PGE-M Levels Research Articles

Elevated Prostaglandin E2 Synthesis Is Associated with Clinical and Radiological Disease Severity in Cystic Fibrosis.

Background: Previous studies found high but very variable levels of tetranor-PGEM and PGDM (urine metabolites of prostaglandin (PG) E2 and PGD2, respectively) in persons with cystic fibrosis (pwCF). This study aims to assess the role of cyclooxygenase COX-1 and COX-2 genetic polymorphisms in PG production and of PG metabolites as potential markers of symptoms' severity and imaging findings. Methods: A total of 30 healthy subjects and 103 pwCF were included in this study. Clinical and radiological CF severity was evaluated using clinical scoring methods and chest computed tomography (CT), respectively. Urine metabolites were measured using liquid chromatography/tandem mass spectrometry. Variants in the COX-1 gene (PTGS1 639 C>A, PTGS1 762+14delA and COX-2 gene: PTGS2-899G>C (-765G>C) and PTGS2 (8473T>C) were also analyzed. Results: PGE-M and PGD-M urine concentrations were significantly higher in pwCF than in controls. There were also statistically significant differences between clinically mild and moderate disease and severe disease. Patients with bronchiectasis and/or air trapping had higher PGE-M levels than patients without these complications. The four polymorphisms did not associate with clinical severity, air trapping, bronchiectasis, or urinary PG levels. Conclusions: These results suggest that urinary PG level testing can be used as a biomarker of CF severity. COX genetic polymorphisms are not involved in the variability of PG production.

Correlation between Metabolite of Prostaglandin E2 and the incidence of colorectal adenomas.

Colorectal cancer is a common malignancy, and the incidence and mortality rates continue to rise. An important factor in the emergence of inflammation-induced colorectal carcinogenesis is elevated cyclooxygenase-2. Prostaglandin E2 (PGE2) over-production is frequently equated with cyclooxygenase-2 gene over-expression. PGE2 can be assessed by measuring the level of prostaglandin's main metabolite, PGE-M, in urine. Colorectal adenoma is a precancerous lesion that can lead to colorectal cancer. We conducted research to evaluate the association between urinary levels of the PGE-M and the risk of colorectal adenomas. In a western Chinese population, we identified 152 cases of adenoma and 152 controls patients without polyps. Adenoma cases were categorized into control, low-risk and high-risk groups. There was no significant change in PGE-M levels, between the control group and the low-risk adenoma group. In the high-risk group, the PGE-M levels were 23% higher than the control group. When compared to people with the lowest urine PGE-M levels (first quartile), people with greater urinary PGE-M levels had a higher chance of developing high-risk colorectal adenomas, with an adjusted odds ratio (95% CI) of 1.65 (0.76-3.57) in the fourth quartile group, (p= 0.013). We conclude urinary PGE-M is associated with the risk of developing high-risk adenomas. Urinary PGE-M level may be used as a non-invasive indicator for estimating cancer risk.

Association of urinary prostaglandin E2 metabolite and mortality among adults

Prostaglandins play a critical role in inflammatory response. To investigate the association of urinary PGE-M, a stable end-product of prostaglandin E2 (PGE2) with overall and cause-specific mortality and examine potential effect modifiers, we obtained urinary PGE-M levels of 2927 non-cancerous adults from our previous case-control studies nested in the Shanghai Women’s Health Study and Shanghai Men’s Health Study, two cohort studies conducted in Shanghai, China. Mortality data and modifiable factors associated with urinary PGE-M were obtained from the parent cohort studies. Using linear regression models, we found that high urinary PGE-M levels were significantly associated with low education, heaving smoking, old age at urine collection, and abdominal obesity. Using Cox proportional hazards models, we found that increase (per standard deviation) of urinary PGE-M levels were significantly associated with overall mortality (adjusted hazard ratio = 1.19, 95% confidence interval: 1.07, 1.33) and particularly deaths from cardiometabolic diseases (adjusted hazard ratio = 1.27, 95% confidence interval: 1.11, 1.44). The increased death risks persisted across different time intervals during the follow-up and were stronger among participants who were younger than 60 (P = 0.0014 for all- cause mortality and P = 0.007 for deaths from cardiometabolic diseases) at urine collection or perhaps among those who had higher education.

