Ras signaling is activated during melanocyte anchorage blockade and its inhibition abrogates increased Dnmt1 protein level and global DNA hypermethylation observed in this condition.

<p><b>A.</b> Ras activity was evaluated in adhered (D0) and deadhered melanocytes (D30′) <b>B.</b> Dnmt1 protein expression using whole cell extracts was measured in the same conditions. <b>C.</b> The 5-methylcytosine (5 mC) content was determined by FACS using a specific antibody in adhered (D0) and deadhered (D3 h) melan-a melanocytes, treated (FTI) or not (NT) with 12.5 µM farnesyltransferase inhibitor. <b>D.</b> Melanocyte anchorage impediment results in Ras activation, which leads to increased Dnmt1 level and global DNA hypermethylation. **p<0.01.