Background: The amplification of Murine Double Minute 2 (MDM2) and mutation of P53 are significant processes in the incidence of gastric cancer. APG-115, a small molecular inhibitor of MDM2-P53, is a novel potential anticancer agent. We aim to investigate the anticancer effect of APG-115 in gastric cancer.

Methods: We selected 87 pairs of gastric cancer tissues (primary tumors and metastatic tissues). Using Immunohistochemistry (IHC) and Fluorescence in situ hybridization (FISH), we examined the expression and amplification of MDM2 and P53. Using MTS, we examined the anti-proliferation activity of APG-115 in five gastric cancer cell lines (AGS, MKN-45, BGC-823, NCI-N87, NUGC-3) by CCK-8 assay. We used western blot analysis and siRNA interference for mechanism exploration to examine the anti-cancer activity of APG-115 in p53 wild type gastric cancer cell lines. Gastric cancer cell xenograft nude mice models were used for in vivo efficacy evaluation.

Results: We examined 87 pairs of gastric cancer tissues in IHC. The results suggested that the primary tumors and metastatic tissues with high expression of MDM2 and P53 have shortened survival. The proliferation inhibition of APG-115 on p53 wild-type gastric cancer cells of AGS and MKN45 was concentration and time dependent. APG-115 induced apoptosis in gastric cancer cells. APG-115 can induced cell-cycle arrest in G1/G0 phase in the p53 wild-type of gastric cancer cells. APG-115 exhibited potent antitumor activity against established human gastric cancer xenografts.

Conclusions: APG-115 can inhibitor tumor growth in p53 wild-type gastric cancer cells by inducing apoptosis and cell cycle arrest both in vitro and vivo. APG-115 can serve as an effective and precise therapeutic strategy for gastric cancer.

Citation Format: Lin Zhang, Luo Qiuyun, Yan Xianglei, Xueping Wan, Luping Yuan, Yuxing Zhang, Suna Zhou, Wentao Pan, Mengxian Pan, Miaozhen Qiu, Shijuan Mai, Dajun Yang. A novel small molecule inhibitor of MDM2-p53 (APG-115) has antitumor activity in gastric adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2061.