Thioredoxin 1 as a serum marker for breast cancer and its use in combination with CEA or CA15-3 for improving the sensitivity of breast cancer diagnoses

1,3,5-Triazine as a promising scaffold in the development of therapeutic agents against breast cancer

1,3,5-Triazine scaffold has garnered considerable interest due to its wide-ranging pharmacological properties, particularly in the field of cancer research. Breast cancer is the most commonly diagnosed cancer among women. Approximately one in eight women will receive a diagnosis of invasive breast cancer during their lifetime. The five-year survival rate for invasive breast cancer is less than 30 %, indicating a need to develop a more effective therapeutic agent targeting breast cancer. This review discusses bioactive 1,3,5-triazines targeting breast cancer cells by the inhibition of different enzymes, which include PI3K, mTOR, EGFR, VEGFR, FAK, CDK, DHFR, DNA topoisomerase, ubiquitin-conjugating enzyme, carbonic anhydrase, and matrix metalloproteinase. The anticancer agent search in some drug discovery programs is based on compound screening for antiproliferative activity. Often, multiple targets contribute to the anticancer effect of 1,3,5-triazines and this approach allows identification of active molecules prior to identification of their targets.

CEA (CEACAM5) expression is common in muscle-invasive urothelial carcinoma of the bladder but unrelated to the disease course

Objectives

Carcinoembryonic antigen (CEA) is a cell surface glycoprotein that represents a promising therapeutic target. Serum measurement of shedded CEA can be utilized for monitoring of cancer patients.

Material and Methods

To evaluate the potential clinical significance of CEA expression in urothelial bladder neoplasms, CEA was analysed by immunohistochemistry in more than 2500 urothelial bladder carcinomas in a tissue microarray format.

Results

CEA staining was largely absent in normal urothelial cells but was observed in 30.4% of urothelial bladder carcinomas including 406 (16.7%) with weak, 140 (5.8%) with moderate, and 192 (7.9%) with strong staining. CEA positivity occurred in 10.9% of 411 pTaG2 low-grade, 32.0% of 178 pTaG2 high-grade, and 43.0% of 93 pTaG3 tumours (p < 0.0001). In 1335 pT2-4 carcinomas, CEA positivity (34.1%) was lower than in pTaG3 tumours. Within pT2-4 carcinomas, CEA staining was unrelated to pT, pN, grade, L-status, V-status, overall survival, recurrence free survival, and cancer specific survival (p > 0.25).

Conclusion

CEA increases markedly with grade progression in pTa tumours, and expression occurs in a significant fraction of pT2-4 urothelial bladder carcinomas. The high rate of CEA positivity in pT2-4 carcinomas offers the opportunity of using CEA serum measurement for monitoring the clinical course of these cancers. Moreover, CEA positive urothelial carcinomas are candidates for a treatment by targeted anti-CEA drugs.

Colorimetric and Electrochemical Dual-Mode Detection of Thioredoxin 1 Based on the Efficient Peroxidase-Mimicking and Electrocatalytic Property of Prussian Blue Nanoparticles

As a potent detection method for cancer biomarkers in physiological fluid, a colorimetric and electrochemical dual-mode sensing platform for breast cancer biomarker thioredoxin 1 (TRX1) was developed based on the excellent peroxidase-mimicking and electrocatalytic property of Prussian blue nanoparticles (PBNPs). PBNPs were hydrothermally synthesized using K3[Fe(CN)6] as a precursor and polyvinylpyrrolidone (PVP) as a capping agent. The synthesized spherical PBNPs showed a significant peroxidase-like activity, having approximately 20 and 60% lower Km values for 3,3',5,5'-tetramethylbenzidine (TMB) and H2O2, respectively, compared to those of horseradish peroxidase (HRP). The PBNPs also enhanced the electron transfer on the electrode surface. Based on the beneficial features, PBNPs were used to detect target TRX1 via sandwich-type immunoassay procedures. Using the strategies, TRX1 was selectively and sensitively detected, yielding limit of detection (LOD) values as low as 9.0 and 6.5 ng mL-1 via colorimetric and electrochemical approaches, respectively, with a linear range of 10-50 ng mL-1 in both strategies. The PBNP-based TRX1 immunoassays also exhibited a high degree of precision when applied to real human serum samples, demonstrating significant potentials to replace conventional HRP-based immunoassay systems into rapid, robust, reliable, and convenient dual-mode assay systems which can be widely utilized for the identification of important target molecules including cancer biomarkers.

