Anti-proliferative Effects of Atractylis lancea (Thunb.) DC. via Down-regulation of the c-myc/hTERT/Telomerase Pathway in Hep-G2 Cells

Abstract

Atractylis lancea (Thunb.) DC. (AL), an important medicinal herb in Asia, has been shown to have anti-tumoreffects on cancer cells, but the involved mechanisms are poorly understood. This study focused on potentialeffects and molecular mechanisms of AL on the proliferation of the Hep-G2 liver cancer cell line in vitro. Cellviability was assessed by MTT test in Hep-G2 cells incubated with an ethanol extract of AL. Then, the effects ofAL on apoptosis and cell cycle progression were determined by flow cytometry. Telomeric repeat amplificationprotocol (TRAP) assays was performed to investigate telomerase activity. The mRNA and protein expressionof human telomerase reverse transcriptase (hTERT) and c-myc were determined by real-time RT-PCR andWestern blotting. Our results show that AL effectively inhibits proliferation in Hep-G2 cells in a concentrationandtime-dependent manner. When Hep-G2 cells were treated with AL after 48h,the IC50 was about 72.1 μg/mL. Apoptosis was induced by AL via arresting the cells in the G1 phase. Furthermore, AL effectively reducedtelomerase activity through inhibition of mRNA and protein expression of hTERT and c-myc. Hence, these datademonstrate that AL exerts anti-proliferative effects in Hep-G2 cells via down-regulation of the c-myc/hTERT/telomerase pathway.