Cigarette smoking, cyclooxygenase-2 pathway and cancer

Expression of PTGS2 along with genes regulating VEGF signalling pathway and association with high-risk factors in locally advanced oral squamous cell carcinoma

BACKGROUND

PTGS2 encodes cyclooxygenase-2 (COX-2), which catalyses the committed step in prostaglandin synthesis. Various in vivo and in vitro data suggest that COX-2 mediates the VEGF signalling pathway. In silico analysis performed in TCGA, PanCancer Atlas for head and neck cancers, demonstrated significant expression and co-expression of PTGS2 and genes that regulate VEGF signalling. This study was designed to elucidate the expression pattern of PTGS2 and genes regulating VEGF signalling in patients with locally advanced oral squamous cell carcinoma (OSCC).

METHODOLOGY

Tumour and normal tissue samples were collected from patients with locally advanced OSCC. RNA was isolated from tissue samples, followed by cDNA synthesis. The cDNA was used for gene expression analysis (RT-PCR) using target-specific primers. The results obtained were compared with the in silico gene expression of the target genes in the TCGA datasets. Co-expression analysis was performed to establish an association between PTGS2 and VEGF signalling genes.

RESULTS

Tumour and normal tissue samples were collected from 24 OSCC patients. Significant upregulation of PTGS2 expression was observed. Furthermore, VEGFA, KDR, CXCR1 and CXCR2 were significantly upregulated in tumour samples compared with paired normal samples, except for VEGFB, whose expression was not statistically significant. A similar expression pattern was observed in silico, except for CXCR2 which was highly expressed in the normal samples. Co-expression analysis showed a significant positive correlation between PTGS2 and VEGF signalling genes, except for VEGFB which showed a negative correlation.

CONCLUSION

PTGS2 and VEGF signalling genes are upregulated in OSCC, which has a profound impact on clinical outcomes.

Drug repurposing for reducing the risk of cataract extraction in patients with diabetes mellitus: integration of artificial intelligence-based drug prediction and clinical corroboration

Diabetes mellitus (DM) increases the incidence of age-related cataracts. Currently, no medication is approved or known to delay clinical cataract progression. Using a novel approach based on AI, we searched for drugs with potential cataract surgery-suppressing effects. We developed a drug discovery strategy that combines AI-based potential candidate prediction among 2650 Food and Drug Administration (FDA)-approved drugs with clinical corroboration leveraging multicenter electronic health records (EHRs) of approximately 800,000 cataract patients from the TriNetX platform. Among the top-10 AI-predicted repurposed candidate drugs, we identified three DM diagnostic ICD code groups, such as cataract patients with type 1 diabetes mellitus (T1DM), type 2 diabetes mellitus (T2DM), or hyperglycemia, and conducted retrospective cohort analyses to evaluate the efficacy of these candidate drugs in reducing the risk of cataract extraction. Aspirin, melatonin, and ibuprofen were associated with a reduced 5-, 10-, and 20-year cataract extraction risk in all types of diabetes. Acetylcysteine was associated with a reduced 5-, 10-, and 20-year cataract extraction risk in T2DM and hyperglycemia but not in T1DM patient groups. The suppressive effects of aspirin, acetylcysteine, and ibuprofen waned over time, while those of melatonin became stronger in both genders. Thus, the four repositioned drugs have the potential to delay cataract progression in both genders. All four drugs share the ability to directly or indirectly inhibit cyclooxygenase-2 (COX-2), an enzyme that is increased by multiple cataractogenic stimuli.

β-Caryophyllene Counteracts Chemoresistance Induced by Cigarette Smoke in Triple-Negative Breast Cancer MDA-MB-468 Cells

Exposure to cigarette smoke (CS) has been associated with an increased risk of fatal breast cancers and recurrence, along with chemoresistance and chemotherapy impairment. This strengthens the interest in chemopreventive agents to be exploited both in healthy and oncological subjects to prevent or repair CS damage. In the present study, we evaluated the chemopreventive properties of the natural sesquiterpene β-caryophyllene towards the damage induced by cigarette smoke condensate (CSC) in triple negative breast cancer MDA-MB-468 cells. Particularly, we assessed the ability of the sesquiterpene to interfere with the mechanisms exploited by CSC to promote cell survival and chemoresistance, including genomic instability, cell cycle progress, autophagy/apoptosis, cell migration and related pathways. β-Caryophyllene was found to be able to increase the CSC-induced death of MDA-MB-468 cells, likely triggering oxidative stress, cell cycle arrest and apoptosis; moreover, it hindered cell recovery, autophagy activation and cell migration; at last, a marked inhibition of the signal transducer and activator of transcription 3 (STAT3) activation was highlighted: this could represent a key mechanism of the chemoprevention by β-caryophyllene. Although further studies are required to confirm the in vivo efficacy of β-caryophyllene, the present results suggest a novel strategy to reduce the harmful effect of smoke in cancer patients and to improve the survival expectations in breast cancer women.

Classification models and SAR analysis on thromboxane A2 synthase inhibitors by machine learning methods

Thromboxane A2 synthase (TXS) is a promising drug target for cardiovascular diseases and cancer. In this work, we conducted a structure-activity relationship (SAR) study on 526 TXS inhibitors for bioactivity prediction. Three types of descriptors (MACCS fingerprints, ECFP4 fingerprints, and MOE descriptors) were utilized to characterize inhibitors, 24 classification models were developed by support vector machine (SVM), random forest (RF), extreme gradient boosting (XGBoost), and deep neural networks (DNN). Then we reduced the number of fingerprints according to the contribution of descriptors to the models, and constructed 16 extra models on simplified fingerprints. In general, Model_4D built by DNN algorithm and 67 bits MACCS fingerprints performs best. The prediction accuracy of the model on the test set is 0.969, and Matthews correlation coefficient (MCC) is 0.936. The distance between compound and model (dSTD-PRO) was used to characterize the application domain of the model. In the test set of Model_4D, dSTD-PRO of 91.5% compounds is lower than the corresponding training set threshold (threshold0.90 = 0.1055), and the accuracy of these compounds is 0.983. In addition, the important descriptors were summarized and further analyzed. It showed that aromatic nitrogenous heterocyclic groups were beneficial to improve the bioactivity of TXS inhibitors.

Identification of SRXN1 and KRT6A as Key Genes in Smoking-Related Non-Small-Cell Lung Cancer Through Bioinformatics and Functional Analyses

Background

Lung cancer is the leading cause of cancer-related mortality worldwide. Although cigarette smoking is an established risk factor for lung cancer, few reliable smoking-related biomarkers for non-small-cell lung cancer (NSCLC) are available. An improved understanding of these biomarkers would further the development of new biomarker-targeted therapies and lead to improvements in overall patient survival.

Methods

We performed bioinformatic analysis to screened potential target genes, then quantitative PCR, western, siRNA, CCK-8, flow cytometry, tumorigenicity assays in nude mice were performed to validated the function.

Results

In this study, we identified 83 smoking-related genes (SRGs) based on an integration analysis of two Gene Expression Omnibus (GEO) datasets, and 27 hub SRGs with potential carcinogenic effects by analyzing a dataset of smokers with NSCLC in The Cancer Genome Atlas (TCGA) database. A survival analysis revealed three genes with potential prognostic value, namely SRXN1, KRT6A and JAKMIP3. A univariate Cox analysis revealed significant associations of elevated SRXN1 and KRT6A expression with prognosis. A receiver operating characteristic (ROC) curve analysis indicated the high diagnostic value of SRXN1 and KRT6A for smoking and cancer. Quantitative PCR and western blotting validated the increased expression of SRXN1 and KRT6A mRNA and protein, respectively, in lung cancer cell lines and NSCLC tissues. In patients with NSCLC, SRXN1 and KRT6A expression was associated with the tumor–node–metastasis (TNM) stage, presence of metastasis, history of smoking and daily smoking consumption. Furthermore, inhibition of SRXN1 or KRT6A suppressed viability and enhanced apoptosis in the A549 human lung carcinoma cell line. Tumorigenicity assays in nude mice confirmed that the siRNA-mediated downregulation of SRXN1 and KRT6A expression inhibited tumor growth in vivo.