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.

Thioredoxin System and miR-21, miR-23a/b and let-7a as Potential Biomarkers for Brain Tumor Progression: Preliminary Case Data

BACKGROUND

The thioredoxin system and microRNAs (miRNAs) are potential targets for both cancer progression and treatment. However, the role of miRNAs and their relation with the expression profile of thioredoxin system in brain tumor progression remains unclear.

METHODS

In this study, we aimed to determine the expression profiles of redox components Trx-1, TrxR-1 and PRDX-1, and oncogenic miR-21, miR-23a/b and let-7a and oncosuppressor miR-125 in different brain tumor tissues and their association with increasing tumor grade. We studied Trx-1, TrxR-1, and PRDX-1 messenger RNA expression levels by quantitative real-time polymerase chain reaction and protein levels by Western blot and miR-23a, miR-23b, miR-125a, miR-21, and let-7a miRNA expression levels by quantitative real-time polymerase chain reaction in 16 glioma, 15 meningioma, 5 metastatic, and 2 benign tumor samples. We also examined Trx-1, TrxR-1, and PRDX-1 protein levels in serum samples of 36 patients with brain tumor and 37 healthy volunteers by enzyme-linked immunosorbent assay.

RESULTS

We found that Trx-1, TrxR-1, and PRDX-1 presented high messenger RNA expression but low protein expression in low-grade brain tumor tissues, whereas they showed higher protein expression in sera of patients with low-grade brain tumors. miR-23b, miR-21, miR-23a, and let-7a were highly expressed in low-grade brain tumor tissues and positively correlated with the increase in thioredoxin system activity.

CONCLUSIONS

Our findings showed that Trx-1, TrxR-1, miR-21, miR-23a/b, and let-7a might be used for brain tumor diagnosis in the clinic. Further prospective studies including molecular pathway analyses are required to validate the miRNA/Trx system regulatory axis in brain tumor progression.

The blood level of thioredoxin 1 as a supporting biomarker in the detection of breast cancer

BACKGROUND

There is a long-time unmet need for a means to detect breast cancer (BC) using blood. Although mammography is accepted as the gold standard for screening, a blood-based diagnostic can complement mammography and assist in the accurate detection of BC in the diagnostic process period of early diagnosis. We have previously reported the possible use of thioredoxin 1 (Trx1) in serum as a novel means to detect BC. In the present study, we validated the clinical utility of Trx1 to identify BC by testing sera from biopsy-confirmed cancer patients and women without cancer.

METHODS

We have generated monoclonal antibodies against Trx1 and developed an ELISA kit that can quantitate Trx1 in sera. The level of Trx1 was determined in each serum from women without cancer (n = 114), as well as in serum from patients with BC (n = 106) and other types of cancers (n = 74), including cervical, lung, stomach, colorectal, and thyroid cancer. The sera from BC patients were collected and classified by the subjects' age and cancer stage. In addition to the Trx1 levels of BC patients, several pathological and molecular aspects of BC were analyzed. Test results were retrospectively compared to those from mammography. Each test was duplicated, and test results were analyzed by ROC analysis, one-way ANOVA tests, and unpaired t-tests.

RESULTS

The mean level of Trx1 from women without cancer was 5.45 ± 4.16 (±SD) ng/ml, that of the other malignant cancer patient group was 2.70 ± 2.01 ng/ml, and that from the BC group was 21.96 ± 6.79 ng/ml. The difference among these values was large enough to distinguish BC sera from non-BC control sera with a sensitivity of 97.17% and specificity of 94.15% (AUC 0.990, p < 0.0001). Most Trx1 levels from BC patients' sera were higher than the cut-off value of 11.4 ng/ml regardless of age, stage, histological grade, type, and specific receptors' expression profile of BC. The level of Trx1 could rescue women from most cases of misread or incomplete mammography diagnoses.

