Thioredoxin reductase: a novel, independent prognostic marker in patients with hepatocellular carcinoma

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

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

Thioredoxin reductase as a novel biomarker for the diagnosis and efficacy prediction of gastrointestinal malignancy: a large-scale, retrospective study

BACKGROUND

Our aim was to investigate the rationality and accuracy of plasma TrxR activity as an efficient tool in the early diagnosis of gastrointestinal malignancy, and whether TrxR can be used to evaluate the therapeutic efficacy of gastrointestinal malignancy.

METHODS

We enrolled a total of 5091 cases, including 3736 cases in gastrointestinal malignancy, 964 in benign diseases, and 391 cases in healthy controls. We also performed receiver operating characteristic (ROC) analysis to evaluate diagnostic efficiency of TrxR. Finally, we detected pre- and post-treatment level of TrxR and common tumor markers.

RESULTS

The plasma TrxR level in patients with gastrointestinal malignancy [8.4 (6.9, 9.7) U/mL] was higher than that in patients with benign disease [5.8 (4.6, 6.9) U/mL] and healthy control [3.5 (1.4, 5.4) U/mL]. Plasma TrxR showed a significant diagnostic advantage with an AUC of 0.897, compared with conventional tumor markers. In addition, the combination of TrxR and conventional tumor markers can further improve the diagnostic efficiency. We derived the optimal cut-off value of plasma TrxR as a diagnostic marker of gastrointestinal malignancy according to Youden index of 6.15 U/mL. After measuring the change trend of TrxR activity and conventional tumor markers before and after anti-tumor treatments, we found that their change trend was generally consistent, and the plasma TrxR activity was significantly decreased in patients treated with chemotherapy, targeted therapy and immunotherapy.

CONCLUSIONS

Our findings recommend that plasma TrxR activity could be monitored as an efficient tool for the early diagnosis of gastrointestinal malignancy and as a feasible tool to evaluate the therapeutic effect.

Plasma thioredoxin reductase: a potential diagnostic biomarker for gastric cancer

To improve the early detection of gastric cancer (GC), there is a growing need for novel and efficient biomarkers. We aimed to evaluate diagnostic value of thioredoxin reductase 1 (TXNRD1), which was found to be overexpressed in various malignancies. We found that TXNRD1 has a higher expression level in GC tissues compared with adjacent normal tissues, and high TXNRD1 expression was significantly associated with poor outcomes of GC patients. Next, a total of 1446 cases were collected, with 896 cases in gastric cancer, 322 in benign gastric disease and 228 in healthy controls. We noticed plasma thioredoxin reductase (TrxR) level in GC [8.4 (7.1, 9.7) U/mL] was significantly higher than that in benign disease [6.1 (5.4, 7.2) U/mL] or healthy controls [3.7 (1.7, 5.6) U/mL]. Receiver operating characteristic (ROC) analysis showed that the optimal cut-off value of TrxR activity for GC diagnosis was set at 5.75 U/mL with an area under the curve (AUC) of 0.945. Moreover, a combined panel of TrxR and routine tumor markers could further elevate the diagnostic efficacy compared to a single biomarker. Finally, by measuring pre- and post-treatment TrxR activity and routine tumor markers, we found the change trend of them was broadly consistent, and plasma TrxR activity was significantly decreased in patients treated with platinum/fluorouracil-based therapy. Our findings recommend plasma TrxR activity combined with tumor markers as effective diagnostic tools for GC patients. As well, plasma TrxR has the potential to monitor therapeutic efficacy.

HCC-Mark: a simple non-invasive model based on routine parameters for predicting hepatitis C virus related hepatocellular carcinoma

BACKGROUND

Early detection of hepatocellular carcinoma (HCC) is crucial in providing more effective therapies. As routine laboratory variables are readily accessible, this study aimed to develop a simple non-invasive model for predicting hepatocellular cancer.

METHODS

Two groups of patients were recruited: an estimation group (n = 300) and a validation group (n = 625). Each comprised two categories: hepatocellular cancer and liver cirrhosis. Logistic regression analyses and receiver operating characteristic (ROC) curves were used to develop and validate the HCC-Mark model comprising AFP, high-sensitivity C-reactive protein, albumin and platelet count. This model was tested in cancer patients classified by the Barcelona Clinic Liver Cancer (BCLC), Cancer of Liver Italian Program (CLIP) and Okuda systems, and was compared with other non-invasive models for predicting hepatocellular cancer.

