S100A4 promotes squamous cell laryngeal cancer Hep-2 cell invasion via NF-kB/MMP-9 signal.

S100A4 is a member of the S100 family of calcium-binding proteins, which possesses a wide range of biological functions, such as regulation of angiogenesis, cell survival, motility, and invasion. Here, we demonstrate for the first time a major role of S100A4 in the cell invasion properties of the human laryngeal squamous carcinoma cells (LSCC) and evaluated the mechanism. Cultured human LSCC cell line Hep-2 was overexpressed by transfection of pcDNA3.1-S100A4 plasmid. For this, cellular Hep-2 expression was quantified by Western blot analysis. Moreover, cell invasion and migration assays were performed. Furthermore, the impact of the S100A4 on NF-kB activity and MMP-9 expression was detected. We found S100A4 potently promoted Hep-2 invasion, by increasing cell motility and matrix metalloproteinase-9 (MMP-9) production. The increase in MMP-9 production was mediated by activation of nuclear factor-kB transcriptional activity by S100A4. After MMP-9 and NF-kBp65 was inhibited by BB94 treatment and NF-kBp65 siRNA transfected, pcDNA3.1-S100A4 induced cell invasion and migration was decreased. Our findings thus establish S100A4 as a major factor in the invasive abilities of Hep-2 cells.