Discovery of an Orally Bioavailable Inhibitor of Defective in Cullin Neddylation 1 (DCN1)-Mediated Cullin Neddylation

Abstract

We previously reported the discovery, validation, and structure-activity relationships of a series of piperidinyl ureas that potently inhibit the DCN1-UBE2M interaction. We demonstrated that compound 7 inhibits both the DCN1-UBE2M protein-protein interaction and DCN1-mediated cullin neddylation in biochemical assays and reduces levels of steady-state cullin neddylation in a squamous carcinoma cell line harboring DCN1 amplification. Although compound 7 exhibits good solubility and permeability, it is rapidly metabolized in microsomal models (CL = 170 mL/min/kg). This work lays out the discovery of an orally bioavailable analogue, NAcM-OPT (67). Compound 67 retains the favorable biochemical and cellular activity of compound 7 but is significantly more stable both in vitro and in vivo. Compound 67 is orally bioavailable, well tolerated in mice, and currently used to study the effects of acute pharmacologic inhibition of the DCN1-UBE2M interaction on the NEDD8/CUL pathway.

Targeting NEDDylation as a Novel Approach to Improve the Treatment of Head and Neck Cancer

“…The reasons behind the disparity in in vitro activity between DI-591 and NAcM-OPT is not fully understood, given the compounds similarity in proposed mechanism of action. In vivo work has shown that NAcM-OPT is orally bioavailable and has a half-life of 4.2 h in mice [71]. These data provide evidence that NAcM-OPT may have therapeutic value, particularly in cancers with elevated levels of DCN1.…”

Immunomodulatory effect of NEDD8-activating enzyme inhibition in Multiple Myeloma: upregulation of NKG2D ligands and sensitization to Natural Killer cell recognition

“…Recent reports have described the development of novel small molecules endowed with selective pharmacologic modulation of the N-terminal acetylation-dependent regulatory interaction of UBE2M with DCN1 (DCUN1D1/SCCRO) [ 51 , 52 ], a regulatory subunit of the multiprotein E3 ligase for the ubiquitin-like protein NEDD8. This allows a more targeted and nuanced activity relative to the complete ablation of neddylation afforded by MLN4924 or other NEDD8 E1 inhibitors, with preferential selectivity toward CUL1 and CUL3 [ 52 , 53 ]. Based on these premises, we investigated the activity of the pharmacologic inhibitor of DCN1-UBE2M complex, NAcM-OPT, a small molecule with high level of selectivity for inhibition of DCN1 over the highly homologous human DCN isoforms [ 52 , 53 ].…”

“…This allows a more targeted and nuanced activity relative to the complete ablation of neddylation afforded by MLN4924 or other NEDD8 E1 inhibitors, with preferential selectivity toward CUL1 and CUL3 [ 52 , 53 ]. Based on these premises, we investigated the activity of the pharmacologic inhibitor of DCN1-UBE2M complex, NAcM-OPT, a small molecule with high level of selectivity for inhibition of DCN1 over the highly homologous human DCN isoforms [ 52 , 53 ]. As shown in Supplementary Figure 6A,B and F,G , treatment of SKO-007(J3) cells with NAcM-OPT (micromolar concentration range, previously shown to be effective in cell-based studies [ 52 ]), significantly increased cell surface expression of MICA and MICB, as detected by flow cytometry.…”

“…In an effort to maintain efficacy and reduce toxicity, targeting protein–protein interactions of the neddylation complexes has been pursued as a potential strategy to selectively inhibit the activity of individual CRLs. Recently, crystal structures of DCN1 (a subunit of a multiprotein E3 ligase for the ubiquitin-like protein NEDD8) and its binding partners UBE2M/UBC12 (an E2 neddylation enzyme) suggested that it may be suitable for the design of tailored small-molecule inhibitors [ 52 , 53 ]. In this context, we investigated the activity of the pharmacologic inhibitor of the DCN1-UBE2M complex, NAcM-OPT, described to selectively reduce the steady-state neddylation of Cullin-1 and Cullin-3 with respect to other Cullins [ 52 , 53 ].…”

Targeting the DCN1–UBC12 Protein–Protein Interaction: Novel Approaches and Future Directions

“…The structural analysis of the DCN1-UBC12 interaction suggests that this interaction is amenable for structure-based design of DCN1 inhibitors. Guy et al identified piperidinyl urea based DCN1 inhibitors after screening a library containing 601,194 compounds [10][11][12]. Of these compounds, NAcM-OPT effectively interrupted the DCN1-UBC12 interaction (IC 50 = 80 nM).…”