Oxidative stress in non-small cell lung cancer patients after chemotherapy: Association with treatment response

Identification of m7G-Related miRNA Signatures Associated with Prognosis, Oxidative Stress, and Immune Landscape in Lung Adenocarcinoma

The role of N7-methylguanosine(m7G)-related miRNAs in lung adenocarcinoma (LUAD) remains unclear. We used LUAD data from The Cancer Genome Atlas (TCGA) to establish a risk model based on the m7G-related miRNAs, and divided patients into high-risk or low-risk subgroups. A nomogram for predicting overall survival (OS) was then constructed based on the independent risk factors. In addition, we performed a functional enrichment analysis and defined the oxidative stress-related genes, immune landscape as well as a drug response profile in the high-risk and low-risk subgroups. This study incorporated 28 m7G-related miRNAs into the risk model. The data showed a significant difference in the OS between the high-risk and low-risk subgroups. The receiver operating characteristic curve (ROC) predicted that the area under the curve (AUC) of one-year, three-year and five-year OS was 0.781, 0.804 and 0.853, respectively. The C-index of the prognostic nomogram for predicting OS was 0.739. We then analyzed the oxidative stress-related genes and immune landscape in the high-risk and low-risk subgroups. The data demonstrated significant differences in the expression of albumin (ALB), estimated score, immune score, stromal score, immune cell infiltration and functions between the high-risk and low-risk subgroups. In addition, the drug response analysis showed that low-risk subgroups may be more sensitive to tyrosine kinase inhibitor (TKI) and histone deacetylase (HDAC) inhibitors. We successfully developed a novel risk model based on m7G-related miRNAs in this study. The model can predict clinical prognosis and guide therapeutic regimens in patients with LUAD. Our data also provided new insights into the molecular mechanisms of m7G in LUAD.

Levels of oxidative stress in patients with neoadjuvant chemotherapy for gastric cancer: correlation with treatment response

Objective

The intent of this study was to investigate the relationship between oxidative stress and treatment response in gastric cancer patients undergoing neoadjuvant chemotherapy.

Methods

Blood samples from 108 patients and 108 healthy subjects were collected, and all patients were enrolled in SOX chemotherapy. The patients received four cycles of neoadjuvant chemotherapy. Blood samples were collected to determine oxidative stress levels at baseline prior to beginning chemotherapy, and at the end of cycles 2 and 4. The patients receiving neoadjuvant chemotherapy were followed up for several months to years. A survival curve was created according to the follow-up information from the patients. In addition, the correlation between oxidative stress level and treatment effect was evaluated and ROC curves were plotted according to the final collected data.

Results

Compared with the normal group, the levels of the antioxidant index decreased while the peroxide index increased in the patients. Conversely, when patients were compared before and after chemotherapy, the antioxidant index increased but the peroxide index decreased. Furthermore, the antioxidant index increased in the response group while the peroxide index decreased in the non-response group.

Conclusion

Patients with an increased antioxidant index after chemotherapy have good treatment responsiveness. These indicators can also be used as predictors to judge the patients' response to chemotherapy.

Disulfide Bond-Based SN38 Prodrug Nanoassemblies with High Drug Loading and Reduction-Triggered Drug Release for Pancreatic Cancer Therapy

Purpose

Chemotherapy is a significant and effective therapeutic strategy that is frequently utilized in the treatment of cancer. Small molecular prodrug-based nanoassemblies (SMPDNAs) combine the benefits of both prodrugs and nanomedicine into a single nanoassembly with high drug loading, increased stability, and improved biocompatibility.

Methods

In this study, a disulfide bond inserted 7-ethyl-10-hydroxycamptothecin (SN38) prodrug was rationally designed and then used to prepare nanoassemblies (SNSS NAs) that were selectively activated by rich glutathione (GSH) in the tumor site. The characterization of SNSS NAs and the in vitro and in vivo evaluation of their antitumor effect on a pancreatic cancer model were performed.

Results

In vitro findings demonstrated that SNSS NAs exhibited GSH-induced SN38 release and cytotoxicity. SNSS NAs have demonstrated a passive targeting effect on tumor tissues, a superior antitumor effect compared to irinotecan (CPT-11), and satisfactory biocompatibility with double dosage treatment.

Conclusion

The SNSS NAs developed in this study provide a new method for the preparation of SN38-based nano-delivery systems with improved antitumor effect and biosafety.

Establishment and validation of a redox-related long non-coding RNAs prognostic signature in head and neck squamous cell carcinoma

Reduction and oxidation (redox) reactions occur in living organisms as part of normal cellular metabolism. Here, we established a novel redox-related long non-coding RNAs (rrlncRNAs) signature to predict the prognosis and therapeutic response in Head and neck squamous cell carcinoma (HNSCC). The expression profile and clinical information were obtained from the TCGA project. In total, 10 differently expressed rrlncRNAs associated with prognosis were identified and involved in a prognostic risk score signature by the least absolute shrinkage and selection operator penalized Cox analysis. The area under the receiver operating characteristic curves of the survival rates predicted by the rrlncRNAs signature over one, two, and three years were found to be 0.651, 0.670, and 0.679. Following the completion of the Kaplan-Meier survival study, we discovered that the lower-risk cohort exhibited a much longer overall survival period in contrast with the higher-risk cohort. Univariate and multivariable Cox regression analyses demonstrated that the risk score independently served as a significant predictive factor. GO annotation and KEGG pathway analyses illustrated that the rrlncRNAs signature was strongly associated with immune-related functions as well as signaling pathways. The tumor-infiltrating immune cells, tumor microenvironment, immune-related functions, HLA gene family expression, immune checkpoint genes expression, and somatic variants differed substantially between the low- and high-risk cohorts. Moreover, patients in low-risk group were predicted to present a favorable immunotherapy responsiveness, while in contrast, the high-risk group patients might have a stronger sensitivity to "docetaxel". According to our findings, the rrlncRNAs signature showed an excellent prognosis predictive value and might indicate therapeutic response to immunotherapy in HNSCC.

Pulsed electric fields with calcium ions stimulate oxidative alternations and lipid peroxidation in human non-small cell lung cancer

Pulsed electric fields (PEFs) are commonly used to facilitate the delivery of various molecules, including pharmaceuticals, into living cells. However, the applied protocols still require optimization regarding the conditions of the permeabilization process, i.e., pulse waveform, voltage, duration, and the number of pulses in a burst. This study highlights the importance of electrochemical processes involved in the electropermeabilization process, known as electroporation. This research investigated the effects of electroporation on human non-small cell lung cancer cells (A549) in potassium (SKM) and HEPES-based buffers (SHM) using sub-microsecond and microsecond range pulses. The experiments were performed using 100 ns - 100 μs (0.6-15 kV/cm) bursts with 8 pulses in a sequence. It was shown that depending on the buffer composition, the susceptibility of cells to PEF varies, while calcium enhances the cytotoxic effects of PEF, if high cell membrane permeabilization is triggered. It was also determined that electroporation with calcium ions induces oxidative stress in cells, including lipid peroxidation (LPO), generation of reactive oxygen species (ROS), and neutral lipid droplets. Here, we demonstrated that calcium ions and optimized pulse parameters could potentiate PEF efficacy and oxidative alternations in lung cancer cells. Thus, the anticancer efficacy of PEF in lung cancers in combination with standard cytostatic drugs or calcium ions should be considered, but this issue still requires in-depth detailed studies with in vivo models.

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.

