Oxidative stress, inflammation, and cancer: how are they linked?

Successful tumour necrosis factor (TNF) blocking therapy suppresses oxidative stress and hypoxia-induced mitochondrial mutagenesis in inflammatory arthritis

Introduction

To examine the effects of tumour necrosis factor (TNF) blocking therapy on the levels of early mitochondrial genome alterations and oxidative stress.

Methods

Eighteen inflammatory arthritis patients underwent synovial tissue oxygen (tpO₂) measurements and clinical assessment of disease activity (DAS28-CRP) at baseline (T0) and three months (T3) after starting biologic therapy. Synovial tissue lipid peroxidation (4-HNE), T and B cell specific markers and synovial vascular endothelial growth factor (VEGF) were quantified by immunohistochemistry. Synovial levels of random mitochondrial DNA (mtDNA) mutations were assessed using Random Mutation Capture (RMC) assay.

Results

4-HNE levels pre/post anti TNF-α therapy were inversely correlated with in vivo tpO₂ (P < 0.008; r = -0.60). Biologic therapy responders showed a significantly reduced 4-HNE expression (P < 0.05). High 4-HNE expression correlated with high DAS28-CRP (P = 0.02; r = 0.53), tender joint count for 28 joints (TJC-28) (P = 0.03; r = 0.49), swollen joint count for 28 joints (SJC-28) (P = 0.03; r = 0.50) and visual analogue scale (VAS) (P = 0.04; r = 0.48). Strong positive association was found between the number of 4-HNE positive cells and CD4+ cells (P = 0.04; r = 0.60), CD8+ cells (P = 0.001; r = 0.70), CD20+ cells (P = 0.04; r = 0.68), CD68+ cells (P = 0.04; r = 0.47) and synovial VEGF expression (P = 0.01; r = 063). In patients whose in vivo tpO₂ levels improved post treatment, significant reduction in mtDNA mutations and DAS28-CRP was observed (P < 0.05). In contrast in those patients whose tpO₂ levels remained the same or reduced at T3, no significant changes for mtDNA mutations and DAS28-CRP were found.

Conclusions

High levels of synovial oxidative stress and mitochondrial mutation burden are strongly associated with low in vivo oxygen tension and synovial inflammation. Furthermore these significant mitochondrial genome alterations are rescued following successful anti TNF-α treatment.

TCTP is a critical survival factor that protects cancer cells from oxidative stress-induced cell-death

The translationally controlled tumor protein (TCTP) displays growth-promoting and antiapoptotic properties. To gain information on the role of TCTP in cancer disease, we studied the modulation of TCTP and cell survival under stress conditions on tumor cell lines of different origins. When cancer cells were exposed to a mild oxidative stress, such low doses of Arsenic trioxide (ATO) or hydrogen peroxide (H(2)O(2)), up-regulation of TCTP was observed in cells survived to the treatment. Differently, a strong oxidative hit provided by ATO combined with glutathione (GSH) depletion or condition of glucose deprivation caused a down-modulation of TCTP followed by cell death. Clones with a forced expression of TCTP or with silenced TCTP were obtained from the breast cancer cell line MDA-MB-231. The sensitivity to oxidative stress was strongly enhanced in down-modulated TCTP cells while decreasing in cells with high levels of TCTP. Together these results indicate that TCTP is a survival factor that protects cancer cells from oxidative stress-induced cell-death. We propose TCTP as a "stress hallmark" that may be exploited as a therapeutic target to decrease the resistance of cancer cells to anticancer therapy.

Bioluminescence imaging: progress and applications

Application of bioluminescence imaging has increased tremendously in the past decade and has significantly contributed to core conceptual advances in biomedical research. This technology provides valuable means for monitoring of different biological processes in immunology, oncology, virology and neuroscience. In this review, we discuss current trends in bioluminescence and its application in different fields with an emphasis on cancer research.

