FIGURE 7.

Src-mediated regulation of CAF1 subunits is DNA methylation-dependent. A, total RNA from MCF10A Src-ER cells treated with a combination of vehicles, 1 μm 4-OHT, and 0.3 μm 5-AzaC were analyzed by qRT-PCR. Expression levels of p150 and p60 were normalized by GAPDH pre-mRNA level and expression levels in cells treated with vehicles were set to 1. The individual values (gray circle), means (black box), and S.D. of means of relative mRNA levels are shown. The means ± S.D. were derived from three biological replicates. B, total cell lysates from MCF10A Src-ER cells treated with a combination of vehicles, 1 μm 4-OHT, and 0.3 μm 5-AzaC were immunoblotted with antibodies against p150, p60, and α-tubulin. C, an illustrative model of how Src activation leads to increased invasiveness and motility through regulating CAF1 levels, consistent with the data presented in this study. This shows Src activation (green upward arrow) promoting decreased CAF1 levels (red downward arrow), resulting in an increase in motility, scattering, and invasion phenotypes (green upward arrows). The model envisages a role for CAF1 in untransformed cells in suppressing motility and invasiveness. Pretreatment with 5-AzaC does not prevent Src activation but strongly suppresses the downstream activation of motility and invasion phenotypes normally caused by Src.