Dysregulation of miRNAs and their potential as biomarkers for the diagnosis of gastric cancer.

Recent studies demonstrated that microRNA (miRNA) expression is dysregulated in numerous human cancers. In this study, we investigated the expression patterns of 8 miRNAs in gastric cancer and evaluated their clinical significance in order to identify potential biomarkers for gastric cancer diagnosis. Total RNA was extracted from gastric cancer and normal tissues from 20 pairs of paraffin-embedded specimens. The expression levels of the miRNAs were detected by quantitative reverse transcriptase polymerase chain reaction using specific stem-loop primers, with U6 as the internal reference gene. The association between miRNA expression level and clinicopathological factors was investigated. The expression of miR-21, -103, -106a, -221 and -222 in gastric cancer samples was significantly higher compared to that in the paired normal samples. Conversely, the expression of miR-143 and -195 in cancer tissues was significantly lower compared to that in normal tissues. However, miR-126 exhibited no difference between gastric cancer and normal tissues. A multivariate analysis demonstrated that the expression of miR-143 and -195 were associated with clinicopathological parameters, including depth of invasion and lymph node metastasis. This association may be applicable to future decisions regarding treatment or as a diagnostic biomarker.