IL-36γ and IL-36Ra Reciprocally Regulate NSCLC Progression by Modulating GSH Homeostasis and Oxidative Stress-Induced Cell Death

The balance between antioxidants and reactive oxygen species (ROS) critically regulates tumor initiation and progression. However, whether and how the tumor-favoring redox status is controlled by cytokine networks remain poorly defined. Here, it is shown that IL-36γ and IL-36Ra reciprocally regulate the progression of non-small cell lung cancer (NSCLC) by modulating glutathione metabolism and ROS resolution. Knockout, inhibition, or neutralization of IL-36γ significantly inhibits NSCLC progression and prolongs survival of the KrasLSL-G12D/+ Tp53fl/fl and KrasLSL-G12D/+ Lkb1fl/fl mice after tumor induction, whereas knockout of IL-36Ra exacerbates tumorigenesis in these NSCLC mouse models and accelerates death of mice. Mechanistically, IL-36γ directly upregulates an array of genes involved in glutathione homeostasis to reduce ROS and prevent oxidative stress-induced cell death, which is mitigated by IL-36Ra or IL-36γ neutralizing antibody. Consistently, IL-36γ staining is positively and negatively correlated with glutathione biosynthesis and ROS in human NSCLC tumor biopsies, respectively. These findings highlight essential roles of cytokine networks in redox for tumorigenesis and provide potential therapeutic strategy for NSCLC.

Systemic Profiles of microRNAs, Redox Balance, and Inflammation in Lung Cancer Patients: Influence of COPD

Lung cancer (LC) risk increases in patients with chronic respiratory diseases (COPD). MicroRNAs and redox imbalance are involved in lung tumorigenesis in COPD patients. Whether systemic alterations of those events may also take place in LC patients remains unknown. Our objectives were to assess the plasma levels of microRNAs, redox balance, and cytokines in LC patients with/without COPD. MicroRNAs (RT-PCR) involved in LC, oxidized DNA, MDA-protein adducts, GSH, TEAC, VEGF, and TGF-beta (ELISA) were quantified in plasma samples from non-LC controls (n = 45), LC-only patients (n = 32), and LC-COPD patients (n = 91). In LC-COPD patients compared to controls and LC-only, MDA-protein adduct levels increased, while those of GSH decreased, and two patterns of plasma microRNA were detected. In both LC patient groups, miR-451 expression was downregulated, while those of microRNA-let7c were upregulated, and levels of TEAC and TGF-beta increased compared to the controls. Correlations were found between clinical and biological variables. A differential expression profile of microRNAs was detected in patients with LC. Moreover, in LC patients with COPD, plasma oxidative stress levels increased, whereas those of GSH declined. Systemic oxidative and antioxidant markers are differentially expressed in LC patients with respiratory diseases, thus implying its contribution to the pathogenesis of tumorigenesis in these patients.

Development of a gene signature associated with iron metabolism in lung adenocarcinoma

There are few studies on the role of iron metabolism genes in predicting the prognosis of lung adenocarcinoma (LUAD). Therefore, our research aims to screen key genes and to establish a prognostic signature that can predict the overall survival rate of lung adenocarcinoma patients. RNA-Seq data and corresponding clinical materials of 594 adenocarcinoma patients from The Cancer Genome Atlas(TCGA) were downloaded. GSE42127 of Gene Expression Omnibus (GEO) database was further verified. The multi-gene prognostic signature was constructed by the Cox regression model of the Least Absolute Shrinkage and Selection Operator (LASSO). We constructed a prediction signature with 12 genes (HAVCR1, SPN, GAPDH, ANGPTL4, PRSS3, KRT8, LDHA, HMMR, SLC2A1, CYP24A1, LOXL2, TIMP1), and patients were split into high and low-risk groups. The survival graph results revealed that the survival prognosis between the high and low-risk groups was significantly different (TCGA: P < 0.001, GEO: P = 0.001). Univariate and multivariate Cox regression analysis confirmed that the risk value is a predictor of patient OS (P < 0.001). The area under the time-dependent ROC curve (AUC) indicated that our signature had a relatively high true positive rate when predicting the 1-year, 3-year, and 5-year OS of the TCGA cohort, which was 0.735, 0.711, and 0.601, respectively. In addition, immune-related pathways were highlighted in the functional enrichment analysis. In conclusion, we developed and verified a 12-gene prognostic signature, which may be help predict the prognosis of lung adenocarcinoma and offer a variety of targeted options for the precise treatment of lung cancer.

Glutathione-Depleting Nanomedicines for Synergistic Cancer Therapy

Cancer cells frequently exhibit resistance to various molecular and nanoscale drugs, which inevitably affects the drugs' therapeutic outcomes. Overexpression of glutathione (GSH) has been observed in many cancer cells, and solid evidence has corroborated the resulting tumor resistance to a variety of anticancer therapies, suggesting that this biochemical characteristic of cancer cells can be developed as a potential target for cancer treatments. The single treatment of GSH-depleting agents can potentiate the responses of the cancer cells to different cell death stimuli; therefore, as an adjunctive strategy, GSH depletion is usually combined with mainstream cancer therapies for enhancing the therapeutic outcomes. Propelled by the rapid development of nanotechnology, GSH-depleting agents can be readily constructed into anticancer nanomedicines, which have shown a steep rise over the past decade. Here, we review the common GSH-depleting nanomedicines which have been widely applied in synergistic cancer treatments in recent years. Some current challenges and future perspectives for GSH depletion-based cancer therapies are also presented. With the understanding of the structure-property relationship and action mechanisms of these biomaterials, we hope that the GSH-depleting nanotechnology will be further developed to realize more effective disease treatments and even achieve successful clinical translations.

Serum Malondialdehyde as a Biomarker of Oxidative Stress in Patients with Primary Ocular Carcinoma: Impact on Response to Chemotherapy

Purpose

To study the level of serum malondialdehyde (MDA), a biomarker of oxidative stress before and after chemotherapy in various ocular malignancies and to correlate its significance with clinicopathological parameters.

Methods

Thirty two histopathologically confirmed cases of primary ocular malignancies were included in this longitudinal cohort study. Detailed clinicopathological assessment was done. Analysis of serum MDA level in the patient before and after chemotherapy was measured and its prognostic significance was analyzed.

Results

Maximum cases were of eyelid malignancy (n=18, 56.2%) followed by retinoblastoma (18.8%) and OSSN (6, 18.8%). About 43.75% patients were in the advanced-stage. The tumor was histopathologically well-differentiated in 20 (62.5%) cases. Most common malignancy was sebaceous gland carcinoma of the eyelid (n=10,31.25%). Serum MDA level in patients were significantly higher than controls [5.5712±0.32779 vs 2.5531±0.08056 nmol/mL, p<0.001]. Level was significantly reduced after chemotherapy (4.5146±0.23209 nmol/mL). Serum MDA was maximum in cases of rhabdomyosarcoma (5.9450±0.23335 nmol/mL) and retinoblastoma (5.7433±0.14334 nmol/mL). It was minimum in basal cell carcinoma (5.3775±0.17746 nmol/mL). Pre chemotherapy serum MDA level was significantly higher in patients having larger tumor (>20mm, p< 0.001) and having lymph node metastasis than those without lymph node metastasis [5.8350±0.17113 vs 5.4833± 0.32193 nmol/mL, p<0.006]. No significant difference was observed in post chemotherapy serum MDA level as for as size of tumor (p=0.947) and histopathological differentiation (p=0.109) was concerned.

