Oxidative stress induced lung cancer and COPD: opportunities for epigenetic therapy

Formoterol Exerts Anti-Cancer Effects Modulating Oxidative Stress and Epithelial-Mesenchymal Transition Processes in Cigarette Smoke Extract Exposed Lung Adenocarcinoma Cells

Lung cancer frequently affects patients with Chronic Obstructive Pulmonary Disease (COPD). Cigarette smoke (CS) fosters cancer progression by increasing oxidative stress and by modulating epithelial-mesenchymal transition (EMT) processes in cancer cells. Formoterol (FO), a long-acting β2-agonist widely used for the treatment of COPD, exerts antioxidant activities. This study explored in a lung adenocarcinoma cell line (A549) whether FO counteracted the effects of cigarette smoke extract (CSE) relative to oxidative stress, inflammation, EMT processes, and cell migration and proliferation. A549 was stimulated with CSE and FO, ROS were evaluated by flow-cytometry and by nanostructured electrochemical sensor, EMT markers were evaluated by flow-cytometry and Real-Time PCR, IL-8 was evaluated by ELISA, cell migration was assessed by scratch and phalloidin test, and cell proliferation was assessed by clonogenic assay. CSE significantly increased the production of ROS, IL-8 release, cell migration and proliferation, and SNAIL1 expression but significantly decreased E-cadherin expression. FO reverted all these phenomena in CSE-stimulated A549 cells. The present study provides intriguing evidence that FO may exert anti-cancer effects by reverting oxidative stress, inflammation, and EMT markers induced by CS. These findings must be validated in future clinical studies to support FO as a valuable add-on treatment for lung cancer management.

Dimethylarginine Dimethylaminohydrolase - 1 expression is increased under tBHP-induced oxidative stress regulates nitric oxide production in PCa cells attenuates mitochondrial ROS-mediated apoptosis

Dimethylarginine dimethylaminohydrolase-1 (DDAH1) expression is frequently elevated in different cancers including prostate cancer (PCa) and enhances nitric oxide (NO) production in tumor cells by metabolising endogenous nitric oxide synthase (NOS) inhibitors. DDAH1 protects the PCa cells from cell death and promotes survival. In this study, we have investigated the cytoprotective role of DDAH1 and determined the mechanism of DDAH1 in protecting the cells in tumor microenvironment. Proteomic analysis of PCa cells with stable overexpression of DDAH1 has identified that oxidative stress-related activity is altered. Oxidative stress promotes cancer cell proliferation, survival and causes chemoresistance. A known inducer of oxidative stress, tert-Butyl Hydroperoxide (tBHP) treatment to PCa cells led to elevated DDAH1 level that is actively involved in protecting the PCa cells from oxidative stress induced cell damage. In PC3-DDAH1- cells, tBHP treatment led to higher mROS levels indicating that the loss of DDAH1 increases the oxidative stress and eventually leads to cell death. Under oxidative stress, nuclear Nrf2 controlled by SIRT1 positively regulates DDAH1 expression in PC3 cells. In PC3-DDAH1+ cells, tBHP induced DNA damage is well tolerated compared to wild-type cells while PC3-DDAH1- became sensitive to tBHP. In PC3 cells, tBHPexposure has increased the production of NO and GSH which may be acting as an antioxidant defence to overcome oxidative stress. Furthermore, in tBHP treated PCa cells, DDAH1 is controlling the expression of Bcl2, active PARP and caspase 3. Taken together, these results confirm that DDAH1 is involved in the antioxidant defence system and promotes cell survival.

Treatment Strategies for KRAS-Mutated Non-Small-Cell Lung Cancer

Activating mutations in KRAS are highly prevalent in solid tumours and are frequently found in 35% of lung, 45% of colorectal, and up to 90% of pancreatic cancers. Mutated KRAS is a prognostic factor for disease-free survival (DFS) and overall survival (OS) in NSCLC and is associated with a more aggressive clinical phenotype, highlighting the need for KRAS-targeted therapy. Once considered undruggable due to its smooth shallow surface, a breakthrough showed that the activated G12C-mutated KRAS isozyme can be directly inhibited via a newly identified switch II pocket. This discovery led to the development of a new class of selective small-molecule inhibitors against the KRAS G12C isoform. Sotorasib and adagrasib are approved in locally advanced or metastatic NSCLC patients who have received at least one prior systemic therapy. Currently, there are at least twelve KRAS G12C inhibitors being tested in clinical trials, either as a single agent or in combination. In this study, KRAS mutation prevalence, subtypes, rates of occurrence in treatment-resistant invasive mucinous adenocarcinomas (IMAs), and novel drug delivery options are reviewed. Additionally, the current status of KRAS inhibitors, multiple resistance mechanisms that limit efficacy, and their use in combination treatment strategies and novel multitargeted approaches in NSCLC are discussed.

Multifactorial Diseases of the Heart, Kidneys, Lungs, and Liver and Incident Cancer: Epidemiology and Shared Mechanisms

Within the aging population, the frequency of cancer is increasing dramatically. In addition, multiple genetic and environmental factors lead to common multifactorial diseases, including cardiovascular disease, chronic kidney disease, chronic obstructive pulmonary disease, and metabolic-associated fatty liver disease. In recent years, there has been a growing awareness of the connection between cancer and multifactorial diseases, as well as how one can affect the other, resulting in a vicious cycle. Although the exact mechanistic explanations behind this remain to be fully explored, some progress has been made in uncovering the common pathologic mechanisms. In this review, we focus on the nature of the link between cancer and common multifactorial conditions, as well as specific shared mechanisms, some of which may represent either preventive or therapeutic targets. Rather than organ-specific interactions, we herein focus on the shared mechanisms among the multifactorial diseases, which may explain the increased cancer risk. More research on this subject will highlight the significance of developing new drugs that target multiple systems rather than just one disease.

Epigenomic interplay in tumor heterogeneity: Potential of epidrugs as adjunct therapy

"Heterogeneity" in tumor mass has immense importance in cancer progression and therapy. The impact of tumor heterogeneity is an emerging field and not yet fully explored. Tumor heterogeneity is mainly considered as intra-tumor heterogeneity and inter-tumor heterogeneity based on their origin. Intra-tumor heterogeneity refers to the discrepancy within the same cancer mass while inter-tumor heterogeneity refers to the discrepancy between different patients having the same tumor type. Both of these heterogeneity types lead to variation in the histopathological as well as clinical properties of the cancer mass which drives disease resistance towards therapeutic approaches. Cancer stem cells (CSCs) act as pinnacle progenitors for heterogeneity development along with various other genetic and epigenetic parameters that are regulating this process. In recent times epigenetic factors are one of the most studied parameters that drive oxidative stress pathways essential during cancer progression. These epigenetic changes are modulated by various epidrugs and have an impact on tumor heterogeneity. The present review summarizes various aspects of epigenetic regulation in the tumor microenvironment, oxidative stress, and progression towards tumor heterogeneity that creates complications during cancer treatment. This review also explores the possible role of epidrugs in regulating tumor heterogeneity and personalized therapy against drug resistance.

