Neutral Red is a nitrogenous pH-indicator that can stains lysosomes red, also is a selective, uncompetitive USP4 inhibitor with IC50 of 50 uM.
Neutral Red displays no effective activity on other DUBs (YOD1, USP5, UCHL1, and USP14).
Neutral Red inhibited the deubiquitinating activity of USP4 in colon cancer cells.
Neutral Red affected the protein stability of β-catenin, and the target genes expression of β-catenin.
Neutral Red significantly reduced colony formation and cell migration, reduced the tumor volume in mouse xenograft models.