Conclusion

The serum MDA level is a potential biomarker in primary ocular carcinoma to assess oxidative stress and its impact on response to chemotherapy.

pH/Reduction Dual Stimuli-Triggered Self-Assembly of NIR Theranostic Probes for Enhanced Dual-Modal Imaging and Photothermal Therapy of Tumors

Tumor microenvironment plays a pivotal role in the growth and metastasis of tumors, and has become a promising target for precise diagnosis and treatment of tumors. Herein, a novel smart NIR theranostic probe Cy-1 that can simultaneously respond to low intracellular pH and reductive glutathione (GSH) is reported. This probe has demonstrated to be able to intermolecularly undergo a biologically compatible CBT-Cys condensation reaction to selectively form large nanoaggregates in the tumor microenvironment resulting in its enhanced accumulation and retention in the tumor, which as a consequence significantly improves the sensitivity of NIR/photoacoustic imaging and photothermal therapeutic efficacy of tumors in living mice. We thus believe that this dual stimuli-mediated self-assembly strategy may offer a promising and universal platform for cancer theranostics.

Kaempferol inhibits Nrf2 signalling pathway via downregulation of Nrf2 mRNA and induces apoptosis in NSCLC cells

Chemoprevention failure is considered to be the most emerging problem that makes non-small cell lung cancer (NSCLC) as one of the deadliest malignancies in the world. In NSCLC cells, Nuclear factor erythroid 2-related factor 2 (Nrf2), a redox sensitive transcription factor, promotes cancer cell survival and fosters mechanism for drug resistance. Here we report identification of Kaempferol, a dietary flavonoid, as a potent Nrf2 inhibitor using Nrf2 reporter assay in NSCLC cells (A549 and NCIH460). Kaempferol selectively reduces Nrf2 mRNA and protein levels and lower level of nuclear Nrf2 downregulates transcription of Nrf2 target genes (NQO1, HO1, AKR1C1 and GST). Kaempferol (25 μM) mediated downregulation of GST, NQO1 and HO1 expression is also observed even after stimulation of Nrf2 by tert-butylhydroquinone (tBHQ). Again, Kaempferol incubation does not change the levels of NFκBp65 and phospho NFκBp65, suggesting it hampers Nrf2 signalling pathway in these cells. Nrf2 inhibition by Kaempferol induces ROS accumulation after 48 h of treatment and makes NSCLC cells sensitive to apoptosis at physiological concentration. Taken together, our study demonstrates that Kaempferol is a potent inhibitor of Nrf2 and can be used as a natural sensitizer and anti-cancer agent for lung cancer therapeutics.

Nrf2 Mediates Metabolic Reprogramming in Non-Small Cell Lung Cancer

Nuclear factor erythroid-2–related factor-2 (NFE2L2/Nrf2) is a transcription factor that regulates the expression of antioxidant genes. Both Kelch-like ECH-associated protein 1 (Keap1) mutations and Nrf2 mutations contribute to the activation of Nrf2 in non-small cell lung cancer (NSCLC). Nrf2 activity is associated with poor prognosis in NSCLC. Metabolic reprogramming represents a cancer hallmark. Increasing studies reveal that Nrf2 activation promotes metabolic reprogramming in cancer. In this review, we discuss the underlying mechanisms of Nrf2-mediated metabolic reprogramming and elucidate its role in NSCLC. Inhibition of Nrf2 can alter metabolic processes, thus suppress tumor growth, prevent metastasis, and increase sensitivity to chemotherapy in NSCLC. In conclusion, Nrf2 may serve as a therapeutic target for the treatment of NSCLC.

Evaluation of Thiol/Disulfide Homeostasis in Lung Cancer

OBJECTIVES

Lung cancer is one of the most common causes of mortality all around the world. The increased production of reactive oxygen species occurs with cell damage, and cysteine is an important factor in preventing oxidative damage by its functional thiol group. The objective of this study was to evaluate the relationship between thiol/disulfide homeostasis (TDH) and the risk factors, disease severity, and physical condition of patients with lung cancer.

MATERIALS AND METHODS

This is a prospective, controlled, nonblinded study, which included healthy volunteers and patients diagnosed with lung cancer who had not yet started any treatment.

RESULTS

There were 45 male (90%) and five female (5%) patients (mean age 64±9 years), and 41 male (82%) and nine female (18%) healthy volunteers (mean age 65±17 years) were included in this research. Overall, the thiol levels were lower in patients than the control group (p<0.001). The native thiol level means were 275±72 μmol/l in the patient group and 414±80 μmol/l in the control group, and the total thiol level means were 309±74 and 451±79 μmol/l, respectively. However, the disulfide parameter was not statistically significantly different between the two groups. There were no correlations between the tumor size and overall survival and the total thiol, native thiol, and disulfide levels.

CONCLUSION

This study showed that there is a significant relationship between lung cancer and TDH, but there were no correlations with the disease stage and the clinical performance status.

Gold nanorods functionalized by a glutathione response near-infrared fluorescent probe as a promising nanoplatform for fluorescence imaging guided precision therapy

Theranostics nanoplatforms offer opportunities for imaging-guided precision therapy and hold great potential for clinical applications. In most reported works, the imaging unit has a lack of site selectivity, and is always kept in the "on" modality regardless of whether it is in normal tissues or tumor sites, increasing the risk of unsafe treatment. Herein, we designed a near-infrared (NIR) fluorescence-guided theranostics nanoplatform by integrating the functions of tumor-response and photodynamic therapy (PDT)/photothermal therapy (PTT). A novel NIR fluorescent dye, CyPT, with excellent optical and PDT/PTT properties, was synthesized and linked onto the gold nanorods (AuNRs) to form CyPT-AuNRs nanohybrids via a sulfur-sulfur bond that can be broken by glutathione (GSH) with high selectivity and sensitivity. In normal cells where the concentration of GSH is low, the fluorescence of CyPT is quenched by the AuNRs. By contrast, the high level of GSH in tumor cells leads to the breaking of the sulfur-sulfur bond, resulting in the release of CyPT and the accomplishment of a "off-on" fluorescence response. Followed by precise NIR tumor-imaging diagnosis, the PDT and PTT treatment which rely on the released CyPT and AuNRs, respectively, can be effectively performed. The CyPT-AuNRs nanoplatform has been successfully applied to the treatment of tumor xenograft models and no distinct damage has been observed in the nearby normal tissues. This versatile nanoplatform has potential for use in targeted tumor imaging and precision therapy.

A highly GSH-sensitive SN-38 prodrug with an "OFF-to-ON" fluorescence switch as a bifunctional anticancer agent

SN-38 (7-ethyl-10-hydroxy-camptothecin) is an active metabolite of irinotecan (CPT-11) and the most potent camptothecin analogue. In this study, 2,4-dinitrobenzene sulfonyl (DNS) was covalently conjugated as a GSH-sensitive trigger to 10'-OH of SN-38 to yield a GSH-sensitive prodrug, denoted as DNS-SN38, with virtually quenched fluorescence due to donor-excited photo-induced electron transfer (d-PeT). By investigating DNS-SN38's activation properties upon fluorescence restoration and cytotoxic potency against ovarian cancer cell lines (A2780 and m-Cherry + OCSC1-F2), its potential applicability as a useful chemotherapeutic agent was demonstrated.

Redox control of cancer cell destruction

Redox regulation has been proposed to control various aspects of carcinogenesis, cancer cell growth, metabolism, migration, invasion, metastasis and cancer vascularization. As cancer has many faces, the role of redox control in different cancers and in the numerous cancer-related processes often point in different directions. In this review, we focus on the redox control mechanisms of tumor cell destruction. The review covers the tumor-intrinsic role of oxidants derived from the reduction of oxygen and nitrogen in the control of tumor cell proliferation as well as the roles of oxidants and antioxidant systems in cancer cell death caused by traditional anticancer weapons (chemotherapeutic agents, radiotherapy, photodynamic therapy). Emphasis is also put on the role of oxidants and redox status in the outcome following interactions between cancer cells, cytotoxic lymphocytes and tumor infiltrating macrophages.

