Figure 1

Increase of lysosomes and lysosomal protease activity during TGFβ-1 induced EMT in NMuMG cells and the MMTV-PyMT breast cancer cell line iPL32. (A) Representative phase contrast images show morphological changes after two and four days TGFβ-1 (2 ng/ml) treatment in NMuMG and iPL32 cells. (B,C) Western blot analysis of selected cathepsins in NMuMG (B) and iPL32 (C) whole cell lysates is shown with α-tubulin as loading control. NMuMG day 0 ( I ) and iPL32 day 0 ( II ) were used as positive controls. (D) Ctsl and Ctsb activity were measured by z-PheArg-AMC hydrolysis in presence or absence of Ca074 after four days of TGFβ-1 treatment in NMuMG and iPL32 cells, normalized to untreated (untr.) and are shown as the mean ± SEM (n = 3, *p ≤ 0.05 by one sample two tailed t test). (E) Abundance of acidic organelles of untreated and four days TGFβ-1 treated NMuMG and iPL32 cells were analyzed by quantitative LysoTracker^TM flow cytometry. The mean ± SEM is shown (n = 3, *p ≤ 0.05 by two tailed t-test on independent groups).