ANGPTL1 attenuates colorectal cancer metastasis by up-regulating microRNA-138

BACKGROUND Angiopoietin-like protein 1 (ANGPTL1) has been reported to suppress migration and invasion in lung and breast cancer, acting as a novel tumor suppressor candidate. Nevertheless, its effects on colorectal cancer (CRC) remain poorly defined. In this study, we aim to demonstrate the biological function of ANGPTL1 in CRC cells. METHODS We explored ANGPTL1 mRNA expression in human CRC tissues and its association with prognosis. CRC cell lines overexpressing ANGPTL1 or with ANGPTL1 knocked down were constructed and analyzed for changes in proliferation, colony formation, migration and invasion. ANGPTL1-regulated microRNAs were analyzed, and microRNA inhibitor and mimics were used to explore the role of microRNA in ANGPTL1-associated biological function. RESULTS ANGPTL1 mRNA expression was down-regulated in CRC tissues, and high ANGPTL1 expression predicted better survival in CRC patients. ANGPTL1 overexpression resulted in suppressed migration and invasion in vitro, and it prolonged overall survival in mouse models. By contrast, its down-regulation enhanced migration and invasion of CRC cells. MicroRNA-138 expression was positively correlated with ANGPTL1 mRNA level in CRC tissues and up-regulated by ANGPTL1 in CRC cells. In addition, the microRNA-138 inhibitor or mimics could reverse or promote the ANGPTL1-mediated inhibition of the migratory capacity of CRC cells, respectively. CONCLUSIONS This study is the first to demonstrate the biological function of ANGPTL1 in CRC cells. ANGPTL1 expression was down-regulated in CRC tissues and inversely correlated with poor survival. ANGPTL1 repressed migration and invasion of CRC cells, and microRNA-138 was involved in this process.