Differential expressions of microRNAs in gastric carcinoma tissues

Objective To study the difference in microRNAs (miRNAs) expressions between gastric cancer tissues and adjacent normal tissues.Methods Snap frozen tissues of gastric carcinoma confirmed histologically and normal gastric tissues located ＞ 5 cm away from the tumor margin were collected during surgical intervention from 25 patients.Seven samples from the 25 patients were extracted for total RNA which was then used to detect differential miRNAs expression in gastric cancer tissues and adjacent normal tissues on Illumina microarray platform.Quantitative real-time PCR analysis was performed in 25patients to compare the expressions of differential miRNAs between cancer tissues and normal gastric tissues.And the correlation between clinicopathological features and differential miRNAs in 25 patients was analyzed.Results Illumina microarray showed down-regulation of HS-138,HS-153 and HS-157,and up-regulation of miR-181a,miR-21,miR-21*,miR-27a,miR-584 and miR-93 in gastric cancer tissues.Compared with normal gastric tissues,a statistically differential up- regulation of miR- 18 la (56.848 ±135.551 vs 3.950±12.101,P＜0.05) but not of miR-584 (P＞0.05) was noted in gastric cancer tissue by quantitative real-time PCR.The expression of miR- 181a in gastric cancer tissue was correlated with lymph node metastasis (rp=0.462,P=0.009) and patient age (rp=0.414,P=0.023),but was not with gender (P=0.220) and pathological types (P=0.106).Conclusion Differentially expressed miRNAs in gastric carcinoma tissues may be detectable with miRNAs microarray and fluorescent quantitative PCR. Key words: MicroRNAs;  Gastric cancer;  Microchip analytical procedures;  Fluorescent quantitative PCR