Figure 2: Human lung cancer cells A549 (A) and H441 (B), or human colon cancer cells COLO 205 (C) and WiDr (D) cell lines were plated in 96-well plates and were left untreated (NT), received transfection reagent only (Mock), were treated with 25 nM control/non-silencing siRNA (NS siRNA), siRNA specifi c to p53 (p53 siRNA), or were treated with the chemical inhibitor to p53, Pifi thrin a (Pifi thrin). After 24 hours, colon cells were treated with 125 ÁM of linoleic acid (LA), docosahexaenoic acid (DHA), or ethanol (EtOH). Lung cells received 100 ÁM concentrations of the same fatty acids. Proliferation was assessed 48 hours later by MTT. Results represent at least 3 independent experiments. Statistical significance versus NT EtOH (*) and NT DHA (#, only versus other DHA treatments) groups are indicated and represent p values 0.05.