E-cadherin Downregulation and MicroRNAs in Sporadic Intestinal-Type Gastric Cancer

gene, encoding E-cadherin, is a tumor suppressor gene frequently altered in gastric cancers (GCs) of both diffuse (DGC) and intestinal (IGC) histotypes, albeit through different mechanisms. The study aimed to characterize expression in sporadic IGC and to investigate whether microRNAs (miRs) are involved in its transcriptional control. We evaluated expression by quantitative real-time PCR (RT-qPCR) in 33 IGC patients and found a significant downregulation in tumor tissues compared to normal counterparts (-value = 0.025). Moreover, 14 miRs, predicted to be involved in regulation in both a direct and indirect manner, were selected and analyzed by RT-qPCR in an independent case series of 17 IGCs and matched normal tissues. miR-101, miR-26b, and miR-200c emerged as significantly downregulated and were confirmed in the case series of 33 patients (-value < 0.001). Finally, we evaluated expression, a target of both miR-101 and miR-26b, which showed significant upregulation in IGCs (-value = 0.005). A significant inverse correlation was observed between overexpression and , miR-101, and miR-26b levels (-value < 0.001). Our results reinforce the link between and IGC, highlighting the role of miRs in its transcriptional control and improving our understanding of GC subtypes and biomarkers.