Urinary lipid profile of atopic dermatitis in murine model and human patients.

Atopic dermatitis (AD) is the most common inflammatory skin disease in children. The serum level of thymus and activation-regulated chemokine (TARC) is a useful AD index to reflect disease severity; however, it requires blood collection from young children. In comparison, urine samples are easier to collect in a pediatric clinical setting. Here, we analyzed the lipids excreted in urine to identify a diagnostic biomarker for AD. We generated a murine dermatitis model by repeated topical application of 2,4-dinitrofluorobenzene (DNFB) or tape-stripping the dorsal skin. Lipid metabolites excreted in the urine were comprehensively analyzed using liquid chromatography-tandem mass spectrometry. To corroborate our findings, we also analyzed urine samples from patients with AD. DNFB application induced AD-like skin lesions, including epidermal thickening, infiltration of eosinophils and T cells, and an increase in Th2 cytokine levels. Assessment of lipids excreted in urine showed a dominance of prostaglandins (PGs), namely, a PGF2α metabolite (13,14-dihydro-15-keto-tetranor-PGF1α ), a PGE2 metabolite (13,14-dihydro-15-keto-tetranor-PGE2 ), and a PGD2 metabolite (13,14-dihydro-15-keto PGJ2 ). mRNA and protein expression of PGF2α , PGE2 , and PGD2 synthase was upregulated in DNFB-treated skin. The tape-stripping model also caused dermatitis but without Th2 inflammation; urine PGF2α and PGD2 metabolite levels remained unaffected. Finally, we confirmed that the urinary levels of the aforementioned PG metabolites, as well as PGI2 metabolite, 6,15-diketo-13,14-dihydro-PGF1α and arachidonic acid metabolite, 17-hydroxyeicosatetraenoic acid (17-HETE) increased in patients with AD. Our data highlights the unique urinary lipid profile in patients with AD, which may provide insight into novel urinary biomarkers for AD diagnosis.

Urinary Leukotriene E4 and Prostaglandin D2 Metabolites Increase in Adult and Childhood Severe Asthma Characterized by Type 2 Inflammation. A Clinical Observational Study.

Rationale: New approaches are needed to guide personalized treatment of asthma.Objectives: To test if urinary eicosanoid metabolites can direct asthma phenotyping.Methods: Urinary metabolites of prostaglandins (PGs), cysteinyl leukotrienes (CysLTs), and isoprostanes were quantified in the U-BIOPRED (Unbiased Biomarkers for the Prediction of Respiratory Diseases Outcomes) study including 86 adults with mild-to-moderate asthma (MMA), 411 with severe asthma (SA), and 100 healthy control participants. Validation was performed internally in 302 participants with SA followed up after 12-18 months and externally in 95 adolescents with asthma.Measurement and Main Results: Metabolite concentrations in healthy control participants were unrelated to age, body mass index, and sex, except for the PGE2 pathway. Eicosanoid concentrations were generally greater in participants with MMA relative to healthy control participants, with further elevations in participants with SA. However, PGE2 metabolite concentrations were either the same or lower in male nonsmokers with asthma than in healthy control participants. Metabolite concentrations were unchanged in those with asthma who adhered to oral corticosteroid treatment as documented by urinary prednisolone detection, whereas those with SA treated with omalizumab had lower concentrations of LTE4 and the PGD2 metabolite 2,3-dinor-11ß-PGF2α. High concentrations of LTE4 and PGD2 metabolites were associated with lower lung function and increased amounts of exhaled nitric oxide and eosinophil markers in blood, sputum, and urine in U-BIOPRED participants and in adolescents with asthma. These type 2 (T2) asthma associations were reproduced in the follow-up visit of the U-BIOPRED study and were found to be as sensitive to detect T2 inflammation as the established biomarkers.Conclusions: Monitoring of urinary eicosanoids can identify T2 asthma and introduces a new noninvasive approach for molecular phenotyping of adult and adolescent asthma.Clinical trial registered with www.clinicaltrials.gov (NCT01976767).

A novel mutation in the SLCO2A1 gene, encoding a prostaglandin transporter, induces chronic enteropathy.

