Evaluation of miR-143 and miR-338 Expression Profiles in Tumor Tissue and Margin in Patients with Gastric Cancer

Micro-RNAs are non-coding RNAs with a length of approximately 22 nucleotides, which, by binding to the target gene's mRNA, regulate its expression and play an important role in tumor suppression. Changes in the expression level of microRNAs play a crucial role in the pathobiology of multiple cancers. In this study, the expression levels of miR-143 and miR-338 were compared in gastric cancer and its margin.
This case-control study was performed on 35 biopsy samples of gastric cancer and adjacent tissue of the patients who were admitted to Imam Reza Hospital. Total RNA was extracted from the tissue using Trizol reagent and based on the company's instructions. Then, the acquired microRNAs were used to synthetize cDNA. Expression of microRNAs was measured by RT-PCR. U6 was used as a house keeping gene. Statistically, the obtained results were analyzed using Graph pad Prism software.
According to the results obtained in this study, the expression levels of miR-143 (p≤0.1244) and miR-338 (p≤0.0059) in tumor tissue, compared to the adjacent tissue, were down-regulated. Reduced expression of miR-143 and miR-338 in the tumor tissue, in comparison to margin tissue, was about four folds.
This study showed that the average expression level of miR-143 and miR-338 was significantly decreased in gastric cancer tissues compared to adjacent non-tumor tissues, and these results strongly suggest that miR-143 and miR-338 may play a key role in gastric cancer progression; therefore, they may be considered tumor markers.