RESULTS

HCC-Mark produced a ROC AUC of 0.89 (95% CI 0.85-0.90) for discriminating hepatocellular carcinoma from liver cirrhosis in the estimation group and 0.90 (0.86-0.90) in the validation group (both p < 0.0001). This AUC exceeded all other models, that had AUCs from 0.41 to 0.81. AUCs of HCC-Mark for discriminating patients with a single focal lesion, absent macrovascular invasion, tumour size <2 cm, BCLC (0-A), CLIP (0-1) and Okuda (stage Ι) from cirrhotic patients were 0.88 (0.85-0.90), 0.87 (0.85-0.89), 0.89 (0.85-0.93), 0.87 (0.84-0.89), 0.85 (0.82-0.87) and 0.86 (0.83-0.89), respectively (all p < 0.0001).

CONCLUSION

HCC-Mark is an accurate and validated model for the detection of hepatocellular cancer and certain of its clinical features.

Dual Antimicrobial and Antiproliferative Activity of TcPaSK Peptide Derived from a Tribolium castaneum Insect Defensin

Antimicrobial peptides (AMPs) found in the innate immune system of a wide range of organisms might prove useful to fight infections, due to the reported slower development of resistance to AMPs. Increasing the cationicity and keeping moderate hydrophobicity of the AMPs have been described to improve antimicrobial activity. We previously found a peptide derived from the Tribolium castaneum insect defensin 3, exhibiting antrimicrobial activity against several human pathogens. Here, we analyzed the effect against Staphyloccocus aureus of an extended peptide (TcPaSK) containing two additional amino acids, lysine and asparagine, flanking the former peptide fragment in the original insect defensin 3 protein. TcPaSK peptide displayed higher antimicrobial activity against S. aureus, and additionally showed antiproliferative activity against the MDA-MB-231 triple negative breast cancer cell line. A SWATH proteomic analysis revealed the downregulation of proteins involved in cell growth and tumor progression upon TcPaSK cell treatment. The dual role of TcPaSK peptide as antimicrobial and antiproliferative agent makes it a versatile molecule that warrants exploration for its use in novel therapeutic developments as an alternative approach to overcome bacterial antibiotic resistance and to increase the efficacy of conventional cancer treatments.

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.

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.

Plasma activity of Thioredoxin Reductase as a Novel Biomarker in Gastric Cancer

Gastric cancer (GC) is one of the leading malignancies around the world. Identification of novel and efficient biomarkers for GC diagnosis and evaluation of therapeutic efficiency could improve the therapeutic strategy in future clinical application. This study aims to evaluate the levels of plasma thioredoxin reductase (TrxR) activity in GC patients to confirm its validity and efficacy in GC diagnosis and evaluation of therapeutic efficiency. 923 cases were enrolled in the current study. In the group of GC patients before clinical intervention, plasma TrxR activity [9.09 (7.96, 10.45) U/mL] was significantly higher than in healthy controls [3.69 (2.38, 5.32) U/mL]. The threshold of TrxR activity for GC diagnosis was set at 7.34 U/mL with a sensitivity of 85.5% and a specificity of 97.9%. In GC patients after chemotherapy, plasma TrxR activity was remarkably higher in patients with progressive disease or uncontrolled condition [10.07 (8.19, 11.02) U/mL] compared with patients with complete or partial response [7.12 (6.08, 8.37) U/mL] in response to chemotherapy. TrxR activity displayed the higher efficiency to distinguish between GC patients with two distinct clinical outcomes than carcinoembryonic antigen (CEA), cancer antigen 72-4 (CA72-4) and cancer antigen 19-9 (CA19-9). Moreover, combination of TrxR, CEA, CA72-4 and CA19-9 was demonstrated to be more effective in both GC diagnosis and evaluation of therapeutic efficiency than was each biomarker individually. Together, plasma TrxR activity was identified as a novel and efficient biomarker of GC, both in diagnosis and monitoring of therapeutic efficiency in response to chemotherapy.

