Prostaglandin E-Major Urinary Metabolite (PGE-MUM) as a Tumor Marker for Lung Adenocarcinoma

A novel aptasensor platform for the detection of carcinoembryonic antigen using quartz crystal microbalance

In this study, a quartz crystal microbalance (QCM) aptasensor for carcinoembryonic antigen (CEA), a well-known biomarker for various cancer types, was reported, utilizing two different aptamers. To achieve this, a nanofilm of 4-mercaptophenyl was electrochemically attached to gold-coated QCM crystal surfaces via the reduction of 4-mercaptobenzenediazonium salt (4 MB-DAT) using cyclic voltammetry. Subsequently, gold nanoparticles (AuNP) were affixed to this structure, and then aptamers (antiCEA1 and antiCEA2) modified with SH-functional ends bound to AuNPs completed the modification. The analytical performance of the CEA sensor was evaluated through simultaneous QCM measurements employing CEA solutions ranging from 0.1 ng/mL to 25 ng/mL. The detection limit (LOD) for CEA was determined to be 102 pg/mL for antiCEA1 and 108 pg/mL for antiCEA2 aptamers. Interday and intraday precision and accuracy tests yielded maximum results of 4.3 and + 3.8, respectively, for both aptasensors, as measured by relative standard deviation (RSD%) and relative error (RE%). The kinetic data of the aptasensors resulted in affinity values (KD) of 0.43 ± 0.14 nM for antiCEA1 and 0.75 ± 0.42 nM for antiCEA2. These values were lower than the reported values of 3.9 nM and 37.8 nM for both aptamers, respectively. The selectivity of the aptasensor was evaluated by measuring the signal changes caused by alpha-fetoprotein (AFP), cancer antigen (CA-125), and vascular endothelial growth factor (VEGF-165) individually and together at a concentration of 500 ng/mL, resulting in a maximum 4.1 % change, which was comparable to precision and accuracy values reported in the literature. After confirming the selectivity of the aptamers, recovery experiments were conducted using spiked commercial serum samples to simulate real samples, and the lowest recovery value obtained was 95.4 %. It was determined that two different aptasensors could be successfully used for the QCM-based detection of CEA in this study.

Prostaglandin E-major urinary metabolites as a new biomarker for acute mesenteric ischemia

BACKGROUND

Acute mesenteric ischemia (AMI) is an emergent vascular disease caused by cessation of the blood supply to the small intestine. Despite advances in the diagnosis, intervention, and surgical procedures, AMI remains a life-threatening condition. Prostaglandin E2 major urinary metabolite (PGE-MUM), the urinary metabolite of prostaglandin E2, is known to be stable in urine and has been suggested to be a valuable biomarker for intestinal mucosal inflammation, such as ulcerative colitis. We therefore investigated whether or not PGE-MUM levels reflect the degree of ischemia in an intestinal ischemia-reperfusion model.

METHODS

Male rats were used to establish a superior mesenteric artery occlusion (SMAO) group, in which the superior mesenteric artery was clamped, and a sham group. The clamping times in the SMAO group were either 30 minutes or 60 minutes, and reperfusion times were either 3 hours or 6 hours, after which PGE-MUM values were measured.

RESULTS

The histological injury score of the SMAO (30-minute ischemia and 6-hour reperfusion group, 1.8 ± 0.4; 60-minute ischemia and 6-hour reperfusion group, 4.7 ± 0.5) and were significantly greater than that of the sham group (0.4 ± 0.7, p < 0.05). The PGE-MUM levels in the SMAO group (30-minutes ischemia and 6-hour reperfusion group, 483 ± 256; 60-minutes ischemia and 6-hour reperfusion group, 889 ± 402 ng/mL) were significantly higher than in the sham group (30-minute and 6-hour observation group, 51 ± 20; 60-minute and 6-hour observation group, 73 ± 32 ng/mL; p < 0.05). Furthermore, the PGE-MUM value was corrected by the concentration of urinary creatinine (Cr). The PGE-MUM/urinary Cr levels in the SMAO group were also significantly higher than in the sham group ( p < 0.05).

CONCLUSION

We found that intestinal ischemia-reperfusion increased urinary PGE-MUM levels depending on the ischemic time. This suggests the potential utility of PGE-MUM as a noninvasive marker of intestinal ischemia.