CONCLUSION

These results indicated that the blood level of Trx1 could be an effective and accurate means to assist the detection of BC during the early diagnosis period.

Pumpless three-dimensional photo paper-based microfluidic analytical device for automatic detection of thioredoxin-1 using enzyme-linked immunosorbent assay

Microfluidic-based biosensors have been developed for their precise automatic reaction control. However, these biosensors require external devices that are difficult to transport and use. To overcome this disadvantage, our group made an easy-to-use, cheap, and light pumpless three-dimensional photo paper-based microfluidic analytical device (3D-μPAD; weight: 1.5 g). Unlike conventional paper-based microfluidic analytical devices, the 3D-μPAD can be used to control fluid flow in a 3D manner, thus allowing sophisticated multi-step reaction control. This device can control fluid flow speed and direction accurately using only the capillary-driven flow without an external device like a pump. The flow speed is controlled by the width of the microfluidic channel and its surface property. In addition, fluid speed control and 3D-bridge structure enable the control of fluid flow direction. Using these methods, multi-step enzyme-linked immunosorbent assay (ELISA) can be done automatically in sequence by injecting solutions (sample, washing, and enzyme's substrate) at the same time in the 3D-μPAD. All the steps can be performed in 14 min, and data can be analyzed immediately. To test this device, thioredoxin-1 (Trx-1), a biomarker of breast cancer, is used as the target. In the 3D-μPAD, it can detect 0-200 ng/mL of Trx-1, and the prepared 3D-μPAD Trx-1 sensor displays excellent selectivity. Moreover, by analyzing the concentration of Trx-1 in real patients and healthy individuals' blood serum samples using the 3D-μPAD, and comparing results to ELISA, it can be confirmed that the 3D-μPAD is a good tool for cancer diagnosis.

Current research on circular RNAs and their potential clinical implications in breast cancer

Breast cancer (BC) is one of the most common cancers and the leading causes of death among women worldwide, and its morbidity rate is growing. Discovery of novel biomarkers is necessary for early BC detection, treatment, and prognostication. Circular RNAs (circRNAs), a novel type of endogenous non-coding RNAs with covalently closed continuous loops, have been found to have a crucial role in tumorigenesis. Studies have demonstrated that circRNAs are aberrantly expressed in the tumor tissues and plasma of patients with BC, and they modulate gene expression affecting the proliferation, metastasis, and chemoresistance of BC by specifically binding and regulating the expression of microRNAs (miRNAs). Therefore, circRNAs can be used as novel potential diagnostic and prognostic markers, and therapeutic targets for BC. This article summarizes the properties, functions, and regulatory mechanisms of circRNAs, particularly current research on their association with BC proliferation, metastasis, and chemoresistance.

Electrochemical Nanobiosensors for Detection of Breast Cancer Biomarkers

This comprehensive review paper describes recent advances made in the field of electrochemical nanobiosensors for the detection of breast cancer (BC) biomarkers such as specific genes, microRNA, proteins, circulating tumor cells, BC cell lines, and exosomes or exosome-derived biomarkers. Besides the description of key functional characteristics of electrochemical nanobiosensors, the reader can find basic statistic information about BC incidence and mortality, breast pathology, and current clinically used BC biomarkers. The final part of the review is focused on challenges that need to be addressed in order to apply electrochemical nanobiosensors in a clinical practice.