The multiple roles of autophagy in cancer

Autophagy is an evolutionarily conserved, catabolic process that involves the entrapment of cytoplasmic components within characteristic vesicles for their delivery to and degradation within lysosomes. Autophagy is regulated via a group of genes called AuTophaGy-related genes and is executed at basal levels in virtually all cells as a homeostatic mechanism for maintaining cellular integrity. The levels and cargos of autophagy can be modulated in response to a variety of intra- and extracellular cues to bring about specific and selective events. Autophagy is a multifaceted process and alterations in autophagic signalling pathways are frequently found in cancer and many other diseases. During tumour development and in cancer therapy, autophagy has paradoxically been reported to have roles in promoting both cell survival and cell death. In addition, autophagy has been reported to control other processes relevant to the aetiology of malignant disease, including oxidative stress, inflammation and both innate and acquired immunity. It is the aim of this review to describe the molecular basis and the signalling events that control autophagy in mammalian cells and to summarize the cellular functions that contribute to tumourigenesis when autophagy is perturbed.

Dichloroacetate induces apoptosis of epithelial ovarian cancer cells through a mechanism involving modulation of oxidative stress

Epithelial ovarian cancer (EOC) cells are under intrinsic oxidative stress, which alters metabolic activity and reduces apoptosis. Key oxidative stress enzymes, including myeloperoxidase (MPO) and inducible nitric oxide synthase (iNOS), are upregulated and colocalized in EOC cells. Oxidative stress is also regulated, in part, by superoxide dismutase (SOD) and hypoxia-inducible factor (HIF) 1a. Dichloroacetate (DCA) converts anaerobic to aerobic metabolism and thus was utilized to determine the effects on apoptosis, iNOS, MPO, extracellular SOD (SOD-3), and HIF-1a, in EOC cells. Protein and messenger RNA (mRNA) levels of iNOS, MPO, SOD-3, and HIF-1a were evaluated by immunoprecipitation/Western blot and real-time reverse transcriptase-polymerase chain reaction (RT-PCR), respectively, utilizing SKOV-3 and MDAH-2774 treated with DCA. Apoptosis was assessed by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) and caspase 3 assays. Dichloroacetate induced apoptosis, reduced MPO, iNOS, and HIF-1a, whereas increased SOD, in both EOC cell lines. In conclusion, reduction of enhanced oxidative stress-induced apoptosis of EOC cells, which may serve as future therapeutic intervention for ovarian cancer.

Anti-inflammatory activity of Chios mastic gum is associated with inhibition of TNF-alpha induced oxidative stress

Background

Gum of Chios mastic (Pistacia lentiscus var. chia) is a natural antimicrobial agent that has found extensive use in pharmaceutical products and as a nutritional supplement. The molecular mechanisms of its anti-inflammatory activity, however, are not clear. In this work, the potential role of antioxidant activity of Chios mastic gum has been evaluated.

Methods

Scavenging of superoxide radical was investigated by electron spin resonance and spin trapping technique using EMPO spin trap in xanthine oxidase system. Superoxide production in endothelial and smooth muscle cells stimulated with TNF-α or angiotensin II and treated with vehicle (DMSO) or mastic gum (0.1-10 μg/ml) was measured by DHE and HPLC. Cellular H₂O₂ was measured by Amplex Red. Inhibition of protein kinase C (PKC) with mastic gum was determined by the decrease of purified PKC activity, by inhibition of PKC activity in cellular homogenate and by attenuation of superoxide production in cells treated with PKC activator phorbol 12-myristate 13-acetate (PMA).

Results

Spin trapping study did not show significant scavenging of superoxide by mastic gum itself. However, mastic gum inhibited cellular production of superoxide and H₂O₂ in dose dependent manner in TNF-α treated rat aortic smooth muscle cells but did not affect unstimulated cells. TNF-α significantly increased the cellular superoxide production by NADPH oxidase, while mastic gum completely abolished this stimulation. Mastic gum inhibited the activity of purified PKC, decreased PKC activity in cell homogenate, and attenuated superoxide production in cells stimulated with PKC activator PMA and PKC-dependent angiotensin II in endothelial cells.

