No abstract

Background Dysregulation of N6-methyladenosine (m6A) is associated with various human diseases including cancer. This study aimed to evaluate the level of m6A as a biomarker for gastric cancer (GC) diagnosis. Methods Peripheral blood samples were collected from 100 GC patients, 30 benign gastric disease (BGD) patients, and 75 healthy controls (HCs). Levels of m6A in total RNA and expression of m6A-related proteins were analyzed. Results The m6A levels in peripheral blood RNA were significantly increased in the GC group compared with those in the BGD or HC groups; moreover, levels increased with the progression and metastasis of GC and decreased in GC patients after surgery. The area under the curve (AUC) for m6A in the GC group was 0.929 (95% CI, 0.88–0.96), which is markedly greater than the AUCs for carcinoembryonic antigen (CEA; 0.694) and carbohydrate antigen 199 (CA199; 0.603). The combination of CEA and CA199 with m6A improved the AUC to 0.955 (95% CI, 0.91–0.98). The expressions of m6A demethylases ALKBH5 and FTO were significantly downregulated in the GC group compared with the HC group. Coculture with GC cells increased the m6A of RNA in promyelocytic (HL-60) and monocytic (THP-1) leukemia cells and nontumorigenic human peripheral blood B lymphocyte cells (PENG-EBV). Furthermore, a xenograft model enhanced the m6A in peripheral blood RNA of mice. Accordingly, expressions of ALKBH5 and FTO were decreased both in vitro and in vivo. Conclusions Level of m6A in peripheral blood RNA is a promising noninvasive diagnostic biomarker for GC patients.

Background It has been reported that several microRNAs (miRNAs), such as miR-141, miR-9, and miR-122, are involved in the regulation of pancreatitis-related proteins or that their levels change in acute pancreatitis (AP) animal models. However, the serum levels, as well as the clinical diagnostic and prognostic values, of these miRNAs in AP patients remain unclear. Furthermore, as a pancreas- (islet) enriched miRNA, miR-7 was reported to be downregulated in AP patients, which requires further verification. Methods The levels of miR-7, miR-9, miR-122, and miR-141 were examined and compared using qRT-PCR among 80 severe AP patients, 80 mild AP patients, and 74 healthy controls. Results The serum levels of these four miRNAs were increased markedly in the AP patients compared with the controls, and these levels decreased significantly after effective therapy. Particularly, the level of miR-7 was higher in severe AP patients than in mild AP patients. ROC curve analysis demonstrated that four miRNAs could be used as potential biomarkers for AP. Moreover, these miRNAs showed strong positive correlations with CRP, which may be associated with inflammation. Conclusions The serum miR-7, miR-9, miR-122, and miR-141 levels were increased in AP patients. These 4 miRNAs may represent diagnostic and prognostic biomarkers for AP.