Profile of epigenetic mechanisms in lung tumors of patients with underlying chronic respiratory conditions

Background

Chronic lung diseases such as chronic obstructive pulmonary disease (COPD) and epigenetic events underlie lung cancer (LC) development. The study objective was that lung tumor expression levels of specific microRNAs and their downstream biomarkers may be differentially regulated in patients with and without COPD.

Methods

In lung specimens (tumor and non-tumor), microRNAs known to be involved in lung tumorigenesis (miR-21, miR-200b, miR-126, miR-451, miR-210, miR-let7c, miR-30a-30p, miR-155 and miR-let7a, qRT-PCR), DNA methylation, and downstream biomarkers were determined (qRT-PCR and immunoblotting) in 40 patients with LC (prospective study, subdivided into LC-COPD and LC, N = 20/group).

Results

Expression of miR-21, miR-200b, miR-210, and miR-let7c and DNA methylation were greater in lung tumor specimens of LC-COPD than of LC patients. Expression of downstream markers PTEN, MARCKs, TPM-1, PDCD4, SPRY-2, ETS-1, ZEB-2, FGFRL-1, EFNA-3, and k-RAS together with P53 were selectively downregulated in tumor samples of LC-COPD patients. In these patients, tumor expression of miR-126 and miR-451 and that of the biomarkers PTEN, MARCKs, FGFRL-1, SNAIL-1, P63, and k-RAS were reduced.

Conclusions

Biomarkers of mechanisms involved in tumor growth, angiogenesis, migration, and apoptosis were differentially expressed in tumors of patients with underlying respiratory disease. These findings shed light into the underlying biology of the reported greater risk to develop LC seen in patients with chronic respiratory conditions. The presence of an underlying respiratory disease should be identified in all patients with LC as the differential biological profile may help determine tumor progression and the therapeutic response. Additionally, epigenetic events offer a niche for pharmacological therapeutic targets.

A small molecule targeting glutathione activates Nrf2 and inhibits cancer cell growth through promoting Keap-1S-glutathionylation and inducing apoptosis

The level of glutathione (GSH) is increased in many cancer cells. Consuming intracellular GSH by chemical small molecules that specifically target GSH is a new strategy to treat cancer. Recently, we synthesized and proved that a new compound 2-(7-(diethylamino)-2-oxo-2H-chromen-3-yl)cyclohexa-2,5-diene-1,4-dione (PBQC) could target to and consume intracellular GSH specifically, but, it is not clear if PBQC can affect cancer cell growth and the activity of the nuclear factor-erythroid 2-related factor 2 (Nrf2) which is a key factor involved in regulation of cancer cell growth. In this study, we addressed these questions. We found that PBQC suppressed cancer cell growth through increasing the activity of Nrf2, while it did not inhibit normal vascular endothelial cell growth. Furthermore, we demonstrated that PBQC can cause Keap-1 protein S-glutathionylation and promote Nrf2 nuclear translocation as well as the expression of pro-apoptosis genes. As a result, the cancer cells underwent apoptosis. Here, we provide a new Nrf2 activator, PBQC that can promote the expressions of pro-apoptosis genes downstream Nrf2. The data suggest that PBQC is a potential lead-compound for development of new anti-cancer drugs.

The level of glutathione (GSH) is increased in many cancer cells.

Inhibition of TrxR2 suppressed NSCLC cell proliferation, metabolism and induced cell apoptosis through decreasing antioxidant activity

AIMS

This study aims to analyze the effect of thioredoxin reductase 2 (TrxR2) on lung cancer cell proliferation, apoptosis, invasion and migration in vitro.

MAIN METHODS

Real-time PCR was used to measure the expression of TrxR2 in NSCLC tumor tissues. After pAd-TrxR2 or shRNA-TrxR2 was transfected into A549 or NCI-H1299 cells, the cell proliferation was measured by CCK-8 method; cell apoptosis was measured by flow cytometry; cell invasion and migration was measured by Transwell method. The production of ROS was measured by DCFH-DA method; the activity of SOD, CAT and GSH-Px was measured by relative ELISA kit.

KEY FINDINGS

The results showed that TrxR2 was up-regulated in NSCLC tumor tissues. Inhibition of TrxR2 suppressed NSCLC cell proliferation and induced apoptosis, and inhibited cell invasion and migration. However, overexpression of TrxR2 showed the opposite effect. Furthermore, when cells were transfected with shRNA-TrxR2, the production of ROS was significantly increased, and SOD, CAT and GSH-Px activity was decreased. Conversely, pAd-TrxR2 transfection showed the opposite effect.

SIGNIFICANCE

Taken together, our results suggest that TrxR2 acts as an oncogenic gene in the context of lung cancer progression. The inhibition of TrxR2 suppressed lung cancer cell proliferation, invasion and migration and induced cell apoptosis by inducing ROS production and decreasing antioxidant activity. TrxR2 may be a potential target for NSCLC treatment.

Antioxidant activity of ginger extract as a daily supplement in cancer patients receiving adjuvant chemotherapy: a pilot study

Purpose

The aim of this study was to examine the antioxidant activity of ginger extract oral supplement in newly diagnosed cancer patients receiving adjuvant chemotherapy compared to placebo.

Patients and methods

Newly diagnosed cancer patients receiving moderate-to-high emetogenic potential adjuvant chemotherapy were randomized to receive either a ginger extract (standardized 6-gingerol 20 mg/day) or a placebo 3 days prior to chemotherapy, which they continued daily. Oxidant/antioxidant parameters, including the activities of superoxide dismutase (SOD) and catalase (CAT) and levels of glutathione peroxidase (GPx), total glutathione (GSH/GSSG), lipid peroxidation products detected as malondialdehyde (MDA) and NO₂⁻/NO₃⁻, were measured at baseline and at days 1, 22, 43 and 64 after undergoing chemotherapy. Two-sided statistical analysis, with P < 0.05, was used to determine statistical significance.

Results

A total of 43 patients were included in the study: 19 and 24 patients were randomly assigned to the ginger group and placebo group, respectively. Antioxidant activity parameters, including SOD, CAT, GPx and GSH/GSSG, were significantly increased at day 64 in the ginger group compared to those in the placebo group, while MDA and NO₂⁻/NO₃⁻ levels were significantly decreased (P < 0.0001). When compared to the baseline, the activities of SOD and CAT and the levels of GPx and GSH/GSSG were significantly higher on day 64 (P = 0.01), while the blood levels of MDA and NO₂⁻/NO₃⁻ were significantly decreased (P < 0.01).

Conclusion

Daily supplement of ginger extract started 3 days prior to chemotherapy has been shown to significantly elevate antioxidant activity and reduce oxidative marker levels in patients who received moderate-to-high emetogenic potential chemotherapy compared to placebo.

