Title:Regulation of Apoptosis by SYB in HepG2 Liver Cancer Cells is Mediated by the P53/Caspase 9 Axis
Volume: 17
Issue: 7
Author(s): Sharula and Zhongjun Wu*
Affiliation:
- Department of Hepatobiliary Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016,China
Keywords:
SYB, p53, Caspase 9, HepG2, miR-34a.
Abstract: Objective: To explore the function of miR-34a in promotion of apoptosis by SYB.
Methods: In this study, the most effective concentration of SYB was determined by measuring cell proliferation.
Relative miR-34a mRNA levels were detected by quantitative RT-PCR. Apoptosis was assessed using Annexin-
V/PI assays, whereas protein levels of p53, caspase 3, caspase 9, caspase 8 and Bcl2 were evaluated by western
blotting.
Results: Minimum HepG2 cell growth was observed after 36h of exposure to 150 nmol/L SYB. miR-34a expression
was highest 40min after the addition of SYB. SYB slightly decreased the abundance of Bcl-2, but increased
the abundance of p53, caspase 3, caspase 9 and caspase 8. SYB failed to alter miR-34a expression when p53 was
inhibited. Bcl-2 abundance remained low over time, whereas the abundance of caspase 3, caspase 9 and caspase 8
gradually increased. Inhibition of p53 promoted HepG2 cell growth in comparison with that of the control group.
miR-34a was silenced to assess the role of miR-34a in the inhibitory effect of SYB on HepG2 cell growth. When
p53 was silenced, protein abundance of Bcl2, caspase 3, caspase 8 and caspase 9 remained unchanged following
the addition of SYB; moreover, HepG2 cell growth was increased.
Conlusion: SYB represents a promising therapeutic approach for liver cancer patients.
