Fig. 4.

FSIP1 deficiency enhances autophagy and drug resistance in TNBC. (A and B) Expression levels of LC3-I, LC3-II, ATG5, ATG7, Beclin 1, SQSTM1, and ULK1, as well as ULK1 Ser317 and Ser757 phosphorylation in control (Ctl) and shFSIP1 MDA-MB-231 and MDA-MB-468 cells were determined by Western blot. Shown also are LC3-I and LC3-II expression levels in Ctl and FSIP1-KO MDA-MB-231 cells. Autophagosome number was examined by transmission election microscopy (n = 12 per group). (Scale bar in A: 1 µm.) (C) Expression levels of LC3, ATG5, and ATG7 in Ctl and shFSIP1 MDA-MB-231 tumor tissues (two sections each, from Fig. 1D) were examined by immunohistochemistry and semiquantified. (Scale bars in C: 100 µm.) (D) Inhibition of autophagy sensitizes TNBC cells to docetaxel in vitro. Ctl and shFSIP1 MDA-MB-231 cells were treated with vehicle or docetaxel (20 µg/mL) in the presence or absence of Baf-A1 (10 nM) or 3-MA (5 mM). Cell viability was measured at 12, 24, and 48 h (MTS). Data are representative images or expressed as mean ± SEM; one-way ANOVA followed by post hoc Newman-Keuls test; **P < 0.01.