NF-κB/miR-18a-3p and miR-4286/BZRAP1 axis may mediate carcinogenesis in Helicobacter pylori―Associated gastric cancer

•miR-18a-3p and miR-4286 correlated with clinicopathological parameters in H. pylori―associated gastric cancer.•miR-18a-3p and miR-4286 promote cancer cell growth and motility in vitro.•BZRAP1 is a direct target of miR-18a-3p and miR-4286.•The transcription factor NF-κB binds to the miR-18a-3p and miR-4286 promoters following LPS exposure. Helicobacter pylori infection is an important pathogenic risk factor for gastric cancer, but it is still unclear what tumor markers for gastric cancer induced by H. pylori can be consistently detected. Using an miRNA microarray, we found that miR-18a-3p (6.02-fold) and miR-4286 (5.73-fold) were significantly increased in H. pylori― associated gastric cancer. In a cohort of gastric cancer patients (N = 104), serum expression of miR-18a-3p and miR-4286 was positively and significantly correlated with H. pylori; furthermore, miR-18a-3p was positively correlated with invasion (P = 0.029), and miR-4286 was positively correlated with tumor stage (P = 0.033), tumor size (P = 0.041), and lymph node metastasis (P = 0.009). Overexpression of miR-18a-3p and miR-4286 also increased cancer cell proliferation and motility and both inhibited expression of BZRAP1, resulting in tumor progression in vitro. In addition, lipopolysaccharide co-mediated the expression of miR-18a-3p and miR-4286 by activating the NF-κB transcription factor, but TAK-242 (TLR4 inhibitor) blocked this effect. These results demonstrate that serum miR-18a-3p and miR-4286 levels in H. pylori―associated gastric cancer may be useful prognostic biomarkers and suggest a novel signaling pathway of targeting BZRAP1 in gastric cancer.