Chronic enteropathy associated with SLCO2A1 gene (CEAS) is caused by loss-of-function mutations in SLCO2A1, which encodes a prostaglandin (PG) transporter. In this study, we report a sibling case of CEAS with a novel pathogenic variant of the SLCO2A1 gene. Compound heterozygous variants in SLCO2A1 were identified in an 8-year-old boy and 12-year-old girl, and multiple chronic nonspecific ulcers were observed in the patients using capsule endoscopy. The splice site mutation (c.940 + 1G>A) of the paternal allele was previously reported to be pathogenic, whereas the missense variant (c.1688T>C) of the maternal allele was novel and had not yet been reported. The affected residue (p.Leu563Pro) is located in the 11th transmembrane domain (helix 11) of SLCO2A1. Because SLCO2A1 mediates the uptake and clearance of PGs, the urinary PG metabolites were measured by liquid chromatography coupled to tandem mass spectrometry. The urinary tetranor-prostaglandin E metabolite levels in the patients were significantly higher than those in unaffected individuals. We established cell lines with doxycycline-inducible expression of wild type SLCO2A1 (WT-SLCO2A1) and the L563P mutant. Immunofluorescence staining showed that WT-SLCO2A1 and the L563P mutant were dominantly expressed on the plasma membranes of these cells. Cells expressing WT-SLCO2A1 exhibited time- and dose-dependent uptake of PGE2, while the mutant did not show any uptake activity. Residue L563 is very close to the putative substrate-binding site in SLCO2A1, R561 in helix 11. However, in a molecular model of SLCO2A1, the side chain of L563 projected outside of helix 11, indicating that L563 is likely not directly involved in substrate binding. Instead, the substitution of Pro may twist the helix and impair the transporter function. In summary, we identified a novel pathogenic variant of SLCO2A1 that caused loss-of-function and induced CEAS.

Simultaneous Determination of Prostaglandin and Hormones in Excreta of Trogopterus xanthipes.

The excreta of Trogopterus xanthipes (also called Wulingzhi in Chinese, WLZ) is a well-known traditional Chinese medicine used for the treatment of irregular menstruation in clinic. Few reports are available on the chemical profiling of WLZ. In this work, qualitative and quantitative analyses of endogenous prostaglandin and hormones in WLZ were performed using UHPLC-orbitrap-MSn. In total, 48 compounds were identified in urine of T. xanthipes. Furthermore, the contents of four target compounds were simultaneously quantitated in 20 batches of samples by UPLC-MS/MS. The quantitative method showed a good linear correlation (R > 0.995) in a wide range for each compound. The method had a high sensitivity with LOD (0.5-1.0 ng/mL) and LOQ (1.0-2.5 ng/mL). The intra- and inter-day precisions were < 9.17 (RSD %), and repeatability and stability were < 6.14 (RSD %). The recovery of the analytes varied between 85.8% and 97.3% at three different concentrations. The present integrated qualitative and quantitative assessment of WLZ provides an evaluation strategy to assess the constituent in traditional Chinese medicine.

Associations of urinary 8-iso-prostaglandin F2α levels with all-cause dementia, Alzheimer's disease, and vascular dementia incidence: results from a prospective cohort study.

INTRODUCTION: Prospective studies on a potential association of 8-iso-prostaglandin F2α (8-iso-PGF2α ) levels, a biomarker of lipid peroxidation, with dementia are limited. METHODS: Multivariate Cox regression models were used to assess potential associations of urinary 8-iso-PGF2α levels with all-cause, Alzheimer's disease (AD), and vascular dementia (VD) incidence in 5853 older adults from a German, population-based cohort. RESULTS: Over 14 years of follow-up, 365 all-cause dementia cases including 127 VD and 109 AD cases were diagnosed. Participants in the top compared to the bottom 8-iso-PGF2α tertile had a 45% increased risk of all-cause dementia incidence (hazard ratio [95% confidence interval]: 1.45 [1.12 to 1.88]). Interaction with the apolipoprotein E (APOE) ԑ4/ԑ4 genotype was detected (P = .02). Furthermore, continuously modeled, logarithmized 8-iso-PGF2α levels were statistically significantly associated with all-cause dementia and AD incidence. DISCUSSION: Oxidative stress may be involved in the pathogenesis of dementia. Individuals with increased 8-iso-PGF2α levels and the APOE ԑ4/ԑ4 genotype showed a considerably increased dementia risk.