Conclusions

In summary, SRXN1 and KRT6A act as oncogenes in NSCLC and might be potential biomarkers of smoking exposure and the early diagnosis and prognosis of NSCLC in smokers, which is vital for lung cancer therapy.

Effect of Nicotine on STAT1 Pathway and Oxidative Stress in Rat Lungs

Background

Tobacco use is responsible for millions of preventable deaths due to cancer. Nicotine, an alkaloid chemical found in tobacco was proved to cause chronic inflammation and oxidative stress. The transcription factor STAT1 induces the expression of many proinflammatory genes and has been suggested to be a target for anti-inflammatory therapeutics. The following study investigated the effect of Nicotine on STAT1 pathway and oxidative stress in rat lung tissue.

Methods

Thirty rats were divided into 3 groups; group I considered as control, group II; its rats were daily injected with Nicotine at a dose of 0.4 mg/100 gm body for 8 successive weeks and group III; its rats were daily injected with Nicotine as group II, but the injection was stopped for another 4 weeks. STAT1α protein was assessed by immunohistochemistry, COX-2 and iNOS genes expression were evaluated by real time PCR and thiobarbituric acid reactive substances (TBARS) and total thiols were measured using spectrophotometric methods in the lung tissues of the rats.

Results

The results of the study revealed that group II rats had the highest expression of STAT1α protein and COX-2 and iNOS genes and oxidative stress in their lung tissues. Nicotine cessation for 4 weeks caused a marked reduction in the expression of STAT1α protein, COX-2 and iNOS genes and oxidative stress.

Conclusion

Induction of STAT1 pathway and the increase in oxidative stress may be the mechanisms through which Nicotine may induce its harmful effects.

Analysis of Sex-Specific Prostanoid Production Using a Mouse Model of Selective Cyclooxygenase-2 Inhibition

Background:

Prostanoids are a family of lipid mediators formed from arachidonic acid by cyclooxygenase enzymes and serve as biomarkers of vascular function. Prostanoid production may be different in males and females indicating that different therapeutic approaches may be required during disease.

Objectives:

We examined sex-dependent differences in COX-related metabolites in genetically modified mice that produce a cyclooxygenase-2 (COX2) enzyme containing a tyrosine 385 to phenylalanine (Y385F) mutation. This mutation renders the COX2 enzyme unable to form a key intermediate radical required for complete arachidonic acid metabolism and provides a model of selective COX2 inhibition.

Design and Methods:

Mice heterozygous for the Y385F mutation in COX2 were mated to produce cohorts of wild-type, heterozygous, and COX2 mutant mice. We investigated whether the genotype distribution followed Mendelian genetics and studied whether sex-specific differences could be found in certain prostanoid levels measured in peritoneal macrophages and in urinary samples.

Results:

The inheritance of the COX2 mutation displayed a significant deviation with respect to Mendel’s laws of genetics, with a lower-than-expected progeny of weaned COX2 mutant pups. In macrophages, prostaglandin E2 (PGE2) production following lipopolysaccharide (LPS) and interferon gamma (IFNγ) stimulation was COX2-dependent in both males and females, and data indicated that crosstalk between the nitric oxide (NO) and COX2 pathways may be sex specific. We observed significant differences in urinary PGE2 production by male and female COX2 mutant mice, with the loss of COX2 activity in male mice decreasing their ability to produce urinary PGE2. Finally, female mice across all 3 genotypes produced similar levels of urinary thromboxane (measured as 11-dehydro TxB2) at significantly higher levels than males, indicating a sex-related difference that is likely COX1-derived.

Conclusions:

Our findings clearly demonstrate that sex-related differences in COX-derived metabolites can be observed, and that other pathways (such as the NO pathway) are affected.

Do Redox Balance and Inflammatory Events Take Place in Mild Bronchiectasis? A Hint to Clinical Implications

We hypothesized that in mild bronchiectasis patients, increased systemic inflammation and redox imbalance may take place and correlate with clinical parameters. In plasma samples from patients with very mild bronchiectasis, inflammatory cells and molecules and redox balance parameters were analyzed. In the patients, lung function and exercise capacity, nutritional status, bacterial colonization, and radiological extension were assessed. Correlations between biological and clinical variables were determined. Compared to healthy controls, levels of acute phase reactants, neutrophils, IgG, IgA, myeloperoxidase, protein oxidation, and GSH increased and lung function and exercise capacity were mildly reduced. GSH levels were even greater in ex-smoker and Pseudomona-colonized patients. Furthermore, radiological extension inversely correlated with airway obstruction and, disease severity, and positively correlated with neutrophil numbers in mild bronchiectasis patients with no nutritional abnormalities. In stable patients with mild bronchiectasis, several important inflammatory and oxidative stress events take place in plasma. These findings suggest that the extension of bronchiectasis probably plays a role in the development of redox imbalance and systemic inflammation in patients with mild bronchiectasis. These results have therapeutic implications in the management of bronchiectasis patients.

Interplay between Epstein-Barr virus infection and environmental xenobiotic exposure in cancer

Epstein-Barr virus (EBV) is a herpesvirus associated with lymphoid and epithelial malignancies. Both B cells and epithelial cells are susceptible and permissive to EBV infection. However, considering that 90% of the human population is persistently EBV-infected, with a minority of them developing cancer, additional factors are necessary for tumor development. Xenobiotics such as tobacco smoke (TS) components, pollutants, pesticides, and food chemicals have been suggested as cofactors involved in EBV-associated cancers. In this review, the suggested mechanisms by which xenobiotics cooperate with EBV for carcinogenesis are discussed. Additionally, a model is proposed in which xenobiotics, which promote oxidative stress (OS) and DNA damage, regulate EBV replication, promoting either the maintenance of viral genomes or lytic activation, ultimately leading to cancer. Interactions between EBV and xenobiotics represent an opportunity to identify mechanisms by which this virus is involved in carcinogenesis and may, in turn, suggest both prevention and control strategies for EBV-associated cancers.

The head and neck cancer genome in the era of immunotherapy

The recent success of immunotherapy in head and neck squamous cell carcinoma (HNSCC) has necessitated a new perspective on the cancer genome. Here we review recent advances in the carcinogenesis and molecular genetics of HNSCC with an eye on their implications for cancer immunity. Newer sequencing technologies have recently facilitated dissection of the complex interaction between the HPV virus, tumor, host factors, and the tumor microenvironment (TME) that help shed light on how the immune system interacts with head and neck malignancies.

The effect of smoking on chronic inflammation, immune function and blood cell composition

Smoking is the number one risk factor for cancer mortality but only 15-20% of heavy smokers develop lung cancer. It would, therefore, be of great benefit to identify those at high risk early on so that preventative measures can be initiated. To investigate this, we evaluated the effects of smoking on inflammatory markers, innate and adaptive immune responses to bacterial and viral challenges and blood cell composition. We found that plasma samples from 30 heavy smokers (16 men and 14 women) had significantly higher CRP, fibrinogen, IL-6 and CEA levels than 36 non-smoking controls. Whole blood samples from smokers, incubated for 7 h at 37 °C in the absence of any exogenous stimuli, secreted significantly higher levels of IL-8 and a number of other cytokines/chemokines than non-smokers. When challenged for 7 h with E. coli, whole blood samples from smokers secreted significantly lower levels of many inflammatory cytokines/chemokines. However, when stimulated with HSV-1, significantly higher levels of both PGE₂ and many cytokines/chemokines were secreted from smokers' blood samples than from controls. In terms of blood cell composition, red blood cells, hematocrits, hemoglobin levels, MCV, MCH, MCHC, Pct and RDW levels were all elevated in smokers, in keeping with their compromised lung capacity. As well, total leukocytes were significantly higher, driven by increases in granulocytes and monocytes. In addition, smokers had lower NK cells and higher Tregs than controls, suggesting that smoking may reduce the ability to kill nascent tumor cells. Importantly, there was substantial person-to person variation amongst smokers with some showing markedly different values from controls and others showing normal levels of many parameters measured, indicating the former may be at significantly higher risk of developing lung cancer.