Abstract PO-168: Association of urinary PGE-M with all-cause mortality in men with prostate cancer is influenced by aspirin use

Abstract Background: Chronic inflammation has been implicated in prostate cancer etiology and progression. The pro-inflammatory cyclooxygenase (COX) pathway, where arachidonic acid is converted to bioactive prostaglandins and eicosanoids via the COX1 and COX2 enzymes, has been linked to elevated systemic inflammation. Urinary PGE-M is a stable and measurable metabolite of prostaglandin E2 (PGE2). PGE2 is a product of the inflammatory COX signaling pathway and elevated levels have been associated with risk of cancer in many sites including colorectal and gastric cancers. PGE2 synthesis can be inhibited by aspirin. We investigated the association of PGE-M with lethal prostate cancer in a case-control study of African American and European American men. Identifying PGE-M as a novel marker of aggressive disease would have importance for high risk groups like men of African descent who experience a disproportionately high burden of prostate cancer lethality. Methods: We measured urinary PGE-M using mass-spectrometry. Samples were obtained from 977 cases and 1022 controls at time of recruitment. For analysis, we assessed PGE-M as either a continuous measure or assigned PGE-M values to quartiles and median with cutoff points determined using the distribution of PGE-M values among all controls. We applied multivariable logistic and Cox regression modeling to examine associations of PGE-M with prostate cancer and participant survival. Median survival follow-up was 8.4 years with 246 deaths among cases. Self-reported aspirin use over the past five years was assessed with a questionnaire. Race/ethnicity was self-reported. Results: Urinary PGE-M levels did not differ between men with prostate cancer and population-based controls. We report a lack of robust PGE-M inhibition in both cases and controls who reported aspirin use in our study. We observed no association between PGE-M and aggressive disease as defined by the National Comprehensive Cancer Network risk score. We also observed no association between PGE-M and prostate cancer-specific survival. However, we observed a statistically significant association between higher (> median) PGE-M and all-cause mortality in African American cases who did not regularly use aspirin (HR = 2.04, 95% CI 1.23-3.37). Among cases, who reported using aspirin, there was no association. Conclusions: Our study does not support a meaningful association between urinary PGE-M and prostate cancer. Moreover, PGE-M levels were not associated with aggressive prostate cancer. However, the observed association between elevated PGE-M and all-cause mortality in AA non-aspirin users reinforces the potential benefit of aspirin to reduce mortality among African American men with prostate cancer. Citation Format: Maeve Kiely, Ginger L. Milne, Tsion Z. Minas, Tiffany H. Dorsey, Wei Tang, Cheryl J. Smith, Francine Baker, Christopher A. Loffredo, Clayton Yates, Michael B. Cook, Stefan Ambs. Association of urinary PGE-M with all-cause mortality in men with prostate cancer is influenced by aspirin use [abstract]. In: Proceedings of the AACR Virtual Conference: 14th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2021 Oct 6-8. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr PO-168.

Urinary PGE-M Levels and Risk of Ovarian Cancer.

Regular aspirin use may lower ovarian cancer risk by blocking the cyclooxygenase enzymes, resulting in lower expression of prostaglandins, including prostaglandin E2 (PGE2). We evaluated whether higher prediagnosis PGE-M (a urinary biomarker of PGE2) was associated with increased ovarian cancer risk in three prospective cohorts. We conducted a case-control study nested in the Nurses' Health Study (NHS), NHSII, and Shanghai Women's Health Study. Our analyses included 304 cases of epithelial ovarian cancer diagnosed from 1996 to 2015 and 600 matched controls. We measured urinary PGE-M using LC/MS with normalization to creatinine. Measures from each study were recalibrated to a common standard. We estimated ORs and 95% confidence intervals (CI) using conditional logistic regression, with PGE-M levels modeled in quartiles. Multivariable models were adjusted for ovarian cancer risk factors. There was no evidence of an association between urinary PGE-M levels and ovarian cancer risk for women with PGE-M levels in the top versus bottom quartile (OR = 0.80; 95% CI, 0.51-1.27; P trend = 0.37). We did not observe heterogeneity by histotype (P = 0.53), and there was no evidence of effect modification by body mass index (P interaction = 0.82), aspirin use (P interaction = 0.59), or smoking (P interaction = 0.14). Prediagnosis urinary PGE-M levels were not significantly associated with ovarian cancer risk. Larger sample sizes are needed to consider a more modest association and to evaluate associations for specific tumor subtypes. Systemic prostaglandin levels do not appear strongly associated with ovarian cancer risk. Future research into aspirin use and ovarian cancer risk should consider local prostaglandins and prostaglandin-independent mechanisms.