A 17-gene expression-based prognostic signature associated with the prognosis of patients with breast cancer: A STROBE-compliant study

Identification of reliable predictive biomarkers for patients with breast cancer (BC).Univariate Cox proportional hazards regression model was conducted to identify genes correlated with the overall survival (OS) of patients in the TCGA-BRCA cohort. Functional enrichment analysis was conducted to investigate the biological meaning of these survival related genes. Then, patients in TCGA-BCRA were randomly divided into training set and test. Least absolute shrinkage and selection operator (LASSO) penalized Cox regression model was performed and the risk score of BC patients in this model was used to build a prognostic signature. The prognostic performance of the signature was evaluated in the training set, test set, and an independent validation set GSE7390.2519 genes were demonstrated to be significantly associated with the OS of BC patients. Functional annotation of the 2519 genes suggested that these genes were associated with immune response and protein synthesis related gene ontology terms and pathways. 17 genes were identified in the LASSO Cox regression model and used to construct a 17-gene signature. Patients in the 17-gene signature low risk group have better OS and event-free survival compared with those in the 17-gene signature high risk group in the TCGA-BRCA cohort. The prognostic role of the 17-gene signature has been confirmed in the validation cohort. Multivariable Cox proportional hazards regression model suggested the 17-gene signature was an independent prognostic factor in BC.The 17-gene signature we developed could successfully classify patients into high- and low-risk groups, indicating that it might serve as candidate biomarker in BC.

Detection of thioredoxin-1 using ultra-sensitive ELISA with enzyme-encapsulated human serum albumin nanoparticle

Many methods for early diagnosis of the disease use biomarker tests, which measure indicators of biological state in body fluids or blood. However, a limitation of these methods is their low sensitivity to biomarkers. In this study, human serum albumin (HSA) based nanoparticles capable of encapsulating excess horseradish peroxidase (HRP) are synthesized and applied to the development of enzyme-linked immunosorbent assay (ELISA) kit with ultra-high sensitivity. The size of the nanoparticles and the amount of encapsulated enzyme are controlled by varying the synthesis conditions of pH and protein concentration, and the surface of the nanoparticles is modified with protein A (proA) to immobilize antibodies to the nanoparticles by self-assembly. Using the synthesized nanoparticles, the biomarker of breast cancer, thioredoxin-1, can be measured in the range of 10 fM to 100 pM by direct sandwich ELISA, which is 10⁵ times more sensitive than conventional methods.

Circulating circular RNA hsa_circ_0001785 acts as a diagnostic biomarker for breast cancer detection

BACKGROUND

Circular RNAs (circRNAs) are a class of non-coding RNAs (ncRNAs) and characterized by covalently closed loop without 5' and 3' end. Recently, the diagnostic value of circRNAs has received more and more attention. However, the in-depth study about circRNAs diagnosis in breast cancer is still rarely reported. In present study, we try to investigate the circRNAs expression profiles in breast cancer peripheral blood and discover valuable diagnostic biomarkers.

METHODS

The expression profiles of circRNAs in plasma specimens were screened from five breast cancer and paired healthy volunteer s. The expression levels of selected candidate circRNAs were detected by RT-PCR. The diagnostic value was performed using receiver operating characteristic (ROC) curve.

RESULTS

CircRNAs microarray assay showed that 41 circRNAs were aberrantly expressed with 2 fold change, including 19 up-regulated and 22 down-regulated circRNAs. Among these circRNAs, 3 candidate circRNAs were validated to be significantly dysregulated using RT-PCR, including hsa_circ_0001785, hsa_circ_0108942 and hsa_circ_0068033. In lager study cohort (n=20), ROC curve showed that hsa_circ_0001785 had better diagnostic value (AUC=0.771) than others. Moreover, in further extensive study cohort (n=57), we found that hsa_circ_0001785 plasma had better diagnostic accuracy (AUC=0.784) than CEA (AUC=0.562) and CA15-3 (AUC=0.629). Besides, hsa_circ_0001785 plasma level was closely related to histological grade (P=0.013), TNM stage (P=0.008) and distant metastasis (P=0.016). Furthermore, hsa_circ_0001785 plasma level in postoperative patients (0.283±0.043) was significantly lower than that of preoperative patients (0.109±0.037, P<0.01).

