Abstract:

Background and purpose: MicroRNAs (miRNAs) play an important role in tumor biological behavior. miRNAs are down-regulated or up-regulated in various cancer types, triggering abnormal cell differentiation, proliferation and apoptosis. This study was designed to investigate the expression and clinical significance of miR-187* in colorectal cancer (CRC), and further to investigate its roles in promoting cell apoptosis. Methods: The expressions of miR-187* in 40 CRC cases were examined by real-time quantitative reverse transcription-PCR (qRT-PCR). The relationship between miR-187* expression and clinical features of CRC was analyzed. HCT116 cells were transfected with a miR-187* mimic and the apoptosis of the transfected cells were examined by flow cytometry (FCM). Results: The expression of miR-187* was down-regulated in CRC tissues 0.165 (0.106, 0.428) compared with those in normal tissues 0.334 (0.211, 0.712) (P<0.05), especially in mucinous carcinoma and older age CRC (P<0.05). Transfection of HCT116 cells with a miR-187* mimic up-regulated the expression of miR-187* and increased cell early apoptosis (P<0.05). Conclusion: The expression level of miR-187* was lower in CRC. miR-187* expression correlates with histological type and age. Transfection of HCT116 cells with a miR-187* mimic accelerates apoptosis of tumor cells, suggesting that miR-187* is a potent tumor suppressor.

Key words: Colorectal cancer, microRNA, microRNA-187*, Apoptosis