Abstract B08: Urinary PGE-M levels and risk of ovarian cancer

Abstract Introduction: Prostaglandin E2 (PGE2) is thought to influence ovarian carcinogenesis by increasing cell proliferation, tumor cell invasiveness, and angiogenesis. PGE-M is the major metabolite of PGE2 and a marker of systemic PGE2 production. Prior research has reported positive associations between urinary PGE-M and risk of colorectal, gastric, lung, pancreatic, and breast cancer; however, this is the first study to evaluate the association between urinary PGE-M and risk of ovarian cancer. Methods: We conducted a prospective case-control study nested in the Nurses’ Health Study (NHS) and NHSII cohorts. We included 194 cases of invasive epithelial ovarian cancer and 387 matched controls. All cases were diagnosed between the time of urine specimen collection (1996-97 NHSII; 2000-2002 NHS) and the end of follow-up (2015). Controls were selected using incidence density sampling and matched to cases on year of birth, menopausal status at collection and diagnosis, date and time of day of collection, hormone therapy use at collection, and fasting status. We measured PGE-M levels using LC/MS methods, and used the PGE-M distribution among controls to identify tertile cutpoints. We estimated the association between prediagnosis urinary PGE-M (in tertiles) and risk of ovarian cancer using conditional logistic regression. Results: We observed a suggestively lower risk of ovarian cancer for those with the highest PGE-M levels in NHS (OR=0.66; 95%CI=0.36-1.21; p-trend=0.15; n=123 cases), and no association in NHSII (OR=1.15; 95%CI=0.50-2.67; p-trend=0.75; n=71 cases). When results from the two cohorts were pooled, we observed nonsignificant, lower odds of ovarian cancer among those in the highest tertile of PGE-M compared to the lowest tertile (OR=0.80; 95%CI=0.50-1.27; p-trend=0.34), particularly after restricting our analysis to study participants who provided first morning urine samples (OR=0.68; 95%CI=0.40-1.14; p-trend=0.13). However, when we examined quartiles, no clear association was observed, although power was limited. Conclusions: Overall, our results suggest that higher prediagnosis PGE-M levels are not associated with an increased risk of ovarian cancer. Further analyses are under way to evaluate the potential for effect modification by menopausal status, BMI, and NSAID use. Citation Format: Mollie E. Barnard, A. Heather Eliassen, Bernard A. Rosner, Kathryn L. Terry, Ginger L. Milne, Shelley S. Tworoger. Urinary PGE-M levels and risk of ovarian cancer. [abstract]. In: Proceedings of the AACR Conference: Addressing Critical Questions in Ovarian Cancer Research and Treatment; Oct 1-4, 2017; Pittsburgh, PA. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(15_Suppl):Abstract nr B08.

Abstract CT065: A phase Ib biomarker trial of naproxen in patients at risk for DNA mismatch repair deficient colorectal cancer

