Pristimerin inhibits proliferation, migration and invasion, and induces apoptosis in HCT-116 colorectal cancer cells

Colorectal cancer (CRC) is one of the world's most common cancers with a high mortality rate mainly due to metastasis. Our previous study showed that pristimerin had potent antitumor activities against human CRC cells. In the present study, we further evaluated pristimerin anti-tumor and anti-metastatic properties. MTT assay, Hoechst staining, Annexin V/PI double staining, reactive oxygen species (ROS) measurements were used to assess pristimerin cytotoxicity and apoptotic-inducing effects on HCT-116 cells. Wound healing assay and Transwell assay were used to estimate pristimerin anti-migration and anti-invasion activities on CRC cells. Meanwhile, HCT-116 xenograft model applied for investigating in vivo antitumor activities. Our results showed that pristimerin mediated in vitro HCT-116 cell death, through generation of intracellular ROS and apoptosis induction. Tumor volumes and weights measurements, pathological analysis and Tunnel assay proved that pristimerin inhibited in vivo HCT-116 xenografts growth. Pristimerin was also able to limit CRC invasion and metastasis. It caused downregulation of PI3K/AKT/mTOR pathway and its subsequent downstream p70S6K and E4-BP1 proteins. Collectively, pristimerin exerted both in vitro and in vivo cytotoxic and anti-metastatic effects on HCT-116 cells, suggesting that pristimerin has potential as a new anticancer drug for treatment of colon cancer. (C) 2016 Elsevier Masson SAS. All rights reserved.