New insights into the functions of Cox-2 in skin and esophageal malignancies

Understanding the cellular and molecular mechanisms of tumor initiation and progression for each cancer type is central to making improvements in both prevention and therapy. Identifying the cancer cells of origin and the necessary and sufficient mechanisms of transformation and progression provide opportunities for improved specific clinical interventions. In the last few decades, advanced genetic manipulation techniques have facilitated rapid progress in defining the etiologies of cancers and their cells of origin. Recent studies driven by various groups have provided experimental evidence indicating the cellular origins for each type of skin and esophageal cancer and have identified underlying mechanisms that stem/progenitor cells use to initiate tumor development. Specifically, cyclooxygenase-2 (Cox-2) is associated with tumor initiation and progression in many cancer types. Recent studies provide data demonstrating the roles of Cox-2 in skin and esophageal malignancies, especially in squamous cell carcinomas (SCCs) occurring in both sites. Here, we review experimental evidence aiming to define the origins of skin and esophageal cancers and discuss how Cox-2 contributes to tumorigenesis and differentiation.

ADA activity is decreased in lymphocytes from patients with advanced stage of lung cancer

Cigarette smoking is directly associated with lung cancer. Non-small cell lung carcinoma (NSCLC) represents approximately 80% from all types of lung cancer. This latter is hard to diagnose and to treat due to the lack of symptoms in early stages of the disease. The aim of this study was to evaluate ADA activity and the expression of P2X7, A1, and A2A receptors and in lymphocytes. In addition, the profile of pro-inflammatory and anti-inflammatory cytokines serum levels of patients with lung cancer in advanced stage was evaluated. Patients (n = 13) previously treated for lung cancer at stage IV (UICC) with chemotherapy had their blood collected. Cancer patients showed a decrease in ADA activity and an increase in A1 receptor expression in lymphocytes when compared to the control group. Moreover, patients exhibited an increase in IL-6 and TNF-α, while IL-17 and INF-ϒ serum levels were lower in patients with lung cancer. The decreased ADA activity and the increase in A1 receptor expression may contribute to adenosine pro-tumor effects by increasing IL-6 and TNF-α and decreasing IL-17 and INF-γ serum levels. Our data show an indirect evidence that purinergic signaling may have a role in promoting a profile of cytokines levels that favors tumor progression.

Investigation of Precise Molecular Mechanistic Action of Tobacco-Associated Carcinogen `NNK´ Induced Carcinogenesis: A System Biology Approach

Cancer is the second deadliest disease listed by the WHO. One of the major causes of cancer disease is tobacco and consumption possibly due to its main component, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). A plethora of studies have been conducted in the past aiming to decipher the association of NNK with other diseases. However, it is strongly linked with cancer development. Despite these studies, a clear molecular mechanism and the impact of NNK on various system-level networks is not known. In the present study, system biology tools were employed to understand the key regulatory mechanisms and the perturbations that will happen in the cellular processes due to NNK. To investigate the system level influence of the carcinogen, NNK rewired protein–protein interaction network (PPIN) was generated from 544 reported proteins drawn out from 1317 articles retrieved from PubMed. The noise was removed from PPIN by the method of modulation. Gene ontology (GO) enrichment was performed on the seed proteins extracted from various modules to find the most affected pathways by the genes/proteins. For the modulation, Molecular COmplex DEtection (MCODE) was used to generate 19 modules containing 115 seed proteins. Further, scrutiny of the targeted biomolecules was done by the graph theory and molecular docking. GO enrichment analysis revealed that mostly cell cycle regulatory proteins were affected by NNK.

Cigarette smoke extracts and cadmium induce COX-2 expression through γ-secretase-mediated p38 MAPK activation in C6 astroglia cells

Exposure to cigarette smoke has been implicated in the progression of cerebrovascular and neurological disorders like stroke through inflammation and blood-brain barrier disruption. In this study, we investigated the signaling cascade activated by cigarette smoke extracts (CSE) and cadmium (Cd) resulting in the COX-2 induction in C6 rat astroglia cells. CSE or Cd induced Notch1 cleavage and activated p38 MAPK and CREB signaling pathways in C6 astroglia cells. Knockdown of nicastrin using siRNA or γ-secretase inhibitors, DAPT and L-685,486, reduced Notch1 cleavage and phosphorylation of p38 MAPK and CREB, while phosphorylation of ERK and JNK remained unaffected. Additionally, the blockage of γ-secretase activity did not show any effect on the phosphorylation of AKT, another upstream activator of CREB, indicating that γ-secretase-mediated CREB activation occurs via p38 MAPK. γ-secretase inhibitor also inhibited the CSE and Cd-mediated increase in the expression of COX-2. Furthermore, recombinant overexpression of Notch1 intracellular domain resulted in an increase in the expression of COX-2. Notch signaling induced by CSE and Cd induced apoptosis in C6 cells. Our results demonstrate that CSE exposure activated the p38 MAPK and CREB-mediated induction in COX-2 expression in astrocytes via γ-secretase-mediated Notch1 signaling. Our data provides novel insights into the potential mechanism of pro-inflammatory response activated by exposure to cigarette smoke.

Galgeun-tang Attenuates Cigarette Smoke and Lipopolysaccharide Induced Pulmonary Inflammation via IκBα/NF-κB Signaling

Galgeun-tang water extract (GGWE) is used to treat various diseases such as the common cold, eczema and asthma in China and Korea. In this study, we investigated the anti-inflammatory effect of GGWE using a cigarette smoke (CS)- and lipopolysaccharide (LPS)-induced induced pulmonary inflammation mouse model. The mice were exposed to CS for a total of seven days (eight cigarettes per day for 1 h) and LPS was administered intranasally to mice on day 4. GGWE was administered by oral gavage at doses of 50 mg/kg or 100 mg/kg 1 h before exposure to CS. GGWE decreased inflammatory cell counts, and expression of inflammatory cytokines such as interleukin (IL)-6 and tumor necrosis factor alpha (TNF-α) in bronchoalveolar lavage fluid (BALF) from mice exposed to CS and LPS. GGWE reduced the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), as well as the phosphorylation of inhibitor of kappa-B subunit alpha (IκBα) and nuclear factor kappa-B (NF-κB) in CS- and LPS-exposed mice. Histological examinations revealed that GGWE suppressed inflammatory cell infiltration into lung tissue compared to untreated CS- and LPS-exposed mice. In conclusion, GGWE effectively suppressed CS- and LPS-induced pulmonary inflammation. Our results indicate that GGWE may be used as a protective drug to control pulmonary inflammation diseases such as chronic obstructive pulmonary disease.

Associations between obesity, smoking and lymph node status at breast cancer diagnosis in the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial

INTRODUCTION

There is evidence suggesting that smoking and obesity prior to a breast cancer diagnosis is associated with poorer outcomes. In this study, we investigate the associations between smoking and obesity prior to a breast cancer diagnosis and the presence of lymph node metastases at diagnosis.

METHODS

Women with stage I-III breast cancer (n = 3,304) were identified from the National Cancer Institute's Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. Univariable and multivariable log-binomial models were used to estimate relative risks (RR) and 95% confidence intervals (CIs) for associations between lymph node positive breast cancer and; i) smoking, and ii) obesity prior to diagnosis.

RESULTS

Pre-diagnostic smoking/obesity was not associated with lymph node metastasis at diagnosis in multivariable analyses; (RR 0.82, 95%CI 0.61, 1.10) and (RR 0.95, 95% CI 0.81, 1.12), respectively.

CONCLUSION

Obesity and smoking information was recorded a number of years prior to breast cancer diagnosis, therefore these findings should to be replicated in a larger cohort of women, with more detailed smoking and obesity information.

Objective clinical pain analysis using serum cyclooxygenase-2 and inducible nitric oxide synthase in American patients

BACKGROUND

Pain is a multidimensional condition of multiple origins. Determining both intensity and underlying cause are critical for effective management. Utilization of painkillers does not follow any guidelines relying on biomarkers, which effectively eliminates objective treatment. The aim of this study was to evaluate the use of serum cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) as pain biomarkers. This work could significantly advance the diagnosis and treatment of pain.

