Abstract 5374: Amentoflavone induces apoptosis and promotes G1 phase cell cycle arrest through regulating p53 pathway in HT29 human colorectal cancer

Abstract

Abstract Amentoflavone (AF) is a nature diflavonoid compound that could extract from Ginkgo biloba and Chamaecyparis obtusa. AF had been proven with many biological properties, including anti-oxidant activity, anti-inflammatory, and could also inhibit NF-κB mediating apoptosis to achieve anti-tumor effects in hepatocellular carcinoma. p53, a tumor suppressor gene that could inhibit cell division and proliferation through regulating with cell cycle and apoptosis related molecules. Patients with p53 gene mutation were often resistant to current standard treatment in clinic. Several studies also reported that the activation of p53 could induce apoptosis in colorectal cancer (CRC). Currently, there is no study determine whether AF can inhibit the growth of colorectal cancer by upregulating p53 gene expression. The aim of this study was to investigate the anticancer effect and the underlying mechanism of AF in CRC in vitro and in vivo. First, we indicated the cytotoxic effect was induced by AF in human CRC (HT29) cells. The suppression of metastasis ability including migration and invasion were found to be suppressed by AF treatment group using transwell assay. Also, in colony formation assay, AF inhibited the proliferation of CRC cells. The tumor suppressor gene p53 was upregulating with AF treatment, and the cell cycle related protein, such as CyclinD1 and CDK4 were all downregulated by AF which identified by Western blotting assay. Additionally, AF induced apoptosis in CRC cells were detected by Western blotting and flow cytometry with cleaved caspase-3, -8, -9 and Annexin V/PI assay. Moreover, Western blotting results indicated that DNA damage proteins (cleaved PARP-1 and ATM) were upregulated by AF. The nucleus translocation of caspase-dependent mitochondria initiated apoptotic protein (EndoG and AIF) were induced by AF in CRC cells. In animal experiments, the CRC tumors volume were effectively reduced in AF treatment groups as compared to non-treated control. In summary, AF mediated anti-CRC effects, such as inhibiting cell proliferation, suppressing migration/invasion ability, inducing apoptosis and triggering DNA damage is associated with the induction of p53. Citation Format: Hsiang-Ju Ku, Yuan Chang, I-Tsang Chiang, Fei-Ting Hsu. Amentoflavone induces apoptosis and promotes G1 phase cell cycle arrest through regulating p53 pathway in HT29 human colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5374.