The Role of HDACs in the Response of Cancer Cells to Cellular Stress and the Potential for Therapeutic Intervention

Throughout the process of carcinogenesis, cancer cells develop intricate networks to adapt to a variety of stressful conditions including DNA damage, nutrient deprivation, and hypoxia. These molecular networks encounter genomic instability and mutations coupled with changes in the gene expression programs due to genetic and epigenetic alterations. Histone deacetylases (HDACs) are important modulators of the epigenetic constitution of cancer cells. It has become increasingly known that HDACs have the capacity to regulate various cellular systems through the deacetylation of histone and bounteous nonhistone proteins that are rooted in complex pathways in cancer cells to evade death pathways and immune surveillance. Elucidation of the signaling pathways involved in the adaptive responses to cellular stress and the role of HDACs may lead to the development of novel therapeutic agents. In this article, we overview the dominant stress types including metabolic, oxidative, genotoxic, and proteotoxic stress imposed on cancer cells in the context of HDACs, which guide stress adaptation responses. Next, we expose a closer view on the therapeutic interventions and clinical trials that involve HDACs inhibitors, in addition to highlighting the impact of using HDAC inhibitors in combination with stress-inducing agents for the management of cancer and to overcome the resistance to current cancer therapy.

Identification of the Signature Genes and Network of Reactive Oxygen Species Related Genes and DNA Repair Genes in Lung Adenocarcinoma

Reactive Oxygen Species (ROS) are present in excess amounts in patients with tumors, and these ROS can kill and destroy tumor cells. Therefore, tumor cells upregulate ROS-related genes to protect them and reduce their destructing effects. Cancer cells already damaged by ROS can be repaired by expressing DNA repair genes consequently promoting their proliferation. The present study aimed to identify the signature genes of and regulating network of ROS-related genes and DNA repair genes in lung adenocarcinoma (LUAD) using transcriptomic data of public databases. The LUAD transcriptome data in the TCGA database and gene expressions from Gene Expression Omnibus (GEO) were analyzed and samples were clustered into 5 ROS-related categories and 6 DNA repair categories. Survival analysis revealed a significant difference in patient survival between the two classification methods. In addition, the samples corresponding to the two categories overlap, thus, the gene expression profile of the same sample with different categories and survival prognosis was further explored, and the connection between ROS-related and DNA repair genes was investigated. The interactive sample recombination classification was used, revealing that the patient's prognosis was worse when the ROS-related and DNA repair genes were expressed at the same time. The further research on the potential regulatory network of the two categories of genes and the correlation analysis revealed that ROS-related genes and DNA repair genes have a mutual regulatory relationship. The ROS-related genes namely NQO1, TXNRD1, and PRDX4 could establish links with other DNA repair genes through the DNA repair gene NEIL3, thereby balancing the level of ROS. Therefore, targeting ROS-related genes and DNA repair genes might be a promising strategy in the treatment of LUAD. Finally, a survival prognostic model of ROS-related genes and DNA repair genes was established (TERT, PRKDC, PTTG1, SMUG1, TXNRD1, CAT, H2AFX, and PFKP). The risk score obtained from our survival prognostic model could be used as an independent prognostic factor in LUAD patients.

Relationship between glucosamine use and the risk of lung cancer: data from a nationwide prospective cohort study

BACKGROUND

Research on glucosamine shows anti-inflammatory and anti-cancer benefits with a minimal adverse effects. We aimed to explore the relationship between use of glucosamine and risk of lung cancer and lung cancer mortality based on data from the large-scale nationwide prospective UK Biobank cohort study.

METHODS

Participants were enrolled between the year 2006 and 2010 and followed up to 2020. Cox proportion hazards model were used to assess the relationship between glucosamine use and risk of lung cancer and lung cancer mortality. Subgroup analyses and sensitivity analyses were performed to explore the potential effect modifications and the robustness of main findings.

RESULTS

A total of 439,393 participants (mean age: 56 years; 53% females) with a mean follow-up of 11 years were included for analyses. There were 82,603 (18.80%) participants reporting regular use of glucosamine at baseline. During follow-up, there were 1,971 (0.45%) lung cancer events documented. Glucosamine use was significantly associated with a decreased risk of lung cancer (hazard ratio=0.84, 95% CI: 0.75-0.92, p<0.001) and lung cancer mortality (hazard ratio=0.88, 95% CI: 0.81-0.96, p=0.002) in fully-adjusted models. A stronger association between glucosamine use and decreased lung cancer risk was observed in participants with a family history of lung cancer when compared to those without a family history.

CONCLUSION

Regular use of glucosamine was significantly related with decreased risk of lung cancer and lung cancer mortality, based on data from this nationwide prospective cohort study.

The Relationship between Serum Trace Elements and Oxidative Stress of Patients with Different Types of Cancer

Objective

Many studies have identified causal and promotive roles of oxidative stress (OxS) and oxidative damage caused by OxS in the occurrence and progression of cancer. Many biomarkers in the blood circulation of patients may change correspondingly with the development of tumors. This study is aimed at investigating the correlation between OxS and serum trace element (TE) levels of patients with different types of cancer.

Methods

1143 different types of cancer patients and 178 healthy controls from Mar. 2018 to Aug. 2020 in Mianyang Central Hospital were involved in this study. Their levels of OxS parameters (including total oxidant status (TOS), total antioxidant status (TAS), and oxidant stress index (OSI)) and the concentrations of serum TEs (including Cu, Zn, Fe, and Se) were determined.

Results

Compared with healthy controls, all types of cancer patients had higher TOS level (all P_adj < 0.001) and OSI level (z = 6.228 ~ 9.909, all P_adj < 0.001) and lower TAS level (all P_adj < 0.001). Compared with healthy controls, the changes of four TE levels in serum were different in different types of cancer patients, among which Cu increased in all groups, but there was no statistical difference in gastric and brain cancer; Se decreased in all groups, but there was no statistical difference in gastric, colorectal, esophageal, and other cancer; Zn was significantly decreased in breast cancer patients (P_adj < 0.001); there was no statistical difference in the change of Fe in liver, kidney, and other cancer. Spearman correlation showed that the change of Cu concentration was most closely related to the three OxS parameters and was strongly correlated in the observed several types of tumors (r_s > 0.6). Multinomial logistic regression showed that the risks of different tumors are related to the level change of multiple TEs and OxS parameters (OR_TOS = 1.19 ~ 2.82, OR_OSI = 2.56 ~ 4.70, OR_TAS = 0.20 ~ 0.46, OR_Cu = 0.73 ~ 1.44, OR_Zn = 0.81 ~ 0.91, OR_Fe = 0.68 ~ 1.18, and OR_Se = 0.22 ~ 0.45, all P < 0.006).

Conclusions

The OxS exists in the occurrence and development of cancer, which may be related to the changes of certain trace elements. In order to evaluate OxS correctly, it is necessary to detect TAS and TOS and at the same time, their ratio OSI should be detected. Assessment of markers representing the overall level of OxS and TEs may guarantee improved the monitoring of disease occurrence and development risk in cancer patients.