Thioredoxin Reductase as a Novel and Efficient Plasma Biomarker for the Detection of Non-Small Cell Lung Cancer: a Large-scale, Multicenter study

There is an increased demand for efficient biomarkers for the diagnosis of non-small cell lung cancer (NSCLC). This study aimed to evaluate plasma levels of TrxR activity in a large population to confirm its validity and efficacy in NSCLC diagnosis. Blood samples were obtained from 1922 participants (638 cases of NSCLC, 555 cases of benign lung diseases (BLDs) and 729 sex- and age-matched healthy controls). The plasma levels of TrxR activity in patients with NSCLC (15.66 ± 11.44 U/ml) were significantly higher (P < 0.01) than in patients with BLDs (6.27 ± 3.78 U/ml) or healthy controls (2.05 ± 1.86 U/ml). The critical value of plasma TrxR activity levels for diagnosis of NSCLC was set at 10.18 U/ml, with a sensitivity of 71.6% and a specificity of 91.9%. The combination of NSE, CEA, CA19-9, Cyfra21-1, and TrxR was more effective for NSCLC diagnosis (sensitivity and specificity in the training set: 85.6%, 90.2%; validation set: 86.2%, 92.4%) than was each biomarker individually (P < 0.001). TrxR can also efficiently distinguish the metastatic status of the tumor, and it can further differentiate between various histological differentiations. Together, plasma TrxR activity was identified as a convenient, non-invasive, and efficient biomarker for the diagnosis of NSCLCs, particularly for discriminating between metastatic and non-metastatic tumors, or for histologic differentiation.

Inhibiting TrxR suppresses liver cancer by inducing apoptosis and eliciting potent antitumor immunity

Liver cancer is one of the most common malignant tumors worldwide. Thioredoxin reductase (TrxR) is highly expressed in liver cancer cells. The present study aimed to investigate the effect of inhibiting TrxR on liver cancer and to better understand the underlying molecular and immuno-logical mechanisms associated with inhibition. It was demonstrated that targeting TrxR inhibited the growth and induced apoptosis of liver cancer cells, which was accompanied by activation of the mitogen associated protein kinase pathway. This inhibition was dependent on the production of reactive oxygen species (ROS). Blockage of ROS production reversed TrxR inhibitor‑induced antitumor effects. Blocking the Trx/TrxR system activated the mammalian target of rapamycin pathway and inhibited autophagy, which occurred in a ROS‑independent manner. TrxR inhibition led to lesions in the mitochondrial membrane, indicated by alterations in membrane potential. Mouse xenograft experiments were highly consistent with in vitro studies. Most importantly, blocking the Trx/TrxR system improved the tumor immune microenvironment. Together, these data demonstrated that TrxR is a potential target for liver cancer therapy, which could inhibit hepatocarcinogenesis and progression, and improve the antitumor immune response.

Preoperative high-sensitivity C-reactive protein to lymphocyte ratio index plays a vital role in the prognosis of hepatocellular carcinoma after surgical resection

Background

At present, the predictive ability of the prognostic indicator of hepatocellular carcinoma (HCC) is still limited. This study aims to analyze the relationship between the preoperative high-sensitivity C-reactive protein to lymphocyte ratio (HCLR) and the clinicopathologic characteristics of HCC.

Patients and methods

A total of 229 HCC patients undergoing surgical resection were retrospectively analyzed. The majority of the patients (132/229) had tumors larger than 5 cm, and 45 out of 229 had more than one tumor focus. Receiver operating characteristic curve analysis was used to decide the cutoff value of HCLR. The overall survival (OS) and progression-free survival (PFS) rates were evaluated by adopting the Kaplan–Meier method.

Results

The cutoff value of HCLR for the best discrimination of HCC prognosis was 1.3 with a sensitivity of 75.5% and a specificity of 71.8%. The area under the receiver operating characteristic curve was 0.791 (95% CI, 0.731–0.840). Preoperative HCLR at a high level (>1.3) was positively correlated with large tumor size, TNM stage, microvascular invasion, and recurrence. The mean OS and PFS in patients with HCLR >1.3 were significantly shorter than in those with HCLR ≤1.3. Univariate and multivariate analyses revealed the HCLR was an independent predictor of OS and PFS.

