Figure 2

Sequence-specific downregulation and cytotoxic effects of antisense Bcl-2 oligodeoxynucleotides on BT-474 and ZR-75-1 cells. (a) Specific inhibition of Bcl-2 protein expression by treatment with antisense (AS) Bcl-2 oligodeoxynucleotides (ODNs). Cells were treated with 10 μg/ml Lipofectamine alone (control) or 1.0 μM AS, mismatch control (MM), or random control (RC) ODNs for 24 hours. Cells were then cultured in standard medium, total protein was extracted, and Bcl-2 and β-actin protein levels were analyzed by Western blotting. (b) Quantification of Bcl-2 expression by densitometric analysis. The expression of Bcl-2 in cells treated with control, AS Bcl-2, RC Bcl-2, and MM Bcl-2 ODNs was normalized with β-actin, and the relative values are presented. Error bars indicate SD. The data presented are from three independent experiments. (c) Effects of AS Bcl-2 ODNs on the proliferation of BT-474 and ZR-75-1 breast cancer cells in vitro. Cells were treated with various concentrations of AS Bcl-2 ODNs in 24-well dishes. Four days after treatment, cells were stained with trypan blue and counted. Error bars indicate SD. The data presented are from three independent experiments.