PDLIM2 repression by ROS in alveolar macrophages promotes lung tumorigenesis

One of the most fundamental and challenging questions in the field of cancer is how immunity is transformed from tumor immunosurveillance to tumor-promoting inflammation. Here, we identified the tumor suppressor PDZ-LIM domain–containing protein 2 (PDLIM2) as a checkpoint of alveolar macrophages (AMs) important for lung tumor suppression. During lung tumorigenesis, PDLIM2 expression in AMs is downregulated by ROS-activated transcription repressor BTB and CNC homology 1 (BACH1). PDLIM2 downregulation leads to constitutive activation of the transcription factor STAT3, driving AM protumorigenic polarization/activation and differentiation from monocytes attracted from the circulation to suppress cytotoxic T lymphocytes and promote lung cancer. PDLIM2 downregulation also decreases AM phagocytosis. These findings establish ROS/BACH1/PDLIM2/STAT3 as a signaling pathway driving AMs for lung tumor promotion.

Reactive oxygen species modulator 1 expression predicts lymph node metastasis and survival in early-stage non-small cell lung cancer

Reactive oxygen species modulator 1 (romo1) causes cell hyperplasia and promotes cancer cell invasion. Based recent studies, the overexpression of romo1 is associated with lymphatic metastasis and poor prognosis in lung cancer. We aimed to evaluate associations between romo1 expression and lymph node metastasis in non-small cell lung cancer (NSCLC). Clinical data and pathological results were retrospectively reviewed for 98 subjects diagnosed with NSCLC and who underwent surgical biopsy between 1994 and 2009. A total 98 tumor specimens were analyzed. The romo1 H score was correlated with stage and was significantly higher in subjects with lymph node metastasis than in those without metastasis (173 vs 116; P < 0.05). The area (%) of grade 1 expression was significantly smaller (19.5 vs 37.0; P = 0.005) and the area of grade 3 expression was significantly larger (27.9 vs 6.00; P < 0.001) in subjects with lymph node metastasis than in those without metastasis. In stage I patients, disease free survival (DFS) (191 ± 18.8 vs. 75.6 ± 22.4 months, P = 0.004) was significantly longer in the low romo1 group than in the high romo1 group. A multivariate analysis showed a significant association between high romo1 expression and poor DFS (hazard ratio 5.59, 95 confidence interval, 1.54–20.3, P = 0.009). These findings support the prognostic value of romo1 in NSCLC, especially in stage I.

Understanding the Interplay Between Health Disparities and Epigenomics

Social epigenomics has emerged as an integrative field of research focused on identification of socio-environmental factors, their influence on human biology through epigenomic modifications, and how they contribute to current health disparities. Several health disparities studies have been published using genetic-based approaches; however, increasing accessibility and affordability of molecular technologies have allowed for an in-depth investigation of the influence of external factors on epigenetic modifications (e.g., DNA methylation, micro-RNA expression). Currently, research is focused on epigenetic changes in response to environment, as well as targeted epigenetic therapies and environmental/social strategies for potentially minimizing certain health disparities. Here, we will review recent findings in this field pertaining to conditions and diseases over life span encompassing prenatal to adult stages.

When Oxidative Stress Meets Epigenetics: Implications in Cancer Development

Cancer is one of the leading causes of death worldwide and it can affect any part of the organism. It arises as a consequence of the genetic and epigenetic changes that lead to the uncontrolled growth of the cells. The epigenetic machinery can regulate gene expression without altering the DNA sequence, and it comprises methylation of the DNA, histones modifications, and non-coding RNAs. Alterations of these gene-expression regulatory elements can be produced by an imbalance of the intracellular environment, such as the one derived by oxidative stress, to promote cancer development, progression, and resistance to chemotherapeutic treatments. Here we review the current literature on the effect of oxidative stress in the epigenetic machinery, especially over the largely unknown ncRNAs and its consequences toward cancer development and progression.

Identification of Putative Regulatory Alterations Leading to Changes in Gene Expression in Chronic Obstructive Pulmonary Disease

Various genetic and environmental factors are known to be associated with chronic obstructive pulmonary disease (COPD). We identified COPD-related differentially expressed genes (DEGs) using 189 samples accompanying either adenocarcinoma (AC) or squamous cell carcinoma (SC), comprising 91 normal and 98 COPD samples. DEGs were obtained from the intersection of two DEG sets separately identified for AC and SC to exclude the influence of different cancer backgrounds co-occurring with COPD. We also measured patient samples named group 'I', which were unable to be determined as normal or COPD based on alterations in gene expression. The Gene Ontology (GO) analysis revealed significant alterations in the expression of genes categorized with the 'cell adhesion', 'inflammatory response', and 'mitochondrial functions', i.e., well-known functions related to COPD, in samples from patients with COPD. Multi-omics data were subsequently integrated to decipher the upstream regulatory changes linked to the gene expression alterations in COPD. COPD-associated expression quantitative trait loci (eQTLs) were located at the upstream regulatory regions of 96 DEGs. Additionally, 45 previously identified COPD-related miRNAs were predicted to target 66 of the DEGs. The eQTLs and miRNAs might affect the expression of 'respiratory electron transport chain' genes and 'cell proliferation' genes, respectively, while both eQTLs and miRNAs might affect the expression of 'apoptosis' genes. We think that our present study will contribute to our understanding of the molecular etiology of COPD accompanying lung cancer.

Inflammatory mediators in exhaled breath condensate and peripheral blood of healthy donors and stable COPD patients

Objective: The aim of this work was to compare matrix metalloproteinase-9 and -12, tissue inhibitor of metalloproteinase-1 and -4, and neutrophil elastase in exhaled breath condensate (EBC) and peripheral blood of patients with COPD. Methods: Peripheral blood and EBC samples from COPD patients and healthy donors were collected. In serum and EBC, MMP-9, MMP-12, NE, TIMP-1, and TIMP-4 proteins were detected by ELISA. The mRNA expression levels of MMP-9, MMP-12, NE, TIMP-1, and TIMP-4 in peripheral blood mononuclear cells (PBMCs) were analyzed by qRT-PCR. Results: The protein levels of MMP-9 (p=.034) and MMP-12 (p=.041) in the EBC of COPD smokers were higher than those of COPD never-smokers. The concentrations of TIMP-1 (p=.072) and TIMP-4 (p=.084) in the EBC of COPD smokers were higher than those of COPD never-smokers; however, the difference was not statistically significant. MMP-9 (r=-0.78, p<.0001) and TIMP-1 (r=-0.71, p<.0001) levels in EBC were significantly negatively correlated with pulmonary function FEV1%pred. The protein levels of MMP-12 (r=-0.37, p=.034) and TIMP-4 (r=-0.34, p=.041) were also negatively correlated with FEV1%pred. The expression of MMP-9, MMP-12, NE, TIMP-1, and TIMP-4 in PBMCs and serum of COPD smokers were significantly higher than those of control never-smokers (p<.05). Conclusions: Exhaled MMP-9, MMP-12, TIMP-1, and TIMP-4 levels increased in stable COPD patients and were negatively correlated with FEV1%pred, which suggests the usefulness of their measurement in EBC for the monitoring of airway inflammation. However, to better assess their diagnostic or prognostic value, larger studies are necessary.

