Inhibitory effect of curcumin on motility of human oral squamous carcinoma YD-10B cells via suppression of ERK and NF-kappaB activations. 
Oral squamous cell carcinomas (OSCCs) are characterized by a marked propensity for local invasion, so the identification of agents inhibiting the onset and progression of OSCC has recently gained interest.  Here, we found that curcumin inhibited cell proliferation and motility with decreased activities of matrix metalloproteinase (MMP)-2/9 and decreased mRNA expressions of urokinase-type plasminogen activator (uPA) and its receptor uPAR in the highly invasive human YD-10B OSCC cells.  Western blot analysis showed that curcumin inhibited the activation of MAP kinases (especially ERK) and NF-kappaB, which are involved in the transcriptional regulation of proteolytic enzymes.  In conclusion, curcumin is one of the strong phytochemicals with antimotility activity of OSCC; the inhibitory effect of curcumin on the motility of YD-10B cells could result from its potential to inhibit the activation of ERK/MAP kinase and NF-kappaB that consequently down-regulate the mRNA expressions and activities of proteolytic enzymes such as uPA and MMP-2/9.