Evaluation of MicroRNA expression pattern of gastric adenocarcinoma associated with socioeconomic, environmental and lifestyle factors in northwestern Hungary.

Aim: Gastric cancer is among the most common causes of cancer-related death worldwide. Since microRNAs (miRNAs) represent an emerging field of cancer research, there is an increasing interest regarding the miRNA responses to environmental and lifestyle exposures. The aim of our study was to analyze whether social status, living conditions and lifestyle behaviours, such as cigarette smoking and alcohol consumption, are associated with specific miRNA expression patterns of gastric adenocarcinoma.
Materials and Methods: Thirty-nine formalin-fixed paraffin-embedded primary gastric adenocarcinoma and nine non-tumourous samples were analyzed by real-time polymerase chain reaction. The expression levels of miR-21, miR-34a, miR-93, miR-143, miR-203, miR-205, miR-223 were compared in gastric adenocarcinoma samples of patients with different demographical characteristics, social status, drinking and smoking habits.
Results: Overexpression of miR-21, miR-143 and underexpression of miR-34a were observed in gastric cancer samples relative to the controls. Elevated expression of miR-21 was detected in patients with low social status. Smokers showed higher expression of miR-21 and lower expression of miR-143. Up-regulation of miR-203, miR-205 and miR-223 was identified in patients with regular alcohol consumption. Patients living in an urban environment had elevated expression levels of miR-143 and miR-34a.
Discussion: Differential miRNA expression patterns of gastric adenocarcinoma of the same histopathology from a small geographic region's population show homogenous correlations with the existence of common risk factors.