Assessment of lipid peroxidation and artificial neural network models in early Alzheimer Disease diagnosis.

OBJECTIVE: Lipid peroxidation constitutes a molecular mechanism involved in early Alzheimer Disease (AD) stages, and artificial neural network (ANN) analysis is a promising non-linear regression model, characterized by its high flexibility and utility in clinical diagnosis. ANN simulates neuron learning procedures and it could provide good diagnostic performances in this complex and heterogeneous disease compared with linear regression analysis. DESIGN AND METHODS: In our study, a new set of lipid peroxidation compounds were determined in urine and plasma samples from patients diagnosed with early Alzheimer Disease (n = 70) and healthy controls (n = 26) by means of ultra-performance liquid chromatography coupled with tandem mass-spectrometry. Then, a model based on ANN was developed to classify groups of participants. RESULTS: The diagnostic performances obtained using an ANN model for each biological matrix were compared with the corresponding linear regression model based on partial least squares (PLS), and with the non-linear (radial and polynomial) support vector machine (SVM) models. Better accuracy, in terms of receiver operating characteristic-area under curve (ROC-AUC), was obtained for the ANN models (ROC-AUC 0.882 in plasma and 0.839 in urine) than for PLS and SVM models. CONCLUSION: Lipid peroxidation and ANN constitute a useful approach to establish a reliable diagnosis when the prognosis is complex, multidimensional and non-linear.

Camelina sativa Oil, Fatty Fish, and Lean Fish Do Not Markedly Affect Urinary Prostanoids in Subjects with Impaired Glucose Metabolism.

Dietary fatty acids are suggested to affect oxidative stress; however, results from interventions have been inconclusive. The aim was to examine if fatty fish, lean fish, and Camelina sativa oil (CSO) affect the urinary prostanoid levels in subjects with impaired glucose metabolism. Altogether 79 participants aged 43-72 years completed a randomized controlled study lasting 12 weeks. There were four parallel groups, fatty fish, lean fish (four fish meals/week in both), CSO providing 10 g/day alpha-linolenic acid (ALA), and control diet with limited fish and ALA containing oil consumption. Urinary prostanoids (prostaglandin F2α , 5-F2t -isoprostanes and 15-F2t -isoprostane metabolites, isofuran, 8-F3t -isoprostanes, and 4-(RS)-4-F4t -neuroprostane) of 72 participants (age: mean (±SD) 58.9 ± 6.5 years; body mass index: 29.3 ± 2.5 kg/m2 ) collected over 12-h were measured using liquid chromatography tandem-mass spectrometry. Plasma phospholipid fatty acids were determined using gas chromatography. Our study showed that the proportion of ALA in plasma phospholipids increased in the CSO group (overall difference among the groups p-value <0.001). In the fatty fish group, proportions of eicosapentaenoic and docosahexaenoic acids increased (overall p-value <0.001 for both). Prostaglandin F2α was higher in the CSO group than in the control group (p < 0.05), however, there were no other significant changes in urinary excretion of other prostanoids among the study groups. At baseline, arachidonic acid in plasma phospholipids was positively (r = 0.247, p < 0.05) and ALA negatively (r = -0.326, p < 0.05) associated with urinary total isoprostanes. In conclusion, CSO, fatty fish, and lean fish consumption do not cause major changes in oxidative stress markers in subjects with impaired glucose tolerance.

Effectiveness and Renal Functions Safety of Treatments Used for Neonates with Patent Ductus Arteriosus: A Prospective Cohort Study.

