MicroRNA-449a suppresses liver cancer migration and invasion through targeting CXC chemokine ligand 5

Abstract

Objective To explore the expression of microRNA (miRNA, miR)-449a in liver cancer, the effect on migration and invasion, and the possible regulatory mechanism. Methods Eighteen cases of liver cancer tissues and adjacent tissues were collected. The expression of miR-449a in liver cancer tissues and adjacent tissues, 4 kinds of human liver cancer cell lines, and human normal hepatocytes was detected by reverse transcriptase-polymerase chain reaction (RT-PCR). The human liver cancer cell lines were transfected with miR-449a mimic and the negative control (NC) plasmid. The expression of miR-449a after transfection was detected by RT-PCR. The cell number of invasion and migration after transfection in the two groups was measured by Transwell assays. The expression of CXC chemokine ligand 5 (CXCL5) protein in the cells was detected by Western blotting. Results As compared with the adjacent tissues, the expression of miR-449a in liver cancer tissues was significantly reduced (0.957±0.165 vs. 0.462±0.221, t=4.137, P=0.021). As compared with the human normal hepatocytes, the expression of miR-449a in four kinds of human liver cancer cell lines was significantly reduced too (P=0.009, 0.008, 0.005, 0.020), the difference being statistically significant (BEL-7402: 6.873±1.293, HepG2: 7.246±1.320, NC: 1.000, P=0.012, 0.017). Two kinds of human liver cancer cell lines with the middle expression of miR-449a were chosen, and the expression of miR-449a after transfection was statistically increased, and the cell number of invasion (BEL-7402 vs. NC: 21.57±13.32 vs. 79.84±11.68; HepG2 vs. NC: 45.32±12.65 vs. 92.21±15.43, t=24.331, 21.109, P=0.011, 0.019) and migration (BEL-7402 vs. NC: 10.25±3.21 vs. 26.63±6.48; HepG2 vs. NC: 23.44±10.08 vs. 65.65±12.26, t=11.039, 12.224, P=0.010, 0.008) after transfection was significantly reduced. The expression of CXCL5 protein after transfection was statistically significantly reduced (BEL-7402 vs. NC: 0.367±0.083 vs. 0.965±0.110; HepG2 vs. NC: 0.163±0.043 vs. 0.949±0.141, t=20.176, 25.158) (P=0.021, 0.016). Conclusion The miR-449a in liver cancer is expressed weakly, and can serve as a tumor suppressor to influence the migration and invasion of liver cancer cells through targeting CXCL5. Key words: MicroRNA-449a; CXC chemokine ligand 5; Liver cancer; Migration; Invasion