CONCLUSION

Our study reveals the aberrant circRNAs expression profiles in breast cancer peripheral blood, and identifies the potential diagnostic value of plasma hsa_circ_0001785, providing a stable biomarkers for the diagnosis and progress of breast cancer.

Oxidative Stress Gene Expression Profile Correlates with Cancer Patient Poor Prognosis: Identification of Crucial Pathways Might Select Novel Therapeutic Approaches

The role of altered redox status and high reactive oxygen species (ROS) is still controversial in cancer development and progression. Intracellular levels of ROS are elevated in cancer cells suggesting a role in cancer initiation and progression; on the contrary, ROS elevated levels may induce programmed cell death and have been associated with cancer suppression. Thus, it is crucial to consider the double-face of ROS, for novel therapeutic strategies targeting redox regulatory mechanisms. In this review, in order to derive cancer-type specific oxidative stress genes' profile and their potential prognostic role, we integrated a publicly available oxidative stress gene signature with patient survival data from the Cancer Genome Atlas database. Overall, we found several genes statistically significant associated with poor prognosis in the examined six tumor types. Among them, FoxM1 and thioredoxin reductase1 expression showed the same pattern in four out of six cancers, suggesting their specific critical role in cancer-related oxidative stress adaptation. Our analysis also unveiled an enriched cellular network, highlighting specific pathways, in which many genes are strictly correlated. Finally, we discussed novel findings on the correlation between oxidative stress and cancer stem cells in order to define those pathways to be prioritized in drug development.

Top-down nanofabrication of silicon nanoribbon field effect transistor (Si-NR FET) for carcinoembryonic antigen detection

Sensitive and quantitative detection of tumor markers is highly required in the clinic for cancer diagnosis and consequent treatment. A field-effect transistor-based (FET-based) nanobiosensor emerges with characteristics of being label-free, real-time, having high sensitivity, and providing direct electrical readout for detection of biomarkers. In this paper, a top–down approach is proposed and implemented to fulfill a novel silicon nano-ribbon FET, which acts as biomarker sensor for future clinical application. Compared with the bottom–up approach, a top–down fabrication approach can confine width and length of the silicon FET precisely to control its electrical properties. The silicon nanoribbon (Si-NR) transistor is fabricated on a Silicon-on-Insulator (SOI) substrate by a top–down approach with complementary metal oxide semiconductor (CMOS)-compatible technology. After the preparation, the surface of Si-NR is functionalized with 3-aminopropyltriethoxysilane (APTES). Glutaraldehyde is utilized to bind the amino terminals of APTES and antibody on the surface. Finally, a microfluidic channel is integrated on the top of the device, acting as a flowing channel for the carcinoembryonic antigen (CEA) solution. The Si-NR FET is 120 nm in width and 25 nm in height, with ambipolar electrical characteristics. A logarithmic relationship between the changing ratio of the current and the CEA concentration is measured in the range of 0.1–100 ng/mL. The sensitivity of detection is measured as 10 pg/mL. The top–down fabricated biochip shows feasibility in direct detecting of CEA with the benefits of real-time, low cost, and high sensitivity as a promising biosensor for tumor early diagnosis.

Expression of the thioredoxin system in an in vivo-like cancer cell environment upon auranofin treatment

As essential elements of the tumor microenvironment, the variable oxygenation state of the tumor tissue, the extracellular matrix (ECM) and different cell types are important determinants of carcinogenesis. These elements may also influence how tumor cells respond to therapeutic treatments. In the present study, we assessed the anti-cancer activity of auranofin and its effect on the thioredoxin (Trx) system under conditions that closely resemble the in vivo tumor microenvironment with respect to the oxygen levels and tissue architecture. We utilised an oxygen scheme involving growth of cancer cells under normoxia (20%) and hypoxia (0.1%). We also preconditioned cells with intermittent hypoxia (IH) prior to a prolonged hypoxic incubation. This oxygen scheme did not affect the cytotoxicity of auranofin; however, IH preconditioned cells were less sensitive towards the inhibition of thioredoxin reductase (TrxR) specific activity upon treatment with auranofin. IH preconditioning also upregulated Trx protein levels in auranofin treated cells. We also compared the activity of auranofin against cancer cells cultured in 2D monolayer and 3D spheroid-based culture models. Auranofin was less potent against cells grown under a more in vivo-like 3D environment. The results presented in this paper implicate the importance of the tumor oxygen environment and tissue architecture in influencing the response of cancer cells towards auranofin.