METHODS

We assessed the potential utility of serum COX-2 and iNOS as objective measures of pain in a sample of American patients. Pain was scaled between level 0-5 in accordance with the level reported by the patients. Blood samples were collected from 102 patients in the emergency room. Sandwich ELISA was used to determine the COX-2 and iNOS levels in the blood serum while statistical analysis was performed using Pearson product-moment correlation coefficients, Regression and Receiver Operating Characteristics (ROC) analyses. The biomarker results were also compared with self-reports of pain by the patients using conventional pain ratings and patients were asked to report the cause of the pain. Pain levels were clustered into four groups as 0 [self-reported 0], 1 [self-reported as 1], 2 [self-reported as 2 and 3] and 3 [self-reported as 4 and 5]. Co-expression of COX-2 and iNOS could significantly alter pain development and its sensitization. Therefore, iNOS dependent COX-2 levels were employed as categorized level.

RESULTS

Self-reported pain levels did not show a correlation with the serum level of COX-2 and iNOS. The lack of correlation is attributed to multiple reasons including patients' intake of painkillers prior to participation, painkiller intake habit, chronic diseases, and subjectivity of self-reported pain. Increased serum COX-2 levels were reported in relation to the subtypes of these health issues. Further, 83% of the patients who reported pain also showed the presence of COX-2 in serum, while only 53% of the patients showed the presence of iNOS in serum. Moderate relation was found between the clustered pain level and categorized COX-2 and iNOS- levels.

CONCLUSIONS

The findings support the requirement of further studies to use COX-2 and iNOS as prognostic biomarkers for objective quantification of pain at the clinical level.

Cigarette smoke enhances oncogene addiction to c-MET and desensitizes EGFR-expressing non-small cell lung cancer to EGFR TKIs

Cigarette smoking is one of the leading risks for lung cancer and is associated with the insensitivity of non‐small cell lung cancer (NSCLC) to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs). However, it remains undetermined whether and how cigarette smoke affects the therapeutic efficacy of EGFR TKIs. In this study, our data showed that chronic exposure to cigarette smoke extract (CSE) or tobacco smoke‐derived carcinogen benzo[α]pyrene, B[α]P, but not nicotine‐derived nitrosamine ketone (NNK), reduced the sensitivity of wild‐type EGFR‐expressing NSCLC cells to EGFR TKIs. Treatment with TKIs almost abolished EGFR tyrosine kinase activity but did not show an inhibitory effect on downstream Akt and ERK pathways in B[α]P‐treated NSCLC cells. CSE and B[α]P transcriptionally upregulate c‐MET and activate its downstream Akt pathway, which is not inhibited by EGFR TKIs. Silencing of c‐MET reduces B[α]P‐induced Akt activation. The CSE‐treated NSCLC cells are sensitive to the c‐MET inhibitor crizotinib. These findings suggest that cigarette smoke augments oncogene addiction to c‐MET in NSCLC cells and that MET inhibitors may show clinical benefits for lung cancer patients with a smoking history.

Increased chemoresistance via Snail-Raf kinase inhibitor protein signaling in colorectal cancer in response to a nicotine derivative

A tobacco-specific component, 4-methylnitrosamino-1-3-pyridyl-1-butanone (NNK), is a major risk factor for many cancers. Recent reports have demonstrated that NNK exposure may be associated with tumor progression and chemoresistance in certain cancers. However, the underlying NNK-induced mechanism contributing to the aggressiveness of colorectal cancer (CRC) has not been thoroughly studied. In this study, we used HT29 cells treated with NNK to simulate the long-term exposure of cigarette smoke. A comparative analysis was performed to evaluate cell proliferation, migration, and invasion as well as epithelial-mesenchymal transition (EMT) markers and drug-resistance genes expression, cancer stem cell (CSC) properties, and anti-apoptotic activity. Signaling pathways related to chemoresistance were also investigated. As a result, NNK exposure dose-dependently stimulates cell proliferation, enhance abilities of migration and invasion, induce EMT phenomenon, and attenuate apoptosis. Furthermore, NNK exposure also promotes the capabilities of sphere formation, upregulation of Snail, and overexpression of CD133, Nanog, OCT4, and the drug-resistant genes. Knockdown of Snail results in upregulation of Raf kinase inhibitor protein (RKIP), increased apoptosis, reversal of EMT phenomenon, and reducation of expression of CSC markers, all of which contribute to a decrease of chemoresistance. Our study demonstrates a number of related mechanisms that mediate the effect of NNK exposure on increasing CRC therapeutic resistance via the Snail signaling pathway. Targeting Snail may provide a feasible strategy for the treatment of CRC.

Study on Clinical Factors Involved in Helicobacter pylori-Uninfected, Undifferentiated-Type Early Gastric Cancer

BACKGROUND

The factors associated with the pathogenesis of Helicobacter pylori-uninfected undifferentiated-type early gastric cancer (HPUGC) remain unclear. This study compared patient characteristics, including medical history and alcohol/tobacco use, of HPUGC patients with characteristics of patients with H. pylori-positive undifferentiated-type early gastric cancer (HPPGC) to clarify and gain understanding on those differences that could play a role in the pathogenesis.

METHODS

This retrospective study included 282 patients who were treated endoscopically from March 2005 to March 2014. This cohort consisted of 232 patients with HPPGC (82.3%) and 50 patients with HPUGC (17.7%). Patient characteristics were analyzed by subgroups of HPUGC vs. HPPGC, with comparisons for age, gender, cancer history, comorbidity of lifestyle diseases requiring medication (hypertension, type 2 diabetes, and dyslipidemia), cumulative amount of alcohol consumption, and smoking history (Brinkman index [BI]).

RESULTS

HPUGC patients were typically younger, had less frequent hypertension, and had higher BI values (p < 0.05 for all parameters). In a younger non-hypertensive subgroup, the OR for high BI (BI ≥340) in the HPUGC group vs. HPPGC group was 5.049 (95% CI 2.458-10.373, p < 0.0001).

CONCLUSIONS

The investigation of clinical factors identified smoking history as being possibly contributing to the pathogenesis of HPUGC. Future research is necessary at the cellular and genetic levels.

Chronic low-grade peripheral inflammation is associated with severe nicotine dependence in schizophrenia: results from the national multicentric FACE-SZ cohort

Chronic peripheral inflammation (CPI) has been associated with cognitive impairment in schizophrenia (SZ). However, its sources remain unclear, more specifically it is not known whether tobacco smoking is a source of inflammation or not in SZ subjects. Moreover, nicotine (NIC), the major psychoactive compound of tobacco, shows strong anti-inflammatory properties in vitro, as well as inducing a severe biological dependence when administered repeatedly. The objective of the present study was to determine if CPI was associated with tobacco smoking and/or NIC dependence in schizophrenia. Three hundred and forty five stabilized community-dwelling SZ subjects aged 16 years or older (mean age = 32 years, 73% male) were consecutively included in the network of the FondaMental Expert Centers for Schizophrenia and assessed with validated scales. CPI was defined by a highly sensitive C-reactive protein (hsCRP) ≥3 mg/L. Current tobacco status was self-declared. Severe NIC dependence was defined by a Fagerstrom Test for Nicotine Dependence score ≥7. Overall, 159 (46.1%) were non-smokers, 117 (33.9%) and 69 (20%) were current tobacco smokers with, respectively, low and severe nicotine dependence. In a multivariate model, CPI remained associated with severe NIC dependence (29 vs 15%, OR = 2.8, p = 0.003) and body mass index (OR = 1.1, p < 0.0001), independently of socio-demographic characteristics and antidepressant intake. No association of CPI with low to moderate tobacco smoking dependence, number of daily smoked cigarettes, cannabis use, alcohol use or illness characteristics was found (all p > 0.05). CPI was associated with severe NIC dependence but not with tobacco smoking with low to moderate NIC dependence in SZ, independently of socio-demographic variables, body mass index, alcohol consumption and antidepressant intake. This result highlights the potential CPI consequences of the high prevalence of heavy tobacco smoking in SZ, indicating the importance of new therapeutic strategies for tobacco cessation in SZ.

Can active components of licorice, glycyrrhizin and glycyrrhetinic acid, lick rheumatoid arthritis?

OBJECTIVES

This review stated the possible application of the active components of licorice, glycyrrhizin (GL) and glycyrrhetinic acid (GA), in rheumatoid arthritis (RA) treatment based on the cyclooxygenase (COX)-2/thromboxane A2 (TxA2) pathway.

METHODS

The extensive literature from inception to July 2015 was searched in PubMed central, and relevant reports were identified according to the purpose of this study.