Conclusion

We suggest that mastic gum inhibits PKC which attenuates production of superoxide and H₂O₂ by NADPH oxidases. This antioxidant property may have direct implication to the anti-inflammatory activity of the Chios mastic gum.

Measurement of oxidatively generated base damage in cellular DNA

This survey focuses on the critical evaluation of the main methods that are currently available for monitoring single and complex oxidatively generated damage to cellular DNA. Among chromatographic methods, HPLC-ESI-MS/MS and to a lesser extent HPLC-ECD which is restricted to a few electroactive nucleobases and nucleosides are appropriate for measuring the formation of single and clustered DNA lesions. Such methods that require optimized protocols for DNA extraction and digestion are sensitive enough for measuring base lesions formed under conditions of severe oxidative stress including exposure to ionizing radiation, UVA light and high intensity UVC laser pulses. In contrast application of GC-MS and HPLC-MS methods that are subject to major drawbacks have been shown to lead to overestimated values of DNA damage. Enzymatic methods that are based on the use of DNA repair glycosylases in order to convert oxidized bases into strand breaks are suitable, even if they are far less specific than HPLC methods, to deal with low levels of single modifications. Several other methods including immunoassays and (32)P-postlabeling methods that are still used suffer from drawbacks and therefore are not recommended. Another difficult topic is the measurement of oxidatively generated clustered DNA lesions that is currently achieved using enzymatic approaches and that would necessitate further investigations.

Estrogen promotes benzo[a]pyrene-induced lung carcinogenesis through oxidative stress damage and cytochrome c-mediated caspase-3 activation pathways in female mice

Estrogen may contribute to the development of smoking-induced lung cancer in women. To test this hypothesis, an mouse model was used to investigate the effects of 17 beta-estradiol (E2) on benzo[a]pyrene (B[a]P)-induced lung carcinogenesis. We found that B[a]P could cause oxidative stress damage, upregulate mitochondrial cytochrome-c and caspase-3 expression, induce lung carcinogenesis in female mice, E2 promoted these effects of B[a]P while tamoxifen (TAM) inhibited this effects of E2. We conclude that E2 can promote the tumorigenic effects of B[a]P in female mice, and oxidative stress damage and activation of cytochrome-c-mediated caspase-3 pathway may be involved in this process.

Reactive species and DNA damage in chronic inflammation: reconciling chemical mechanisms and biological fates

Chronic inflammation has long been recognized as a risk factor for many human cancers. One mechanistic link between inflammation and cancer involves the generation of nitric oxide, superoxide and other reactive oxygen and nitrogen species by macrophages and neutrophils that infiltrate sites of inflammation. Although pathologically high levels of these reactive species cause damage to biological molecules, including DNA, nitric oxide at lower levels plays important physiological roles in cell signaling and apoptosis. This raises the question of inflammation-induced imbalances in physiological and pathological pathways mediated by chemical mediators of inflammation. At pathological levels, the damage sustained by nucleic acids represents the full spectrum of chemistries and likely plays an important role in carcinogenesis. This suggests that DNA damage products could serve as biomarkers of inflammation and oxidative stress in clinically accessible compartments such as blood and urine. However, recent studies of the biotransformation of DNA damage products before excretion point to a weakness in our understanding of the biological fates of the DNA lesions and thus to a limitation in the use of DNA lesions as biomarkers. This review will address these and other issues surrounding inflammation-mediated DNA damage on the road to cancer.