The thioredoxin system in breast cancer cell invasion and migration

Metastasis is the most life threatening aspect of breast cancer. It is a multi-step process involving invasion and migration of primary tumor cells with a subsequent colonization of these cells at a secondary location. The aim of the present study was to investigate the role of thioredoxin (Trx1) in the invasion and migration of breast cancer cells and to assess the strength of the association between high levels of Trx1 and thioredoxin reductase (TrxR1) expression with breast cancer patient survival. Our results indicate that the expression of both Trx1 and TrxR1 are statistically significantly increased in breast cancer patient cells compared with paired normal breast tissue from the same patient. Over-expression of Trx1 in MDA-MB-231 breast cancer cell lines enhanced cell invasion in in vitro assays while expression of a redox inactive mutant form of Trx1 (designated 1SS) or the antisense mRNA inhibited cell invasion. Addition of exogenous Trx1 also enhanced cell invasion, while addition of a specific monoclonal antibody that inhibits Trx1 redox function decreased cell invasion. Over-expression of intracellular Trx1 did not increase cell migration but expression of intracellular 1SS inhibited migration. Addition of exogenous Trx1 enhanced cell migration while 1SS had no effect. Treatment with auranofin inhibited TrxR activity, cell migration and clonogenic activity of MDA-MB-231 cells, while increasing reactive oxygen species (ROS) levels. Analysis of 25 independent cohorts with 5910 patients showed that Trx1 and TrxR1 were both associated with a poor patient prognosis in terms of overall survival, distant metastasis free survival and disease free survival. Therefore, targeting the Trx system with auranofin or other specific inhibitors may provide improved breast cancer patient outcomes through inhibition of cancer invasion and migration.

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Over expression of thioredoxin in MDA-MB-231 cells enhanced cell invasion in vitro.

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Thioredoxin inhibition reduced cell invasion and migration of MDA-MB-231 cells.

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Addition of thioredoxin enhanced migration of MDA-MB-231 cells in vitro.

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Auranofin treatment inhibited MDA-MB-231 cell migration and clonogenic activity.

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High Trx1 and TrxR1 expression is associated with a poor breast cancer prognosis.

Elevated level of serum glycoprotein bifucosylation and prognostic value in Chinese breast cancer

Aberrant glycosylation is highly associated with cancer progression. The aim of this study was to compare bifucosylated N-glycans in sera obtained from healthy controls and breast cancer patients, with the goal of identifying a potential indicator for monitoring the recurrence and metastasis of breast cancer. A unique structural pattern of bifucosylated N-glycan, with both core and antennary fucosylation, was identified in breast cancer patients. The spectrum of antennary fucosylation was a composite of the standard spectra of Lewis X and H2, indicating a mixture of the two epitopes. Permethylated N-glycans of the glycoproteins extracted from 91 breast cancer patients and 43 healthy controls were detected using linear ion-trap quadrupole-electrospray ionization mass spectrometry, which appeared to be a highly sensitive and useful approach in the detection and identification of N-glycans. To evaluate MS profile data, several statistical tools were applied, including Student'st-test, partial least squares discriminant analysis and receiver-operating characteristic curve. The results showed that the measurement of bifucosylation degree and CEA levels had an improved diagnostic performance compared with that of CEA alone. We compared the potential of bifucosylated N-glycan as an indicator of breast cancer recurrence with the current clinical biomarkers, i.e., CEA, CA 15-3 and CA125. The result revealed that, compared with CEA, CA 15-3 and CA125, the bifucosylation degree of N-glycans could be a more reliable indicator of breast cancer recurrence.