RESULTS

The active components of licorice GL and GA exert the potential anti-inflammatory effects through, at least in part, suppressing COX-2 and its downstream product TxA2. Additionally, the COX-2/TxA2 pathway, an auto-regulatory feedback loop, has been recently found to be a crucial mechanism underlying the pathogenesis of RA. However, TxA2 is neither the pharmacological target of non-steroidal anti-inflammatory drugs (NSAIDs) nor the target of disease modifying anti-rheumatic drugs (DMARDs), and the limitations and side effects of those drugs may be, at least in part, attributable to lack of the effects on the COX-2/TxA2 pathway. Therefore, GL and GA capable of targeting this pathway hold the potential as a novel add-on therapy in therapeutic strategy, which is supported by several bench experiments.

CONCLUSIONS

The active components of licorice, GL and GA, could not only potentiate the therapeutic effects but also decrease the adverse effects of NSAIDs or DMARDs through suppressing the COX-2/TxA2 pathway during treatment course of RA.

Nicotine Inhibits Cisplatin-Induced Apoptosis via Regulating α5-nAChR/AKT Signaling in Human Gastric Cancer Cells

Gastric cancer incidence demonstrates a strong etiologic association with smoking. Nicotine, the major component in tobacco, is a survival agonist that inhibits apoptosis induced by certain chemotherapeutic agents, but the precise mechanisms involved remain largely unknown. Recently studies have indicated that α5-nicotinic acetylcholine receptor (α5-nAChR) is highly associated with lung cancer risk and nicotine dependence. Nevertheless, no information has been available about whether nicotine also affects proliferation of human gastric cancer cells through regulation of α5-nAChR. To evaluate the hypothesis that α5-nAChR may play a role in gastric cancer, we investigated its expression in gastric cancer tissues and cell lines. The expression of α5-nAChR increased in gastric cancer tissue compared with para-carcinoma tissues. In view of the results, we proceeded to investigate whether nicotine inhibits cisplatin-induced apoptosis via regulating α5-nAChR in gastric cancer cell. The results showed that nicotine significantly promoted cell proliferation in a dose and time-dependent manner through α5-nAChR activation in human gastric cells. Furthermore, nicotine inhibited apoptosis induced by cisplatin. Silence of α5-nAChR ablated the protective effects of nicotine. However, when co-administrating LY294002, an inhibitor of PI3K/AKT pathway, an increased apoptosis was observed. This effect correlated with the induction of Bcl-2, Bax, Survivin and Caspase-3 by nicotine in gastric cell lines. These results suggest that exposure to nicotine might negatively impact the apoptotic potential of chemotherapeutic drugs and that α5-nAChR/AKT signaling plays a key role in the anti-apoptotic activity of nicotine induced by cisplatin.

4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone promotes esophageal squamous cell carcinoma growth via beta-adrenoceptors in vitro and in vivo

Cigarette smoke is a risk factor for esophageal squamous cell carcinoma (ESCC). It contains several carcinogens known to initiate and promote tumorigenesis as well as metastasis. The nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is one of the strongest carcinogens in tobacco and our previous studies have shown its proliferation-promoting role in the progression of ESCC. Recently, NNK was identified as an agonist for both beta1- and beta2-adrenoceptors. Thus, we hypothesized that the cancer-promoting effect of NNK was likely mediated through beta-adrenoceptors in ESCC. Therefore, we investigated the comprehensive role of NNK in ESCC in vitro and in vivo, and found that NNK promoted many oncogenic features including ESCC cell proliferation and xenograft tumor growth as well as ESCC cell migration and invasion. Western blotting showed that NNK induced significant up-regulation of phosphorylated ERK1/2, cyclin D1, Bcl-2, and vascular endothelial growth factor as well as down-regulation of Bax. Importantly, the oncogenic effects of NNK in ESCC and the altered protein expression were reversed to some extent by down-regulation of beta1- and beta2-adrenoceptors with the beta2-adrenoceptor showing a greater rescue effect. Taken together, our in vitro and in vivo results demonstrate that NNK plays an oncogenic role in ESCC through beta-adrenoceptors. Furthermore, beta2-adrenoceptor might play a more important role in this process. Our findings might provide a chemoprevention and therapy strategy for cigarette smoke-related ESCC carcinogenesis.

Effect of a single nucleotide polymorphism in miR-146a on COX-2 protein expression and lung function in smokers with chronic obstructive pulmonary disease

OBJECTIVE

To evaluate the effect of a single nucleotide polymorphism (rs2910164) in the miR-146a precursor on the expression level of miR-146a, cyclooxygenase-2 (COX2), and production of prostaglandin E2 (PGE2) in lung tissue harvested from smokers with chronic obstructive pulmonary disease, as well as the lung function and disease stages from the same patient population.

METHODS AND RESULTS

One-hundred and sixty-eight smokers with diagnosed chronic obstructive pulmonary disease were recruited. The patients were genotyped for rs2910164 polymorphism using Sanger sequencing, and their lung function/disease stages were evaluated following Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria. Meanwhile, messenger ribonucleic acid and protein expression levels of miR-146a and COX2 as well as PGE2 production were determined in 66 lung tissue samples collected in the patients who received surgical treatment. We confirmed that COX2 is a validated target of miR-146a in human fibroblast cells, and identified the differential expression patterns of miR-146a and COX2 in each rs2910164 genotype group. We observed a significant association between rs2910164 in miR-146a and the levels of either COX2 or PGE2 using real-time polymerase chain reaction and Western blot. Consistently, we were able to demonstrate that the rs2910164 single nucleotide polymorphism has a functional effect on the baseline lung function in the study population.

CONCLUSION

In the present study, the rs2910164 CC and GC genotype was found to be associated with an improved lung function and milder disease stages, at least partially, mediated by its ability to increase in COX2 expression and PGE2 production.

Inflammation and cancer: role of annexin A1 and FPR2/ALX in proliferation and metastasis in human laryngeal squamous cell carcinoma

The anti-inflammatory protein annexin A1 (ANXA1) has been associated with cancer progression and metastasis, suggesting its role in regulating tumor cell proliferation. We investigated the mechanism of ANXA1 interaction with formylated peptide receptor 2 (FPR2/ALX) in control, peritumoral and tumor larynx tissue samples from 20 patients, to quantitate the neutrophils and mast cells, and to evaluate the protein expression and co-localization of ANXA1/FPR2 in these inflammatory cells and laryngeal squamous cells by immunocytochemistry. In addition, we performed in vitro experiments to further investigate the functional role of ANXA1/FPR2 in the proliferation and metastasis of Hep-2 cells, a cell line from larynx epidermoid carcinoma, after treatment with ANXA1_2–26 (annexin A1 N-terminal-derived peptide), Boc2 (antagonist of FPR) and/or dexamethasone. Under these treatments, the level of Hep-2 cell proliferation, pro-inflammatory cytokines, ANXA1/FPR2 co-localization, and the prostaglandin signalling were analyzed using ELISA, immunocytochemistry and real-time PCR. An influx of neutrophils and degranulated mast cells was detected in tumor samples. In these inflammatory cells of peritumoral and tumor samples, ANXA1/FPR2 expression was markedly exacerbated, however, in laryngeal carcinoma cells, this expression was down-regulated. ANXA1_2–26 treatment reduced the proliferation of the Hep-2 cells, an effect that was blocked by Boc2, and up-regulated ANXA1/FPR2 expression. ANXA1_2–26 treatment also reduced the levels of pro-inflammatory cytokines and affected the expression of metalloproteinases and EP receptors, which are involved in the prostaglandin signalling. Overall, this study identified potential roles for the molecular mechanism of the ANXA1/FPR2 interaction in laryngeal cancer, including its relationship with the prostaglandin pathway, providing promising starting points for future research. ANXA1 may contribute to the regulation of tumor growth and metastasis through paracrine mechanisms that are mediated by FPR2/ALX. These data may lead to new biological targets for therapeutic intervention in human laryngeal cancer.