Isolation and characterization of two flavonoids, engeletin and astilbin, from the leaves of Engelhardia roxburghiana and their potential anti-inflammatory properties

Engeletin, a flavonoid compound, was isolated from the leaves of Engelhardia roxburghiana for the first time, along with astilbin, another flavonoid. The chemical structures of engeletin and astilbin were confirmed by (1)H and (13)C nuclear magnetic resonance (NMR) and mass spectrometry (MS) spectra, and their anti-inflammatory activities were studied in lipopolysaccharide (LPS)-stimulated mouse J774A.1 macrophage cells. LPS induced the inflammatory state in macrophage cells and increased mRNA expressions of pro-inflammatory cytokines. Engeletin and astilbin exhibited remarkable inhibitory effects on interleukin (IL)-1β and IL-6 mRNA expression. Significant inhibition of LPS-mediated mRNA expressions were also seen in LPS binding toll-like receptor (TLR)-4, pro-inflammatory cytokine tumor necrosis factor (TNF)-α, IL-10, chemoattractant monocyte chemotactic protein (MCP)-1, and cyclooxygenase (COX)-2 genes. The reduced expression of these cytokines may alleviate immune response and reduce inflammatory activation, indicating that engeletin and astilbin may serve as potential anti-inflammatory agents.

A combination of two antioxidants (an SOD mimic and ascorbate) produces a pro-oxidative effect forcing Escherichia coli to adapt via induction of oxyR regulon

Cationic Mn(III) N-alkylpyridyl (MnTalkyl-2(or 3)-PyP(5+)) and N, N'-dialkylimidazolylporphyrins (MnTDalkyl-2-ImP(5+)) have been regarded as the most powerful SOD mimics/peroxynitrite scavengers - i. e. antioxidants. The ethyl-, MnTE-2-PyP(5+) (AEOL10113), and hexylpyridyl-, MnTnHex-2-PyP(5+) and diethylimidazolylporphyrin, MnTDE-2-ImP(5+) (AEOL10150) have been mostly studied in vitro and in vivo. Given the in vivo abundance of cellular reductants, MnPs can couple with them in removing superoxide. Thus, they could be readily reduced from Mn(III)P to Mn(II)P with ascorbate and glutathione, and in a subsequent step reduce either O(2)(.-) (while acting as superoxide reductase) or oxygen (while exerting pro-oxidative action). Moreover, MnPs can catalyze ascorbate oxidation and in turn hydrogen peroxide production. The in vivo type of MnP action (anti- or pro-oxidative) will depend upon the cellular levels of reactive species, endogenous antioxidants, availability of oxygen, ratio of O(2)(.-)- to peroxide-removing systems, redox ability of MnPs and their cellular localization/bioavailibility. To exemplify the switch from an anti- to pro-oxidative action we have explored a very simple and straightforward system - the superoxide-specific aerobic growth of SOD-deficient E. coli. In such a system, cationic MnPs, ortho and meta MnTE-2-(or 3)-PyP(5+) act as powerful SOD mimics. Yet, in the presence of exogenous ascorbate, the SOD mimics catalyze the H(2)O(2) production, causing oxidative damage to both wild and SOD-deficient strains and inhibiting their growth. Catalase added to the medium reversed the effect indicating that H(2)O(2) is a major damaging/signaling species involved in cell growth suppression. The experiments with oxyR- and soxRS-deficient E. coli were conducted to show that E. coli responds to increased oxidative stress exerted by MnP/ascorbate system by induction of oxyR regulon and thus upregulation of antioxidative defenses such as catalases and peroxidases. As anticipated, when catalase was added into medium to remove H(2)O(2), E. coli did not respond with upregulation of its own antioxidant systems.

Analysis of the effects of iron and vitamin C co-supplementation on oxidative damage, antioxidant response and inflammation in THP-1 macrophages

OBJECTIVES

The aims of the study were to test the susceptibility of THP-1 macrophages to develop oxidative stress and to deploy antioxidant defense mechanisms that insure the balance between the pro- and antioxidant molecules.