PX-12 inhibits the growth of hepatocelluar carcinoma by inducing S-phase arrest, ROS-dependent apoptosis and enhances 5-FU cytotoxicity

BACKGROUND

1-methylpropyl 2-imidazolyl disulfide (PX-12), a thioredoxin 1 (Trx1) inhibitor, has been investigated in a number of ancers, but its effectiveness in the treatment of hepatocellular carcinoma (HCC) has not been reported. PX-12 has generated considerable interest in its use in a variety of solid tumors, yet most studies have confined their interests to using PX-12 as a single agent. The aim of this study is to investigate whether PX-12 inhibits cell growth and has a synergistic anti-tumor effect in combination with 5-fluorouracil (5-FU) in HCC.

METHODS

Cells were treated with different concentrations of PX-12 and 5-FU. Cell viability assays, colony formation assay, cell cycle assay, reactive oxygen species (ROS) assay, apoptosis analysis, western blot assay, immunohistochemistry and xenograft tumorigenicity assay were performed.

RESULTS

Treatment with PX-12 inhibited cell growth, induced S-phase arrest, and increased ROS levels. PX-12-induced apoptosis and inhibition of colony formation were associated with the generation of ROS, and inhibition of ROS attenuated PX-12-induced apoptosis and inhibition of colony formation. Treatment with PX-12 increased the expression of bax and reduced the expression of bcl-2, indicating that PX-12-mediated apoptosis is mitochondria-dependent. PX-12 also exerted a synergistic effect with 5-FU tosignificantly suppress tumorigenicity both in vitro and in vivo. Inhibition of ROS accumulation reduced the synergistic effect of PX-12 and 5-FU.

CONCLUSIONS

PX-12 has anti-tumor activity and a synergistic effect in combination with 5-FU in HCC. Treatment with PX-12 alone or in combination with 5-FU may have clinical use in the treatment of HCC and other cancers.

Hydrogen peroxide - production, fate and role in redox signaling of tumor cells

Hydrogen peroxide (H₂O₂) is involved in various signal transduction pathways and cell fate decisions. The mechanism of the so called “redox signaling” includes the H₂O₂-mediated reversible oxidation of redox sensitive cysteine residues in enzymes and transcription factors thereby altering their activities. Depending on its intracellular concentration and localization, H₂O₂ exhibits either pro- or anti-apoptotic activities. In comparison to normal cells, cancer cells are characterized by an increased H₂O₂ production rate and an impaired redox balance thereby affecting the microenvironment as well as the anti-tumoral immune response. This article reviews the current knowledge about the intracellular production of H₂O₂ along with redox signaling pathways mediating either the growth or apoptosis of tumor cells. In addition it will be discussed how the targeting of H₂O₂-linked sources and/or signaling components involved in tumor progression and survival might lead to novel therapeutic targets.

Diagnostic and prognostic value of serum thioredoxin and DJ-1 in non-small cell lung carcinoma patients

