Discovery of small-molecule inhibitors of RUVBL1/2 ATPase

RUVBL1 and RUVBL2 are highly conserved AAA ATPases (ATPases Associated with various cellular Activities) and highly relevant to the progression of cancer, which makes them attractive targets for novel therapeutic anticancer drugs. In this work, docking-based virtual screening was performed to identify compounds with activity against the RUVBL1/2 complex. Seven compounds showed inhibitory activity against the complex in both enzymatic and cellular assays. A series of pyrazolo[1,5-a]pyrimidine-3-carboxamide analogs were synthesized based on the scaffold of compound 15 with inhibitory activity and good potential for structural manipulation. Analysis of the structure-activity relationship identified the benzyl group on R2 and aromatic ring-substituted piperazinyl on R4 as essential for inhibitory activity against the RUVBL1/2 complex. Of these, compound 18, which has IC50 values of 6.0 +/- 0.6 mu M and 7.7 +/- 0.9 mu M against RUVBL1/2 complex and RUVBL1 respectively, showed the most potent inhibition in cell lines A549, H1795, HCT116, and MDA-MB-231 with IC50 values of 15 +/- 1.2 mu M, 15 +/- 1.8 mu M, 11 +/- 1.0 mu M, and 8.9 +/- 0.9 mu M respectively. A docking study of the compound was performed to predict the binding mode of pyrazolo[1,5-a]pyrimidine-3-carboxamides. Furthermore, mass spectrometry-based proteomic analysis was employed to explore cellular proteins dysregulated by treatment with compounds 16, 18, and 19. Together, the data from these analyses suggest that that compound 18 could serve as a starting point for structural modifications in order to improve potency, selectivity, and pharmacokinetic parameters of potential therapeutic molecules.

Automated summary

RUVBL1 and RUVBL2 are highly conserved AAA ATPases that play a significant role in cancer progression. This study utilized docking-based virtual screening to identify compounds that inhibit the RUVBL1/2 complex. Seven compounds were found to have inhibitory activity in enzymatic and cellular assays. A series of pyrazolo[1,5-a]pyrimidine-3-carboxamide analogs were synthesized based on compound 15, which showed good potential for structural manipulation. Analysis of the structure-activity relationship revealed the importance of the benzyl group on R2 and the aromatic ring-substituted piperazinyl on R4 for inhibitory activity. Compound 18 exhibited the strongest inhibition and showed potential anticancer activity in multiple cell lines. Proteomic analysis identified cellular proteins dysregulated by compounds 16, 18, and 19. These findings suggest that compound 18 could serve as a starting point for structural modifications to improve potential therapeutic molecules.