BACKGROUND Neutrophil gelatinase-associated lipocalin plays an important role in renal dysfunctions. The objective of this study was to test the hypothesis that indomethacin used in treating patent ductus arteriosus protects infants from renal dysfunction. MATERIAL AND METHODS This prospective cohort study assessed data on urine prostaglandin metabolites, urinary neutrophil gelatinase-associated lipocalin, and the renal functions of preterm infants with confirmed patent ductus arteriosus who had been injected with indomethacin (n=144, ID group) or acetaminophen (n=144, AP group). RESULTS A reduction of neutrophil gelatinase-associated lipocalin in urine samples was found in the ID group (993±48 µG/L vs. 103±5 µG/L, p<0.0001). The reduction in prostaglandin (673±32 pg/mL vs. 139±7 pg/mL, p<0.0001) and the closure of ductus (2.64±0.89 mm vs. 2.31±0.81 mm, p=0.001) were found in the ID group after the first dose of indomethacin, but the closure of ductus (2.47±0.54 mm vs. 2.32±0.55 mm, p=0.02) and prostaglandin reduction (667±31 pg/mL vs. 129±7 pg/mL, p<0.0001) were found after the second dose of acetaminophen. Indomethacin had greater effect in reducing the risk of acute kidney injury than did acetaminophen (p=0.042). CONCLUSIONS Indomethacin treatment used in treating patent ductus arteriosus protects infants from renal dysfunction.

Quantitative metabolic profiling of urinary eicosanoids for clinical phenotyping.

The eicosanoids are a family of lipid mediators of pain and inflammation involved in multiple pathologies, including asthma, hypertension, cancer, atherosclerosis, and neurodegenerative diseases. These signaling mediators act locally, but are rapidly metabolized and transported to the systemic circulation as a mixture of primary and secondary metabolites. Accordingly, urine has become a useful readily accessible biofluid for monitoring the endogenous synthesis of these molecules. Herein, we present the validation of a rapid, repeatable, and precise method for the extraction and quantification of 32 eicosanoid urinary metabolites by LC-MS/MS. For 12 out of 17 deconjugated glucuronide eicosanoids, there was no improvement in recovered signal. These metabolites cover the major synthetic pathways, including prostaglandins, leukotrienes, and isoprostanes. The method linearity was >0.99 for all metabolites analyzed, the limit of detection ranged from 0.05-5 ng/ml, and the average extraction recoveries were >90%. All analytes were stable for at least three freeze/thaw cycles. The method was formatted for large-scale analysis of clinical cohorts, and the long-term repeatability was demonstrated over 15 months of acquisition, evidencing high precision (CV <15%, except for tetranorPGEM and 2,3-dinor-11ß-PGF2α, which were <30%). The presented method is suitable for focused mechanistic studies as well as large-scale clinical and epidemiological studies that require repeatable methods capable of producing data that can be concatenated across multiple cohorts.

Simultaneous determination of androgens and prostaglandins in human urine using ultra-high-performance liquid chromatography-tandem mass spectrometry.

A simultaneous quantitative profiling method for androgens and prostaglandins using ultra-high-performance liquid chromatography-tandem mass spectrometry was developed and validated to evaluate urinary androgen and prostaglandin levels. Solid-phase extraction and liquid-liquid extraction steps were combined during the sample preparation. ß-Glucuronidase/arylsulfatase was also used in the enzyme hydrolysis step. Chemical derivatization was performed using 2-hydrazinopyridine for simultaneous determination of androgen and prostaglandin in the same ionization mode. The analytes were all separated and measured using multiple reaction monitoring in the positive ion mode within a run time of 22 min. The method was validated, achieving overall recoveries ranging from 81.0 to 102.9% with limits of quantification ranging from 0.01 to 2 ng/mL. The intra-day accuracy and precision ranged from 6.5 to 14.3% and from 77.1 to 106.8%, respectively. The inter-day accuracy and precision ranged from 8.9 to 18.2% and 89.9 to 101.4%, respectively. The linearity was expressed using the correlation coefficient, which was >0.99. The method developed herein was used to investigate the effects of a one-year finasteride treatment through differences in urinary androgen and prostaglandin levels between treated male pattern baldness patients and normal controls. The urinary androgen and prostaglandin levels were not significantly different between the two groups because of the administration of finasteride. The results confirmed that finasteride affects androgens and PGs related to hair regrowth and growth length, and a one-year finasteride treatment is effective for MPB. The mass spectrometry-based quantitative profiling method used herein for the investigation of male pattern baldness also holds great potential for the evaluation of androgens and prostaglandins associated with the metabolism of various inflammatory diseases.

Urinary prostaglandin D2 metabolite excretion during the first six months of life was significantly lower in breast-fed than formula-fed infants.

