1 |
Goniothalamin induces TP53-dependent and -independent apoptosis in hepatocellular carcinoma derived cellsTsai, Cheng-Hui 15 July 2008 (has links)
The objective was to study apoptotic effects and underlying molecular mechanisms of goniothalamin (GTN) in hepatocellular carcinoma (HCC)-derived cells. The GTN that isolated from Goniothalamus amuyon, was found to possess profound cytotoxic activities against human SK-Hep1 and Hep-3B cells in vitro. The cytotoxicity of GTN/cell viability was measured by MTT assay at 570-nm absorbance and the IC50 at 72 h were determined as 7.5, 17 mM in SK-Hep1 and Hep-3B respectively. The GTN induced cell death and accumulation of reactive oxygen species in HCC-derived cells. One reactive oxygen species inhibitor, N-actylcysteine, further restored cell viabilities post-GTN treatments. Formation of £^-H2AX foci suggested that GTN-induced DNA damages were double-strand breaks. The GTN arrested cell cycle at G0/G1 by regulation of CCND, CCNE1, RB1 and E2F1 proteins in SK-Hep1, and at G2/M by regulation of CCNB1 in Hep-3B cells. The GTN-induced apoptosis in HCC-derived cells were evidenced by phosphatidylserine externalization and involved both extrinsic and intrinsic pathways in SK-Hep1 cells, but only extrinsic pathway in Hep-3B cells. In SK-Hep1 cells, GTN induced apoptosis and cell cycle arrest through TP53-mediated pathway in contrast to that of TP53/FAS mutated Hep-3B cells. Importantly, GTN was able to induce apoptosis in both TP53 wild type and TP53/FAS mutated HCC-derived cells. On the other hand, GTN was able to induce TP53 and p21WAF1/Cip1 up-regulation in SK-Hep1 and Hep-3B cells and p27Kip1 up-regulation in Hep-3B cells. These results demonstrated that GTN induced apoptosis in HCC cells through distinct signaling pathways.
|
Page generated in 0.0151 seconds