Involvement of microRNA-224 in cell proliferation, migration, invasion, and anti-apoptosis in hepatocellular carcinoma.

BACKGROUND AND AIM: Changes in microRNA (miRNA) expression have been detected in a broad range of biological processes including cancer. Here we determined the role of miRNA dysregulation in hepatocellular carcinoma (HCC).

METHODS: We investigated the expression of nine cancer-related miRNAs in HCC. Among these, miR-224 was the most significantly uprgulated in HCC tissues (n = 18), compared with normal (n = 9) and HCC adjacent non-tumorous liver tissues (n = 18). After leading-in currently reported gene targets from Sanger miRBase, we characterized the expression profiles of target genes of miR-224 using cDNA microarray. The altered expression was subsequently validated by real-time polymerase chain reaction and Western blot. The phenotypic changes by miR-224 expression were identified by cell viability, apoptosis, and in vitro scratch assays.

RESULTS: The microarray analysis and miRNA target prediction analysis allowed the identification of significant changes in 68 putative gene targets after overexpression of miR-224. The high-ranking genes CDC42, CDH1, PAK2, BCL-2, and MAPK1 were confirmed as important targets of miR-224 and involvement in hepatocarcinogenesis. Overexpression of miR-224 significantly in Hek293 and Huh7 cells altered the expression levels of CDC42, CDH1, PAK2, and BCL-2 at both mRNA and protein levels. Similar changes in the expression of the same genes were also observed in HCC tissues. Via functional analyses, cell proliferation, migration and anti-apoptosis were proved to be affected by miR-224 expression.

CONCLUSION: The results suggest that miR-224 plays a role in cell proliferation, migration, invasion, and anti-apoptosis in HCC by directly binding to its gene targets, implicating this RNA in HCC development and progression.