The impact of PRDX4 and the EGFR mutation status on cellular proliferation in lung adenocarcinoma

Background: Oxidative stress plays key roles in the progression of lung adenocarcinoma. Recently, we reported that peroxiredoxin 4 (PRDX4), an antioxidant enzyme, can be a prognostic marker of lung adenocarcinoma (LUAD). In the present study, we aimed to further investigate the relationship among the PRDX4 expression, epidermal growth factor receptor (EGFR) mutations and cell proliferation in LUAD. Methods: The expression of PRDX4 was immunohistochemically analyzed and the EGFR mutation status was examined in 127 paraffin-embedded human surgical specimens from patients with stage I LUAD. The PRDX4 expression was considered to be high when >40% of the adenocarcinoma cells were positively stained. In vitro, using plasmid transfection methods, PRDX4 plasmid DNAs were transfected into human lung adenocarcinoma cell lines, A549 (EGFR-wild) or PC-9 (EGFR mutant). The viability of these cells was analyzed using a Cell Counting Kit-8 kit. Results: The number of cases with high PRDX4 expression levels among patients with LUAD with EGFR mutations was significantly larger than that in patients with EGFR wild-type. The combination of the PRDX4 expression level with the EGFR mutation status was closely associated with the prognosis of patients with stage I LUAD. Viability assays showed that the proliferation of A549 cells was significantly suppressed after PRDX4 plasmid transfection, while the overexpression of PRDX4 had no effect on the proliferation of EGFR-mutant PC-9 cells. Conclusions: The PRDX4 expression and EGFR mutation status were significantly associated with the prognosis of patients with stage I LUAD, and EGFR mutations affected the role of PRDX4 in the proliferation of LUAD cells.

The interplay of reactive oxygen species and the epidermal growth factor receptor in tumor progression and drug resistance

Background

The epidermal growth factor receptor (EGFR) plays important roles in cell survival, growth, differentiation, and tumorigenesis. Dysregulation of the EGFR is a common mechanism in cancer progression especially in non-small cell lung cancer (NSCLC).

Main body

Suppression of the EGFR-mediated signaling pathway is used in cancer treatment. Furthermore, reactive oxygen species (ROS)-induced oxidative stress from mitochondrial dysfunction or NADPH oxidase (NOX) overactivation and ectopic expression of antioxidative enzymes were also indicated to be involved in EGFR-mediated tumor progression (proliferation, differentiation, migration, and invasion) and drug resistance (EGFR tyrosine kinase inhibitor (TKI)). The products of NOX, superoxide and hydrogen peroxide, are considered to be major types of ROS. ROS are not only toxic materials to cells but also signaling regulators of tumor progression. Oxidation of both the EGFR and downstream phosphatases by ROS enhances EGFR-mediated signaling and promotes tumor progression. This review primarily focuses on the recent literature with respect to the roles of the EGFR and ROS and correlations between ROS and the EGFR in tumor progression and EGFR TKI resistance.

Short conclusion

The evidence discussed in this article can serve as a basis for basic and clinical research to understand how to modulate ROS levels to control the development and drug resistance of cancers.

Oxidative stress destabilizes protein arginine methyltransferase 4 via glycogen synthase kinase 3β to impede lung epithelial cell migration

Oxidative stress impacts normal cellular function leading to the pathogenesis of various diseases including pulmonary illnesses. Protein arginine methyltransferase 4 (PRMT4) is critical for normal lung alveolar epithelial cell development; however, the regulation of PRMT4 within such pulmonary diseases has yet to be elucidated. Using biochemical approaches, we uncovered that peroxide (H₂O₂) treatment decreases PRMT4 protein stability in murine lung epithelial (MLE12) cells to impede cell migration. Protein kinase glycogen synthase kinase 3β (GSK-3β) interacts with PRMT4 and catalyzes PRMT4 T132 phosphorylation that protects PRMT4 from ubiquitin proteasomal degradation. H₂O₂ downregulates GSK-3β to reduce PRMT4 at protein level. PRMT4 promotes cell migration and H₂O₂ degrades PRMT4 to inhibit lung epithelial cell migration. These observations demonstrate that oxidative stress destabilizes PRMT4 via GSK-3β signaling to impede lung epithelial cell migration that may hinder the lung repair and regeneration process.

Mitochondria in chronic obstructive pulmonary disease and lung cancer: where are we now?

Recent advances in mitochondrial biogenesis have provided the emerging recognition that mitochondria do much more than 'simply providing energy for cellular function'. Currently, a constantly improving understanding of the mitochondrial structure and function has been providing valuable insights into the contribution of defects in mitochondrial metabolism to various human diseases, including chronic obstructive pulmonary disease and lung cancer. The growing interest in mitochondria research led to development of new biomedical fields in the two main smoking-related lung diseases. However, there is considerable paucity in our understanding of mechanisms by which mitochondrial dynamics regulate lung diseases. In this review, we will discuss our current knowledge on the role of mitochondrial dysfunction in the pathogenesis of chronic obstructive pulmonary disease and non-small-cell lung cancer.

An exploratory look at NETosis in atherosclerosis

Current evidence suggests the likelihood of a link between venous thromboembolism (VTE) and atherosclerosis, although they have been traditionally considered as different pathological entities. The contribution of neutrophils to human atherogenesis has been underestimated, if compared to their contribution established in VTE. This is due to the major importance attributed to macrophages in plaque destabilization. Nevertheless, the role of neutrophils in atherogenesis deserves increasing attention. In particular, neutrophil extracellular traps (NETs) are net-like chromatin fibres that are released from dying neutrophils. The death of neutrophils with NETs formation is called NETosis. During activation, neutrophils produce reactive oxygen species (ROS), through the activation of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. The main function of NETs is trapping and killing pathogens. Nevertheless, NETs formation has been observed in various chronic inflammatory diseases, autoimmune diseases, vasculitis, lung diseases, cancer and VTE. Recent studies suggest that NETs formation might contribute also to atherosclerosis progression. New data report the presence of NETs in the luminal portion of human atherosclerotic vessels and coronary specimens obtained from patients after acute myocardial infarction. Programmed death mechanisms in atherosclerosis such as apoptosis, efferocytosis and also NETosis, share common features and triggers. If defective, they can lead the cells to a switch from programmed death to necrosis, resulting in the release of pro-atherogenic factors, accumulation of cell debris and progression of the disease. This review provides evidence on the emerging role of neutrophils focusing on NETosis and oxidative stress burden in orchestrating common mechanisms in atherosclerosis and thrombosis.

A systematic approach to cancer: evolution beyond selection

Cancer is typically scrutinized as a pathological process characterized by chromosomal aberrations and clonal expansion subject to stochastic Darwinian selection within adaptive cellular ecosystems. Cognition based evolution is suggested as an alternative approach to cancer development and progression in which neoplastic cells of differing karyotypes and cellular lineages are assessed as self-referential agencies with purposive participation within tissue microenvironments. As distinct self-aware entities, neoplastic cells occupy unique participant/observer status within tissue ecologies. In consequence, neoplastic proliferation by clonal lineages is enhanced by the advantaged utilization of ecological resources through flexible re-connection with progenitor evolutionary stages.

