BMP2 inhibits cell proliferation by downregulating EZH2 in gastric cancer.

Gastric cancer is among the most common gastrointestinal malignancies. Recent studies have suggested that bone morphogenetic protein-2 (BMP2) is related to the development and progression of various cancers. Meanwhile, evidence suggests that BMP2 might lead to epigenetic changes in gastric cancer. Thus, we investigated whether BMP2 plays a role in the development of gastric cancer via epigenetic regulation. Cell viability, colony formation, and cell cycle assays were performed to assess the effect of recombinant human BMP2 (rhBMP2) in gastric cancer cells. LDN-193189 and Noggins were used as antagonists of the canonical BMP-SMAD signaling pathway. The protein levels were determined using a western blot analysis. Lentiviral vectors with EZH2 shRNA or EZH2 overexpression were used to mediate the role of EZH2 and the relationship between BMP2 and EZH2 in gastric cancer. We found that rhBMP2 inhibits cell proliferation by arresting the cell cycle in HGC-27 and SNU-216 gastric cancer cells. Neither LDN-193189 nor Noggins, antagonists of the canonical BMP-SMAD signaling pathway, can reverse the effect of rhBMP2 on gastric cancer. Molecularly, rhBMP2 downregulates the expression of EZH2 and H3K27me3, leading to increases in P16 and P21 and decreases in CDK2, CDK4, and CDK6. Altogether, in this study, we demonstrate that BMP2 serves as a tumor suppressor in gastric cancer cells by downregulating EZH2 and H3K27me3 through the non-SMAD BMP pathway, suggesting that BMP2 might be a new therapeutic target for gastric cancer treatment. BMP: bone morphogenetic protein; TGF-β: transforming growth factor-beta; EZH2: enhancer of zeste homolog 2; H3K27me3: trimethylation histone H3 lysine 27; HRECs: human retinal endothelial cells; PcG: polycomb group; PRC: polycomb repressive complexes.