Reagentless Electrochemical Detection of Tumor Biomarker Based on Stable Confinement of Electrochemical Probe in Bipolar Silica Nanochannel Film

The development of simple and probe-integrated aptamer sensors for the electrochemical detection of tumor biomarkers is of great significance for the diagnosis of tumors and evaluation of prognosis. In this work, a probe-integrated aptamer sensor is demonstrated based on the stable confinement of an electrochemical probe in a bipolar nanochannel film, which can realize the reagentless electrochemical detection of the tumor biomarker carcinoembryonic antigen (CEA). To realize the stable immobilization of a large amount of the cationic electrochemical probe methylene blue (MB), a two-layer silica nanochannel array (SNF) with asymmetric charge was grown on the supporting electrode from bipolar SNF (bp-SNF). The inner SNF is negatively charged (n-SNF), and the outer-layer SNF is positively charged (p-SNF). The dual electrostatic interaction including the electrostatic adsorption from n-SNF and the electrostatic repulsion from p-SNF achieve the stable confinement of MB in bp-SNF. The recognitive interface is fabricated by the covalent immobilization of the CEA aptamer on the outer surface of bp-SNF, followed by the blocking of non-specific binding sites. Owing to the stable and abundant immobilized probes and highly specific aptamer interface, the developed aptamer sensor enables the sensitive detection of CEA in the range of 1 pg/mL to 1 μg/mL with a low limit of detection (LOD, 0.22 pg/mL, S/N = 3). Owing to the high selectivity and stability of the developed biosensor, reagentless electrochemical detection of CEA in serum was realized.

Prognostic implications of prostaglandin E-major urinary metabolite in resected non-small-cell lung cancer

OBJECTIVES

Cyclooxygenase-2-derived prostaglandin E2 (PGE2) is highly involved in the promotion of cancer progression. The end product of this pathway, PGE-major urinary metabolite (PGE-MUM), is a stable metabolite of PGE2 that can be assessed non-invasively and repeatedly in urine samples. The aim of this study was to assess the dynamic changes in perioperative PGE-MUM levels and their prognostic significance in non-small-cell lung cancer (NSCLC).

METHODS

Between December 2012 and March 2017, 211 patients who underwent complete resection for NSCLC were analysed prospectively. PGE-MUM levels in 2 spot urine samples taken 1 or 2 days preoperatively and 3-6 weeks postoperatively were measured using a radioimmunoassay kit.

RESULTS

Elevated preoperative PGE-MUM levels were associated with tumour size, pleural invasion and advanced stage. Multivariable analysis revealed that age, pleural invasion, lymph node metastasis and postoperative PGE-MUM levels were independent prognostic factors. In matched pre- and postoperative urine samples obtained from patients who are eligible for adjuvant chemotherapy, an increase in PGE-MUM levels following resection was an independent prognostic factor (hazard ratio 3.017, P = 0.005). Adjuvant chemotherapy improved survival in patients with increased PGE-MUM levels after resection (5-year overall survival, 79.0 vs 50.4%, P = 0.027), whereas survival benefit was not observed in those with decreased PGE-MUM levels (5-year overall survival, 82.1 vs 82.3%, P = 0.442).

CONCLUSIONS

Increased preoperative PGE-MUM levels can reflect tumour progression and postoperative PGE-MUM levels are a promising biomarker for survival after complete resection in patients with NSCLC. Perioperative changes in PGE-MUM levels may aid in determining the optimal eligibility for adjuvant chemotherapy.

First-in-human study of ONO-4578, an antagonist of prostaglandin E2 receptor 4, alone and with nivolumab in solid tumors

