Realgar-induced apoptosis of cervical cancer cell line Siha via cytochrome c release and caspase-3 and caspase-9 activation / 中国结合医学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To explore the molecular mechanism of realgar-induced apoptosis of cervical cancer cells.</p><p><b>METHODS</b>The cervical cancer cell line Siha was used to determine the cell viability and apoptosis after treatment with realgar using MTT assay and flow cytometry. The activities of caspase-3, -8, and -9 were detected by fluorescence resonance energy transfer technology and colorimetric assay, while the levels of Bcl-2, cytochrome c, and Bax were detected by Western blot method.</p><p><b>RESULTS</b>Induction of apoptosis by realgar was detected in Siha cell line in a dose-dependent manner. The apoptosis was accompanied by a significant increase in cytochrome c release and activation of caspase-3 and caspase-9 but not caspase-8. Further, the realgar-induced apoptosis was inhibited by a broad-spectrum caspase inhibitor, a caspase-3 inhibitor, and a caspase-9 inhibitor but not by a caspase-8 inhibitor. Bcl-2 and Bax protein expressions were not changed by realgar.</p><p><b>CONCLUSION</b>The induction of apoptosis by realgar is mediated through a cytochrome c-dependent pathway, which sequentially activates caspase-9 and caspase-3.</p>