DESIGN AND METHODS

Differentiated THP-1 were incubated in the presence or absence of iron-ascorbate (Fe/As) (100/1000μM) and the antioxidants Trolox, BHT, α-Tocopherol and NAC.

RESULTS

Fe/As promoted the production of lipid peroxidation as reflected by the formation of malondialdehyde and H(2)O(2) along with reduced PUFA levels and elevated glutathione disulfide/total glutathione ratio, a reliable index of cellular redox status. THP-1 macrophages developed an increase in cytoplasmic SOD activity due in part to high cytoplasmic SOD1. On the other hand, a decline was noted in mRNA and protein of extra-cellular SOD3, as well as the activity of GSH-peroxidase, GSH-transferase and ATOX-1 expression.

CONCLUSIONS

Macrophages activated under conditions of oxidative stress do not adequately deploy a powerful endogenous antioxidant response, a situation that can lead to an enhanced inflammatory response.

Inhibition of aldose reductase prevents angiogenesis in vitro and in vivo

We have recently shown that aldose reductase (AR, EC 1.1.1.21) a nicotinamide adenine dinucleotide phosphate-dependent aldo-keto reductase, known to be involved in oxidative stress-signaling, prevents human colon cancer cell growth in culture as well as in nude mice xenografts. Inhibition of AR also prevents azoxymethane-induced aberrant crypt foci formation in mice. In order to understand the chemopreventive mechanism(s) of AR inhibition in colon cancer, we have investigated the role of AR in the mediation of angiogenic signals in vitro and in vivo models. Our results show that inhibition of AR significantly prevented the VEGF- and FGF -induced proliferation and expression of proliferative marker Ki67 in the human umbilical vein endothelial cells (HUVEC). Further, AR inhibition or ablation with siRNA prevented the VEGF- and FGF -induced invasion and migration in HUVEC. AR inhibition also prevented the VEGF- and FGF- induced secretion/expression of IL-6, MMP2, MMP9, ICAM, and VCAM. The anti-angiogenic feature of AR inhibition in HUVEC was associated with inactivation of PI3 K/AKT and NF-κB (p65) and suppression of VEGF receptor 2 protein levels. Most importantly, matrigel plug model of angiogenesis in rats showed that inhibition of AR prevented infiltration of blood cells, invasion, migration and formation of capillary like structures, and expression of blood vessels markers CD31 and vWF. Thus, our results demonstrate that AR inhibitors could be novel agents to prevent angiogenesis.

Icariin inhibits hydrogen peroxide-induced toxicity through inhibition of phosphorylation of JNK/p38 MAPK and p53 activity

Oxidative stress caused by hydrogen peroxide (H(2)O(2)) plays an important role in the pathogenesis of Alzheimer's disease (AD). The prominent damages caused by H(2)O(2) include the ruin of membrane integrity, loss of intracellular neuronal glutathione (GSH), oxidative damage to DNA as well as the subsequent caspase-3 and p53 activation. Icariin is a flavonoid extracted from the traditional Chinese herb Epimedium brevicornum Maxim. We have previously reported that icariin has a good curative effect on patients with mild cognitive impairment (MCI), AD animal and cell models. However, the molecular mechanism of how icariin exerts neuroprotective effects is still not well understood. To address this question, we exposed undifferentiated neuronal cell lines (PC12 cells) to hydrogen peroxide (H(2)O(2)) and investigated the possible neuroprotective mechanisms of icariin. Vitamin E was used as a positive control. We observed that H(2)O(2) activated the JNK/p38 mitogen-activated protein kinase (MAPK) and induced PC12 cells apoptosis in a concentration-dependent manner. More over, we demonstrated that icariin protected PC12 cells by attenuating LDH leakage, reducing GSH depletion, preventing DNA oxidation damage and inhibiting subsequent activation of caspase-3 and p53, which are the main targets of H(2)O(2)-induced cell damage. In addition, we also found that icariin's neuroprotective effect may partly correlate with its inhibitory effect on JNK/p38 MAPK pathways. Therefore, our findings suggest that icariin is a candidate for a novel neuroprotective drug to against oxidative-stress induced neurodegeneration.