Relationships between chronic obstructive pulmonary disease and lung cancer: biological insights

Lung cancer (LC) has become one of the leading causes of preventable death in the last few decades. Cigarette smoking (CS) stays as the main etiologic factor of LC despite that many other causes such as occupational exposures, air pollution, asbestos, or radiation have also been implicated. Patients with chronic obstructive pulmonary disease (COPD), which also represents a major cause of morbidity and mortality in developed countries, exhibit a significantly greater risk of LC. The study of the underlying biological mechanisms that may predispose patients with chronic respiratory diseases to a higher incidence of LC has also gained much attention in the last few years. The present review has been divided into three major sections in which different aspects have been addressed: (I) relevant etiologic agents of LC; (II) studies confirming the hypothesis that COPD patients are exposed to a greater risk of developing LC; and (III) evidence on the most relevant underlying biological mechanisms that support the links between COPD and LC. Several carcinogenic agents have been described in the last decades but CS remains to be the leading etiologic agent in most geographical regions in which the incidence of LC is very high. Growing evidence has put the line forward the implications of COPD and especially of emphysema in LC development. Hence, COPD represents a major risk factor of LC in patients. Different avenues of research have demonstrated the presence of relevant biological mechanisms that may predispose COPD patients to develop LC. Importantly, the so far identified biological mechanisms offer targets for the design of specific therapeutic strategies that will further the current treatment options for patients with LC. Prospective screening studies, in which patients with COPD should be followed up for several years will help identify biomarkers that may predict the risk of LC among these patients.

Elevated exhalation of hydrogen peroxide in patients with non-small cell lung cancer is not affected by chemotherapy

OBJECTIVES

Reactive oxygen species, which are implicated in the process of carcinogenesis, are also responsible for cell death during chemotherapy (CHT). Therefore, the aim of the study was to evaluate exhaled H₂O₂ levels in non-small cell lung cancer (NSCLC) patients before and after CHT.

METHODS

Thirty patients (age 61.3 ± 9.3 years) with advanced NSCLC (stage IIIB-IV) and 15 age-matched healthy cigarette smokers were enrolled into the study. Patients received four cycles of cisplatin or carboplatin with vinorelbine every three weeks. Before and after the first, second, and fourth cycle, the concentration of H₂O₂ in exhaled breath condensate was measured with respect to treatment response.

RESULTS

At the baseline, NSCLC patients exhaled 3.8 times more H₂O₂ than the control group (0.49 ± 0.14 vs. 0.13 ± 0.03 µmol/L, P < 0.05); this difference persisted throughout the study. CHT had no noticeable effect on exhaled H₂O₂ levels independent of the treatment response (partial remission vs. progressive disease). Pre- and post-CHT cycles of H₂O₂ levels generally correlated positively.

DISCUSSION

The study demonstrated the occurrence of oxidative stress in the airways of advanced NSCLC patients. Exhaled H₂O₂ level was not affected by CHT and independent of treatment results and changes in the number of circulating neutrophils.

Steamed root of Rehmannia glutinosa Libosch (Plantaginaceae) alleviates methotrexate-induced intestinal mucositis in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Intestinal mucositis induced by chemotherapy is a severe clinical problem in cancer patients that currently lack effective interventions. In traditional Chinese medicine, chemotherapeutic toxicity is diagnosed as Qi and Yin deficiency, and steamed rehmannia root (SRR) is frequently prescribed to these patients. Whether SRR can prevent the adverse effects remains to be confirmed experimentally. The present study used a rat model to investigate potential efficacy and action mechanisms of SRR in attenuating the adverse effects caused by chemotherapy.

MATERIALS AND METHODS

Intraperitoneal injection of a single dose of anti-metabolite methotrexate (MTX, 25mg/kg) was given to adult Wistar rats, which also received oral gavage of water or SRR (1.08g/kg twice daily 3 days before and 4 days after MTX treatment), or calcium folinate (CF, a clinically used MTX antidote as a comparison, at 1mg/kg twice daily 36h after MTX treatment), or SRR and CF in combination. Animals were sacrificed 4 days after MTX treatment. Complete blood cell counting was carried out. Jejunum was analyzed histologically for mucosal damage, immunohistochemically for proliferating cell nuclear antigen (PCNA), and biochemically for thiobarbituric acid reactive substances (TBARS) and reduced glutathione (GSH), as well as for tumor necrosis factor alpha (TNF-α).

RESULTS

MTX treatment led to weight loss, leucopenia, polycythemia, increase in large thrombocyte ratio, intestinal villus atrophy, crypt loss and reduction in PCNA positive crypt cells, increases in mucosal TBARS and TNF-α and decrease in GSH. All these alterations were inhibited by SRR administration except leucopenia, and the effects of CF or CF plus SRR supplementation were found to be inferior to those of SRR.

CONCLUSIONS

SRR can alleviate MTX-induced gut mucositis, which may be achieved by inhibiting MTX-induced oxidative stress and inflammatory response. These findings support the application of SRR in chemotherapy but not the combined application of SRR and CF.

Thiol/disulfide homeostasis: A prognostic biomarker for patients with advanced non-small cell lung cancer?

BACKGROUND

The aim of this study was to investigate oxidative stress and thiol/disulfide status with a novel automated homeostasis assay in advanced non-small cell lung cancer (NSCLC).

METHODS

Thirty-five patients with advanced NSCLC, who had been newly diagnosed and previously untreated, and 35 healthy subjects were chosen for the study. We measured plasma total thiol (-SH+-S-S-), native thiol (thiol) (-SH), and disulfide (-S-S-) levels in the patients with NSCLC and the healthy subjects. The thiol/disulfide (-SH/-S-S-) ratio was also calculated.

RESULTS

Statistically significant differences between the patient group and the control group were detected for the thiol/disulfide parameters. The mean native thiol, total thiol, and disulfide levels were significantly lower in the group with advanced stage NSCLC. The cut-off value was 313 and 13.8 for native thiol and disulfide, respectively. Median overall survival (OS) was significantly shorter in patients with low native thiol and disulfide levels according to the cut-off value (respectively, P = 0.001; P = 0.006). Native thiol, total thiol, and disulfide levels were correlated with Karnofsky performance status (KPS), OS, and age. Additionally, hierarchical regression analyses showed gender, KPS, lung metastases, and plasma native thiol levels were the determinants of OS in the final model.

CONCLUSION

These results suggest that in advanced stage NSCLC, the native thiol, total thiol, and disulfide levels decrease, while the native thiol/disulfide ratio does not change. Low levels of thiol/disulfide parameters are related to tumor aggressiveness and may predict a poor outcome for patients with NSCLC.

Redox Imbalance in Lung Cancer of Patients with Underlying Chronic Respiratory Conditions

Chronic respiratory diseases such as obstructive pulmonary disease (COPD) and oxidative stress may underlie lung cancer (LC). We hypothesized that the profile of oxidative and antioxidant events may differ in lung tumors and blood compartments of patients with non-small cell LC (NSCLC) with and without COPD. Redox markers (immunoblotting, ELISA, chemiluminescence, 2D electrophoresis and proteomics) were analyzed in blood samples of 17 control subjects and 80 LC patients (59 LC-COPD and 21 LC) and lung specimens (tumor and nontumor) from those undergoing thoracotomy (35 patients: 23 LC-COPD and 12 LC). As smoking history was more prevalent in LC-COPD patients, these were further analyzed post hoc as heavy and moderate smokers (cutoff, 60 pack-years). Malondialdehyde (MDA)-protein adducts and SOD1 levels were higher in tumor and nontumor samples of LC-COPD than in LC. In tumors compared with nontumors, SOD2 protein content was greater, whereas catalase levels were decreased in both LC and LC-COPD patients. Blood superoxide anion levels, protein carbonylation and nitration were greater in LC and LC-COPD patients than in the controls, and in the latter patients compared with the former. Systemic superoxide anion, protein carbonyls and nitrotyrosine above specific cutoff values best identified underlying COPD among all patients. Smoking did not influence the study results. A differential expression profile of oxidative stress markers exists in blood and, to a lesser extent, in the tumors of LC-COPD patients. These findings suggest that systemic oxidative stress and lung antioxidants (potential biomarkers) may predispose patients with chronic respiratory diseases to a higher risk for LC.

