Figure 4.

Areca nut is the key component of BQ that induces oral cancer cell migration through activation of the SFKs. Water-soluble extracts of BQ ingredients including AN, IPB, and SL were prepared, and optimal working concentrations were determined as described. (A) Ca9-22 cells were treated with the respective BQ components at an identical concentration (0.2 mg/ml) and migration assays were performed as above. Sucrosewas the irrelevant substance control. (B) Areca nut-induced oral cancer cellmigrationwas further examined as was done in Figure 1A, in that the concentration of AN extract was 0.2 mg/ml and PP2 was 2.5 to 10 µM. (C) Induction of phosphorylation at tyrosine 416 (Src416) at different time points by AN extract (0.2 mg/ml) was detected as previously described. The asterisk indicates a 30-minute period of BQ extract treatment on Ca9-22 cells. (D) Ca9-22 cells were treated with AN extract (0.2 mg/ml) for 30 minutes and then cellular Src kinase activities were directly measured on protein A/G-Sepharose beads carrying Src immunocomplex by in vitro kinase assay.