BRIEF COMMUNICATION Decreased MicroRNA miR-181c Expression Associated with Gastric Cancer Luanna Munhoz Zabaglia 1 & Nicole Chiuso Bartolomeu 1 & Mônica Pezenatto dos Santos 1 & Rita Luiza Peruquetti 1 & Elizabeth Chen 2 & Marilia de Arruda Cardoso Smith 2 & Spencer Luiz Marques Payão 1 & Lucas Trevizani Rasmussen 1 # Springer Science+Business Media, LLC, part of Springer Nature 2017 Abstract Purpose This study investigated miRNA-181c expression in control patients (healthy gastric mucosa), patients with gastritis, and patients with gastric cancer. The presence of Helicobacter pylori was determined, and the associations between H. pylori infection, levels of miRNA-181c expression, and gastric disease were also analyzed. Methods A total of 158 subjects were included in the study, and the three groups were respectively composed of 53 controls, 86 patients with gastritis, and 19 patients with gastric cancer. miRNA-181c expression and H. pylori infection were determined by quantitative real-time PCR and PCR, respectively. The subsequent target gene analysis was performed using the bioinformatics approach to understand the possible mechanisms of gastric cancer. Results We determined significantly lower miRNA-181c expression in the gastric cancer group when compared to the control and gastritis groups, regardless of the presence of H. pylori. There was no difference in miRNA-181c expression between the control group and gastritis group, whether the presence of H. pylori was considered or not. The bioinformatics approach identified several genes as possible targets for miRNA-181c, including the X-linked inhibitor of apoptosis (XIAP) gene (which encodes a protein that belongs to a family of apoptotic suppressor proteins), the caspase 9 gene, and the caspase 3 gene. All target genes identified may be involved in gastric cancer and apoptosis pathways. Conclusion The results suggest that the presence of H. pylori has no influence on microRNA expression and that the downreg- ulation of miR-181c may play an important role in gastric cancer progression by controlling important genes associated with apoptosis. Therefore, miRNA-181c may be a potential marker of gastric cancer. Keywords MicroRNA . miRNA-181c . Helicobacter pylori . Gastric cancer Introduction Gastric cancer is the second most frequent cause of death from cancer in the world, and the presence of Helicobacter pylori is considered the main risk factor for the disease. Every year, thousands of dollars are spent on treatments that are largely ineffective; the neoplastic process is complex and multifacto- rial, and the exact molecular mechanism underlying gastric carcinogenesis it is still unknown [1, 2]. Several studies suggest that miRNAs participate in tumor angiogenesis, proliferation, invasion, and metastasis of the neoplastic process; depending on their target, they may also function as tumor suppressors or oncogenes [3–5]. More re- cent studies have reported changes in miRNA expression in various types of cancer, and miRNAs have been established as attractive targets for therapeutic intervention [6, 7]. miRNAs from the miR-181 family are of particular importance: they are the most frequently upregulated miRNAs in gastric cancer. The miR-181 family has been identified as a hematopoietic lineage modulator, and studies have shown that abnormal miR-181c expression is closely related to glioma, breast cancer, squamous cell carcinoma of the tongue, and other tumors [8–11]. * Lucas Trevizani Rasmussen lucasrasmussen@gmail.com 1 Pró-Reitoria de Pesquisa e Pós-graduação, Universidade do Sagrado Coração (USC), Irmã Arminda 10-50, Jardim Brasil, CEP 17011-160, Bauru, São Paulo, Brazil 2 Universidade Federal de São Paulo (UNIFESP), São Paulo, São Paulo, Brazil Journal of Gastrointestinal Cancer https://doi.org/10.1007/s12029-017-0042-7