In response to reactive oxygen species (ROS), thioredoxin and DJ-1 are upregulated to counteract the detrimental effect of ROS under normal condition. However, cancer cells can take advantage of thioredoxin and DJ-1 against ROS-induced cell damage. In several human cancer types, thioredoxin and DJ-1 were found to be overexpressed. The present study aimed to explore the serum levels of thioredoxin and DJ-1 in non-small cell lung cancer (NSCLC) patients and its relationship to the diagnosis and prognosis of this particular malignancy. Sera from 134 NSCLC patients and 168 healthy controls were obtained. Using the enzyme-linked immunosorbent assay (ELISA) method, the levels of serum thioredoxin and DJ-1 were measured and correlated to the clinicopathological characteristics of NSCLC patients. The diagnostic and prognostic significance of the biomarkers were evaluated by using receiver operating curve (ROC), Kaplan-Meier curve, and log-rank analyses and the Cox proportional hazard model, respectively. Serum thioredoxin and DJ-1 levels were significantly higher in the NSCLC patients than that in the controls (23.5 ± 6.57 vs. 13.8 ± 2.49 and 7.11 ± 2.02 vs. 5.18 ± 1.26, respectively). NSCLC patients at later stage cancer showed significantly higher levels of serum thioredoxin and DJ-1 than those at the early stages (P < 0.01 and P < 0.05, respectively). Multivariate logistic regression analysis showed that high serum thioredoxin level was an independent risk factor for lymph nodal metastases and distant metastases (OR = 2.18, 95 % CI 1.26-3.41 and OR = 3.68, 95 % CI 2.16-5.33, respectively). In addition, an increase in the serum DJ-1 level was also identified as an independent risk factor for nodal metastases (OR = 1.37, 95 % CI 1.11-3.04). For predicting the development of NSCLC, ROC/area under the curve (AUC) analysis for thioredoxin indicated an AUC of 0.80 (sensitivity 0.62, specificity 0.92), and ROC/AUC analysis for DJ-1 showed an AUC of 0.78 (sensitivity 0.66, specificity 0.89). NSCLC patients with high serum thioredoxin and DJ-1 levels had lower survival rates than those with low levels, and multivariate analyses for overall survival revealed that high serum thioredoxin levels served as an independent prognostic factor for NSCLC (HR = 2.07, 95 % CI 1.19-3.48). Serum levels of thioredoxin and DJ-1 were significantly higher in NSCLC patients; therefore, these may be utilized as novel diagnostic and prognostic biomarkers for NSCLC.

Thioredoxin 1 as a serum marker for ovarian cancer and its use in combination with CA125 for improving the sensitivity of ovarian cancer diagnoses

The serum levels of Trx1 in patients with ovarian cancer were significantly higher than those in normal persons and patients with non-cancer inflammatory diseases. The level of Trx1 increased with the Figo stage. Ovarian cancer patients who were determined to be negative for CA125, were observed to have serum Trx1 levels as high as those of CA125-positive patients. In addition, patients with non-cancer inflammatory diseases had lower plasma Trx1 1 levels than did controls, showing that Trx1 allows clear distinctions between ovarian cancer and these non-cancer diseases. Combinational analysis of CA125 with Trx1 for the detection of ovarian cancer suggests that the diagnostic capacity of CA125 alone for the early detection of ovarian cancer, especially regarding sensitivity, is significantly improved by its combination with Trx1. Taken together, we conclude that serum Trx1 is useful for the early diagnosis of ovarian cancer.

An investigation into the serum thioredoxin, superoxide dismutase, malondialdehyde, and advanced oxidation protein products in patients with breast cancer

BACKGROUND

Reactive oxygen species (free radicals) play an important role in carcinogenesis. Extensive antioxidant defense mechanisms counteract free radicals in mammalian cells. Oxidative stress is a disturbance in the balance between the production of free radicals and antioxidant defenses. There is direct evidence that oxidative stress and lipid peroxidation (LPO) are linked to the etiology of breast cancer. The increasing global incidence of breast cancer emphasizes the need to understand the various mechanisms involved in breast tumorigenesis. The present study was undertaken to investigate the oxidative stress and antioxidant status in the blood samples of patients with breast cancer.

METHODS

The present study was based on 23 women who were surgically treated at Gazi University, Faculty of Medicine, Department of General Surgery. The malondialdehyde (MDA) levels as an index of LPO along with the examination of superoxide dismutase (SOD) activities and advanced oxidation protein product (AOPP) and thioredoxin (Trx) levels were determined in the blood samples of 23 patients with breast cancer and 13 healthy controls.

RESULTS

MDA, AOPP, and Trx levels and SOD activities were significantly higher in patients with breast cancer than the controls.

CONCLUSIONS

The results showed that oxidative stress may be related to breast cancer and especially some molecules, such as Trx and AOPP, may be useful biomarkers in breast cancer diagnosis and treatment. More detailed knowledge related to the pathophysiology of these molecules could provide valuable information on the origin and development of malignant tumors, such as breast cancer.