Mechanisms Mediating the Effects of γ-Tocotrienol When Used in Combination with PPARγ Agonists or Antagonists on MCF-7 and MDA-MB-231 Breast Cancer Cells
Figure 11
Apoptotic effects of γ-tocotrienol and PPARγ antagonists (GW9662 or T0070907) alone or in combination on caspase-3 and cleaved PARP levels on (a) MCF-7 and (b) MDA-MB-231 human breast cancer cells. For Western blot studies, MCF-7 and MDA-MB-231 cells were initially plated at cells/100 mm culture dish and maintained on control media for a 3-day culture period. Afterwards, cells were divided into the various treatment groups, media was removed, and cells were exposed to their respective treatment media for a 24-h treatment period. In addition, cells were exposed to their respective treatment media for a 96-h treatment period, where fresh media was added every other day. MCF-7 cells were exposed to treatment media containing 0–2 μM γ-tocotrienol, 0–3.2 μM GW9662, or 0–3.2 μM T0070907 alone or in combination, whereas MDA-MB-231 cells exposed to treatment media containing 0–3 μM γ-tocotrienol, 0–6.4 μM GW9662, or 0–6.4 μM T0070907 alone or in combination. Afterwards, whole cell lysates were prepared from cells in each treatment group for subsequent separation by polyacrylamide gel electrophoresis (50 μg/lane) followed by western blot analysis. In parallel studies, (a) MCF-7 cells were plated at a density of (6 wells per group) in 24-well culture plates, whereas (b) MDA-MB-231 cells were plated at a density of (6 wells per group) in 96-well culture plates and exposed to the same treatments as described above. After a 24-h treatment exposure, viable cell number in all treatment groups was determined using MTT assay. Vertical bars indicate the mean cell count ± SEM in each treatment group. as compared with vehicle-treated controls.