Smoking-induced changes in cancer-related factors in patients with upper tract urothelial cancer

Cigarette smoking is a major risk factor for urothelial cancer (UC) development. However, the associations between smoking and changes in the pathological characteristics and molecular expression of cancer-related molecules in upper tract (UT) UC have not been fully elucidated. We investigated the associations between smoking status and cancer-related factors, including cancer cell proliferation, apoptosis, angiogenesis, lymphangiogenesis and expression of vascular endothelial growth factor-A and -C, matrix metalloproteinase (MMP)-2 and -9, cyclooxygenase (COX)-2 and urokinase-type plasminogen activator, in patients with UTUC. A total of 134 patients who underwent nephroureterectomy were retrospectively investigated. Proliferation index (PI), microvessel density and lymphatic vessel density (LVD) were measured using anti-Ki-67, anti-CD105 and anti-D2-40 antibodies in formalin-fixed specimens. The apoptotic index was evaluated using the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling method. Other cancer-related molecules were investigated by immunohistochemistry in similar specimens. The patients were divided into three groups; non-smoker (n=54, 40.3%), former smoker (n=46, 34.3%) and current smoker (n=34, 25.4%). The PI and the apoptotic index were not found to be correlated with smoking status; however, the mean/standard deviation level of LVD in current smokers (40.9/12.9) was significantly higher (P=0.034) compared to that in patients who had never smoked (34.4/10.6). In addition, smoking status was positively correlated with the presence of intratumoral lymphatic vessels (iLV) (P=0.010) and the expression of COX-2 and MMP-9 (P=0.032). The multivariate analysis demonstrated that current smoking was independently associated with all the abovementioned smoking-related factors. However, former smoking was correlated with LVD and the presence of iLV. In the survival analysis, LVD, the presence of iLV and the expression of COX-2 and MMP-9 were identified as predictive factors for metastasis following surgery. In conclusion, lymphangiogenesis and the expression levels of COX-2 and MMP-9 were found to be associated with the smoking status of UTUC patients. Our results may provide important insights into the pathological changes precipitated by smoking in these patients.

Increased level of serum prostaglandin-2 in early stage of esophageal squamous cell carcinoma

INTRODUCTION

Prostaglandin-2 (PGE-2), one of the products of cyclooxygenase-2 (COX-2) induced catalysis, may play a critical role in the carcinogenesis of esophageal squamous cell carcinoma (ESCC). We investigated the efficacy of using serum PGE-2 concentration as a biomarker for this cancer type.

MATERIAL AND METHODS

Prostaglandin-2 levels were analyzed in the serum of 65 ESCC patients and in 47 healthy individuals. The concentrations of cyclooxygenase-2 (COX-2) were measured in tumor tissues and normal tissues obtained from 31 surgically treated ESCC patients.

RESULTS

Serum PGE-2 concentration was significantly higher in ESCC patients than in control patients (p = 0.004), especially in the early stages (I + II) of cancer (p < 0.0001). We observed significant inverse relationships between serum PGE-2 levels and: tumor stage, primary tumor progression, lymph and distant metastasis. The COX-2 concentration was significantly elevated in tumors as compared to normal tissues (p = 0.008). A significant correlation between serum PGE-2 and tumor COX-2 was observed (rho = 0.46, p = 0.009). However, ROC analysis showed that serum PGE-2 may be a weak prognostic factor for ESCC.

CONCLUSIONS

Our results suggest that an elevated concentration of serum PGE-2 in the early stages of cancer may possibly be associated with tumor initiation and cancer development in ESCC. The exact role of these findings in early detection of this highly lethal cancer requires further research.

Pathogenetic mechanisms in gastric cancer

Gastric cancer (GC) is a major public health issue as the fourth most common cancer and the second leading cause of cancer-related death. Recent advances have improved our understanding of its molecular pathogenesis, as best exemplified by elucidating the fundamental role of several major signaling pathways and related molecular derangements. Central to these mechanisms are the genetic and epigenetic alterations in these signaling pathways, such as gene mutations, copy number variants, aberrant gene methylation and histone modification, nucleosome positioning, and microRNAs. Some of these genetic/epigenetic alterations represent effective diagnostic and prognostic biomarkers and therapeutic targets for GC. This information has now opened unprecedented opportunities for better understanding of the molecular mechanisms of gastric carcinogenesis and the development of novel therapeutic strategies for this cancer. The pathogenetic mechanisms of GC are the focus of this review.

18β-Glycyrrhetinic acid suppresses cell proliferation through inhibiting thromboxane synthase in non-small cell lung cancer

18β-glycyrrhetinic acid (18β-GA) is a bioactive component of licorice. The anti-cancer activity of 18β-GA has been studied in many cancer types, whereas its effects in lung cancer remain largely unknown. We first showed that 18β-GA effectively suppressed cell proliferation and inhibited expression as well as activity of thromboxane synthase (TxAS) in non-small cell lung cancer (NSCLC) cells A549 and NCI-H460. In addition, the administration of 18β-GA did not have any additional inhibitory effect on the decrease of cell proliferation induced by transfection with TxAS small interference RNA (siRNA). Moreover, 18β-GA failed to inhibit cell proliferation in the immortalized human bronchial epithelial cells 16HBE-T and another NSCLC cell line NCI-H23, both of which expressed minimal level of TxAS as compared to A549 and NCI-H460. However, 18β-GA abolished the enhancement of cell proliferation induced by transfection of NCI-H23 with pCMV6-TxAS plasmid. Further study found that the activation of both extracellular signal-regulated kinase (ERK)1/2 and cyclic adenosine monophosphate response element binding protein (CREB) induced by TxAS cDNA transfection could be totally blocked by 18β-GA. Altogether, we have delineated that, through inhibiting TxAS and its initiated ERK/CREB signaling, 18β-GA suppresses NSCLC cell proliferation. Our study has highlighted the significance of 18β-GA with respect to prevention and treatment of NSCLC.

The effect of smoking on DNA methylation of peripheral blood mononuclear cells from African American women

Background

Regular smoking is associated with a wide variety of syndromes with prominent inflammatory components such as cancer, obesity and type 2 diabetes. Heavy regular smoking is also associated with changes in the DNA methylation of peripheral mononuclear cells. However, in younger smokers, inflammatory epigenetic findings are largely absent which suggests the inflammatory response(s) to smoking may be dose dependent. To help understand whether peripheral mononuclear cells have a role in mediating these responses in older smokers with higher cumulative smoke exposure, we examined genome-wide DNA methylation in a group of well characterized adult African American subjects informative for smoking, as well as serum C-reactive protein (CRP) and interleukin-6 receptor (IL6R) levels. In addition, complementary bioinformatic analyses were conducted to delineate possible pathways affected by long-term smoking.

Results

Genome-wide DNA methylation analysis with respect to smoking status yielded 910 significant loci after Benjamini-Hochberg correction. In particular, two loci from the AHRR gene (cg05575921 and cg23576855) and one locus from the GPR15 gene (cg19859270) were identified as highly significantly differentially methylated between smokers and non-smokers. The bioinformatic analyses showed that long-term chronic smoking is associated with altered promoter DNA methylation of genes coding for proteins mapping to critical sub-networks moderating inflammation, immune function, and coagulation.

Conclusions

We conclude that chronic regular smoking is associated with changes in peripheral mononuclear cell methylation signature which perturb inflammatory and immune function pathways and may contribute to increased vulnerability for complex illnesses with inflammatory components.

An ethyl acetate fraction of Moringa oleifera Lam. Inhibits human macrophage cytokine production induced by cigarette smoke

Moringa oleifera Lam. (MO) has been reported to harbor anti-oxidation and anti-inflammatory activity and useful in the treatment of inflammatory diseases. However, despite these findings there has been little work done on the effects of MO on immune cellular function. Since macrophages, TNF and related cytokines play an important pathophysiologic role in lung damage induced by cigarette smoke, we examined the effects of MO on cigarette smoke extract (CSE)-induced cytokine production by human macrophages. An ethyl acetate fraction of MO (MOEF) was prepared from fresh leaves extract of Moringa and shown to consist of high levels of phenolic and antioxidant activities. Human monocyte derived macrophages (MDM) pre-treated with varying concentrations of MOEF showed decreased production of TNF, IL-6 and IL-8 in response to both LPS and CSE. The decrease was evident at both cytokine protein and mRNA levels. Furthermore, the extract inhibited the expression of RelA, a gene implicated in the NF-κB p65 signaling in inflammation. The findings highlight the ability of MOEF to inhibit cytokines (IL-8) which promote the infiltration of neutrophils into the lungs and others (TNF, IL-6) which mediate tissue disease and damage.