Abstract Background: Patients diagnosed with Lynch Syndrome (LS) have an approximately 70% lifetime risk of colorectal cancer (CRC) due to the presence of germline mutations in the mismatch repair (MMR) genes. Cyclooxygenases (COX) are key enzymes in the metabolism of Prostaglandins (PGs) being COX-2 induced at sites of inflammation as well as in ~85% of CRC and 50% of premalignant adenomas. Non-steroidal anti-inflammatory drugs (NSAIDs) such as Aspirin and Naproxen exert their therapeutic effects through the inhibition of both COX-1 and COX-2, which causes a reduction in PGs. However, other known non-canonical effects include inhibition of cell growth, induction of cell cycle arrest, and apoptosis. Aspirin has demonstrated chemopreventive properties in LS patients at high doses. Naproxen is widely used for the treatment of pain with an excellent safety profile. In addition, pre-clinical in vivo data using a genetically-engineered mouse model of Lynch Syndrome (Villin-Cre;Msh2LoxP/LoxP) has demonstrated that Naproxen is the most effective NSAID in preventing colorectal tumors and has shown to be superior to Aspirin. The present clinical trial was designed to assess the safety and tolerability of long-term chemoprevention with Naproxen in LS and also to discover novel biomarkers of drug activity. Methods: LS patients at 4 participating sites (The University of Texas MD Anderson Cancer Center, Dana Farber Cancer Institute, The University of Michigan Comprehensive Cancer Center, and Huntsman Cancer Institute) were randomly assigned to Naproxen 440 mg, 220 mg, or placebo once daily for 6 months. To determine the safety profile and tolerability of Naproxen, adverse events (AEs) were reported using CTCAE V4.03. To assess the activity of the drug intervention we measured Prostaglandin E2 (PGE2) levels in normal colorectal mucosa, its metabolite in urine (PGE-M), levels of Naproxen in plasma and colorectal mucosa at baseline and 6 months after treatment. Response to treatment was defined as 30% reduction in PGE2 levels. Results: A total of 86 patients were registered to this study, 28 randomized to Placebo, 25 to Naproxen 440 mg, and 27 to Naproxen 220 mg. Mean age was 44.6 years, 64% of the patients were females, 53% were unaffected carriers, and MLH1 and MSH2 were the most frequently mutated genes. Fifty-eight completed the study (67%). A total of 183 AEs were recorded in 61 patients, 77% were unrelated or unlikely related to the treatment, only 8 were reported as grade 3 AEs and none of these were related to Naproxen. In the group that received Naproxen at 440 mg, the levels of Naproxen in plasma and normal colorectal mucosa were the highest and the levels of PGE2 and PGE-M were significantly lower when compared to patients in the Placebo arm (P=0.027). In addition, the response rate was the highest among patients receiving Naproxen at 440 mg daily compared to Naproxen at 220 mg and Placebo (87.5% vs 75% vs 13%, respectively). Conclusions: The tolerance and safety of long-term chemoprevention with Naproxen at a dose of 440 mg for 6 months was excellent. There was evidence of decreased inflammatory activity among LS patients treated with high dose Naproxen compared to Placebo. Biomarker studies to discover novel non-canonical effects of Naproxen via modulation of miRNA and mRNA profiles using next-generation sequencing approaches are currently ongoing. Citation Format: Laura Reyes Uribe, Ramona Lin, Elena M. Stoffel, N. Jewel Samadder, Patrick Lynch, Priyanka Kanth, Ginger Milne, Lawrence J. Marnett, Valerie Sepeda, Diane D Liu, Y. Nancy You, Lana A. Vornik, J. Jack Lee, Ellen Richmond, Asad Umar, Marjorie Perloff, Steven M. Lipkin, Powel H. Brown, Eduardo Vilar-Sanchez. A phase Ib biomarker trial of naproxen in patients at risk for DNA mismatch repair deficient colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr CT065.

Increased urinary prostaglandin E2 metabolite: A potential therapeutic target of Gitelman syndrome.

BackgroundGitelman syndrome (GS), an inherited autosomal recessive salt-losing renal tubulopathy caused by mutations in SLC12A3 gene, has been associated with normal prostaglandin E2 (PGE2) levels since 1995 by a study involving 11 clinically diagnosed patients. However, it is difficult to explain why cyclooxygenase-2 (COX2) inhibitors, which pharmacologically reduce PGE2 synthesis, are helpful to patients with GS, and few studies performed in the last 20 years have measured PGE2 levels. The relationships between the clinical manifestations and PGE2 levels were never thoroughly analyzed.MethodsThis study involved 39 GS patients diagnosed by SLC12A3 gene sequencing. Plasma and 24-h urine samples as well as the clinical data were collected at admission. PGE2 and PGEM levels were detected in plasma and urine samples by enzyme immunoassays. The in vivo function of the sodium-chloride co-transporter (NCC) in GS patients was evaluated using a modified thiazide test. The association among PGE2 levels, clinical manifestations and the function of NCC in GS patients were analyzed.ResultsSignificantly higher levels of urinary and plasma PGEM were observed in GS patients than in the healthy volunteers. Higher urinary PGEM levels indicated more severe clinical manifestations and NCC dysfunction estimated by the increase of Cl- clearance. A higher PGEM level was found in male GS patients, who showed earlier onset age and more severe hypokalemia, hypochloremia and metabolic alkalosis than female GS patients. No relationship between renin angiotensin aldosterone system activation and PGEM level was observed.ConclusionsHigher urinary PGEM levels indicated more severe clinical manifestations and NCC dysfunction in GS patients. COX2 inhibition might be a potential therapeutic target in GS patients with elevated PGEM levels.