Reduced tumor burden through increased oxidative stress in lung adenocarcinoma cells of PARP-1 and PARP-2 knockout mice

Lung cancer (LC) is currently a major leading cause of cancer deaths worldwide. Poly(ADP-ribose) polymerases (PARP)-1 and -2 play important roles in DNA repair and other cell functions. Oxidative stress triggers autophagy and apoptosis. PARP inhibitors are currently used as anticancer strategies including LC. We hypothesized that inhibition of either PARP-1 or -2 expressions in the host animals influences tumor burden through several biological mechanisms, mainly redox imbalance (enhanced oxidative stress and/or decreased antioxidants, and cell regulators) in wild type (WT) lung adenocarcinoma cells. Compared to WT control tumors, in those of Parp-1(-/-) and Parp-2(-/-) mice: 1) tumor burden, as measured by weight, and cell proliferation rates were decreased, 2) oxidative stress levels were greater, whereas those of the major antioxidant enzymes were lower especially catalase, 3) tumor apoptosis and autophagy levels were significantly increased, and 4) miR-223 and nuclear factor of activated T-cells (NFAT)c-2 expression was decreased (the latter only in Parp-1(-/-) mice). Furthermore, whole body weight gain at the end of the study period also improved in Parp-1(-/-) and Parp-2(-/-) mice compared to WT animals. We conclude that PARP-1 and -2 genetic deletions in the host mice induced a significant reduction in tumor burden most likely through alterations in redox balance (downregulation of antioxidants, NFATc-2 and miR223, and increased oxidative stress), which in turn led to increased apoptosis and autophagy. Furthermore, tumor progression was also reduced probably as a result of cell cycle arrest induced by PARP-1 and -2 inhibition in the host mice. These results highlight the relevance of the host status in tumor biology, at least in this experimental model of lung adenocarcinoma in mice. Future research will shed light on the effects of selective pharmacological inhibitors of PARP-1 and PARP-1 in the host and tumor burden, which could eventually be applied in actual clinical settings.

Toxic effects of n-3 polyunsaturated fatty acids in human lung A549 cells

N-3 polyunsaturated fatty acids (PUFAs), particularly eicosapentaenoic acid (EPA, 20:5) and docosahexaenoic acid (DHA, 22:6) are crucial for the prevention of lung cancer. PUFAs may act through alteration of membrane fluidity and cell surface receptor functions; modulation of cyclooxygenase activity; and increased cellular oxidative stress, which may induce apoptosis and autophagy. Therefore the aim of the study was to investigate whether EPA and DHA (25-100 μM) are able to reduce human lung cancer cell growth through oxidative stress influence on autophagy and apoptosis. It was found that both EPA and DHA in the concentration-dependent manner suppressed the cell viability, enhanced cell death, induced activation of caspase-3/7 and potentiated intracellular oxidative DNA and protein damage. In response to PUFAs intracellular autophagic vacuolization occurred and the observed effect was reverted when the autophagy inhibitor 3-methyladenine (3-MA) was applied. The inhibition of the autophagic process enhanced the cell viability, suppressed cell death, and decreased activation of caspase-3/7 indicating that EPA and DHA-induced autophagy amplified A549 apoptotic cell death.

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.

Potential survival markers in cancer patients undergoing chemotherapy

Due to the importance of the identification of chemotherapy outcome prognostic factors, we attempted to establish the potential of oxidative stress/DNA damage parameters such as prognostic markers. The aim of the study was to determine whether platinum derivative-based chemotherapy in cancer patients (n = 66) is responsible for systemic oxidatively damaged DNA and whether damage biomarkers, such as 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dG) and the modified base 8-oxo-7,8-dihydroguanine (8-oxo-Gua), in urine and DNA may be used as a prognostic factor for the outcome of chemotherapy. All the aforementioned modifications were analyzed using techniques involving high-performance liquid chromatography/electrochemical detection (HPLC/EC) or HPLC/gas chromatography-mass spectrometry (GC-MS). Among all the analyzed parameters, the significantly decreased levels of 8-oxo-Gua in urine collected from a subgroup of patients 24 h after the first infusion of the drug, as compared with the baseline levels, correlated with a significantly longer overall survival (OS) (60 months after therapy) than in the subgroup without any decrease of this parameter after therapy (median OS = 24 months, p = 0.007). Moreover, a significantly longer OS was also observed in a group with increased urine levels of 8-oxo-dG after chemotherapy (38.6 vs. 20.5 months, p = 0.03). The results of our study suggest that patients with decreased 8-oxo-Gua levels and increased 8-oxo-dG levels in urine 24 h after the first dose should be considered as better responders to the administered chemotherapy, with a lower risk of death. The conclusion may permit the use of these parameters as markers for predicting the clinical outcome of platinum derivative-based chemotherapy.

Significance of blood serum catalase activity and malondialdehyde level for survival prognosis of ovarian cancer patients

BACKGROUND AND OBJECTIVE

Several markers were found to be potential prognostic factors in ovarian cancer. Among markers resembling systemic changes in the host's organism are markers of the oxidative stress. In this study we attempted to analyze the oxidant and antioxidant parameters of ovarian cancer patients.

MATERIALS AND METHODS

A total of 42 patients with newly diagnosed stages I-IV primary ovary cancer were examined. Level of malondialdehyde (MDA) and catalytic activity catalase (CAT) were determined spectrophotometrically.

RESULTS

Significantly lower CAT (28.2±15.5 vs. 36.1±14.6nmol/L/min, P=0.019) activity and higher MDA levels (8.7±3.0 vs. 6.7±2.7nmol/L, P=0.002) were observed in cancer patients compared with healthy volunteers. Both variables were not confirmed as prognostic factors according to Kaplan-Meier survival estimates.

CONCLUSIONS

MDA and CAT demonstrate oxidative stress in cancer patients: CAT activity was significantly lower and MDA levels higher in cancer patients compared to healthy controls. These variables were not confirmed to be prognostic factors in ovarian cancer, possibly due to small size of the study group.

Altered glutamate cysteine ligase expression and activity in renal cell carcinoma

Oxidative stress has been linked to the progression of mutations and cancer. Increased glutathione (GSH) contents have been observed in a number of different human cancer tissues. GSH is synthesized de novo in a two-step process catalyzed by glutamate cysteine ligase (GCL). The present study aimed to investigate whether GCL was associated with renal cell carcinoma (RCC). The protein expression levels of the GCL subunits (catalytic subunit, GCLc; and modulatory subunit, GCLm) and GCL activity were examined in renal cancer tissue. A total of 46 patients fulfilling the RCC criteria of the World Health Organization, revised in 2004, were enrolled. The tumor and adjacent tissues were sampled from all the subjects by surgery. The study demonstrated that GCLc and GCLm protein expression and the GCL activity were significantly increased in the tumor tissue from RCC patients. These results indicate that increased expression and enzymatic activity of GCL is closely associated with RCC and thus, this suggests an important role for GSH in the pathogenesis of RCC.

