Gambogic acid suppresses colon cancer cell activity in vitro

The aim of the present study was to elucidate the underlying mechanism of antitumor activity of gambogic acid (GA) in colon cancer. Human colon cancer SW620 cells were divided into five treatment groups, including no-treatment control (NC), low dose GA (10 µg/ml), medium dose GA (50 µg/ml), high dose GA (100 µg/ml) and 5-fluorouracil (10 µg/ml). Differences in cell proliferation, apoptosis and cell cycle, invasion, and migration were measured between groups using MTT, flow cytometry, transwell and wound-healing assays, respectively. Western blotting was used to analyze relative protein expression levels of phosphoinositide 3-kinase (PI3K), protein kinase B (AKT), P21, and matrix metalloprotease (MMP)-2 and -9 between groups. Compared with the NC group, GA (low, middle and high) inhibited SW620 cell proliferation, invasion and migration (all P<0.05). Furthermore, there were significant differences in proliferation, invasion and migration between groups administered with different doses of GA (all P<0.05). Compared with the NC group, the expression levels of PI3K, AKT, phosphorylated-AKT, P21 and MMP-2 and -9 were significantly altered in a dose dependent manner following treatment with GA (all P<0.05). The results of the current study indicated that GA suppressed proliferation and dispersion of human colon cancer cells in a dose-dependent manner, possibly through a PI3K/AKT/P21/MMP-2/9-dependent pathway.