Conclusion

HCLR was an important independent predictor of dismal prognosis in HCC patients and can be used as a sensitive indicator for the dynamic monitoring of postoperative patients.

Butaselen prevents hepatocarcinogenesis and progression through inhibiting thioredoxin reductase activity

Hepatocellular carcinoma (HCC) accounts for most of primary liver cancer, of which five-year survival rate remains low and chemoprevention has become a strategy to reduce disease burden of HCC. We aim to explore the in vivo chemopreventive effect of an organoselenium-containing compound butaselen (BS) against hepatocarcinogenesis and its underlying mechanisms. Pre- and sustained BS treatment (9, 18 and 36mg/Kg BS) could dose-dependently inhibit chronic hepatic inflammation, fibrosis, cirrhosis and HCC on murine models with 24 weeks treatment scheme. The thioredoxin reductase (TrxR), NF-κB pathway and pro-inflammatory factors were activated during hepatocarcinogenesis, while their expression were decreased by BS treatment. BS treatment could also significantly reduce tumor volume in H22-bearing models and remarkably slow tumor growth. HCC cell lines HepG2, Bel7402 and Huh7 were time- and dose-dependently inhibited by BS treatment. G2/M arrest and apoptosis were observed in HepG2 cells after BS treatment, which were mediated by TrxR/Ref-1 and NF-κB pathways inhibition. BS generated reactive oxygen species (ROS), which could be reduced by antioxidant N-acetyl-L-cysteine (NAC) and NADPH oxidase inhibitor DPI. NAC could markedly increase HepG2 cells viability. TrxR activity of HepG2 cells treated with BS were significantly decreased in parallel with proliferative inhibition. The TrxR1-knockdown HepG2 cells also exhibited low TrxR1 activity, high ROS level, relatively low proliferation rate and increased resistance to BS treatment. In conclusion, BS can prevent hepatocarcinogenesis through inhibiting chronic inflammation, cirrhosis and tumor progression. The underlying mechanisms may include TrxR activity inhibition, leading to ROS elevation, G2/M arrest and apoptosis.

The Epidemiology of Selenium and Human Cancer

The relation between selenium and cancer has been one of the most hotly debated topics in human health over the last decades. Early observational studies reported an inverse relation between selenium exposure and cancer risk. Subsequently, randomized controlled trials showed that selenium supplementation does not reduce the risk of cancer and may even increase it for some types, including advanced prostate cancer and skin cancer. An increased risk of diabetes has also been reported. These findings have been consistent in the most methodologically sound trials, suggesting that the early observational studies were misleading. Other studies have investigated selenium compounds as adjuvant therapy for cancer. Though there is currently insufficient evidence regarding the utility and safety of selenium compounds for such treatments, this issue is worthy of further investigation. The study of selenium and cancer is complicated by the existence of a diverse array of organic and inorganic selenium compounds, each with distinct biological properties, and this must be taken into consideration in the interpretation of both observational and experimental human studies.

EF24 induces ROS-mediated apoptosis via targeting thioredoxin reductase 1 in gastric cancer cells

Gastric cancer (GC) is one of the leading causes of cancer mortality in the world, and finding novel agents for the treatment of advanced gastric cancer is of urgent need. Diphenyl difluoroketone (EF24), a molecule having structural similarity to curcumin, exhibits potent anti-tumor activities by arresting cell cycle and inducing apoptosis. Although EF24 demonstrates potent anticancer efficacy in numerous types of human cancer cells, the cellular targets of EF24 have not been fully defined. We report here that EF24 may interact with the thioredoxin reductase 1 (TrxR1), an important selenocysteine (Sec)-containing antioxidant enzyme, to induce reactive oxygen species (ROS)-mediated apoptosis in human gastric cancer cells. By inhibiting TrxR1 activity and increasing intracellular ROS levels, EF24 induces a lethal endoplasmic reticulum stress in human gastric cancer cells. Importantly, knockdown of TrxR1 sensitizes cells to EF24 treatment. In vivo, EF24 treatment markedly reduces the TrxR1 activity and tumor cell burden, and displays synergistic lethality with 5-FU against gastric cancer cells. Targeting TrxR1 with EF24 thus discloses a previously unrecognized mechanism underlying the biological activity of EF24, and reveals that TrxR1 is a good target for gastric cancer therapy.

