Differential expression of miRNAs in colons of STC patients

To investigate the pathogenesis of slow transit constipation (STC), we have employed microarray-based miRNA analysis as a discovery platform to identify miRNAs potentially related with STC pathogenesis.Full-thickness specimens were obtained from colons of STC patients undergoing total colectomy and ileorectal anastomosis or subtotal colectomy with antiperistaltic cecoproctostomy. And patients undergoing radical surgery for non-obstructing colon cancer (left colon cancer) as control. These patients were not constipated and had no colonic dilatation. The control specimens were obtained at least 5 cm from the resection margin in tumor free areas. Expression of five miRNAs (miRNA-128, miRNA-129-3p, miRNA-20b,miRNA-27b and miRNA-30b) from this signature was identified by arbitrarily setting the threshold at a fold change of 1.3 or above combined with p < 0.05 in the same RNA samples. Expression of miRNAs in the colon may be involved in STC pathogenesis. The samples were obtained and washed with cold PBS, transported in liquid nitrogen and immediately stored in liquid nitrogen after removal. Total RNA was isolated from frozen histologic specimens using a mirVana™ RNA isolation Kit.