Concomitant elevations of MMP-9, NGAL, proMMP-9/NGAL and neutrophil elastase in serum of smokers with chronic obstructive pulmonary disease

A growing body of evidence points towards smoking‐related phenotypic differences in chronic obstructive pulmonary disease (COPD). As COPD is associated with systemic inflammation, we determined whether smoking status is related to serum levels of matrix metalloproteinase‐9 (pro‐ and active MMP‐9), neutrophil gelatinase‐associated lipocalin (NGAL) and the proMMP‐9/NGAL complex in patients with COPD. Serum samples were collected in 100 stable‐phase COPD patients (82 smokers, 18 never‐smokers) and 28 healthy adults (21 smokers, 7 never‐smokers). Serum levels of studied factors were measured in ELISA. Our data provide the first evidence of simultaneously elevated serum levels of MMP‐9, NGAL and proMMP‐9/NGAL in COPD smokers. While the triad discriminated between smokers and non‐smokers in the COPD group, MMP‐9 and proMMP‐9/NGAL (but not NGAL) discriminated between smokers with and without COPD. Adjustment for age and smoking pack‐years did not alter the findings. Serum MMP‐9, NGAL and proMMP‐9/NGAL levels were not correlated with the GOLD stage or FEV1 decline. Furthermore, serum levels of neutrophil elastase (NE) and MMP‐3 (but not of IL‐6 and MMP‐12) were also higher in COPD smokers than in healthy smokers before and after adjustment for age and pack‐years. Among COPD smokers, levels of MMP‐9, NGAL and proMMP‐9/NGAL were positively correlated with NE (P < 0.0001) but not with the remaining factors. Gelatin zymography detected proMMP‐9 in serum samples of healthy and COPD smoking groups. Our results suggest that associated serum levels of proMMP‐9, NGAL, proMMP‐9/NGAL and NE may reflect the state of systemic inflammation in COPD related to cigarette smoking.

The IL-17-Th1/Th17 pathway: an attractive target for lung cancer therapy?

INTRODUCTION

There is strong pharmaceutical development of agents targeting the IL-17-TH17 pathway for the treatment of psoriasis (Ps) and psoriatic arthritis (PsA). Lung cancer accounts for 28% of all cancer-related deaths worldwide, and roughly 80% of patients with newly-diagnosed non-small cell lung cancer (NSCLC) present with metastatic disease, with a poor prognosis of around 12 months. Therefore, there is a high unmet medical need for the development of new and potent systemic treatments in this deadly disease. The emergence of immunotherapies such as anti-PD-1 or anti-PDL1 as candidate therapies in non-small cell lung cancer (NSCLC) indicates that targeting critical immuno-modulatory cytokines including those within the IL-17-Th1/Th17 axis may have proven benefit in the treatment of lung cancer. Areas covered: In this review we describe the current evidence for aberrant IL-17-Th1/Th17 settings in cancer, particularly with regard to targeting this axis in NSCLC. We further discuss the current agents under pharmaceutical development which could potentially target this axis, and discuss the current limitations and areas of concern regarding the use of these in lung cancer. Expert opinion: Current evidence suggests that moving forward agents targeting the IL-17-Th1/Th17 pathway may have novel new oncoimmunology indications in the treatment paradigm for NSCLC.

Does at-home bleaching induce systemic oxidative stress in healthy subjects?

BACKGROUND

At-home bleaching is a technique characterized by the use of carbamide peroxide or hydrogen peroxide as a tooth-whitening agent. However, no data exist regarding systemic safety of this technique. The aim of this study was to investigate the effect of at-home bleaching on serum redox homeostasis.

METHODS

Twenty-nine healthy volunteers who requested tooth-whitening participated in this study. Specified bleaching trays were fabricated for the maxilla and mandible arches. Each participant was given two syringes containing 9% hydrogen peroxide gel to use for 30 min/night for 14 nights consecutively. To evaluate the redox status, the serum concentrations of malondialdehyde (MDA), total antioxidant capacity (TAC) and pro-oxidant-antioxidant balance (PAB) were measured. Blood samples were obtained in the morning prior to initiation of study and the morning after expiration of the bleaching period. The collected data were analyzed using Student's t-test with 95% confidence interval.

RESULTS

Twenty-three subjects completed the study. MDA, PAB and TAC were significantly increased after the bleaching period (P = 0.001, 0.001 and 0.002, respectively).

CONCLUSIONS

At-home bleaching revealed the potential to disturb oxidant-antioxidant balance and induce oxidative stress. Its clinical relevance is unfavourable and potential side-effects of at-home bleaching should be considered.

Targeting oxidant-dependent mechanisms for the treatment of COPD and its comorbidities

Chronic obstructive pulmonary disease (COPD) is an incurable global health burden and is characterised by progressive airflow limitation and loss of lung function. In addition to the pulmonary impact of the disease, COPD patients often develop comorbid diseases such as cardiovascular disease, skeletal muscle wasting, lung cancer and osteoporosis. One key feature of COPD, yet often underappreciated, is the contribution of oxidative stress in the onset and development of the disease. Patients experience an increased burden of oxidative stress due to the combined effects of excess reactive oxygen species (ROS) and nitrogen species (RNS) generation, antioxidant depletion and reduced antioxidant enzyme activity. Currently, there is a lack of effective treatments for COPD, and an even greater lack of research regarding interventions that treat both COPD and its comorbidities. Due to the involvement of oxidative stress in the pathogenesis of COPD and many of its comorbidities, a unique therapeutic opportunity arises where the treatment of a multitude of diseases may be possible with only one therapeutic target. In this review, oxidative stress and the roles of ROS/RNS in the context of COPD and comorbid cardiovascular disease, skeletal muscle wasting, lung cancer, and osteoporosis are discussed and the potential for therapeutic benefit of anti-oxidative treatment in these conditions is outlined. Because of the unique interplay between oxidative stress and these diseases, oxidative stress represents a novel target for the treatment of COPD and its comorbidities.

Environmental Epigenetics: Crossroad between Public Health, Lifestyle, and Cancer Prevention

Epigenetics provides the key to transform the genetic information into phenotype and because of its reversibility it is considered an ideal target for therapeutic interventions. This paper reviews the basic mechanisms of epigenetic control: DNA methylation, histone modifications, chromatin remodeling, and ncRNA expression and their role in disease development. We describe also the influence of the environment, lifestyle, nutritional habits, and the psychological influence on epigenetic marks and how these factors are related to cancer and other diseases development. Finally we discuss the potential use of natural epigenetic modifiers in the chemoprevention of cancer to link together public health, environment, and lifestyle.

Redox regulation of genome stability by effects on gene expression, epigenetic pathways and DNA damage/repair

Reactive oxygen and nitrogen species (e.g. H2O2, nitric oxide) confer redox regulation of essential cellular signaling pathways such as cell differentiation, proliferation, migration and apoptosis. In addition, classical regulation of gene expression or activity, including gene transcription to RNA followed by translation to the protein level, by transcription factors (e.g. NF-κB, HIF-1α) and mRNA binding proteins (e.g. GAPDH, HuR) is subject to redox regulation. This review will give an update of recent discoveries in this field, and specifically highlight the impact of reactive oxygen and nitrogen species on DNA repair systems that contribute to genomic stability. Emphasis will be placed on the emerging role of redox mechanisms regulating epigenetic pathways (e.g. miRNA, DNA methylation and histone modifications). By providing clinical correlations we discuss how oxidative stress can impact on gene regulation/activity and vise versa, how epigenetic processes, other gene regulatory mechanisms and DNA repair can influence the cellular redox state and contribute or prevent development or progression of disease.

