Fig. 1

TSN caused LC3-II accumulation stability and suppressed autophagic degradation. A The chemical structure of TSN with a molecular weight of 574.62 g/mol (CAS Number: 58812-37-6). B Western blot analysis of LC3-II and SQSTM1 levels in MDA-MB-231 and MDA-MB-436 cells treated with the indicated concentrations (0.01–5 μM) of TSN for 24 h. C Western blot analysis of LC3-II and SQSTM1 levels in MDA-MB-231 and MDA-MB-436 cells treated with TSN (1 μM) at the time points indicated (0, 4, 8, 12, 24 h). D MDA-MB-231 cells were transiently transfected with GFP-LC3 plasmid. The images were captured under Leica TCS SP8 confocal laser scanning microscope after treatment of TSN (1 μM) or DMSO for 24 h. Scale bar: 10 μm. 20 cells in each group were counted for data analysis. E Cells were transfected with a tandem fluorescent-tagged LC3 (tfLC3), and were exposed to TSN (1 μM), CQ (30 μM) and Torin1 (100 nM) as indicated. The co-localization of GFP-LC3 and RFP-LC3 puncta was examined by confocal microscopy. Scale bars: 10 μm. GFP or RFP puncta were counted at least in 20 cells. F Cells were treated without or with BAF (100 nM) in the presence or absence of 1 μM TSN for 24 h, the expression of SQSTM1 and LC3-II was analyzed by western blot. Comparisons of the intensities were statistically estimated and represented as mean ± SD for three independent experiments (*p < 0.05, **p < 0.01, ***p < 0.001 vs. CTL)