx2 levels were significantly higher in patients with metabolic syndrome. In conclusion, this study illustrates specific correlations of individual redoxins to clinical features of HCC, and implicates the redoxins in the pathogenesis of HCC.

Thioredoxin interacting protein (TXNIP) is a novel tumor suppressor in thyroid cancer

Background

Thyroid cancer is the most common endocrine malignancy, and many patients with metastatic differentiated thyroid cancer (DTC), poorly differentiated thyroid cancer (PDTC), and anaplastic thyroid cancer (ATC) fail to respond to conventional therapies, resulting in morbidity and mortality. Additional therapeutic targets and treatment options are needed for these patients. We recently reported that peroxisome proliferator-activated receptor gamma (PPARγ) is highly expressed in ATC and confers an aggressive phenotype when overexpressed in DTC cells.

Methods

Microarray analysis was used to identify downstream targets of PPARγ in ATC cells. Western blot analysis and immunohistochemistry (IHC) were used to assess thioredoxin interacting protein (TXNIP) expression in thyroid cancer cell lines and primary tumor specimens. Retroviral transduction was used to generate ATC cell lines that overexpress TXNIP, and assays that assess glucose uptake, viable cell proliferation, and invasion were used to characterize the in vitro properties of these cells. An orthotopic thyroid cancer mouse model was used to assess the effect of TXNIP overexpression in ATC cell lines in vivo.

Results

Using microarray analysis, we show that TXNIP is highly upregulated when PPARγ is depleted from ATC cells. Using Western blot analysis and IHC, we show that DTC and ATC cells exhibit differential TXNIP expression patterns. DTC cell lines and patient tumors have high TXNIP expression in contrast to low or absent expression in ATC cell lines and tumors. Overexpression of TXNIP decreases the growth of HTh74 cells compared to vector controls and inhibits glucose uptake in the ATC cell lines HTh74 and T238. Importantly, TXNIP overexpression in T238 cells results in attenuated tumor growth and decreased metastasis in an orthotopic thyroid cancer mouse model.

Conclusions

Our findings indicate that TXNIP functions as a tumor suppressor in thyroid cells, and its downregulation is likely important in the transition from differentiated to advanced thyroid cancer. These studies underscore the potential of TXNIP as a novel therapeutic target and prognostic indicator in advanced thyroid cancer.

Meta-analysis of immunohistochemical expression of hypoxia inducible factor-1α as a prognostic role in gastric cancer

AIM: To conduct a meta-analysis to evaluate the prognostic role of hypoxia inducible factor-1α (HIF-1α) expression in gastric cancer.

METHODS: The PubMed, EMBASE, and Web of Science databases were searched systematically for all articles published in English before August, 2013. Pooled effect was calculated from the available data to evaluate the association between HIF-1α expression and 5-year overall survival and tumor clinicopathological features in gastric cancer patients. Pooled odds ratios (ORs) with 95%CIs were calculated using either a fixed-effects or a random-effects model.

RESULTS: Nine studies matched the selection criteria, which reported on 1103 subjects, 548 of whom had HIF-1α positive expression (50%). This meta-analysis indicated that HIF-1α positive expression in gastric cancer correlated with lower 5-year overall survival (OR = 0.36; 95%CI: 0.21-0.64), worse tumor differentiation (OR = 0.38; 95%CI: 0.23-0.64), deeper invasion (OR = 0.42; 95%CI: 0.32-0.57), higher rates of lymph node metastasis (OR = 2.23; 95%CI: 1.46-3.40), lymphatic invasion (OR = 2.50; 95%CI: 1.46-4.28), and vascular invasion (OR = 1.80; 95%CI: 1.29-2.51), and higher TNM stage (III + IV) (OR = 0.31; 95%CI: 0.15-0.60).

CONCLUSION: HIF-1α positive expression indicates a poor prognosis for patients with gastric cancer. Further studies are required to confirm these results.

Monitoring of peri-distal gastrectomy carbohydrate antigen 19-9 level in gastric juice and its significance

Gastric carcinoma is one of the most common and deadly malignancies nowadays, and carbohydrate antigen 19-9 (CA 19-9) in gastric juice has been rarely studied. To compare peri-distal gastrectomy (DG) gastric juice and serum CA 19-9 and reveal its significance, we selected 67 patients diagnosed with gastric carcinoma who underwent DG, and collected their perioperative gastric juice whose CA 19-9 was detected, with serum CA 19-9 monitored as a comparison. We found that: gastric juice CA 19-9 pre-gastrectomy was significantly correlated with tumor TNM classification, regarding tumor size, level of gastric wall invaded, differentiated grade and number of metastatic lymph nodes as influencing factors, while serum CA 19-9 revealed little information; gastric juice CA 19-9 was significantly correlated with radical degree, and regarded number of resected lymph nodes and classification of cutting edge as impact factors; thirteen patients whose gastric juice CA 19-9 rose post-DG showed features indicating poor prognosis; the difference of gastric juice CA 19-9 between pre- and post-gastrectomy was correlated with tumor TNM classification and radical degree, and regarded tumor size, number of resected metastatic and normal lymph nodes, sum of distances from tumor to cutting edges and classification of cutting edge as influential factors. We conclude that peri-DG gastric juice CA 19-9 reveals much information about tumor and radical gastrectomy, and may indicate prognosis; while serum CA 19-9 has limited significance.