Enhancer of zeste homolog 2 (EZH2) is a histone methyltransferase and a catalytic component of polycomb repressive complex 2 (PRC2). EZH2 catalyzes tri-methylation of histone H3 at Lys 27 (H3K27me3) to regulate gene expression through epigenetic machinery. In addition, EZH2 also functions both as a transcriptional suppressor and a transcriptional co-activator. EZH2 also acts as an oncogene in lung adenocarcinoma (ADC) development. DM-01 shows powerful inhibition of EZH2.

DM-01 has a significant ability to reduce cellular H3K27me3 level in K562 cells in the Western blot test. Meanwhile, knockdown EZH2 in A549 cells results in the decrease of cell sensitivity to DM-01 at 50 and 100 μM. DM-01 also increases the transcription expression of DIRAS3 in a dose-dependent manner, a tumor suppressor in downstream. Western Blot shows that compound inhibits EZH2 at both two concentrations (5 and 10 μM), which results in decreased H3K27me3 levels.

As compared to GSK−126 with a selectivity index of 2.3, DM-01 exhibits highly selective for EZH2 with a selectivity index of 3.7. Furthermore, it also shows comparable inhibitory activity to Tazemetostat (IC₅₀=59.2 μΜ) with an IC₅₀ value of 58.7 μΜ for K562 cells. DM-01 strongly inhibits the activity of EZH2 and results in abolished H3K27me expression in K562 cells. Besides, DM-01 also increases the transcription expression of DIRAS3 in a dose-dependent manner, a tumor suppressor in downstream.

Taken together, the above data suggested that DM-01 can inhibit tumor growth through suppressing EZH2. EZH2 plays a pivotal role in cell proliferation and survival, it is recognized as one of the significant oncogenic signaling pathways through improving the H3K27me3 level. DM-01 exhibited its function showing an obvious dependence on EZH2.