Serum thioredoxin reductase is highly increased in mice with hepatocellular carcinoma and its activity is restrained by several mechanisms

Increased thioredoxin reductase (TrxR) levels in serum were recently identified as possible prognostic markers for human prostate cancer or hepatocellular carcinoma. We had earlier shown that serum levels of TrxR protein are very low in healthy mice, but can in close correlation to alanine aminotransferase (ALT) increase more than 200-fold upon chemically induced liver damage. We also found that enzymatic TrxR activity in serum is counteracted by a yet unidentified oxidase activity in serum. In the present study we found that mice carrying H22 hepatocellular carcinoma tumors present highly increased levels of TrxR in serum, similarly to that reported in human patients. In this case ALT levels did not parallel those of TrxR. We also discovered here that the TrxR-antagonistic oxidase activity in serum is due to the presence of quiescin Q6 sulfhydryl oxidase 1 (QSOX1). We furthermore found that the chemotherapeutic agents cisplatin or auranofin, when given systemically to H22 tumor bearing mice, can further inhibit TrxR activities in serum. The TrxR serum activity was also inhibited by endogenous electrophilic inhibitors, found to increase in tumor-bearing mice and to include protoporphyrin IX (PpIX) and 4-hydroxynonenal (HNE). Thus, hepatocellular carcinoma triggers high levels of serum TrxR that are not paralleled by ALT, and TrxR enzyme activity in serum is counteracted by several different mechanisms. The physiological role of TrxR in serum, if any, as well as its potential value as a prognostic marker for tumor progression, needs to be studied further.

Thioredoxin 1 mediates TGF-β-induced epithelial-mesenchymal transition in salivary adenoid cystic carcinoma

Epithelial-mesenchymal transition (EMT) plays an important role in the invasion and metastasis of salivary adenoid cystic carcinoma (SACC) which is characterized by wide local infiltration, perineural spread, a propensity to local recurrence and late distant metastasis. Our recent studies have disclosed that TGF-β is a crucial factor for EMT in metastatic SACC. In this study, we further uncovered small redox protein thioredoxin 1 (TXN) as a critical mediator of TGF-β induced EMT. Immunohistochemistry analysis revealed significantly higher expressions of TXN, thioredoxin reductase 1 (TXNRD1) and N-cadherin, and lower expression of E-cadherin in human metastatic SACC compared to non-metastatic SACC tissues. Consistently, cultured SACC cells with stable TXN overexpression had decreased E-cadherin and increased N-cadherin as well as Snail and Slug expressions. The enhanced migration and invasion potential of these cells was abrogated by Akt or TXNRD1 inhibitors. Expression of N-cadherin and Akt p-Akt decreased, whereas E-cadherin expression increased in a BBSKE (TXNRD1 inhibitor)-dose-dependent manner. In a xenograft mouse model, TXN overexpression facilitated the metastatic potential of SACC-83 cells to the lung. Our results indicate that TXN plays a key role in SACC invasion and metastasis through the modulation of TGF-β-Akt/GSK-3β on EMT. TXN could be a potential therapeutic target for SACC.

Piperlongumine as a direct TrxR1 inhibitor with suppressive activity against gastric cancer

Piperlongumine (PL), a natural alkaloid isolated from the fruit of long pepper, is known to selectively kill tumor cells while sparing their normal counterparts. However, the cellular target and potent anticancer efficacy of PL in numerous types of human cancer cells have not been fully defined. We report here that PL may interact with the thioredoxin reductase 1 (TrxR1), an important selenocysteine (Sec)-containing antioxidant enzyme, to induce reactive oxygen species (ROS)-mediated apoptosis in human gastric cancer cells. By inhibiting TrxR1 activity and increasing intracellular ROS levels, PL induces a lethal endoplasmic reticulum stress and mitochondrial dysfunction in human gastric cancer cells. Importantly, knockdown of TrxR1 sensitizes cells to PL treatment, and PL displays synergistic lethality with GSH inhibitors (BSO and Erastin) against gastric cancer cells. In vivo, PL treatment markedly reduces the TrxR1 activity and tumor cell burden. Remarkably, TrxR1 was significantly overexpressed in gastric cancer cell lines and human gastric cancer tissues. Targeting TrxR1 with PL thus discloses a previously unrecognized mechanism underlying the biological activity of PL and provides an in-depth insight into the action of PL in the treatment of gastric cancer.

