Fig. 4.

PS-T-induced autophagy reverses EMT by degrading Snail. a Protein levels of Snail in MDA-MB-231-siNC and MDA-MB-231-siATG5 cells treated with or without PS-T are evaluated using western blotting. b The mRNA levels of Snail in MDA-MB-231-siNC and MDA-MB-231-siATG5 cells treated with or without PS-T are evaluated using RT-qPCR. c The E-cadherin promoter reporter gene plasmid pGL3-E-cadherin is constructed and a double luciferase experiment is performed. The firefly/renilla fluorescence ratio is measured (mean  ±  SD, **P  <  0.01). d The colocalization and protein levels of LC3 and Snail in MDA-MB-231 cells treated with or without PS-T are tested using immunocytochemistry and assessed quantitatively. The mean optical density is measured and calculated to indicate protein levels. (mean  ±  SD, *P  <  0.05, **P  <  0.01, ***P  <  0.001, scale bars: 10 μm). e Expression of LC3 and Snail in the lung metastasis nodules of breast cancer mouse models are detected using immunohistochemistry (magnification  ×  20, scale bars: 50 μm). f, g MDA-MB-231 cell line overexpressing Snail is constructed by transfecting cells with pcDNA3.1-Snail. The Transwell invasion assay is performed to verify the invasiveness of cells (mean  ±  SD, ***P  <  0.001)