EP4, a prostaglandin E₂ receptor, has shown an immunosuppressive activity on cancer cells. This first-in-human study evaluated ONO-4578, a highly selective EP4 antagonist, as monotherapy and in combination with nivolumab in patients with advanced or metastatic solid tumors. A daily dose ranging from 30 mg to 100 mg of ONO-4578 monotherapy and that ranging from 2 mg to 60 mg of ONO-4578 with biweekly nivolumab 240 mg were administered. A total of 31 patients were enrolled, 10 receiving monotherapy and 21 receiving combination therapy. Overall, 26 patients experienced treatment-related adverse events. Dose-limiting toxicities were observed in three patients; one of six patients receiving 100 mg monotherapy developed grade 3 duodenal ulcer and two of six patients receiving 60 mg combination therapy developed either grade 3 erythema multiforme or grade 3 increased amylase and grade 4 increased lipase. One patient with small-cell lung cancer who received 40 mg combination therapy had a partial response, and three patients with monotherapy and six patients with combination therapy had stable disease. Pharmacodynamics analyses showed that ONO-4578 had EP4 antagonistic activity at doses as low as 2 mg. In conclusion, the maximum tolerated dose of ONO-4578 alone or in combination with nivolumab was not reached. ONO-4578 was well tolerated at the tested doses and showed signs of antitumor activity. Considering safety, efficacy, and pharmacokinetics/pharmacodynamics results, ONO-4578 40 mg daily with nivolumab 240 mg biweekly was selected as the recommended dose for future clinical trials. (Registration: JapicCTI-173,496 and NCT03155061).

Predicting Ulcerative Colitis Relapse in Clinical Remission With Fecal Immunochemical Occult Blood Test or Prostaglandin E-Major Urinary Metabolite

INTRODUCTION

The fecal immunochemical occult blood test (FIT) and prostaglandin E-major urinary metabolite (PGE-MUM) have been reported to predict the relapse of ulcerative colitis (UC) during remission. In this study, we directly compared FIT and PGE-MUM in predicting relapse and examined the effect of disease duration on these biomarkers.

METHODS

Measurements of 2 biomarkers and endoscopic examination were performed in 73 patients with UC in remission. The patients were followed up for 12 months, and clinical relapse was evaluated. In addition, we divided the patients into long-term disease duration and short-term disease duration groups for analysis.

RESULTS

Twenty-one patients (28.8%) relapsed within 12 months. FIT and PGE-MUM levels were significantly higher in the relapsed group than in the remission group. Cutoff values of FIT and PGE-MUM for predicting relapse using receiver operating characteristic analysis were 65.0 ng/mL (area under the curve [AUC]: 0.723) and 25.2 μg/g·Cr (AUC: 0.701), respectively. Patients with FIT ≥ 65.0 ng/mL and PGE-MUM ≥ 25.2 μg/g·Cr had a higher risk of clinical relapse. In the short-term disease duration group, the AUCs of FIT were larger than those of PGE-MUM using receiver operating characteristic analysis, in most instances. By contrast, the AUCs of PGE-MUM were larger than those of FIT in most cases in the long-term disease groups.

DISCUSSION

FIT and PEG-MUM were highly accurate in predicting clinical relapse in UC patients with short and long disease durations in remission, respectively.

A Label-Free Electrochemical Immunosensor for CEA Detection on a Novel Signal Amplification Platform of Cu2S/Pd/CuO Nanocomposites

Carcinoembryonic antigen (CEA) is regarded as one of the crucial tumor markers for colorectal cancer. In this study, we developed the snowflake Cu₂S/Pd/CuO nanocomposite to construct an original label-free electrochemical immunosensor for the ultrasensitive detection of CEA levels. The nanocomposite of cuprous sulfide (Cu₂S) with Pd nanoparticles (Pd NPs) was synthesized through an in situ formation of Pd NPs on the Cu₂S. Cuprous sulfide (Cu₂S) and CuO can not only be used as a carrier to increase the reaction area but also catalyze the substrate to generate current signal. Palladium nanoparticles (Pd NPs) have excellent catalytic properties and good biocompatibility, as well as the ability of excellent electron transfer. The immunosensor was designed using 5 mmol/L H₂O₂ as the active substrate by optimizing the conditions with a detection range from 100 fg/ml to 100 ng/ml and a minimum detection limit of 33.11 fg/ml. The human serum was detected by electrochemical immunoassay, and the results were consistent with those of the commercial electrochemical immunosensor. Therefore, the electrochemical immunosensor can be used for the detection of human serum samples and have potential value for clinical application.