Mitochondrial reactive oxygen species drive proinflammatory cytokine production

High levels of reactive oxygen species (ROS) are observed in chronic human diseases such as neurodegeneration, Crohn's disease, and cancer. In addition to the presence of oxidative stress, these diseases are also characterized by deregulated inflammatory responses, including but not limited to proinflammatory cytokine production. New work exploring the mechanisms linking ROS and inflammation find that ROS derived from mitochondria act as signal-transducing molecules that provoke the up-regulation of inflammatory cytokine subsets via distinct molecular pathways.

Antioxidant activities and polyphenolic contents of three selected Micromeria species from Croatia

Antioxidant activities of three selected Micromeria species growing in Croatia (M. croatica, M. juliana and M. thymifolia) were evaluated using five different antioxidant assays, in comparison with plant polyphenolic constituents and reference antioxidants. All studied ethanolic extracts exhibited considerable activity to scavenge DPPH and hydroxyl free radicals, reducing power, iron chelating ability and total antioxidant capacity in the order: M. croatica > M. juliana > M. thymifolia. Total polyphenol (9.69-13.66%), phenolic acid (5.26-6.84%), flavonoid (0.01-0.09%) and tannin (3.07-6.48%) contents in dried plant samples were determined spectrophotometrically. A strong positive correlation between antioxidant activities and contents of phenolic acids and tannins was found, indicating their responsibility for effectiveness of tested plants. Our findings established Micromeria species as a rich source of antioxidant polyphenols, especially the endemic M. croatica.

Cellular redox modulator, ortho Mn(III) meso-tetrakis(N-n-hexylpyridinium-2-yl)porphyrin, MnTnHex-2-PyP(5+) in the treatment of brain tumors

Despite intensive efforts to improve multimodal treatment of brain tumor, survival remains limited. Current therapy consists of a combination of surgery, irradiation and chemotherapy with predisposition to long-term complications. Identifying novel targeted therapies is therefore at the forefront of brain tumor research. This study explores the utility of a manganese porphyrin in a brain tumor model. The compound used is ortho isomer, mangnese(III) meso-tetrakis(N-n-hexylpyridinium-2-yl)porphyrin, MnTnHex-2-PyP(5+). It is a powerful SOD mimic and peroxynitrite scavenger and a potent modulator of redox-based cellular transcriptional activity, able to suppress excessive immune and inflammatory responses and in turn proliferative pathways. It is further one of the most lipophilic compound among cationic Mn(III) N-alkylpyridylporphyrins, and thus accumulates predominantly in mitochondria relative to cytosol. In mitochondria, MnTnHex-2-PyP(5+) mimics our key antioxidant system, mitochondrial superoxide dismutase, MnSOD, whose overexpression has been widely shown to suppress tumor growth. Importantly, MnTnHex-2-PyP(5+) crosses blood brain barrier in sufficient amounts to demonstrate efficacy in treating CNS injuries. For those reasons we elected to test its effects in inhibiting brain tumor growth. This study is the first report of the antitumor properties of MnTnHex-2-PyP(5+) as a single agent in adult and pediatric glioblastoma multiforme (D-54 MG, D-245 MG, D-256 MG, D-456 MG) and pediatric medulloblastoma (D-341 MED), and is the first case where a redox-able metal complex has been used in glioma therapy. When given subcutaneously to mice bearing subcutaneous and intracranial xenografts, MnTnHex-2-PyP(5+) caused a significant (P ≤ 0.001) growth delay in D 245 MG, D-256 MG, D-341 MED, and D-456 MG tumors. Growth delay for mice bearing subcutaneous xenografts ranged from 3 days in D-54 MG to 34 days in D-341 MED. With mice bearing intracranial xenografts, MnTnHex-2-PyP(5+) increases median survival by 33% in adult glioblastoma multiforme (D-256 MG; p≤ 0.001) and 173% in pediatric medulloblastoma (D-341 MED, <0.001). The beneficial effects of MnTnHex-2-PyP(5+) are presumably achieved either (1) indirectly via elimination of signaling reactive oxygen and nitrogen species (in particular superoxide and peroxynitrite) which in turn would prevent activation of transcription factors; or (2) directly by coupling with cellular reductants and redox-sensitive signaling proteins. The former action is antioxidative while the latter action is presumably pro-oxidative in nature. Our findings suggest that the use of Mn porphyrin-based SOD mimics, and in particular lipophilic analogues such as MnTnHex-2-PyP(5+), is a promising approach for brain tumor therapy.

