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. 2013 Sep 10;2(9):e121. doi: 10.1038/mtna.2013.45

Figure 6.

Figure 6

Autophagy contributes to cell death induced by Bcl-2 silencing in breast cancer cells. (a) Inhibition of autophagy by knocking down autophagy genes, including Beclin-1 or ATG8 inhibits cell death induced by Bcl-2-siRNA in MDA-MB-231 cells. Bcl-2 siRNA treatment was started 48 hours after control, Beclin1 or ATG8 siRNA transfections in MDA-MB-231 cells and cell death was assessed about 48 hours after Bcl-2 siRNA treatment. (b) Doxorubicin-induced autophagy is mediated by Bcl-2 downregulation in MDA-MB231 breast cancer cells. Doxorubicin treatment leads to Bcl-2 downregulation, which leads to autophagy induction as evidenced by increased expression of LC3-II autophagy marker. (c) Silencing of Bcl-2 by siRNA increased doxorubicin-induced autophagy in MDA-MB-231 cells. Cells were treated Bcl-2 siRNA for 24 hours and later incubated with doxorubicin for 48 hours. Western blot analysis shows that combination therapy (Bcl-2 siRNA and doxorubicin) induces more potent authophagy as evidenced by LC3-II and ATG5 expression. (d) Silencing of Bcl-2 by siRNA leads to autophagy as indicated by upregulation of Beclin-1 autophagy promoting protein in MDA-MB-231 cells. (e) Silencing of Bcl-2 by siRNA also induces autophagy MCF7/DoxR breast cancer cells as evidenced by LC3-II induction and apoptosis.