Figure 6.

Combination of TNFα and N-6 induces cancer cell apoptosis in an RXRα/tRXRα-dependent manner. (A) HeLa cells grown in 6-well plates were treated with or without N-6 (5 μmol/L) and TNFα (10 ng/mL) for 3 days. Colonies were stained with 0.1% crystal violet and counted. (B and C) HCT116 and MCF-7 cells were treated with or without N-6 (10 μmol/L) and TNFα (10 ng/ mL) for 15 h in serum free medium. Cell lysates prepared were analyzed by Western blotting for PARP cleavage. (D) MCF-7 cells grown in 24-well plates were treated with or without N-6 (10 μmol/L) and/or TNFα (10 μg/mL) for 3 days. Apoptotic cells were detected by TUNEL staining and counted. (E) HCT116 cells transfected with RXRα siRNA or control siRNA for 48 h were treated with or without N-6 (10 μmol/L) and TNFα (10 ng/mL) for 15 h. Cell lysates prepared were analyzed by Western blotting for PARP and caspase-8 cleavage. One of three similar experiments is shown