Obesity and cancer risk: recent review and evidence

The prevalence of overweight and obesity is increasing worldwide, and the evidence base for a link between obesity and cancer is growing. In the United States, approximately 85,000 new cancer cases per year are related to obesity. Recent research has found that as the body mass index increases by 5 kg/m2, cancer mortality increases by 10%. Additionally, studies of patients who have had bariatric surgery for weight loss report reductions in cancer incidence and mortality, particularly for women. The goal of this review is to provide an update of recent research, with a focus on epidemiologic studies on the link between obesity and cancer. In addition, we will briefly review hypothesized mechanisms underlying the relationship between obesity and cancer. High priorities for future research involve additional work on the underlying mechanisms, and trials to examine the effect of lifestyle behavior change and weight loss interventions on cancer and intermediate biomarkers.

Chemokines in health and disease

Chemokines and their receptors play a key role in development and homeostasis as well as in the pathogenesis of tumors and autoimmune diseases. Chemokines are involved in the implantation of the early conceptus, the migration of subsets of cells during embryonic development, and the overall growth of the embryo. Chemokines also have an important role in the development and maintenance of innate and adaptive immunity. In addition, they play a significant role in wound healing and angiogenesis. When the physiological role of chemokines is subverted or chronically amplified, disease often follows. Chemokines are involved in the pathobiology of chronic inflammation, tumorigenesis and metastasis, as well as autoimmune diseases. This article reviews the role of chemokines and their receptors in normal and disease processes and the potential for using chemokine antagonists for appropriate targeted therapy.

Nrf2 expression in endometrial serous carcinomas and its precancers

Endometrial serous carcinoma (ESC) is the most aggressive subtype of endometrial cancer. Its aggressive behavior and poor clinical outcome may be partially attributed to lack of early diagnostic markers and unclear patho-genesis. The transcription factor Erythroid-E2-related factor 2 (Nrf2) is a recently identified protein marker, which plays a role in carcinogenesis as well as responsible for poor prognosis of many human cancers. The aim of this study is to determine the Nrf2 expression in benign endometrium (n=28), endometrial cancers (n=122) as well as their precursor lesions (n=81) trying to see whether Nrf2 has any diagnostic usage and is potentially involved in endometrial carcinogenesis. The level of Nrf2 was evaluated by immunohistochemical (IHC) and verified by using Western blots. Among the malignant cases, Nrf2 was positive in 28 (68%) of 50 ESCs, which was significantly more than in 3 (6%) of 50 endometrioid carcinomas (p < 0.001) and 2 (13%) of 15 clear cell carcinomas (p = 0.001) and other histologic types of endometrial cancers. Among endometrial precursor lesions, both serous endometrial glandular dysplasia (EmGD, 40%) and serous endometrial intraepithelial carcinoma (EIC, 44%) showed a significantly higher Nrf2 expression than that in atypical endometrial hyperplasia or endometrial intraepithelial neoplasia (0%), clear cell EmGD (10%), and clear cell EIC (25%), respectively. We conclude that Nrf2 overexpression is closely associated with endometrial neoplasms with serous differentiation. Alteration of Nrf2 expression may represent one of the early molecular events in ESC carcinogenesis and overexpression of Nrf2 may used as a diagnostic marker in surgical pathology.

