Mona Noohi - Department of Microbiology, Karaj Branch, Islamic Azad University, Karaj, Iran.
Mojdeh Hakemi-vala - Department of Microbiology, Medical School, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Jamileh Nowroozi - Department of microbiology, North Tehran Branch, Islamic Azad University, Tehran, Iran.
Seyed-Reza Fatemi - Department of Gasterology and Hepatology, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Mehrouz Dezfulian - Department of Microbiology, Karaj Branch, Islamic Azad University, Karaj, Iran.

Background: The aim of the study was to suggest a high specific and sensitive blood biomarker for early GC diagnosis. Methods: the expression data of miRNAs and mRNAs were collected from the blood samples of the GC patients based on literature mining. Bioinformatics tools and databases (PANTHER, TargetScan, miRTarBase, miRDB, STRING, and Cytoscape) were used to predict the regulatory relationship. Subsequently, expression level of the selected miRNA was evaluated in the blood samples of gastritis patients to recognize the common miRNA between the GC and gastritis patients. Results: Analysis of ۴۰ target genes by MCODE (installed in Cytoscape software) indicated ۴ hub genes (WWP۱, SKP۲, KLHL۴۲, and FBXO۱۱) as a significant cluster in the PPI network related to miR-۲۱, with Node Score Cutoff: ۰.۲, Degree Cutoff: ۲ and K-Core: ۲. In addition, the miRNA RT-qPCR results showed that, the expression level of miR-۲۱ was significantly higher in gastritis group compared to the healthy group (p< ۰.۰۵). Conclusions: the present study clearly demonstrated the increasing level of blood miR-۲۱ among the gastritis patients infected by H. pylori. Therefore, the altered miRNAs, especially overexpression of onco-miRs, may identify a potential link between miRNAs and pathogenesis of the H. pylori–related complications.

Blood Profiling, Gastric Cancer, H. pylori, Mir-۲۱, Regulatory Network.