Plasma metabolome identifies potential biomarkers of gastric precancerous lesions and gastric cancer risk.

OBJECTIVES: Currently, metabolic biomarkers with great practicability of gastric cancer (GC) and gastric precancerous lesions (GPL) are scarce. Thus, we are devoted to determining the plasma metabolic profiles of patients with GPL or GC and validate candidate biomarkers for disease diagnosis. METHODS: In this hospital-based case-control study, 68 plasma samples from 27 non-atrophic gastritis (NAG, control), 31 GPL, and 10 GC patients were collected for targeted metabolomics analysis. Univariate and multivariate analyses were used for selecting the differential metabolites. A receiver operating characteristic curve combined with binary logistic regression analysis was performed to test the diagnostic performance of the differential metabolites. Dietary data were obtained using a semiquantitative food frequency questionnaire. RESULTS: Distinct metabolomic profiles were noted for NAG, GPL, and GC. Compared to the NAG patients, the levels of 5 metabolites in the GPL group and 4 metabolites in the GC group were found to significantly elevate. Compared with the model involving 9 traditional risk factors (AUC: 0.89, 95%CI: 0.78-1.00), Trimethylamine N-oxide, the most significant metabolite (P = 2.00 × 10-5, FDR = 0.003, FC > 2, VIP > 2), showed a good diagnostic performance for the patients with GC (AUC: 0.90, 95%CI: 0.78-1.00), and its diagnostic performance has been further improved with the integration of Rhamnose (AUC: 0.96, 95%CI: 0.89-1.00). CONCLUSION: In our study, 9 defined metabolites might serve as meaningful biomarkers for identifying the high-risk population of GPL and GC, possibly enhancing the prevention and control of GPL and GC.

All-Trans Retinoic Acid Prevents the Progression of Gastric Precancerous Lesions by Regulating Disordered Retinoic Acid Metabolism.

Retinoic acid (RA) is the most biologically active metabolite of vitamin A and is important for stomach physiological function. However, little is known about the metabolic status of RA in human gastric lesions. From 2015 to 2018, 1,392 local residents in Lujiang County were recruited into a cross-sectional survey program, which included a questionnaire interview and blood collection. We detected the mRNA and protein expression of RA metabolism-relevant factors in gastric tissues from 68 local patients with gastric lesions. The effects of all-trans retinoic acid (ATRA) supplementation were investigated in a gastric precancerous lesions (GPLs) rat model. In the cross-sectional survey, no significant differences in the level of RA precursor (P > 0.05) between the H. pylori seronegative and seropositive residents were observed. However, the mRNA and protein expression of RA synthesizing enzymes (RDH10 and ALDH1A1) were significantly decreased and catabolic enzyme (CYP26B1) was significantly increased in the patients (P < 0.05). Consistently, in the GPL rat model, we observed a similar disorder; however, ATRA supplementation significantly not only corrected the disorder by increasing Rdh10, Aldh1a1 and decreasing Cyp26b1, but also reduced claudin-18 (P < 0.05). Our study suggested that RA metabolism is disrupted in individuals with gastric lesions, while ATRA supplementation can prevent GPL from progressing to gastric cancer.