Oxidative stress enhances Axl-mediated cell migration through an Akt1/Rac1-dependent mechanism

Persistent oxidative stress is common in cancer cells because of abnormal generation of reactive oxygen species (ROS) and has been associated with malignant phenotypes, such as chemotherapy resistance and metastasis. Both overexpression of Axl and abnormal ROS elevation have been linked to cell transformation and increased cell migration. However, the relationship between Axl and ROS in malignant cell migration has not been previously evaluated. Using an in vitro human lung cancer model, we examined the redox state of lung adenocarcinoma cell lines of low metastatic (CL1-0) and high metastatic (CL1-5) potentials. Here we report that Axl activation elicits ROS accumulation through the oxidase-coupled small GTPase Rac1. We also observed that oxidative stress could activate Axl phosphorylation to synergistically enhance cell migration. Further, Axl signaling activated by H2O2 treatment results in enhancement of cell migration via a PI3K/Akt-dependent pathway. The kinase activity of Axl is required for the Axl-mediated cell migration and prolongs the half-life of phospho-Akt under oxidative stress. Finally, downregulation of Akt1, but not Akt2, by RNAi in Axl-overexpressing cells inhibits the amount of activated Rac1 and the ability to migrate induced by H2O2 treatment. Together, these results show that a novel Axl-signaling cascade induced by H2O2 treatment triggers cell migration through the PI3K/Akt1/Rac1 pathway. Elucidation of redox regulation in Axl-related malignant migration may provide new molecular insights into the mechanisms underlying tumor progression.

Oxidative stress and inflammation in the normal airways and blood of patients with lung cancer and COPD

Respiratory conditions such as chronic obstructive pulmonary disease (COPD) are associated with a greater risk for lung cancer (LC). Oxidative stress and inflammation are involved in LC pathophysiology. Studies conducted so far have focused solely on lung tumor parenchyma and not the airways. We explored levels of local and systemic oxidative stress and inflammation within normal bronchial epithelium and blood of patients with lung cancer (n=52), with and without COPD, and in control subjects (COPD and non-COPD, n=21). In normal bronchial epithelium specimens (bronchoscopy) and blood from patients with similar smoking history (LC-COPD and LC) and control subjects (both COPD and non-COPD), redox balance and inflammatory markers were measured (ELISA and immunoblotting). All subjects were clinically evaluated. Absence of malignant cells within the bronchial specimens was always pathologically confirmed. Bronchial levels of protein carbonylation, MDA-protein adducts, antioxidants, TNF-α, interferon-γ, TGF-β, and VEGF and blood levels of superoxide anion, oxidatively damaged DNA and proteins, TNF-α, interferon-γ, TGF-β, VEGF, and neutrophils were significantly greater in all LC patients compared to control subjects. Systemic levels of oxidatively damaged DNA, superoxide anion, and TNF-α and bronchial levels of TGF-β and TNF-α showed high sensitivity and specificity for LC among patients. Regardless of the presence of an underlying respiratory condition (COPD), protein oxidation, oxidatively damaged DNA, and inflammation were remarkably increased in the normal airways and blood of patients with LC. Furthermore, the potential predictive value for LC development of these molecular events warrants attention and should be explored in future larger longitudinal studies.

The activation of HMGB1 as a progression factor on inflammation response in normal human bronchial epithelial cells through RAGE/JNK/NF-κB pathway

Extracellular high-mobility group box-1 (HMGB-1) has been implicated in the inflammation response leading to the precancerous lesions of non-small cell lung cancer (NSCLC). However, the role of HMGB-1 in the inflammation response in normal human bronchial epithelial (NHBE) cells and its underlying mechanisms were still not fully understood. In this study, the inflammation response in NHBE cells was stimulated by 2.5, 5, and 10 μg/ml HMGB-1. However, the receptor for advanced glycation end products (RAGE) blocker RAGE-Ab (5 μg/ml) or 10 μM c-Jun N-terminal kinases (JNK) inhibitor SP600125 could inhibit HMGB1-induced the release of inflammation cytokines including TNF-α, IL-8, IL-10, and MCP-1 in a dose-dependent manner. Furthermore, HMGB1-induced RAGE protein expression, JNK and NF-κB activation were attenuated by the pretreatment with RAGE-Ab or JNK inhibitor SP600125 in Western blot analysis. Our data indicated that HMGB-1 induced inflammation response in NHBE cells through activating RAGE/JNK/NF-κB pathway. HMGB-1 could act as a therapeutic target for inflammation leading NHBE cells to the precancerous lesions of NSCLC.

Assessment of 8-isoprostane (8-isoPGF2α) in urine of non- small cell lung cancer (NSCLC) patients undergoing chemotherapy

8-Isoprostane (8-isoPGF2α) is a reliable marker and considered a gold standard for lipid peroxidation. There are very few reports of 8-isoprostane levels in cancer patients, and in patients undergoing chemotherapy. Oxidative stress is however expected and has been observed in patients with cancer. This study measured 8-isoprostane levels in urine by ELISA of 25 patients undergoing chemotherapy for advanced non-small cell lung cancer, at cycles 1, 2, and 3 of treatment. It considers the creatinine clearance of the patients, and correction of 8-isoprostane levels by creatinine clearance, and overnight urine volume methods. The average 8-isoprostane levels in urine increased more than 6 to 12 fold on chemotherapy treatment, from 532±587 pg/mL at cycle 1, 6181±4334 at cycle 2, and 5511±2055 at cycle 3. Similar results were obtained if 8-isoprostane levels were corrected for overnight urine volume, giving averages of 285±244 μg at cycle 1, 4122±3349 at cycle 2, and 3266±1200 at cycle 3. No significant difference was seen in average total overnight urine volume or number of urinations between chemotherapy cycles except for a large variation in urine volume between cycle 2 and 3. Creatinine levels were significantly different only between cycles 1 and 2 (p=0.016). In conclusion, cisplatin therapy has been shown to induce high levels of lipid peroxidation in lung cancer patients and can be assessed from the 8-isoprostane marker in overnight urine, with or without urine volume correction.

Ectoenzymes and cholinesterase activity and biomarkers of oxidative stress in patients with lung cancer

We aimed to examine the nucleoside triphosphate diphosphohydrolases (NTPDase) in lymphocytes; adenosine deaminase (ADA) and butyrylcholinesterase (BChE) in serum; and acetylcholinesterase (AChE), superoxide dismutase (SOD), and catalase (CAT) activity in whole blood; since these enzymes are involved in inflammation responses as well as in oxidative stress conditions. We also checked the levels of total thiols (T-SH), non-protein thiols (NPSH), and thiobarbituric acid reactive substances (TBARS) in serum of patients with lung cancer. We collected blood samples from patients (n = 31) previously treated for lung cancer with chemotherapy. Patients were classified as stage IIIb and IV according to the Union for International Cancer Control (UICC). The results showed a significant increase in the hydrolysis of ATP, ADP, and adenosine in patients when compared with the control group. The activity of AChE, SOD, and CAT as well as the T-SH and NPSH levels were higher in patients group and TBARS levels were lower in patients compared with the control group. These findings demonstrated that the enzymes activity involved in the control of inflammatory and immune processes as well as the oxidative stress parameters are altered in patients with lung cancer.

Serum superoxide dismutase, a potential predictor for radiation pneumonitis following chemoradiotherapy in non-small cell lung cancer patients

PURPOSE

To explore serum superoxide dismutase (SOD) for predicting radiation pneumonitis (RP) in non-small cell lung cancer patients following chemoradiotherapy.

METHODS

Serum levels for SOD were measured by enzyme-linked immunosorbent assays prior to radiation therapy (Pre-RT) and post 40 Gy/4 weeks during the treatment (Pos-RT).

RESULTS

SOD concentrations after delivery of 40 Gy/4 weeks was associated with the development of RP. The best predictive ability of SOD was observed for a cut-off value of 56 unit/ml, with a sensitivity of 0.80 (95% CI 0.28-0.99), and a specificity of 0.67 (95% CI 0.43-0.65) (p = 0.040).

CONCLUSION

Serum SOD may be a potential predictor for RP, which need to be further verified.