Neutrophil extracellular trap (NET) formation characterises stable and exacerbated COPD and correlates with airflow limitation

BACKGROUND

COPD is a progressive disease of the airways that is characterized by neutrophilic inflammation, a condition known to promote the excessive formation of neutrophil extracellular traps (NETs). The presence of large amounts of NETs has recently been demonstrated for a variety of inflammatory lung diseases including cystic fibrosis, asthma and exacerbated COPD.

OBJECTIVE

We test whether excessive NET generation is restricted to exacerbation of COPD or whether it also occurs during stable periods of the disease, and whether NET presence and amount correlates with the severity of airflow limitation.

PATIENTS, MATERIALS AND METHODS

Sputum samples from four study groups were examined: COPD patients during acute exacerbation, patients with stable disease, and smoking and non-smoking controls without airflow limitation. Sputum induction followed the ECLIPSE protocol. Confocal laser microscopy (CLSM) and electron microscopy were used to analyse samples. Immunolabelling and fluorescent DNA staining were applied to trace NETs and related marker proteins. CLSM specimens served for quantitative evaluation.

RESULTS

Sputum of COPD patients is clearly characterised by NETs and NET-forming neutrophils. The presence of large amounts of NET is associated with disease severity (p < 0.001): over 90 % in exacerbated COPD, 45 % in stable COPD, and 25 % in smoking controls, but less than 5% in non-smokers. Quantification of NET-covered areas in sputum preparations confirms these results.

CONCLUSIONS

NET formation is not confined to exacerbation but also present in stable COPD and correlates with the severity of airflow limitation. We infer that NETs are a major contributor to chronic inflammatory and lung tissue damage in COPD.

Epigenetics of lung cancer

Lung cancer is the leading cause of cancer-related mortality in the United States. Epigenetic alterations, including DNA methylation, histone modifications, and noncoding RNA expression, have been reported widely in the literature to play a major role in the genesis of lung cancer. The goal of this review is to summarize the common epigenetic changes associated with lung cancer to give some clarity to its etiology, and to provide an overview of the potential translational applications of these changes, including applications for early detection, diagnosis, prognostication, and therapeutics.

Pooled analysis of mitochondrial DNA copy number and lung cancer risk in three prospective studies

BACKGROUND

We previously reported that higher levels of mitochondrial DNA copy number (mtDNA CN) were associated with lung cancer risk among male heavy smokers (i.e., ≥20 cigarettes per day) in the Alpha-Tocopherol Beta-Carotene (ATBC) study. Here, we present two additional prospective investigations nested in the Prostate, Lung, Colorectal, and Ovarian (PLCO) cancer screening trial and the Shanghai Women's Health Study (SWHS), and pooled with previously published data from ATBC.

MATERIALS

All DNA were extracted from peripheral whole blood samples using the phenol-chloroform method, and mtDNA CN was assayed by fluorescence-based qPCR. Multivariate unconditional logistic regression models were used to estimate ORs and 95% confidence intervals for the association of mtDNA CN and lung cancer risk.

RESULTS

Overall, mtDNA CN was not associated with lung cancer risk in the PLCO, SWHS, or pooled populations (all P trends > 0.42, P heterogeneity = 0.0001), and mtDNA CN was inversely associated with lung cancer risk among male smokers in PLCO, the opposite direction observed in ATBC. In addition, the mtDNA CN association observed among male heavy smokers in ATBC was the opposite direction in PLCO.

CONCLUSIONS

mtDNA CN was not consistently associated with lung cancer risk across three prospective study populations from Europe, Asia, and the United States.

IMPACT

This pooled study suggests no consistent association between prediagnostic mtDNA CN levels and lung cancer risk across several populations. Cancer Epidemiol Biomarkers Prev; 23(12); 2977-80. ©2014 AACR.

A quantitative proteomic approach to identify significantly altered protein networks in the serum of patients with lymphangioleiomyomatosis (LAM)

Lymphangioleiomyomatosis (LAM) is a rare and progressive cystic lung condition affecting approximately 3.4–7.5/million women, with an average lag time between symptom onset and diagnosis of upwards of 4 years. The aim of this work was to identify altered proteins in LAM serum which may be potential biomarkers of disease. Serum from LAM patient volunteers and healthy control volunteers were pooled and analysis carried out using quantitative 4-plex iTRAQ technology. Differentially expressed proteins were validated using ELISAs and pathway analysis was carried out using Ingenuity Pathway Analysis. Fourteen proteins were differentially expressed in LAM serum compared to control serum (p<0.05). Further screening validated the observed differences in extracellular matrix remodelling proteins including fibronectin (30% decrease in LAM, p = 0.03), von Willebrand Factor (40% reduction in LAM, p = 0.03) and Kallikrein III (25% increase in LAM, p = 0.03). Pathway networks elucidated the relationships between the ECM and cell trafficking in LAM. This study was the first to highlight an imbalance in networks important for remodelling in LAM, providing a set of novel potential biomarkers. These understandings may lead to a new effective treatment for LAM in the future.

DNA repair pathways and their therapeutic potential in lung cancer

SUMMARY: 

Lung cancer is the leading cause of cancer-related mortality. According to WHO, 1.37 million deaths occur globally each year as a result of this disease. More than 70% of these cases are associated with prior tobacco consumption and/or cigarette smoking, suggesting a direct causal relationship. The development and progression of lung cancer and other malignancies involves the loss of genetic stability, resulting in acquisition of cumulative genetic changes; this affords the cell increased malignant potential. As such, an understanding of the mechanisms through which these events may occur will potentially allow for development of new anticancer therapies. This review will address the association between lung cancer and genetic instability, with a central focus on genetic mutations in the DNA damage repair pathways. In addition, we will discuss the potential clinical exploitation of these pathways, both in terms of biomarker staging, as well as through direct therapeutic targeting.

Epigenetic-based immune intervention for rheumatic diseases

Rheumatic disease is a large spectrum of heterogeneous conditions affecting the loco-motor system including joints, muscles, connective tissues, and soft tissues around the joints and bones. Many rheumatic diseases have an element of autoimmunity including systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). Aberrant epigenetic regulation of gene expression is emerging as a major factor within rheumatic disease, and indicates potential new therapeutic avenues of approach to these debilitating conditions. Understanding the precise role of epigenetics in the development and treatment of rheumatic diseases particularly those which have an associated autoimmune element may be important for the long-term management of such conditions.

Mitochondrial oxidative stress-induced epigenetic modifications in pancreatic epithelial cells

Emerging studies have linked prooxidative carbamate compound exposures with various human pathologies including pancreatic cancer. In these studies, our aim was to examine mitochondrial oxidative stress-mediated aberrant chromatin responses in human pancreatic ductal epithelial cells. Posttranslational histone modifications, promoter DNA methylation, and micro-RNA (miRNA) expression patterns were evaluated following induction of mitochondrial oxidative stress by N-succinimidyl N-methylcarbamate exposure. In treated cells, perturbation in mitochondrial machinery led to hypermethylation of p16 and smad4 gene promoters and downregulation of respective gene products. Posttranslational histone modifications that include hypoacetylation of acetylated histone (AcH) 3 and AcH4, hypermethylation of monomethylated histone 3 at lysine 9 and trimethylated histone 4 at lysine 20 ubiquitinated histone (uH) 2A/uH2B, and increased phosphorylation of H2AX and H3 were observed in the treated cells. Altered expression of miRNAs denoted possible location of corresponding genes at oxidatively damaged fragile sites. Collectively, our results provide a direct role of mitochondrial oxidative stress-mediated epigenetic imbalance to perturbed genomic integrity in oxygen radical-induced pancreatic injury. Further, identification and characterization of molecular switches that affect these epigenomic signatures and targets thereof will be imperative to understand the complex role of redox-regulatory network in pancreatic milieu.

