Roles of miR-186 and PTTG1 in colorectal neuroendocrine tumors.

Objectives: This work aims to investigate the expression of miRNA-186 in patients with colorectal cancer tissues, blood and feces and its roles in regulating the infiltration and invasion in colorectal cancer. Methods: Totally 39 patients with surgical resection were included from August 2012 to February 2015 in Jilin Province People’s Hospital as the Colorectal Neuroendocrine tumor (CNET). Peripheral blood, stool, and resected tumor tissues with adjacent normal of each patient was collected. In the same period, the blood and stool from 25 patients with hemorrhoids or other non-neoplastic diseases were collected and these samples used as clinical control group. MiR-186 expression and PTTG1 (pituitary tumor-transforming 1) expression were detected by quantitative Real-Time PCR (qRT-PCR). The PTTG1 protein expression in tumor samples were detected by Western Blot, while its expression in blood and stool were detected by Elisa. Results: Compared with the control group, the expression of PTTG1 mRNA and protein was significantly up-regulated in tumor samples, blood, and stool of patients with CNET, while the expression of miR-186 was down-regulated (P < 0.05). Conclusion: PTTG1 expression was significantly up-regulated in patients with CNET, which was induced by the down-regulated miR-186. MiR-186 may participate in the regulation of infiltration and invasion in CNET patients through targeting PTTG1 expression.