Profile of Micrornas in Gastric Cancer Tissues and Normal Gastric Mucosa / J. Kupcinskas, V. Salteniene, A. Link, G. Kiudelis, L. Jonaitis, J. Skieceviciene, S. Jarmalaite, L. Kupcinskas and P. Malfertheiner

Background and Aims: MicroRNAs (miRNAs) are promising biomarkers with diagnostic and prognostic implications. These molecules are a group of small non-coding RNAs that modulate gene expression. MiRNA are deregulated in different tumors including gastric cancer (GC). The data on deregulated microRNA profile in GC tissues mandates further research. Aims & Methods: The aim of our study was to evaluate and compare miRNA profile in GC tissue and normal gastric mucosa from healthy individuals. MiRNAs from fresh frozen tissues were profiled using Applied Biosystems ViiATM 7 RT-PCR system with TaqMan Array Micro Fluidic A Cards in 15 tissue samples of primary GC and 11 normal gastric tissues from healthy controls. Log2-fold change (log2FC) calculations were performed using GenEx software. Results: The results of microRNA profiling revealed 3 down-regulated miRNAs in GC tissue samples compared to normal gastric tissue: hsa-miR-135a (log2FC = 7.96199, p = 1.73E-06), hsa-miR-26b (log2FC = 2.2343, p = 1.2E- 05), hsa-miR-148a (log2FC = 6.73728, p = 2.13E-05). The analysis also revealed 15 significantly up-regulated miRNAs in GC tissues compared to normal gastric mucosa: hsa-miR-214 3 (log2FC = 7.6098, p = 2.32E-06), hsa-miR- 155 (log2FC = 5.53734, p = 2.17E-05), hsa-miR-146b (log2FC = 4.59012, p = 3.17E-05), hsa-miR-345 (log2FC = 2.21088, p = 3.56E-05), hsa-miR-223 (log2FC = 6.21766, p = 5.53E-05), hsa-miR-126 (log2FC = 2.36791, p = 8.32E-05), hsa-miR-345 (log2FC = 2.21088, p = 3.56E-05), hsa-miR-223 (log2FC = 6.21766, p = 5.53E-05), hsa-miR-126 (log2FC = 2.36791, p = 8.32E-05), hsa-miR-484 (log2FC = 3.02072, p = 0.000116), hsa-miR-140-3p (log2FC = 2.55172, p = 0.000123), hsa-miR-10a (log2FC = 2.11934, p = 0.000194), hsa-miR-16 (log2FC = 2.1092, p = 0.0002), hsa-miR-24 (log2FC = 2.48963, p = 0.000221), hsa-miR-331 (log2FC = 2.58057, p = 0.000224). Conclusions: MicroRNA profiling analysis revealed three differentially downregulated

and 15 up-regualted miRNAs in GC tissue compared to normal gastric mucosa. This profile may serve as potential biomarker for GC and needs validation in further studies.