Role of chronic obstructive pulmonary disease in lung cancer pathogenesis

Chronic obstructive pulmonary disease (COPD) and lung cancer are two important smoking related conditions. However, COPD has been shown to be an independent risk factor for lung cancer regardless of smoking history, suggesting that COPD and lung cancer may share a common pathogenesis. This review summarizes the epidemiology of lung cancer and COPD briefly, as well as discussing the potential for shared genetic risk, and shared genomic mechanisms, such as epigenetic changes or DNA damage induced by smoking. How key areas of COPD pathogenesis, such as inflammation, oxidative stress and protease imbalance may contribute to subsequent development of cancer will also be covered. Finally the possibility that consequences of COPD, such as hypoxia, influence carcinogenesis will be reviewed. By understanding the pathogenesis of COPD and lung cancer in detail it is possible that new treatments may be developed and the risk of lung cancer in COPD may be reduced.

Regulation of the cell fate by DNA damage and hypoxia

In order to provide the means for the design of novel rational anti-cancer drug therapies research efforts are concentrated on unravelling the molecular circuits which induce programmed cell death and block proliferation of cancer cells. Modern therapeutic strategies are based on the understanding of the complexity of physiological functions such as differentiation, development, immune responses, cell-cycle arrest, DNA damage repair, apoptosis, autophagy, energy metabolism, and senescence. It has become evident that this knowledge will provide the means to target the components of the pathways involved in these processes in a specific and selective manner thus paving the way for the development of effective and personalised anti-cancer therapies. Transcription is a crucial cellular process that regulates a multitude of physiological functions, which are essential in disease progression and cellular response to therapy. Transcription factors such as the p53 tumor suppressor and the hypoxia-inducible factor-α (HIF-α) are key players in carcinogenesis and cellular response to cancer therapies. Both of these transcription factors regulate gene expression of genes involved in cell death and proliferation, in some cases cooperating towards producing the same outcome and in some others mediating opposing effects. It is thus apparent that fine tuning of the activity of these transcription factors is essential to determine the cellular response to therapeutic regimens, in other words whether tumor cells will commit to apoptosis or evade engagement with the anti-proliferative effects of drugs leading to drug resistance. Our observations support the notion that the functional crosstalk between HIF-1α and p53 pathways and thus the fine tuning of their transcriptional activity is mediated by cofactors shared between the two transcription factors such as components of the p300 co-activator multiprotein complex. In particular, there is evidence to suggest that differential composition of the co-modulatory protein complexes associated with p53 and HIF-1α under diverse types of stress conditions differentially regulate the expression of distinct subsets of p53 and HIF-1α target genes involved in processes such as cell cycle arrest, apoptosis, chronic inflammation, and cellular energy metabolism thereby determining the cellular fate under particular types of micro-environmental stress.

Oxidative stress and epigenetic instability in human hepatocarcinogenesis

Hepatocellular carcinoma (HCC) is a major cause of cancer death, and its development is influenced by the status of inflammation and oxidative stress in the liver. Although oxidative stress might induce genetic changes and play a role in HCC development, many epigenetic alterations have also been reported in this type of tumor, suggesting the importance of epigenetic instability in hepatocarcinogenesis. Epigenetic instability results in 2 types of DNA alterations: hypermethylation of the promoter of tumor suppressor genes (TSGs), and hypomethylation of nonpromoter CpG, such as repetitive elements and satellite DNA. The former causes transcriptional inactivation of TSGs, while the latter reportedly induces chromosomal instability and an abnormal activation of oncogenes as well as mobile genetic elements. Oxidative stress could induce epigenetic instability and inactivate TSGs through the recruitment of the polycomb repressive complex to the promoter sequence carrying DNA damage induced by oxidation. Inflammatory cytokines from immune cells also reportedly induce expression of several histone and DNA modulators. On the other hand, DNA oxidation could lead to activation of DNA repair pathways and affect the binding of methyl cytosine-binding protein to DNA, which could cause DNA hypomethylation. The decrease of the level of methyl group donors also contributes to the alteration in the methylation status. These mechanisms should act in concert and induce epigenetic instability, leading to HCC.

The regulation of hepatic Pon1 by a maternal high-fat diet is gender specific and may occur through promoter histone modifications in neonatal rats

The antioxidant (AOX) defense system is critical for combating whole-body oxidative stress, and the present study aimed to determine the consequences of a maternal high-fat (HF) diet on neonatal hepatic lipid accumulation, oxidative stress, the expression of AOX genes, as well as epigenetic histone modifications within Pon1, an AOX enzyme. Hepatic thiobarbituric acid reactive substances were significantly increased and nonesterified fatty acids decreased in offspring of HF-fed dams, while triglycerides increased in male but not female HF offspring when compared to controls (C). Pon1, Pon2, Pon3 and Sod2 were significantly increased in offspring of HF-fed dams when compared to C. However, the increase in Pon1 and Pon3 was only significant in male but not female offspring. When compared to C, the hepatic Pon1 promoter of male and female HF offspring had significantly more acetylated histone H4 as well as dimethylated histone H3 at lysine residue 4, which are both involved in transcriptional activation. Trimethylation of histone H3 at lysine residue 9, which is involved in transcriptional repression, was only associated with genes in females. Results from the present study reveal that a maternal HF diet affects hepatic metabolism in the neonate in a gender-specific manner, and these differences, in association with epigenetic modification of histones, may contribute to the known gender differences in oxidative balance.

Sequence polymorphisms in the D-loop region of mitochondrial DNA and outcome of non-Hodgkin lymphoma

Accumulation of single nucleotide polymorphisms (SNPs) in the displacement loop (D-loop) of mitochondrial DNA (mtDNA) might be associated with cancer risk and disease outcome. We have identified 140 SNPs including 26 SNPs with frequency distribution of minor allele greater than 5% in a case-control study for non-Hodgkin lymphoma patients previously. In this study, we assessed the predictive power of D-loop SNPs in NHL patients. Five SNP sites were identified by log-rank test for statistically significant prediction of NHL survival in a univariate analysis. In an overall multivariate analysis, allele 16304 was identified as an independent predictor of NHL outcome. The survival time of NHL patients with 16304C was significantly shorter than that of patients with 16304T (relative risk, 0.513; 95% CI, 0.266-0.989; p = 0.046). The analysis of genetic polymorphisms in the mitochondrial D-loop can help identify subgroups of patients who are at a high risk of a poor disease outcome.

