Expression of microRNA let-7 in bladder cancer

Abstract

Objective To detect the differentially expressed microRNAs (miRNAs) in bladder cancer tissue and normal bladder tissue. Methods Total RNA was extracted from bladder cancer tissue and normal bladder tissue by Trizol, and then miRNAs were isolated and enriched from the total RNA. Mammalian miRNA microarrays were used to analyze the differentially expressed miRNAs between the bladder cancer tissue and normal tissue. Data analysis was performed by software of LuxS-can3. 0 and SAM version 2. 1. Choose let-7 gene which was interesting to us, and validation of mi-croarray results was carried out by northern blotting. Results Compared with normal bladder tissues, there were 71 differentially expressed miRNAs in bladder cancer tissue, of which there were 38 down-regulated ones and 33 up-regulated ones. Among these miRNAs, 26 miRNAs were the most significant with 12 up-regulated and 14 down-regulated. The expression of let-7 gene in bladder cancer was down-regulated to normal bladder tissue by northern blotting, which was in agreement with the results of the miRNA microarrays. Conclusion There are differentially expressed miRNAs between bladder cancer tissue and normal bladder tissue, and let-7 gene is probably as a tumor suppressor in bladder cancer. Key words: Bladder neoplasms; Carcinoma; Micro RNA; Genes