Down-regulated miRs specifically correlate with non-cardial gastric cancers and Lauren's classification system

Background and Objectives: Gastric cancers are usually characterized using Lauren's classification into intestinal and diffuse types. We previously documented the down-modulation of miR31, miR148a, miR204, and miR375 in gastric cancers. We aimed this manuscript to investigate these miRs with the end-points of diagnosis, Lauren's classification and prognosis. Methods: A total of 117 resected non-cardial adenocarcinomas were evaluated for miRs' expressions. The performance of miRs' expressions for cancer diagnosis was tested using ROC curves. Logistic regression was conducted with the end-point of Lauren's classification. Kaplan-Meier and Cox analyses were performed for OS, DFS, and DSS. miRs' targets were reviewed using PRISMA method and BCL-2 was further investigated in cell lines. Results: ROC curves documented that miRs' down-modulation was significant in differentiating cancer versus normal tissues. Diffuse type cancers were associated with female sex, young age, and miR375 higher expression. We confirmed BCL-2 as a miR204 target. However, survival analyses confirmed the pathologic criteria (advanced stages, LNR, and low LNH) as the significant variables correlated to worse prognosis. Conclusions: The down-modulation of miR31, miR148a, miR204, and miR375 is significantly associated with non-cardial gastric cancers and miR375 is specifically linked to Lauren's classification. Nevertheless, standard pathological features display as the independent variables associated with worse prognosis.