Identification of sequence polymorphisms in the D-loop region of mitochondrial DNA as a risk factor for non-Hodgkin lymphoma

Accumulation of single nucleotide polymorphisms (SNPs) in the displacement loop (D-loop) of mitochondrial DNA (mtDNA) may be associated with an increased cancer risk. We investigated the non-Hodgkin lymphoma (NHL) risk profile of D-loop SNPs in a case-control study. The minor alleles of nucleotides 73A/G, 263A/G, 315C/C insert were associated with a decreased risk for NHL. The minor alleles of the nucleotides 200G/A were specifically associated with the risk of diffuse large B-cell lymphoma, whereas the minor allele of nucleotides 16362C/T and 249Del/A was specifically associated with the decreased risk of T-cell lymphoma. In conclusion, SNPs in mtDNA are potential modifiers of NHL risk. The analysis of genetic polymorphisms in the mitochondrial D-loop can help identify subgroups of patients who are at a high risk of developing NHL.

IL-23R is Epigenetically Regulated and Modulated by Chemotherapy in Non-Small Cell Lung Cancer

The Interleukin-23 (IL-23)/IL-23R signaling axis is an important inflammatory pathway, involved in the stimulation and regulation of the T helper (Th) 17 lymphocytes, resulting in the production of IL-17. Aside from auto-immunity, this cytokine has also been linked to carcinogenesis and polymorphisms in the IL-23R gene are associated with an increased risk for the development of a number of different cancers. Activation of the IL-23 pathway results in the up-regulation of STAT3 and it is thought that the pathological consequences associated with this are in part due to the production of IL-17. We have previously identified IL-23A as pro-proliferative and epigenetically regulated in non-small cell lung cancer (NSCLC). The current study aims to evaluate IL-23R in greater detail in NSCLC. We demonstrate that IL-23R is expressed and epigenetically regulated in NSCLC through histone post-translation modifications and CpG island methylation. In addition, Gemcitabine treatment, a chemotherapy drug used in the treatment of NSCLC, resulted in the up-regulation of the IL-23R. Furthermore, Apilimod (STA 5326), a small molecule which blocks the expression of IL-23 and IL-12, reduced the proliferative capacity of NSCLC cells, particularly in the adenocarcinoma (A549) sub-type. Apilimod is currently undergoing investigation in a number of clinical trials for the treatment of auto-immune conditions such as Crohn’s disease and Rheumatoid Arthritis. Our results may have implications for treating NSCLC patients with Gemcitabine or epigenetic targeted therapies. However, Apilimod may possibly provide a new treatment avenue for NSCLC patients. Work is currently ongoing to further delineate the IL-23/IL-23R axis in this disease.

Perspectives on epigenetic-based immune intervention for rheumatic diseases

Rheumatic disease can loosely be described as any painful condition affecting the loco-motor system, including joints, muscles, connective tissues, and soft tissues around the joints and bones. There is a wide spectrum of rheumatic diseases, many of which involve autoimmunity, including systemic lupus erythematosus and rheumatoid arthritis. A significant body of evidence now links aberrant epigenetic regulation of gene expression with rheumatic disease and points toward the use of epigenetic targeting agents as potential new treatment options, particularly for those conditions associated with an autoimmune element. In this perspective, I will briefly cover the current knowledge surrounding this area in the field of rheumatology.

Potential therapeutic effects of natural heme oxygenase-1 inducers in cardiovascular diseases

SIGNIFICANCE

Many physiological effects of natural antioxidants, their extracts or their major active components, have been reported in recent decades. Most of these compounds are characterized by a phenolic structure, similar to that of α-tocopherol, and present antioxidant properties that have been demonstrated both in vitro and in vivo. Polyphenols may increase the capacity of endogenous antioxidant defenses and modulate the cellular redox state. Such effects may have wide-ranging consequences for cellular growth and differentiation.

CRITICAL ISSUES

The majority of in vitro and in vivo studies conducted so far have attributed the protective effect of bioactive polyphenols to their chemical reactivity toward free radicals and their capacity to prevent the oxidation of important intracellular components. One possible protective molecular mechanism of polyphenols is nuclear factor erythroid 2-related factor (Nrf2) activation, which in turn regulates a number of detoxification enzymes.

RECENT ADVANCES

Among the latter, the heme oxygenase-1 (HO-1) pathway is likely to contribute to the established and powerful antioxidant/anti-inflammatory properties of polyphenols. In this context, it is interesting to note that induction of HO-1 expression by means of natural compounds contributes to prevention of cardiovascular diseases in various experimental models.

FUTURE DIRECTIONS

The focus of this review is on the role of natural HO-1 inducers as a potential therapeutic strategy to protect the cardiovascular system against various stressors in several pathological conditions.

Bioinformatics analysis reveals biophysical and evolutionary insights into the 3-nitrotyrosine post-translational modification in the human proteome

Protein 3-nitrotyrosine is a post-translational modification that commonly arises from the nitration of tyrosine residues. This modification has been detected under a wide range of pathological conditions and has been shown to alter protein function. Whether 3-nitrotyrosine is important in normal cellular processes or is likely to affect specific biological pathways remains unclear. Using GPS-YNO2, a recently described 3-nitrotyrosine prediction algorithm, a set of predictions for nitrated residues in the human proteome was generated. In total, 9.27 per cent of the proteome was predicted to be nitratable (27 922/301 091). By matching the predictions against a set of curated and experimentally validated 3-nitrotyrosine sites in human proteins, it was found that GPS-YNO2 is able to predict 73.1 per cent (404/553) of these sites. Furthermore, of these sites, 42 have been shown to be nitrated endogenously, with 85.7 per cent (36/42) of these predicted to be nitrated. This demonstrates the feasibility of using the predicted dataset for a whole proteome analysis. A comprehensive bioinformatics analysis was subsequently performed on predicted and all experimentally validated nitrated tyrosine. This found mild but specific biophysical constraints that affect the susceptibility of tyrosine to nitration, and these may play a role in increasing the likelihood of 3-nitrotyrosine to affect processes, including phosphorylation and DNA binding. Furthermore, examining the evolutionary conservation of predicted 3-nitrotyrosine showed that, relative to non-nitrated tyrosine residues, 3-nitrotyrosine residues are generally less conserved. This suggests that, at least in the majority of cases, 3-nitrotyrosine is likely to have a deleterious effect on protein function and less likely to be important in normal cellular function.

Identification of sequence polymorphisms in the D-loop region of mitochondrial DNA as a risk factor for lung cancer

Accumulation of single nucleotide polymorphisms (SNPs) in the displacement loop (D-loop) of mitochondrial DNA (mtDNA) may be associated with an increased cancer risk. We investigated the lung cancer risk profile of D-loop SNPs in a case-controlled study. The minor alleles of nucleotides 235A/G and 324A/G were associated with an increased risk for lung cancer patients. The minor alleles of the nucleotides 151C/T, 200A/G, 524C/CA, and 16274G/A were specifically associated with the cancer risk of squamous cell carcinoma, whereas the minor allele of nucleotide 16298T/C was specifically associated with the risk of small cell lung cancer. In conclusion, SNPs in mtDNA are potential modifiers of lung cancer risk. The analysis of genetic polymorphisms in the mitochondrial D-loop can help identify subgroups of patients who are at a high risk of developing lung cancer.