ZS34 is a potent, orally active, and selective inhibitor of MAT2A, with an IC50 value of 13.7 nM, and it exhibits minimal inhibition of hERG and UGT1A1. By inhibiting SAM synthesis, reducing SDMA levels, and inducing DNA damage, ZS34 selectively inhibits the growth of methylthioadenosine phosphorylase (MTAP)-deficient cancer cells. It demonstrates antitumor activity in HCT116 MTAP-/- xenograft mouse models and is suitable for research on MTAP-deficient cancers.

MAT2A:13.7 nM

ZS34 inhibits the proliferation of MTAP-deficient cells (NCI-H838, NCI-H1437, MCF-7, MDA-MB-231, and MIA PaCa-2) with IC50 values of 1.70, 386, 38.1, 37.2, and 115 nM, respectively, demonstrating selectivity over MTAP-proficient cells (A-375, AsPC-1, DU145, NCI-H460, and NCI-H520) with IC50 values exceeding 10,000 nM. In MTAP-deficient HCT116 cells, ZS34 exhibits strong antiproliferative activity (IC50 = 124 nM) but shows weak activity in WT HCT116 cells (IC50 > 10,000 nM), with an impressive selectivity index (SI) over 80.6. ZS34 (0-10 μM; 96 hours) selectively induces DNA damage in MTAP-deficient HCT116 cells by inhibiting MAT2A. The compound binds to the allosteric site of the MAT2A dimer, forming hydrogen bonds with Arg313 and coordinate water molecules, engaging in π-π stacking with Phe20, Trp274, and Phe18, while its adjacent methyl group interacts with Phe333's CH-π. Western Blot analysis using HCT116 (MTAP -/-) and HCT116 (WT) cell lines at concentrations of 0, 0.1, and 1 μM over 96 hours showed a dose-dependent decrease in SDMA levels and a marked increase in γH2AX levels, a DNA damage marker, specifically in HCT116 MTAP -/- cells but not in HCT116 WT cells. Immunofluorescence with concentrations of 0.1, 1, and 10 μM for 96 hours resulted in a significant rise in γH2AX levels in HCT116 MTAP -/- cells compared to the control, without affecting HCT116 WT cells.

ZS34, administered orally at doses of 10 and 30 mg/kg once daily for 30 days, demonstrated significant in vivo antitumor activity and favorable safety profiles in an HCT116 MTAP -/- xenograft model. A single oral dose of ZS34 (400 mg/kg) showed no observable toxicity in mice.