Small Molecule Inhibition of the Ubiquitin-specific Protease USP2 Accelerates cyclin D1 Degradation and Leads to Cell Cycle Arrest in Colorectal Cancer and Mantle Cell Lymphoma Models
作者:Mindy I. Davis、Rajan Pragani、Jennifer T. Fox、Min Shen、Kalindi Parmar、Emily F. Gaudiano、Li Liu、Cordelle Tanega、Lauren McGee、Matthew D. Hall、Crystal McKnight、Paul Shinn、Henrike Nelson、Debasish Chattopadhyay、Alan D. D'Andrea、Douglas S. Auld、Larry J. DeLucas、Zhuyin Li、Matthew B. Boxer、Anton Simeonov
DOI:10.1074/jbc.m116.738567
日期:2016.11
Deubiquitinases are important components of the protein degradation regulatory network. We report the discovery of ML364, a small molecule inhibitor of the deubiquitinase USP2 and its use to interrogate the biology of USP2 and its putative substrate cyclin DL ML364 has an IC50 of 1.1 mu M in a biochemical assay using an internally quenched fluorescent di-ubiquitin substrate. Direct binding of ML364 to USP2 was demonstrated using microscale thermophoresis. ML364 induced an increase in cellular cyclin D1 degradation and caused cell cycle arrest as shown in Western blottings and flow cytometry assays utilizing both Mino and HCT116 cancer cell lines. ML364, and not the inactive analog 2, was antiproliferative in cancer cell lines. Consistent with the role of cyclin D1 in DNA damage response, ML364 also caused a decrease in homologous recombination mediated DNA repair. These effects by a small molecule inhibitor support a key role for USP2 as a regulator of cell cycle, DNA repair, and tumor cell growth.
Synthesis and structure–activity relationships of USP48 deubiquitinylase inhibitors
yet been resolved and potent inhibitors are not known. We screened a set of 14 commercially available USP inhibitors for their activity against USP48 and identified the USP2 inhibitor “ML364” as a candidate for further optimization. Using a ligand-based approach, we derived and synthesized a series of ML364 analogs. The IC50 concentrations of the new compounds to inhibit USP48 were determined in a deubiquitinylase