MicroRNA-505 suppresses proliferation and invasion in hepatoma cells by directly targeting high-mobility group box 1

Aims: MicroRNA-505(miR-505) expressions have been reported to be altered in the serum of HCC patients. However, the effect and underlying mechanism of miR-505 in hepatoma cells remains poorly understood. The present study intended to investigate the expression levels and the probable role and molecular basis of miR-505 in hepatoma cells. Main methods: Real-time PCR was used to determine the miR-505 expressions in hepatoma cell lines QGY-7703, SMMC-7721 and MHCC97. Furthermore, an up-or down-regulation of miR-505 was performed in MHCC97 by transfected with miR-505 mimics or anti-miR-505, respectively. Cell proliferation, cell invasion, and epithelial-mesenchymal transition were determined. Moreover, the target gene of miR-505 was also investigated. Key findings: The expressions of miR-505 were down-regulated in three hepatoma cell lines. MHCC97 possessed the lowest miR-505 levels among the three hepatoma cell lines. Furthermore, the up-regulation of miR-505 suppressed, whereas the down-regulation of miR-505 promoted proliferation, invasion and epithelial-mesenchymal transition in MHCC97. Moreover, miR-505 could directly bind to the 3'-untranslated region of High-Mobility Group Box 1. Notably, High-Mobility Group Box 1 knockdown apparently promoted cell proliferation and invasion in MHCC97. Significance: We investigated that MiR-505 regulates proliferation and invasion in MHCC97 cells via targeting High-Mobility Group Box 1. (C)16 Elsevier Inc. All rights reserved.