Acta Pharmacologica Sinica (2010) 31: 361–366; doi: 10.1038/aps.2010.4; published online 15 February 2010

Qi-fei WU, Chang LIU^*, Ming-hui TAI, Dong LIU, Lei LEI, Rui-tao WANG, Min TIAN, Yi LÜ

Department of Hepatobiliary Surgery, the First Affiliated Hospital, School of Medicine, Xi’an Jiaotong University, Xi’an 710061, China

Aim: To investigate the effects of small interfering RNA (siRNA) knockdown of forkhead box M1 (FoxM1) on the proliferation and invasion capacities of human hepatocellular carcinoma MHCC-97H cells in vitro.

Methods: The expression levels of FoxM1 in human hepatocellular carcinoma samples, adjacent non-hepatocellular carcinoma liver samples and MHCC-97 cell lines were detected by RT-PCR and Western blotting.  FoxM1 siRNA was transfected into MHCC-97H cells with Lipofectamine 2000.  Cell growth was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and cell cycle analysis was performed by flow cytometry.  Protein expression levels were evaluated by Western blotting.  Anchorage-independent growth and the invasive potency of MHCC-97H cells were measured by soft agar colony formation and a transwell cell invasion assay, respectively.

Results: FoxM1 was over-expressed in hepatocellular carcinoma samples compared to adjacent non-hepatocellular carcinoma liver samples.  FoxM1 siRNA was successfully transfected into MHCC-97H cells, resulting in the significant inhibition of FoxM1 mRNA and protein expression.  Down-regulation of FoxM1 inhibited cell proliferation, caused cell cycle arrest, and decreased invasion of MHCC-97H cells.  Compared with control and mock groups, the FoxM1 siRNA transfected cells showed decreased protein expressions of cyclin B1 and cyclin D1, whereas p27 protein expression was increased.  Down-regulation of FoxM1 reduced the expression of matrix metalloproteinase-2 (MMP-2) and urokinase plasminogen activator (uPA).

Conclusion: FoxM1 is functionally involved in hepatocellular carcinoma cell proliferation and invasion and is a potential target for hepatocellular carcinoma therapy.

Keywords: cell cycle; Forkhead box M1; invasion; small interfering RNA; cell cycle; proliferation; matrix metalloproteinases; urokinase plasminogen activator