Real-time in vivo detection of biomaterial-induced reactive oxygen species

The non-specific host response to implanted biomaterials is often a key challenge of medical device design. To evaluate biocompatibility, measuring the release of reactive oxygen species (ROS) produced by inflammatory cells in response to biomaterial surfaces is a well-established method. However, the detection of ROS in response to materials implanted in vivo has not yet been demonstrated. Here, we develop a bioluminescence whole animal imaging approach to observe ROS released in response to subcutaneously-implanted materials in live animals. We compared the real-time generation of ROS in response to two representative materials, polystyrene and alginate, over the course of 28 days. High levels of ROS were observed near polystyrene, but not alginate implants, and persisted throughout the course of 28 days. Histological analysis revealed that high levels of ROS correlated not only with the presence of phagocytic cells at early timepoints, but also fibrosis at later timepoints, suggesting that ROS may be involved in both the acute and chronic phase of the foreign body response. These data are the first in vivo demonstration of ROS generation in response to implanted materials, and describe a novel technique to evaluate the host response.

The redoxome: Proteomic analysis of cellular redox networks

Redox-regulated proteins play fundamentally important roles not only during the defense of organisms against oxidative stress conditions but also as targets of cellular signaling events. This realization has spurred the development of proteomic techniques geared towards characterizing the redoxome; proteins with highly reactive cysteine residues, whose thiol oxidation state controls the function of the proteins, and by extension, the pathways they are part of. We will here summarize the most recent advances made in the field of redox proteomic analysis, aimed to elucidate the cellular redox networks that appear to control prokaryotic and eukaryotic organisms.

Pathophysiological impact of cigarette smoke exposure on the cerebrovascular system with a focus on the blood-brain barrier: expanding the awareness of smoking toxicity in an underappreciated area

Recent evidence has indicated that active and passive cigarette smoking are associated, in a dose-dependent manner, with dysfunction of normal endothelial physiology. Tobacco smoke (TS) may predispose individuals to atherogenic and thrombotic problems, significantly increasing the risk for ischemic manifestations such as acute coronary syndrome and stroke. Despite the strong evidence for an association between smoking and vascular impairment, the impact of TS exposure on the blood-brain barrier (BBB) has only been marginally addressed. This is a major problem given that the BBB is crucial in the maintenance of brain homeostasis. Recent data have also shown that chronic smokers have a higher incidence of small vessel ischemic disease (SVID), a pathological condition characterized by leaky brain microvessels and loss of BBB integrity. In the brain TS increases the risk of silent cerebral infarction (SCI) and stroke owing to the pro-coagulant and atherogenic effects of smoking. In this article we provide a detailed review and analysis of current knowledge of the pathophysiology of tobacco smoke toxicity at the cerebrovascular levels. We also discuss the potential toxicity of recently marketed “potential-reduced exposure products”.

Potential of the dietary antioxidants resveratrol and curcumin in prevention and treatment of hematologic malignancies

Despite considerable improvements in the tolerance and efficacy of novel chemotherapeutic agents, the mortality of hematological malignancies is still high due to therapy relapse, which is associated with bad prognosis. Dietary polyphenolic compounds are of growing interest as an alternative approach, especially in cancer treatment, as they have been proven to be safe and display strong antioxidant properties. Here, we provide evidence that both resveratrol and curcumin possess huge potential for application as both chemopreventive agents and anticancer drugs and might represent promising candidates for future treatment of leukemia. Both polyphenols are currently being tested in clinical trials. We describe the underlying mechanisms, but also focus on possible limitations and how they might be overcome in future clinical use – either by chemically synthesized derivatives or special formulations that improve bioavailability and pharmacokinetics.