Abstract 2272: A prospective study of urinary prostaglandin E2 metabolite, Helicobacter pylori antibodies, and gastric cancer risk

Abstract Background. Previous studies suggest that a stable end-product of prostaglandin E2, the urinary metabolite PGE-M, is excreted in the urine and can be used as an index of systemic prostaglandin E2 (PGE2) production. In the present study we investigate the PGE-M, Helicobacter pylori (H. pylori), and gastric cancer association. Methods. The present analysis included 359 prospectively ascertained gastric cancer cases and 700 individually matched controls from two population-based prospective cohort studies, the Shanghai Women’s Health Study and Shanghai Men’s Health Study. Urinary PGE-M was measured by a liquid chromatography/tandem mass spectrometric method. Sero-positivity 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, OR=1.76, 95% CI: 1.17-2.66, Ptrend =0.004). This association remained after excluding those diagnosed within two years from sample collection (OR=1.73, 95% CI: 1.12-2.65, Ptrend =0.007). 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: 0.31-1.70). The association of PGE-M with gastric cancer risk was not modified by H. pylori status, but added predictive ability beyond H. pylori; 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 ratio of gastric cancer (OR=5.08, 95% CI: 2.47-10.43). Conclusion. 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. Citation Format: Tianyi Wang, Hui Cai, Wei Zheng, Angelika Michel, Michael Pawlita, Ginger Milne, Yong-Bing Xiang, Yu-Tang Gao, Hong-Lan Li, Nathaniel Rothman, Qing Lan, Xiao-Ou Shu, Meira Epplein. A prospective study of urinary prostaglandin E2 metabolite, Helicobacter pylori antibodies, and gastric cancer risk [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2272. doi:10.1158/1538-7445.AM2017-2272

Abstract A12: Urinary levels of PGE-M and estrogens are independently associated with postmenopausal breast cancer risk

Abstract Prostaglandin E2 (PGE2) induces aromatase expression in adipose tissue leading to increased estrogen production that may promote the development and progression of breast cancer. However, few studies have simultaneously investigated systemic levels of PGE2 and estrogen in relation to postmenopausal breast cancer risk. In a case-cohort study of postmenopausal women (295 cases and 294 subcohort) we previously reported that high levels of PGE-M, a major metabolite of PGE2, were associated with an increased risk of breast cancer among postmenopausal women who did not regularly use nonsteroidal anti-inflammatory drugs (NSAIDs). Here we determined urinary estrogen metabolites (EMs) using mass spectrometry in the same case-cohort set and using linear regression estimated the effect of PGE-M on EMs. Hazard ratios (HRs) for the risk of developing breast cancer in relation to PGE-M and EMs were evaluated in Cox regression models with and without mutual adjustment. PGE-M was a significant predictor of estrone (E1), but not estradiol (E2) levels in multivariable analysis. Elevated E2 levels were associated with an increased risk of developing breast cancer (HRQ5vs.Q1 =1.54, 95% CI: 1.01-2.35), and this association remained unchanged after adjustment for PGE-M (HRQ5vs.Q1 =1.52, 95% CI: 0.99-2.33). Similarly, elevated levels of PGE-M were associated with increased risk of developing breast cancer (HRQ4vs.Q1 =2.01, 95% CI: 1.01-4.29), and this association was only nominally changed after consideration of E1 or E2 levels. Urinary levels of PGE-M and parent estrogens were independently associated with future risk of developing breast cancer among these postmenopausal women. Increased breast cancer risk associated with PGE-M might be attributable both to PGE2-mediated increases in estrogens, and to additional effects related to inflammation. Note: This abstract was not presented at the conference. Citation Format: Sangmi Kim, Jeff Campbell, Wonsuk Yoo, Jack A. Taylor, Dale P. Sandler. Urinary levels of PGE-M and estrogens are independently associated with postmenopausal breast cancer risk. [abstract]. In: Proceedings of the AACR Special Conference: Improving Cancer Risk Prediction for Prevention and Early Detection; Nov 16-19, 2016; Orlando, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2017;26(5 Suppl):Abstract nr A12.

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

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. 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. 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]). 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.

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.

Effects of Lipoic Acid Supplementation on Activities of Cyclooxygenases and Levels of Prostaglandins E2 and F2α Metabolites, in the Offspring of Rats with Streptozotocin-Induced Diabetes.

