I-138 is an orally active, reversible inhibitor of USP1-UAF1, with an IC50 of 4.1 nM and Ki of 5.4 nM. It induces monoubiquitination of FANCD2 and PCNA in cells and eliminates USP1 autocleavage in cells. It is intended for research use only.
- Eliminates USP1 self-lysis in HAP-1 USP1 WT and knockout cells
- Induces monoubiquitination of FANCD2 and PCNA in MDA-MB-436 cells
- Dose-dependently inhibits MDA-MB-436 cell viability
- Results in USP1 inhibition and modest antitumor activity in mice bearing MDA-MB-436 tumors
- Benefits BRCA1/2 mutant tumor inhibition in vivo when combined with Niraparib