Figure 5From: Omega 3 fatty acids chemosensitize multidrug resistant colon cancer cells by down-regulating cholesterol synthesis and altering detergent resistant membranes compositionEffects of ω 3PUFAs on cholesterol and ABC transporters in whole cell and DRMs. HT29 and HT29-dx cells were incubated for 48 h in the absence (CTRL) or in the presence of 50 μM arachidonic acid (AA), docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA). (A) Total lipids were extracted and the amount of cholesterol was measured in triplicate as reported under Methods. Data are presented as mean ± SD (n = 3). Versus respective CTRL: * p < 0.01; HT29-dx versus HT29 cells: ° p < 0.01. (B) DRMs were isolated as detergent-resistant membranes by separation on sucrose gradient; then the amount of cholesterol was measured as reported in Methods. Data are presented as mean ± SD (n = 4). Versus respective CTRL: * p < 0.05; HT29-dx versus HT29 cells: ° p < 0.01. (C) Surface levels of Pgp, MRP1 and BCRP were measured in non-permeabilized cells by flow cytometry. The figures shown here are representative of three similar experiments, performed in triplicate. (D) Western blot detection of Pgp, MRP1 and BCRP on DRM extracts. Flotillin expression was used as control of equal protein loading. The figure is representative of two experiments with similar results. The band density ratio between each protein and flotillin was expressed as arbitrary units. Versus CTRL HT29: * p < 0.05; versus CTRL HT29-dx: p < 0.005.Back to article page