Table 3

Incorporation of [3H]palmitic acid into Cer and GlcCer of treatment and control MCF7 cells

LipidPercentage 3H-lipida
MCF7wtMCF7wt + 5 μm PDMPMCF7/AdrRMCF7/AdrR + 5 μm PDMPMCF7/AdrR + 1 μg/ml valspodarMCF7/AdrR + 1 μg/ml valspodar + 5 μm PDMP
Cer0.54 ± 0.090.25 ± 0.010.21 ± 0.030.35 ± 0.050.86 ± 0.011.33 ± 0.08
GlcCer1.19 ± 0.071.16 ± 0.182.19 ± 0.151.32 ± 0.123.02 ± 0.351.16 ± 0.09
  • a Cells were incubated with 1.0 μCi/ml [3H]palmitic acid in complete medium for 24 h, washed, and harvested by scraping. Total lipids were extracted using equal volumes of methanol-2% acetic acid/chloroform/water. The radioactivity of total extracted lipids was measured by scintillation counting. Lipids were spotted onto TLC plates and developed in chloroform/acetic acid (90:10) for Cer or chloroform/methanol/ammonium hydroxide (70:20:4) for GlcCer. Lipid spots corresponding to cochromatographed standards were scraped into scintillation vials for quantitation by liquid scintillation counting. The lipid amounts presented are expressed as a percentage of the total tritiated lipid extracted from the cells.