AIM: The metabolic changes that occur during the postnatal weaning period appear to be particularly important for future health, and breast milk is considered to provide the optimal source of infant nutrition. This pilot study from September 2013 to May 2015 examined the effect of breastfeeding on prostaglandin metabolism in healthy term infants. METHODS: Urine samples were collected from 19 infants at one month of age in the Juntendo University Hospital, Tokyo, Japan. The 13 infants in the breast-fed group received less than 540 mL/week of their intake from formula, and the other six were exclusively fed on formula. At six months, we sampled 14 infants: nine breast-fed and five receiving formula. The infants were from normal single pregnancies and free from perinatal complications. We analysed urinary prostaglandin metabolites-tetranor prostaglandin E2 metabolite (t-PGEM) and tetranor prostaglandin D2 metabolite (t-PGDM)-using liquid chromatography tandem-mass spectrometry. RESULTS: Urinary t-PGDM excretion at one and six months was significantly lower in breast-fed infants than formula-fed infants. However, urinary t-PGEM excretion at one and six months was not significantly different between the groups. CONCLUSION: Our study showed that the type of feeding in early infancy affected prostaglandin metabolism in healthy term infants.

Prospective study of urinary prostaglandin E2 metabolite and pancreatic cancer risk.

The cyclooxygenase 2 (COX-2) pathway is upregulated in many pancreatic cancer cells, and it is believed that carcinogenetic effects of COX-2 upregulation are largely through prostaglandin E2 (PGE2) overproduction. We tested this hypothesis by evaluating the association between urinary PGE2 metabolites (PGE-M), a biomarker of in vivo PGE2 overproduction, and pancreatic cancer risk. We conducted a case-control study with 722 subjects (239 cases and 483 controls) nested within two prospective cohort studies, the Shanghai Women's Health Study (SWHS) and Shanghai Men's Health Study (SMHS). Pre-diagnosis urine samples were measured for PGE-M using a liquid chromatography/tandem mass spectrometric method. Conditional logistic regression was used to estimate odds ratio (OR) and 95% confidence intervals (95%CI), with adjustment for potential confounders. Compared to those with the lowest urine level of PGE-M (the first quartile), individuals with higher urine levels of PGE-M had an increased risk of developing pancreatic cancer, with adjusted ORs (95%CI) of 1.63 (0.98-2.73), 1.55 (0.90-2.69) and 1.94 (1.07-3.51), for the second to the fourth quartile groups, respectively (p for trend = 0.054). This dose-response positive association was more evident among those who had BMI <25 kg/m2 than overweight individuals (p for interaction = 0.058). After excluding cases diagnosed in the first year of follow-up and their matched controls, this positive association persisted (p for trend = 0.037) and the interaction became statistically significant (p for interaction = 0.017). Our study adds additional evidence that the COX-2 pathway is involved in pancreatic carcinogenesis and suggests that urinary PGE-M may serve as a biomarker for predicting pancreatic cancer risk.

A Prospective Study of Urinary Prostaglandin E2 Metabolite, Helicobacter pylori Antibodies, and Gastric Cancer Risk.

BACKGROUND: Previous studies suggest that a stable end-product of prostaglandin E2, the urinary metabolite PGE-M, is associated with colorectal cancer, and 1 study of relatively small sample size found an association with gastric cancer among women. In the present study we further investigate the PGE-M, Helicobacter pylori, and gastric cancer association. METHODS: The present analysis included 359 prospectively ascertained gastric cancer cases and 700 individually matched controls from the Shanghai Women's and Men's Health Studies. Urinary PGE-M was measured by a liquid chromatography/tandem mass spectrometric method. Seropositivity to 15 H. pylori recombinantly expressed fusion proteins was detected by H. pylori multiplex serology. RESULTS: Adjusting for H. pylori, increasing PGE-M was associated with higher risk of gastric cancer (quartile 4 vs 1: odds ratio [OR], 1.76 [95% confidence interval {CI}, 1.17-2.66], Ptrend = .004). This association remained after excluding those diagnosed within 2 years from sample collection (OR, 1.73 [95% CI, 1.12-2.65], Ptrend = .007). However it was no longer present among individuals with 10 or more years of follow-up (2-4.9 years: OR, 3.15 [95% CI, 1.11-8.91]; 5-9.9 years: OR, 2.23 [95% CI, 1.22-4.06]; ≥10 years: OR, 0.73 [95% CI, .31-1.70]). Compared to H. pylori-negative individuals with below-median PGE-M levels, H. pylori-positive individuals with above-median PGE-M levels had a 5-fold increase in the odds of gastric cancer (OR, 5.08 [95% CI, 2.47-10.43]). CONCLUSIONS: In China, higher PGE-M levels may indicate an increased risk of gastric cancer independent of the risk conferred by H. pylori infection status, particularly for cancers diagnosed within 10 years of sample collection.

