Figure 4.

Decursin reduces cathepsin C expression and activity. A. CTSC expression was confirmed in decursin-treated cells, and lysosome marker LAMP2 was identified to confirm effects on lysosomes. Full-length blots are presented in Supplementary Figure 6. B, C. Autophagic flux was evaluated by western blotting after treatment with siCTSC and rhCTSC. Full-length blots are presented in Supplementary Figure 6. D. Following co-transfection of siCTSC and GFP-LC3 plasmid, puncta were observed using immunocytochemistry (×1000). Scale bar: 2 μm. E. SNU216 and NCI-N87 cells were treated with decursin and rhCTSC, then cultured for 24 h. Full-length blots are presented in Supplementary Figure 6. F. To measure inhibition of CTSC by decursin, fluorescence values generated by CTSC cleavage were measured using Gly-Arg-AMC, a CTSC specific substrate. n.s.: not significant; *P < 0.05; **P < 0.01; ***P < 0.001.