Background. Our aim was to evaluate the protective effect of lipoic acid (LA) on fetal outcome of diabetic mothers. Methods. Diabetes was induced in female rats using streptozotocin and rats were made pregnant. Pregnant control (group 1; n = 9; and group 2; n = 7) or pregnant diabetic (group 3; n = 10; and group 4; n = 8) rats were treated daily with either LA (groups 2 and 4) or vehicle (groups 1 and 3) between gestational days 0 and 15. On day 15 of gestation, the fetuses, placentas, and membranes were dissected, examined morphologically, and then homogenized, to measure cyclooxygenase (COX) activities and metabolisms of prostaglandin (PG) E2 (PGEM) and PGF2 α (PGFM) levels. The level of total glutathione was measured in the maternal liver and plasma and in all fetuses. Results. Supplementation of diabetic rats with LA was found to significantly (p < 0.05) reduce resorption rates in diabetic rats and led to a significant (p < 0.05) increase in liver, plasma, and fetuses total glutathione from LA-TD rats as compared to those from V-TD. Decreased levels of PGEM and elevated levels of PGFM in the fetuses, placentas, and membranes were characteristic of experimental diabetic gestation associated with malformation. The levels of PGEM in malformed fetuses from LA-TD mothers was significantly (p < 0.05) higher than those in malformed fetuses from V-TD rats. Conclusions. LA treatment did not completely prevent the occurrence of malformations. Thus, other factors may be involved in the pathogenesis of the diabetes-induced congenital malformations.

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.

Abstract 2848: Urinary prostaglandin E metabolite as a biomarker predicting response to EGFR therapy in patients with head and neck cancer

Abstract Background: Cross talk between the epidermal growth factor receptor (EGFR) and prostaglandin E2 pathways (PGE2) is well established. Activation of EGFR signaling can induce PGE2. Urinary PGE-M is a stable end metabolite of PGE2. The purpose of this study was to evaluate the role of urinary PGE-M as a biomarker predicting response to anti-EGFR monoclonal antibody therapy in patients with head and neck squamous cell carcinoma (HNSCC). Patients and Methods: Ten HNSCC patients with recurrent and/or metastatic disease received Nimotuzumab, a humanized monoclonal antibody against EGFR. The response to Nimotuzumab was assessed 2 weeks following the fourth cycle using PERCIST criteria. Urine samples were collected before treatment and 2 weeks after the fourth cycle of therapy. Results: Seven patients had progressive disease (PD) while two patients had stable disease (SD) and one patient had a partial response (PR) to therapy. The mean pretreatment value of urinary PGE-M in patients with SD or PR was 63 ng/mg Cr (range 48-78 ng/mg Cr). By comparison, patients with progressive disease had lower baseline levels of urinary PGE-M with mean pretreatment value of 37ng/mg Cr (range 15- 54ng/mg Cr). More than a 20% reduction in post treatment vs. pretreatment urinary PGE-M values was seen in patients with SD and PR. By comparison, patients with progressive disease had either a minimal reduction or an increase in the post treatment levels of urinary PGE-M. Conclusion: Elevated pretreatment levels of urinary PGE-M may predict response to anti-EGFR therapy in patients with HNSCC. These findings need further validation. Citation Format: Vikram D. Kekatpure, Amritha Suresh, Bharath Rangarajan, Gangotri Siddappa, Moni Abraham Kuriakose. Urinary prostaglandin E metabolite as a biomarker predicting response to EGFR therapy in patients with head and neck cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2848. doi:10.1158/1538-7445.AM2014-2848

Quantification of major urinary metabolites of PGE2 and PGD2 in cystic fibrosis: Correlation with disease severity

Cystic fibrosis transmembrane conductance (CFTR) alterations are involved in the overproduction of prostaglandins (PG) in CF in vitro. We assessed the relationship between PGE-M and PGD-M urinary metabolites of PGE2 and PGD2 and CF severity. Twenty-four controls and 35 CF patients were recruited. PGE-M and PGD-M levels were measured by liquid chromatography/mass spectrometry and results were expressed as median and 25th–75th interquartile of ng/mg creatinine (Cr). PGE-M (15.63; 9.07–43.35ng/mg Cr) and PGD-M (2.16; 1.43–3.53ng/mg Cr) concentrations were higher in CF than in controls: PGE-M, (6.63; 4.35–8.60ng/mg Cr); PGD-M (1.23; 0.96–1.54ng/mg Cr). There was no correlation between metabolite levels and spirometric values. Patients with pancreatic insufficiency (n=29) had higher PGE-M levels (19.09; 9.36–52.69ng/mg Cr) than those with conserved function (n=6) (9.61; 5.78–14.34ng/mg Cr). PGE-M levels were associated with genotype severity: mild (7.14; 5.76–8.76, n=8), moderate (16.67; 13.67–28.62ng/mg Cr, n=5) and severe (22.82; 10.67–84.13ng/mg Cr). Our study confirms the key role of CFTR in the regulation of the cyclooxygenase pathway of arachidonic acid metabolism found in in vitro studies.