Human thromboxane A2 receptor genetic variants: in silico, in vitro and "in platelet" analysis

Thromboxane and its receptor have emerged as key players in modulating vascular thrombotic events. Thus, a dysfunctional hTP genetic variant may protect against (hypoactivity) or promote (hyperactivity) vascular events, based upon its activity on platelets. After extensive in silico analysis, six hTP-α variants were selected (C⁶⁸S, V⁸⁰E, E⁹⁴V, A¹⁶⁰T, V¹⁷⁶E, and V²¹⁷I) for detailed biochemical studies based on structural proximity to key regions involved in receptor function and in silico predictions. Variant biochemical profiles ranged from severe instability (C⁶⁸S) to normal (V²¹⁷I), with most variants demonstrating functional alteration in binding, expression or activation (V⁸⁰E, E⁹⁴V, A¹⁶⁰T, and V¹⁷⁶E). In the absence of patient platelet samples, we developed and validated a novel megakaryocyte based system to evaluate human platelet function in the presence of detected dysfunctional genetic variants. Interestingly, variant V80E exhibited reduced platelet activation whereas A160T demonstrated platelet hyperactivity. This report provides the most comprehensive in silico, in vitro and “in platelet” evaluation of hTP variants to date and highlightscurrent inherent problems in evaluating genetic variants, with possible solutions. The study additionally provides clinical relevance to characterized dysfunctional hTP variants.

Wnt5a is associated with cigarette smoke-related lung carcinogenesis via protein kinase C

Wnt5a is overexpressed during the progression of human non-small cell lung cancer. However, the roles of Wnt5a during smoking-related lung carcinogenesis have not been clearly elucidated. We investigated the associations between Wnt5a and the early development of cigarette smoke related lung cancer using human bronchial epithelial (HBE) cells (NHBE, BEAS-2B, 1799, 1198 and 1170I) at different malignant stages established by exposure to cigarette smoke condensate (CSC). Abnormal up-regulation of Wnt5a mRNA and proteins was detected in CSC-exposed transformed 1198 and tumorigenic 1170I cells as compared with other non-CSC exposed HBE cells. Tumor tissues obtained from smokers showed higher Wnt5a expressions than matched normal tissues. In non-CSC exposed 1799 cells, treatment of recombinant Wnt5a caused the activations of PKC and Akt, and the blockage of Wnt5a and PKC significantly decreased the viabilities of CSC-transformed 1198 cells expressing high levels of Wnt5a. This reduced cell survival rate was associated with increased apoptosis via the down-regulation of Bcl2 and the induction of cleaved poly ADP-ribose polymerase. Moreover, CSC-treated 1799 cells showed induction of Wnt5a expression and enhanced colony-forming capacity. The CSC-induced colony forming efficiency was suppressed by the co-incubation with a PKC inhibitor. In conclusion, these results suggest that cigarette smoke induces Wnt5a-coupled PKC activity during lung carcinogenesis, which causes Akt activity and anti-apoptosis in lung cancer. Therefore, current study provides novel clues for the crucial role of Wnt5a in the smoking-related lung carcinogenesis.

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.

Prognostic role of host cyclooxygenase and cytokine genotypes in a Caucasian cohort of patients with gastric adenocarcinoma

Background

Genetic factors influencing the prognosis of gastric adenocarcinoma (GAC) are not well known. Given the relevance of cytokines and other pro-inflammatory mediators in cancer progression and invasiveness, we aimed to assess the prognostic role of several functional cytokine and cyclooxygenase gene polymorphisms in patients with GAC.

Methodology

Genomic DNA from 380 Spanish Caucasian patients with primary GAC was genotyped for 23 polymorphisms in pro-inflammatory (IL1B, TNFA, LTA, IL6, IL12p40), anti-inflammatory (IL4, IL1RN, IL10, TGFB1) cytokine, and cyclooxygenase (PTGS1 and PTGS2) genes by PCR, RFLP and TaqMan assays. Clinical and histological information was collected prospectively. Survival curves were estimated by the Kaplan-Meier method and compared using the log rank test. Outcome was determined by analysis of Cox proportional hazards, adjusting for confounding factors.

Results

The median follow-up period and median overall survival (OS) time were 9.9 months (range 0.4–120.3) and 10.9 months (95% CI: 8.9–14.1), respectively. Multivariate analysis identified tumor stages III (HR, 3.23; 95% CI:2–5.22) and IV (HR, 5.5; 95% CI: 3.51–8.63) as independent factors associated with a significantly reduced OS, whereas surgical treatment (HR: 0.44; 95%CI: 0.3–0.6) was related to a better prognosis of the disease. Concerning genetic factors, none of the 23 polymorphisms evaluated in the current study did influence survival. Moreover, no gene-environment interactions on GAC prognosis were observed.

Conclusions

Our results show that, in our population, the panel of selected pro- and anti-inflammatory cytokine, and cyclooxygenase gene polymorphisms are not relevant in determining the prognosis of gastric adenocarcinoma.

Meta-analysis of the association of CYP1A1 polymorphisms with gastric cancer susceptibility and interaction with tobacco smoking

The association of two cytochrome P4501A1 (CYP1A1) polymorphisms, m1 (T6235C transition) and m2 (A4889G transition), with gastric cancer risk is inconclusive. We conducted a meta-analysis of all available studies to evaluate the potential role of the polymorphisms and their interactions with tobacco smoking in gastric cancer susceptibility. Published literature from PubMed was retrieved by two investigators independently. Fourteen case-control studies with 2,032 gastric cancer cases and 5,099 controls were selected. A fixed effects model or a random-effects model was used to estimate the odds ratio (OR) for the CYP1A1 polymorphisms and the occurrence of gastric cancer. Significant associations between CYP1A1 m1 and m2 polymorphisms and gastric cancer susceptibility were not observed in all genetic models in the overall analyses. Subgroup analyses by ethnicity and source of controls did not reveal significant associations with gastric cancer risk. Stratification analysis by smoking status found that carriers of the heterozygous and homozygous m1 genotypes decreased the susceptibility of gastric cancer among ever-smokers (pooled OR = 0.56, 95 % CI 0.36-0.89, fixed effects). In contrast, the m2 genotypes (G/G and A/G) did not show any relevance to gastric cancer risk among the smoking population (pooled OR = 1.30, 95 % CI 0.84-2.00, fixed effects). Overall, we found that the CYP1A1 polymorphism itself, either m1 or m2, did not represent an independent genetic risk factor influencing gastric cancer. However, subgroup analyses suggest that carriers of the heterozygous and homozygous m1 genotype who are exposed to tobacco smoke have a significantly lower risk of developing gastric cancer. To explain the observed reduction of gastric cancer risk, we proposed a novel hypothesis of "observation bias". This hypothesis is also applicable to explain the combined effects of other genetic polymorphisms and environmental factors on the risk of developing cancers, and the rationality of the hypothesis needs to be further investigated.

A simple and robust UPLC-SRM/MS method to quantify urinary eicosanoids

Eicosanoids are key mediators and regulators of inflammation and oxidative stress often used as biomarkers for diseases and pathological conditions such as cardiovascular and pulmonary diseases and cancer. Analytically, comprehensive and robust quantification of different eicosanoid species in a multi-method approach is problematic because most of these compounds are relatively unstable and may differ in their chemical properties. Here we describe a novel ultra-performance liquid chromatography-selected reaction monitoring mass spectroscopy (UPLC-SRM/MS) method for simultaneous quantification of key urinary eicosanoids, including the prostaglandins (PG) tetranor PGE-M, 8-iso-, and 2,3-dinor-8-iso-PGF(2α); the thromboxanes (TXs) 11-dehydro- and 2,3-dinor-TXB₂; leukotriene E₄; and 12-hydroxyeicosatetraenoic acid. In contrast to previous methods, which used time-consuming and complex solid phase extraction, we prepared samples with a simple liquid/liquid extraction procedure. Because collision-induced dissociation produced characteristic product ions for all analytes, no derivatization step for SRM/MS analysis was necessary. Analytes were separated with a short UPLC reversed-phase column (1.7 µm particles), allowing shorter run times than conventional HPLC columns. The method was validated and applied to human urine samples showing excellent precision, accuracy, detection limits, and robustness. In summary, the developed method allows robust and sensitive profiling of urinary eicosanoid species, making it a useful and valuable tool for biomarker profiling in clinical/toxicological studies.