Role of Biomarkers in the Diagnosis and Treatment of Inflammatory Bowel Disease

The number of patients with inflammatory bowel disease (IBD) is increasing worldwide. Endoscopy is the gold standard to assess the condition of IBD. The problem with this procedure is that the burden and cost on the patient are high. Therefore, the identification of a reliable biomarker to replace endoscopy is desired. Biomarkers are used in various situations such as diagnosis of IBD, evaluation of disease activity, prediction of therapeutic effect, and prediction of relapse. C-reactive protein and fecal calprotectin have a lot of evidence as objective biomarkers of disease activity in IBD. The usefulness of the fecal immunochemical test, serum leucine-rich glycoprotein, and urinary prostaglandin E major metabolite have also been reported. Herein, we comprehensively review the usefulness and limitations of biomarkers that can be used in daily clinical practice regarding IBD. To date, no biomarker is sufficiently accurate to replace endoscopy; however, it is important to understand the characteristics of each biomarker and use the appropriate biomarker at the right time in daily clinical practice.

Comparison between Prostaglandin E-major urinary metabolite and C-reactive protein levels to reflect endoscopic scores in patients with ulcerative colitis

Prostaglandin E-major urinary metabolite (PGE-MUM) and C-reactive protein (CRP) are useful biomarkers in patients with ulcerative colitis. However, whether changes in endoscopic scores over time are reflected in the values of these biomarkers has not been verified. This prospective observational study aimed to assess the relationship between changes in biomarker levels and endoscopic scores in patients with ulcerative colitis. A total of 100 colonoscopy intervals of patients with ulcerative colitis were enrolled. The relationship between variations in the Mayo endoscopic subscore over time and the accompanying changes in biomarker values were investigated. PGE-MUM levels showed a significant rise in the increased endoscopic score group (P = 0.007) and a decrease with reduced endoscopic score group (P = 0.023). CRP levels showed a significant decline with lower endoscopic values (P < 0.001); however, there was no corresponding increase with higher endoscopic scores (P = 0.141). Biomarker levels remained unchanged with stable endoscopic scores (P = 0.090 and P = 0.705). PGE-MUM levels varied significantly, and corresponded to the mucosal healing state (P = 0.019 and P = 0.009). The correlation between changes in PGE-MUM and the endoscopic score was stronger than that for CRP (r = 0.518, P < 0.001 vs. r = 0.444, P < 0.001, respectively). PGE-MUM reflected changes in endoscopic scores more accurately than CRP.

Urinary Biomarkers for Early Diagnosis of Lung Cancer

Lung cancer is the leading cause of cancer deaths worldwide. Its early detection has the potential to significantly impact the burden of the disease. The screening and diagnostic techniques in current use suffer from limited specificity. The need therefore arises for a reliable biomarker to identify the disease earlier, which can be integrated into a test. This test would also allow for the recurrence risk after surgery to be stratified. In this context, urine could represent a non-invasive alternative matrix, with the urinary metabolomic profile offering a potential source for the discovery of diagnostic biomarkers. This paper aims to examine the current state of research and the potential for translation into clinical practice.

Association between Metabolites and the Risk of Lung Cancer: A Systematic Literature Review and Meta-Analysis of Observational Studies

Globally, lung cancer is the most prevalent cancer type. However, screening and early detection is challenging. Previous studies have identified metabolites as promising lung cancer biomarkers. This systematic literature review and meta-analysis aimed to identify metabolites associated with lung cancer risk in observational studies. The literature search was performed in PubMed and EMBASE databases, up to 31 December 2019, for observational studies on the association between metabolites and lung cancer risk. Heterogeneity was assessed using the I2 statistic and Cochran's Q test. Meta-analyses were performed using either a fixed-effects or random-effects model, depending on study heterogeneity. Fifty-three studies with 297 metabolites were included. Most identified metabolites (252 metabolites) were reported in individual studies. Meta-analyses were conducted on 45 metabolites. Five metabolites (cotinine, creatinine riboside, N-acetylneuraminic acid, proline and r-1,t-2,3,c-4-tetrahydroxy-1,2,3,4-tetrahydrophenanthrene) and five metabolite groups (total 3-hydroxycotinine, total cotinine, total nicotine, total 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (sum of concentrations of the metabolite and its glucuronides), and total nicotine equivalent (sum of total 3-hydroxycotinine, total cotinine and total nicotine)) were associated with higher lung cancer risk, while three others (folate, methionine and tryptophan) were associated with lower lung cancer risk. Significant heterogeneity was detected across most studies. These significant metabolites should be further evaluated as potential biomarkers for lung cancer.