ASPirin Intervention for the REDuction of colorectal cancer risk (ASPIRED): a study protocol for a randomized controlled trial.

BACKGROUND: Although aspirin is recommended for the prevention of colorectal cancer, the specific individuals for whom the benefits outweigh the risks are not clearly defined. Moreover, the precise mechanisms by which aspirin reduces the risk of cancer are unclear. We recently launched the ASPirin Intervention for the REDuction of colorectal cancer risk (ASPIRED) trial to address these uncertainties. METHODS/DESIGN: ASPIRED is a prospective, double-blind, multidose, placebo-controlled, biomarker clinical trial of aspirin use in individuals previously diagnosed with colorectal adenoma. Individuals (n = 180) will be randomized in a 1:1:1 ratio to low-dose (81 mg/day) or standard-dose (325 mg/day) aspirin or placebo. At two study visits, participants will provide lifestyle, dietary and biometric data in addition to urine, saliva and blood specimens. Stool, grossly normal colorectal mucosal biopsies and cytology brushings will be collected during a flexible sigmoidoscopy without bowel preparation. The study will examine the effect of aspirin on urinary prostaglandin metabolites (PGE-M; primary endpoint), plasma inflammatory markers (macrophage inhibitory cytokine-1 (MIC-1)), colonic expression of transcription factor binding (transcription factor 7-like 2 (TCF7L2)), colonocyte gene expression, including hydroxyprostaglandin dehydrogenase 15-(NAD) (HPGD) and those that encode Wnt signaling proteins, colonic cellular nanocytology and oral and gut microbial composition and function. DISCUSSION: Aspirin may prevent colorectal cancer through multiple, interrelated mechanisms. The ASPIRED trial will scrutinize these pathways and investigate putative mechanistically based risk-stratification biomarkers. TRIAL REGISTRATION: This protocol is registered with the U.S. National Institutes of Health trial registry, ClinicalTrials.gov, under the identifier NCT02394769 . Registered on 16 March 2015.

Elevated prostaglandin E metabolites and abnormal plasma fatty acids at baseline in pediatric cystic fibrosis patients: a pilot study.

BACKGROUND: Airway inflammation is a significant contributor to the morbidity of cystic fibrosis (CF) disease. One feature of this inflammation is the production of oxygenated metabolites, such as prostaglandins. Individuals with CF are known to have abnormal metabolism of fatty acids, typically resulting in reduced levels of linoleic acid (LA) and docosahexaenoic acid (DHA). METHODS: This is a randomized, double-blind, cross-over clinical trial of DHA supplementation with endpoints of plasma fatty acid levels and prostaglandin E metabolite (PGE-M) levels. Patients with CF age 6-18 years with pancreatic insufficiency were recruited. Each participant completed 3 four-week study periods: DHA at two different doses (high dose and low dose) and placebo with a minimum 4 week wash-out between each period. Blood, urine, and exhaled breath condensate (EBC) were collected at baseline and after each study period for measurement of plasma fatty acids as well as prostaglandin E metabolites. RESULTS: Seventeen participants were enrolled, and 12 participants completed all 3 study periods. Overall, DHA supplementation was well tolerated without significant adverse events. There was a significant increase in plasma DHA levels with supplementation, but no significant change in arachidonic acid (AA) or LA levels. However, at baseline, AA levels were lower and LA levels were higher than previously reported for individuals with CF. Urine PGE-M levels were elevated in the majority of participants at baseline, and while levels decreased with DHA supplementation, they also decreased with placebo. CONCLUSIONS: Urine PGE-M levels are elevated at baseline in this cohort of pediatric CF patients, but there was no significant change in these levels with DHA supplementation compared to placebo. In addition, baseline plasma fatty acid levels for this cohort showed some difference to prior reports, including higher levels of LA and lower levels of AA, which may reflect changes in clinical care, and consequently warrants further investigation.

