Figure 1.

Quantitative proteomics and biochemical approaches discover and verify that indisulam downregulates N-cadherin in gastric cancer cells.A, flowchart for the label-free quantitative proteomics used in this work. B, volcano plot for proteins identified by proteomics analysis of cell lysates obtained from the DMSO- or indisulam-treated (10 μM, 6 h) AGS cells expressing DCAF15. −Log₁₀ (p-value) and Log₂ (Indisulam/DMSO) were obtained from Proteome Discoverer database search and Perseus analysis. Proteins (red circles) with −Log₁₀ (p-value) >1.30 (i.e., p-value < 0.05, horizontal dotted line) and Log₂ (Indisulam/DMSO) >1.0 or <−1.0 (vertical dotted lines) were considered as differentially regulated by indisulam. C, tandem mass spectrometry spectrum of a representative tryptic peptide derived from N-cadherin. The amino acid sequence, charge state (z), MH⁺, and Δmass were provided. D, Western blotting analysis of cell lysates obtained from AGS and MGC803 cells treated with DMSO or indisulam (10 μM) for 72 h. DMSO, dimethyl sulfoxide.