Plasma and Synovial Fluid TrxR Levels are Correlated With Disease Risk and Severity in Patients With Rheumatoid Arthritis

This study was designed and performed to establish the relationship between plasma and synovial fluid (SF) levels of thioredoxin reductase (TrxR) and disease activity in Chinese patients with rheumatoid arthritis (RA).This study consisted of a total of 224 patients diagnosed with RA, 224 age and sex-matched healthy controls, and 156 patient controls. The disease activity of RA patients was calculated as diseases activity score that include 28-joint counts (DAS 28), which was divided into low-diseases activity (LDA) and high-diseases activity (HDA) groups.Increased plasma TrxR was detected in patients with RA than healthy controls (P < 0.0001). With an area under the curve (AUC) of 0.874, plasma TrxR showed a evidently greater discriminatory ability than C-reactive protein (CRP; AUC, 0.815), antistreptolysin-O (ASO; AUC, 0.631), rheumatoid factor (RF, AUC, 0.793), and erythrocyte sedimentation rate (ESR, AUC, 0.789) in diagnosing RA. RA patients with HDA had significantly elevated TrxR levels in plasma and SF than did those with LDA (P < 0.0001). With an AUC of 0.874, plasma TrxR levels as an indicator for screening of HDA showed a significantly greater discriminatory ability than CRP (AUC, 0.690), ASO (AUC, 0.597), RF (AUC, 0.657), and ESR (AUC, 0.603). Similarly, SF TrxR levels as an indicator for screening of HDA also showed a significantly greater discriminatory ability as compared with above biomarkers.TrxR levels in plasma and SF were positively correlated with the severity of RA. TrxR levels may therefore serve as a new biomarker in addition of the traditional biomarkers for assessing the risk and severity of RA. Further analysis of TrxR release machinery may give us a new understanding of pathogenesis of RA.

Oxidative stress measured by thioredoxin reductase level as potential biomarker for prostate cancer

The aims of this study were to determine if Thioredoxin reductase (TR) is detected in the serum, and to establish the sensitivity and specificity of serum TR for diagnosing prostate cancer (PC). We assessed serum TR in 380 participants in the training cohort: 160 patients with PC, 120 with benign prostatic hyperplasia and 100 healthy individuals. The validation cohort comprised 320 participants: 120 with PC, 100 with BPH and 100 healthy individuals. TR was measured in serum by ELISA by independent researchers. The patients with PC were graded using the Gleason system. Receiver operating characteristic (ROC) curves were utilized to evaluate the accuracy of biomarkers to diagnose PC. The influence of serum levels of TR on tumor grade and metastasis was performed by binary logistic regression analysis. The median levels of serum TR in PC were significantly higher than that of healthy subjects and patients with BPH (P < 0.0001). Based on the ROC curve, the optimal cutoff value of serum TR levels as an indicator for auxiliary diagnosis of PC from BPH was projected to be 8.2 U/ml, which yielded a sensitivity of 81.8% and a specificity of 68.9%, with the area under the curve at 0.862 (95% CI, 0.821-0.903). Combined model (TR and PSA) showed a significantly greater discriminatory ability as compared with those markers alone. In regression analysis, after adjusting for other significant predictors, TR remained an independent metastasis predictor with an adjusted OR of 4.99 (95% CI, 2.64-8.09). Similarly, TR also was an independent High-grade tumors (HGT) predictor with an adjusted OR of 5.15 (95% CI, 2.52-9.14). Our study has demonstrated the additional benefit of TR measurement in the diagnosis of PC in the Chinese population. Further studies of the application of TR in this region may be beneficial.