Downregulation of Epidermal Growth Factor Receptor Expression Contributes to 𝛼-TEA's Proapoptotic Effects in Human Ovarian Cancer Cell Lines

Figure 5

Downregulation of ErbB2 or -3 using siRNAs sensitize A2780S and A2780/CP70R cells to $\alpha$-TEA-induced apoptosis and inhibit Akt phosphorylation; whereas overexpression of ErbB2 or -3 blocks $\alpha$-TEA-induced apoptosis and enhances phosphorylation of Akt. (a) Cells were transfected with 20 $\mu$M of sequence-specific synthetic siRNAs against ErbB2 or -3. Nonsilencing (NC) siRNA-transfected cells were used as control. Cells were treated with either vehicle or $\alpha$-TEA for 9 hours and then lysed. 50 $\mu$g of total lysate protein was used for detection of ErbB2, ErbB3, pAkt (Ser 473), total Akt, and PARP by Western blot. Data are depicted as the mean ± SD for three independent experiments. (b) Cells were transiently transfected with empty vector control (pcDNA3), ErbB2 or ErbB3 plasmids. After 24 hours of transfection, cells were treated with or without $\alpha$-TEA for 9 hours, and whole cell extracts examined by immunoblotting. Numbers cited under lanes represent densitometric analyses for comparative purposes. Data are representative of three independent experiments.

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