Discovery of first-in-class DOT1L inhibitors against the R231Q gain-of-function mutation in the catalytic domain with therapeutic potential of lung cancer.

ABSTRACT

Recent research certified that DOT1L and its mutations represented by R231Q were potential targets for the treatment of lung cancer. Herein, a series of adenosine-containing derivatives were identified with DOT1LR231Q inhibition through antiproliferation assay and Western blot analysis in the H460R231Q cell. The most promising compound 37 significantly reduced DOT1LR231Q mediated H3K79 methylation and effectively inhibited the proliferation, self-renewal, migration, and invasion of lung cancer cell lines at low micromolar concentrations. The cell permeability and cellular target engagement of 37 were verified by both CETSA and DARTS assays. In the H460R231Q OE cell-derived xenograft (CDX) model, 37 displayed pronounced tumor growth inhibition after intraperitoneal administration at 20 mg/kg dose for 3 weeks (TGI = 54.38%), without obvious toxicities. A pharmacokinetic study revealed that 37 possessed tolerable properties (t 1/2 = 1.93 ± 0.91 h, F = 97.2%) after intraperitoneal administration in rats. Mechanism study confirmed that 37 suppressed malignant phenotypes of lung cancer carrying R231Q gain-of-function mutation via the MAPK/ERK signaling pathway. Moreover, analysis of the binding modes between molecules and DOT1LWT/R231Q proteins put forward the "Induced-fit" allosteric model in favor to the discovery of potent DOT1L candidates.