Targeted chiral analysis of bioactive arachidonic Acid metabolites using liquid-chromatography-mass spectrometry

A complex structurally diverse series of eicosanoids arises from the metabolism of arachidonic acid. The metabolic profile is further complicated by the enantioselectivity of eicosanoid formation and the variety of regioisomers that arise. In order to investigate the metabolism of arachidonic acid in vitro or in vivo, targeted methods are advantageous in order to distinguish between the complex isomeric mixtures that can arise by different metabolic pathways. Over the last several years this targeted approach has become more popular, although there are still relatively few examples where chiral targeted approaches have been employed to directly analyze complex enantiomeric mixtures. To efficiently conduct targeted eicosanoid analyses, LC separations are coupled with collision induced dissociation (CID) and tandem mass spectrometry (MS/MS). Product ion profiles are often diagnostic for particular regioisomers. The highest sensitivity that can be achieved involves the use of selected reaction monitoring/mass spectrometry (SRM/MS); whereas the highest specificity is obtained with an SRM transitions between an intense parent ion, which contains the intact molecule (M) and a structurally significant product ion. This review article provides an overview of arachidonic acid metabolism and targeted chiral methods that have been utilized for the analysis of the structurally diverse eicosanoids that arise.

Cyclooxygenases and lipoxygenases in cancer

Cancer initiation and progression are multistep events that require cell proliferation, migration, extravasation to the blood or lymphatic vessels, arrest to the metastatic site, and ultimately secondary growth. Tumor cell functions at both primary or secondary sites are controlled by many different factors, including growth factors and their receptors, chemokines, nuclear receptors, cell-cell interactions, cell-matrix interactions, as well as oxygenated metabolites of arachidonic acid. The observation that cyclooxygenases and lipoxygenases and their arachidonic acid-derived eicosanoid products (prostanoids and HETEs) are expressed and produced by tumor cells, together with the finding that these enzymes can regulate cell growth, survival, migration, and invasion, has prompted investigators to analyze the roles of these enzymes in cancer progression. In this review, we focus on the contribution of cyclooxygenase- and lipoxygenase-derived eicosanoids to tumor cell function in vitro and in vivo and discuss hope and tribulations of targeting these enzymes for cancer prevention and treatment.

11-Oxoeicosatetraenoic acid is a cyclooxygenase-2/15-hydroxyprostaglandin dehydrogenase-derived antiproliferative eicosanoid

Previously, we established that 11(R)-hydroxy-5,8,12,14-(Z,Z,E,Z)-eicosatetraenoic acid (HETE) was a significant cyclooxygenase (COX)-2-derived arachidonic acid (AA) metabolite in epithelial cells. Stable isotope dilution chiral liquid chromatography (LC)-electron capture atmospheric pressure chemical ionization (ECAPCI)/mass spectrometry (MS) was used to quantify COX-2-derived eicosanoids in the human colorectal adenocarcinoma (LoVo) epithelial cell line, which expresses both COX-2 and 15-hydroxyprostaglandin dehydrogenase (15-PGDH). 11(R)-HETE secretion reached peak concentrations within minutes after AA addition before rapidly diminishing, suggesting further metabolism had occurred. Surprisingly, recombinant 15-PGDH, which is normally specific for oxidation of eicosanoid 15(S)-hydroxyl groups, was found to convert 11(R)-HETE to 11-oxo-5,8,12,14-(Z,Z,E,Z)-eicosatetraenoic acid (ETE). Furthermore, LoVo cell lysates converted 11(R)-HETE to 11-oxo-ETE and inhibition of 15-PGDH with 5-[[4-(ethoxycarbonyl)phenyl]azo]-2-hydroxy-benzeneacetic acid (CAY10397) (50 μM) significantly suppressed endogenous 11-oxo-ETE production with a corresponding increase in 11(R)-HETE. These data confirmed COX-2 and 15-PGDH as enzymes responsible for 11-oxo-ETE biosynthesis. Finally, addition of AA to the LoVo cells resulted in rapid secretion of 11-oxo-ETE into the media, reaching peak levels within 20 min of starting the incubation. This was followed by a sharp decrease in 11-oxo-ETE levels. Glutathione (GSH) S-transferase (GST) was found to metabolize 11-oxo-ETE to the 11-oxo-ETE-GSH (OEG)-adduct in LoVo cells, as confirmed by LC–MS/MS analysis. Bromodeoxyuridine (BrdU)-based cell proliferation assays in human umbilical vein endothelial cells (HUVECs) revealed that the half-maximal inhibitory concentration (IC₅₀) of 11-oxo-ETE for inhibition of HUVEC proliferation was 2.1 μM. These results show that 11-oxo-ETE is a novel COX-2/15-PGDH-derived eicosanoid, which inhibits endothelial cell proliferation with a potency that is similar to that observed for 15d-PGJ₂.

A cross-talk between NFAT and NF-κB pathways is crucial for nickel-induced COX-2 expression in Beas-2B cells

Cyclooxygenase-2 (COX-2) is a critical enzyme implicated in chronic inflammation-associated cancer development. Our studies have shown that the exposure of Beas-2B cells, a human bronchial epithelial cell line, to lung carcinogenic nickel compounds results in increased COX-2 expression. However, the signaling pathways leading to nickel-induced COX-2 expression are not well understood. In the current study, we found that the exposure of Beas-2B cells to nickel compounds resulted in the activation of both nuclear factor of activated T cell (NFAT) and nuclear factor-κB (NF-κB). The expression of COX-2 induced upon nickel exposure was inhibited by either a NFAT pharmacological inhibitor or the knockdown of NFAT3 by specific siRNA. We further found that the activation of NFAT and NF-κB was dependent on each other. Since our previous studies have shown that NF-κB activation is critical for nickel-induced COX-2 expression in Beas-2B cells exposed to nickel compounds under same experimental condition, we anticipate that there might be a cross-talk between the activation of NFAT and NF-κB for the COX-2 induction due to nickel exposure in Beas-2B cells. Furthermore, we showed that the scavenging of reactive oxygen species (ROS) by introduction of mitochondrial catalase inhibited the activation of both NFAT and NF-κB, and the induction of COX-2 due to nickel exposure. Taken together, our results defining the evidence showing a key role of the cross-talk between NFAT and NF-κB pathways in regulating nickel-induced COX-2 expression, further provide insight into the understanding of the molecular mechanisms linking nickel exposure to its lung carcinogenic effects.

Smoking and COX-2 functional polymorphisms interact to increase the risk of gastric cardia adenocarcinoma in Chinese population

BACKGROUND

Over-expression and increased activity of cyclooxygenase (COX)-2 induced by smoking has been implicated in the development of cancer. This study aimed to explore the interaction between smoking and functional polymorphisms of COX-2 in modulation of gastric cardia adenocarcinoma (GCA) risk.

METHODS AND FINDINGS

Three COX-2 polymorphisms, including -1195G>A (rs689466), -765G>C (rs20417), and 587Gly>Arg (rs3218625), were genotyped in 357 GCA patients and 985 controls. In the multivariate logistic regression analysis, we found that the -1195AA, -765GC, and 587Arg/Arg genotypes were associated with increased risk of GCA (OR = 1.50, 95% CI = 1.05-2.13; OR = 2.06, 95% CI = 1.29-3.29 and OR = 1.67, 95% CI = 1.04-2.66, respectively). Haplotype association analysis showed that compared with G(-1195)-G(-765)- G(Gly587Arg), the A(-1195)-C(-765)-A(Gly587Arg) conferred an increased risk of GCA (OR = 2.49, 95% CI = 1.54-4.01). Moreover, significant multiplicative interactions were observed between smoking and these three polymorphisms of -1195G>A, -765G>C, and 587Gly>Arg, even after correction by false discovery rate (FDR) method for multiple comparisons (FDR-P(interaction) = 0.006, 5.239×10(-4) and 0.017, respectively). Similarly, haplotypes incorporating these three polymorphisms also showed significant interaction with smoking in the development of GCA (P for multiplicative interaction = 2.65×10(-6)).

CONCLUSION

These findings indicated that the functional polymorphisms of COX-2, in interaction with smoking, may play a substantial role in the development of GCA.