Abstract 122: Prospective study of urinary prostaglandin E2 and prostacyclin metabolites and lung cancer risk .

Abstract Cumulative evidence from both in vitro and animal studies suggests that cyclooxygenase-2 (COX-2) may be involved in the development and progression of lung cancer. Overproduction of prostaglandin E synthase and prostaglandin E2 (PGE2), one of the end products of the COX-2 pathway, has been implicated in the pathogenesis of non-small cell lung cancer. On the other hand, evidence suggests that prostacyclin (PGI2), another end products of the COX-2 pathway, may differ from other bioactive prostaglandins and may exert cancer-inhibitory effects on the development of lung cancer. PGE2 is quickly converted to 11α-hydroxy-9,15-dioxo-2,3,4,5-tetranor-prostane-1,20-dioic acid (PGE-M), a major PGE2 metabolite and excreted in urine. PGI2 is rapidly converted into 6-keto-PGF1a, a chemically stable but biologically inactive hydration product. Circulatory 6-keto-PGF1a undergoes ß-oxidation and appears in the urine as 2,3-dinor-6-keto-PGF1a (PGI-M), the primary breakdown product of PGI2. Urinary PGE-M and PGI-M are stable compounds and can be measured accurately and reliably with newly developed and validated LC-MS and GC-MS assays. In this study, we evaluated the association of pre-diagnostic urinary PGE-M and PGI-M levels with subsequent risk of developing lung cancer. We conducted a nested case-control study using resources of the Shanghai Men's Health Study, a prospective cohort study, in which 61,491 Chinese men aged 40-74 years were recruited from 2002 to 2006 and followed for up to 7 years. Urinary PGE-M and PGI-M in 349 incident lung cancer patients were compared to 349 matched controls. Overall, the geometric mean of baseline level of urinary PGE-M did not differ significantly between cases and controls. Compared with the lowest quartile, the risks (odds ratios, ORs) of developing lung cancer were non-significantly elevated (1.48, 95% CI=0.91-2.40 for the highest quartile). No dose-response relationship was evident. The baseline level of urinary PGI-M was more than 20% higher in cases than in controls. The ORs for developing lung cancer increased from 1.0 to 1.14 (95% CI=0.66-1.95), 1.45 (95% CI=0.86-2.45), and 1.70 (95% CI=0.99-2.92) across the quartiles of urinary PGI-M levels (P for trend=0.0056). Excluding 63 case-control pairs who were diagnosed with lung cancer within one year of follow-up did not change the associations for PGE-M and PGI-M. No interaction was found between PGE-M and PGI-M in relation to lung cancer risk. In summary, using data from a large prospective cohort study, we found that high levels of urinary PGI-M, and possibly PGE-M, were associated with subsequent risk of developing lung cancer. Our data suggest that high activity of the COX-2 pathway, rather than the prostaglandin E2 alone, may play a major role in lung cancer development. Further studies are needed to evaluate these two urinary markers as possible biomarkers for lung cancer risk assessment. Citation Format: Qiuyin Cai, Yong-Bing Xiang, Wanqing Wen, Ginger L. Milne, Hong-Lan Li, Jie Wu, Gong Yang, Jing Gao, Tsogzolmaa Dorjgochoo, Yu-Tang Gao, Wei Zheng, Xiao Ou Shu. Prospective study of urinary prostaglandin E2 and prostacyclin metabolites and lung cancer risk . [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 122. doi:10.1158/1538-7445.AM2013-122