Could exhaled ferritin and SOD be used as markers for lung cancer and prognosis prediction purposes?

BACKGROUND

Today an increasing interest is being generated by the study of lung cancer markers in the exhaled breath condensate (EBC), precisely because this sample seems to lend itself to lung cancer early screening and follow-up. Indeed, ferritin and superoxide dismutase (SOD) have recently been recognized to play a role in lung cancerogenesis and patients' survival. The aim of this study was to evaluate the clinical value and the prognostic power of exhaled ferritin and exhaled SOD in patients with lung cancer.

MATERIAL AND METHODS

Forty patients with nonsmall cell lung cancer (NSCLC) and 15 controls were enrolled in the study. All subjects under study underwent EBC collection and analysis of ferritin and SOD. A total of 36 patients were either given a follow-up of at least 25.5 months or followed up until death.

RESULTS

Exhaled ferritin and SOD resulted as being higher in NSCLC than in controls and as being influenced by the stage of cancer. A pronounced survival difference was found in the presence of exhaled ferritin 300 ng/mL and exhaled SOD > 13.5 U/μL.

CONCLUSIONS

In conclusion, although the results need to be confirmed on a larger and homogeneous population, we hypothesized that the notion of using the measurement of ferritin and SOD in the EBC could, if deemed feasible, have clinical implications in the monitoring of lung cancer and as an outcome predictor.

Short-term exposure to 50 Hz ELF-EMF alters the cisplatin-induced oxidative response in AT478 murine squamous cell carcinoma cells

The aim of this study was to assess the influence of cisplatin and an extremely low frequency electromagnetic field (ELF-EMF) on antioxidant enzyme activity and the lipid peroxidation ratio, as well as the level of DNA damage and reactive oxygen species (ROS) production in AT478 carcinoma cells. Cells were cultured for 24 and 72 h in culture medium with cisplatin. Additionally, the cells were irradiated with 50 Hz/1 mT ELF-EMF for 16 min using a solenoid as a source of the ELF-EMF. The amount of ROS, superoxide dismutase (SOD) isoenzyme activity, glutathione peroxidase (GSH-Px) activity, DNA damage, and malondialdehyde (MDA) levels were assessed. Cells that were exposed to cisplatin exhibited a significant increase in ROS and antioxidant enzyme activity. The addition of ELF-EMF exposure to cisplatin treatment resulted in decreased ROS levels and antioxidant enzyme activity. A significant reduction in MDA concentrations was observed in all of the study groups, with the greatest decrease associated with treatment by both cisplatin and ELF-EMF. Cisplatin induced the most severe DNA damage; however, when cells were also irradiated with ELF-EMF, less DNA damage occurred. Exposure to ELF-EMF alone resulted in an increase in DNA damage compared to control cells. ELF-EMF lessened the effects of oxidative stress and DNA damage that were induced by cisplatin; however, ELF-EMF alone was a mild oxidative stressor and DNA damage inducer. We speculate that ELF-EMF exerts differential effects depending on the exogenous conditions. This information may be of value for appraising the pathophysiologic consequences of exposure to ELF-EMF.

Assessment of 8-oxo-7, 8-dihydro-2'-deoxyguanosine and malondialdehyde levels as oxidative stress markers and antioxidant status in non-small cell lung cancer

OBJECTIVE

The present investigation was taken up to evaluate the 8-oxo-7,8-dihydro-2'-deoxyguanosine and malondialdehyde as markers of oxidative stress, the levels of antioxidants and the correlations between these oxidative stress markers and antioxidants in lung cancer patients.

METHODS

The study included 222 patients (158 men and 64 women, age ranging from 32 to 85 years) and 207 control subjects (153 men and 54 women, aged 30-80 years) for the analysis of urinary excretion of 8-oxodG using an ELISA assay, plasma malondialdehyde using spectrophotometer and red cell Cu-Zn SOD and GPx activities by kit methods.

RESULTS

The levels of 8-oxodG and malondialdehyde were significantly higher (p < 0.001) and red cell superoxide dismutase and glutathione peroxidase activities (p < 0.001) were significantly lower in lung cancer patients than in controls. There was a significantly positive correlation between 8-oxodG and malondialdehyde (r=0.912, p < 0.001) and a negative correlation between 8-oxodG and antioxidants.

CONCLUSIONS

Our results demonstrate that an increased rate of oxidative stress might play a role in the pathogenesis of lung cancer as evidenced by a failure in the oxidant/antioxidant balance in favour of lipid peroxidation and DNA damage.

Sequence polymorphisms of the mitochondrial displacement loop and outcome of non-small cell lung cancer

Accumulation of single-nucleotide polymorphisms (SNPs) in the displacement loop (D-loop) of mitochondrial DNA (mtDNA) may be associated with disease outcome. Our team investigated the prediction power of D-loop SNPs in non-small cell lung cancer (NSCLC) outcome. In an overall multivariate analysis, allele 16390 was identified as an independent predictor for NSCLC outcome. The length of survival of patients with allele 16390A was significantly shorter than that of patients with allele 16390G (relative risk, 0.323; 95% CI, 0.109-0.951; p=0.040). The analysis of genetic polymorphisms in the mitochondrial D-loop can help identify NSCLC patient subgroups at a high risk for a poor disease outcome.

Chemotherapy-induced weakness and fatigue in skeletal muscle: the role of oxidative stress

SIGNIFICANCE

Fatigue is one of the most common symptoms of cancer and its treatment, manifested in the clinic through weakness and exercise intolerance. These side effects not only compromise patient's quality of life (QOL), but also diminish physical activity, resulting in limited treatment and increased morbidity.

RECENT ADVANCES

Oxidative stress, mediated by cancer or chemotherapeutic agents, is an underlying mechanism of the drug-induced toxicity. Nontargeted tissues, such as striated muscle, are severely affected by oxidative stress during chemotherapy, leading to toxicity and dysfunction.

CRITICAL ISSUES

These findings highlight the importance of investigating clinically applicable interventions to alleviate the debilitating side effects. This article discusses the clinically available chemotherapy drugs that cause fatigue and oxidative stress in cancer patients, with an in-depth focus on the anthracycline doxorubicin. Doxorubicin, an effective anticancer drug, is a primary example of how chemotherapeutic agents disrupt striated muscle function through oxidative stress.

FUTURE DIRECTIONS

Further research investigating antioxidants could provide relief for cancer patients from debilitating muscle weakness, leading to improved quality of life.

Antioxidant activities of total phenols of Prunella vulgaris L. in vitro and in tumor-bearing mice

Prunella vulgaris L. (PV, Labiatae) is known as a self-heal herb. The different extracts of dried spikes were studied for the best antioxidant active compounds. The 60% ethanol extract (P-60) showed strong antioxidant activity based on the results of 2,2'-azino-di(3-ethylbenzthiazoline-6-sulfonic acid (ABTS˙+), 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assay methods. High performance liquid chromatography (HPLC) and LC/MS analysis showed that the main active compounds in P-60 were phenols, such as caffeic acid, rosmarinic acid, rutin and quercetin. Total phenols were highly correlated with the antioxidant activity (R2=0.9988 in ABTS˙+; 0.6284 in DPPH and 0.9673 FRAP tests). P-60 could inhibit significantly the tumor growth in C57BL/6 mice. It can also been showed that increased superoxide dismutase (SOD) activity and decreased malondialdehyde (MDA) content in serum of tumor-bearing mice. These results suggested that P-60 extract had high antioxidant activity in vitro and in vivo and total phenols played an important role in antioxidant activity for inhibition of tumor growth.