Autophagy inhibitors increase cell death at an early time of siramesine and lapatinib treatment but inhibit cell death at a later time.

<p><b>(A)</b> Inhibition of autophagy by autophagy inhibitors 3-methyladenine (3-MA, 2 mM, and same hereafter) and spautin-1 (3 microM, and same hereafter) under siramesine and lapatinib treatment as demonstrated by LC3-II western blot in MDA MB 231 cells. <b>(B)</b> The effects of 3-MA on cell death under siramesine and lapatinib treatment in MDA MB 231 cells for 4 and 24 hours. <b>(C)</b> The effects of spautin-1 on cell death under siramesine and lapatinib treatment in MDA MB 231 for 4 and 24 hours. Cell death was quantified by flow cytometry as described in the Materials and Methods section (and same hereafter). Before treatment with siramesine and lapatinib, cells were pretreated with 3-MA or spautin-1 for 1 hour (and same hereafter). (D) Inhibition of autophagy by autophagy inhibitors 3-methyladenine (3-MA, 2 mM) and spautin-1 (3 microM) under siramesine and lapatinib treatment as demonstrated by LC3-II western blot in SKBR3 cells. (E) The effects of 3-MA on cell death under siramesine and lapatinib treatment in SKBR3 cells for 4 and 24 hours. These results were representative of three independent experiments (n = 3). *p<0.05; **p<0.01.