Widespread
metastasis of
hepatocellular carcinoma (HCC) was a complex cascade of events, which is still beyond full appreciation. Screening key
proteins, which play a critical role in
metastasis, using high-throughput proteomics approach help discover valuable
biomarkers and elucidate the mechanism of
metastasis. This study was to find out some
metastasis candidate
proteins among HCC cell lines with various metastatic potential by comparative proteomics, and then further validate the
biological function of these
proteins in
metastasis in vitro. The
protein profiles of metastatic HCC cell lines (MHCC97H and MHCC97L) displayed obvious differences compared with nonmetastatic ones (Hep3B). Twenty-six
metastasis candidate
proteins, which were identified by on-line LC-ESI-MS/MS, such as
S100 calcium-binding protein A4 (S100A4),
annexin 1, etc., might have much application in diagnostic procedures and prognosis evaluation. S100A4, as a leading different
metastasis candidate
protein, which overexpressed only in the metastatic cells, was selected for further investigation. A series of assays related to invasion and
metastasis in vitro, including cell motility, invasion, and
matrix metalloproteinases (
MMPs) secretion, were performed in MHCC97H/antisense recombinant plasmid to S100A4 (pcDNA3.1(+) AS S100A4) and the mock controls. All the data in the present study suggested that S100A4 might contribute to HCC invasion and
metastasis through two paths of
matrix metalloproteinase (MMP9) secretion regulation and strengthened motility and invasion properties.