Elevated Levels of Urinary PGE-M Are Found in Tobacco Users and Indicate a Poor Prognosis for Oral Squamous Cell Carcinoma Patients.

Cyclooxygenase-2 (COX-2)-derived prostaglandin E2 (PGE2) plays a role in the development and progression of epithelial malignancies. Measurements of urinary PGE-M, a stable metabolite of PGE2, reflect systemic PGE2 levels. Here, we investigated whether urinary PGE-M levels were elevated in healthy tobacco users and in patients with oral squamous cell carcinoma (OSCC). Median urinary PGE-M levels were increased in healthy tobacco quid chewers [21.3 ng/mg creatinine (Cr); n = 33; P = 0.03] and smokers (32.1 ng/mg Cr; n = 31; P < 0.001) compared with never tobacco quid chewers-never smokers (18.8 ng/mg Cr; n = 30). Urinary PGE-M levels were also compared in OSCC patients versus healthy tobacco users. An approximately 1-fold increase in median urinary PGE-M level was found in OSCC patients (48.7 ng/mg Cr, n = 78) versus healthy controls (24.5 ng/mg Cr, n = 64; P < 0.001). We further determined whether baseline urinary PGE-M levels were prognostic in OSCC patients who underwent treatment with curative intent. A nearly 1-fold increase in baseline urinary PGE-M levels (64.7 vs. 33.8 ng/mg Cr, P < 0.001) was found in the group of OSCC patients who progressed (n = 37) compared with the group that remained progression free (n = 41). Patients with high baseline levels of urinary PGE-M had both worse disease-specific survival [HR, 1.01 per unit increase; 95% confidence interval (CI), 1.01-1.02; P < 0.001] and overall survival (HR, 1.01 per unit increase; 95% CI, 1.00-1.02; P = 0.03). Taken together, our findings raise the possibility that NSAIDs, prototypic inhibitors of PGE2 synthesis, may be beneficial for reducing the risk of tobacco-related aerodigestive malignancies or treating OSCC patients with high urinary PGE-M levels. Cancer Prev Res; 9(6); 428-36. ©2016 AACR.

Urinary metabolites of prostanoids and risk of recurrent colorectal adenomas in the Aspirin/Folate Polyp Prevention Study (AFPPS).

Aspirin has been shown to protect against colorectal neoplasms; however, the optimal chemopreventive dose and underlying mechanisms are unclear. We aimed to study the relationship between prostanoid metabolites and aspirin's effect on adenoma occurrence. We used data from the Aspirin/Folate Polyp Prevention Study, in which 1,121 participants with a recent adenoma were randomized to placebo or two doses of aspirin (81 or 325 mg/d) to be taken until the next surveillance colonoscopy, anticipated about 3 years later. Urinary metabolites of prostanoids (PGE-M, PGI-M, and dTxB2) were measured using liquid chromatography/mass spectrometry or GC/NICI-MS in 876 participants near the end of treatment follow-up. Poisson regression with a robust error variance was used to calculate relative risks and 95% confidence intervals. PGE-M, PGI-M, and dTxB2 levels were 28%, 37%, and 60% proportionately lower, respectively, in individuals who took 325 mg of aspirin compared with individuals who took placebo (all P < 0.001). Similarly, among individuals who took 81 mg of aspirin, PGE-M, PGI-M, and dTxB2 were, respectively, 18%, 30%, and 57% proportionally lower compared with placebo (all P < 0.005). None of the metabolites or their ratios were statistically significantly associated with the risk of adenoma occurrence. The effect of aspirin in reducing adenoma risk was independent of prostanoid levels. Aspirin use is associated with lower levels of urinary prostanoid metabolites. However, our findings do not support the hypothesis that these metabolites are associated with adenoma occurrence, suggesting that COX-dependent mechanisms may not completely explain the chemopreventive effect of aspirin on colorectal neoplasms.