Exhaled eicosanoid profiles in children with atopic asthma and healthy controls

Chronic endobronchial inflammation is a hallmark of pediatric asthma and involves the arachidonic acid pathway. Its non-volatile metabolites can be quantified in the exhaled breath condensate (EBC), and single substances have been studied as non-invasive biomarkers for the diagnosis and monitoring of children with asthma. The aim of this study was to compare the content and profile of a wider range of eicosanoids in the EBC between patients and a control group. EBC was sampled from 33 children (aged 12.4 ± 3.1 years) with stable atopic asthma (26 on inhaled steroid treatment) and 25 healthy controls (11.8 ± 3.2 years). Validated high performance liquid chromatography coupled with a tandem mass spectrometry platform (HPLC-MS2 ) was used to measure 13 different compounds. In addition, exhaled nitric oxide levels (FeNO) were measured and bronchial hyperresponsiveness (BHR) was assessed by an exercise challenge test in all subjects. An analytical approach was used for multivariate regression modeling of disease status using the most relevant variables. The levels of PGEM (P < 0.001), PGD2 (P < 0.001), 6keto-PGF1α (P = 0.03), LTC4 (P < 0.001), trans-LTC4 (P = 0.04), and 5HETE (P = 0.02) were significantly higher in asthmatics compared to healthy children, while 11-dehydro TXB2 was significantly less abundant (P = 0.02). The eicosanoids asthma classification ratio (EACR) was computed as the logistic regression function using four variables: PGEM, PGD2, LTC4, and 5HETE. This composite parameter discriminated asthmatic from healthy children better than FEV1, FeNO, or BHR. Complementary measurements of PGEM, PGD2, LTC4, and 5HETE in small-volume EBC samples are feasible by HPLC-MS2 and showed a specific profile in our study population. EACR should be evaluated further in the context of diagnosing and monitoring childhood asthma.

Urinary Prostaglandin E2 Metabolite and Risk for Colorectal Adenoma

COX-2 is upregulated in most colorectal cancers. Most of the COX-2 tumor-inducing effects are believed to be mediated through overproduction of prostaglandin E(2) (PGE(2)), which can be measured using a urinary metabolite of PGE(2), PGE-M. Urinary PGE-M was assessed in a case-control study of colorectal adenoma. Included in the analysis were 224 cases with at least one advanced adenoma, 152 cases with multiple small tubular adenomas, 300 cases with only a single small tubular adenoma, and 364 polyp-free controls. There were no statistical differences in PGE-M levels between controls and cases with a single small tubular adenoma. However, cases with either an advanced adenoma or multiple small tubular adenomas had more than 25% higher levels of PGE-M than controls. Participants with the highest quartile level of PGE-M were approximately 2.5-fold more likely to have advanced or multiple small tubular adenoma in comparison with those with the lowest level of PGE-M [OR = 2.53; 95% confidence interval (CI), 1.54-4.14; P(trend) < 0.001]. The association was strongest among women. PGE-M level was associated with increased risk for multiple or advanced adenoma but not single small adenoma. Our study suggests that PGE-M may be a useful risk marker for assessing the risk of harboring clinically more important versus less important colorectal neoplasia.

The effect of HIV and HPV coinfection on cervical COX-2 expression and systemic prostaglandin E2 levels.

Human immunodeficiency virus (HIV-1) infection causes chronic inflammation. COX-2-derived prostaglandin E(2) (PGE(2)) has been linked to both inflammation and carcinogenesis. We hypothesized that HIV-1 could induce COX-2 in cervical tissue and increase systemic PGE(2) levels and that these alterations could play a role in AIDS-related cervical cancer. Levels of cervical COX-2 mRNA and urinary PGE-M, a biomarker of systemic PGE(2) levels, were determined in 17 HIV-negative women with a negative cervical human papilloma virus (HPV) test, 18 HIV-infected women with a negative HPV test, and 13 HIV-infected women with cervical HPV and high-grade squamous intraepithelial lesions on cytology. Cervical COX-2 levels were significantly associated with HIV and HPV status (P = 0.006 and 0.002, respectively). Median levels of urinary PGE-M were increased in HIV-infected compared with uninfected women (11.2 vs. 6.8 ng/mg creatinine, P = 0.02). Among HIV-infected women, urinary PGE-M levels were positively correlated with plasma HIV-1 RNA levels (P = 0.003). Finally, levels of cervical COX-2 correlated with urinary PGE-M levels (P = 0.005). This study shows that HIV-1 infection is associated with increased cervical COX-2 and elevated systemic PGE(2) levels. Drugs that inhibit the synthesis of PGE(2) may prove useful in reducing the risk of cervical cancer or systemic inflammation in HIV-infected women.