SMAC exhibits anti-tumor effects in ECA109 cells by regulating expression of inhibitor of apoptosis protein family.

BACKGROUND: The poor prognosis and rising incidence of esophageal cancer highlight the need for improved therapeutics that are essential prior to treatment. LCL161 is an SMAC (second mitochondrial activator of caspases) mimic and inhibitor of apoptosis protein (IAP) antagonist which exhibits anti-tumor effects and improves the chemical sensitivity of many cancers. AIM: To ascertain the effects and mechanisms of the SMAC analog LCL161 on esophageal cancer cells. METHODS: MTT assay and TUNEL assay were used to detect cell proliferation and apoptosis, respectively. Western blot analysis was used to study the molecular mechanisms of LCL161-induced death of ECA109 cells. RESULTS: LCL161 decreased ECA109 cell proliferation in dose- and time-dependent manner and induced apoptosis of ECA109 cells in a dose-dependent manner. Also, LCL161 induced a significant decrease in the expression of the XIAP and significant increase in the expression of Caspase-3. In addition, Bax increased significantly with increasing concentrations of LCL161, and the relative expression of Bax was significantly different between groups. CONCLUSION: These findings support the hypothesis that LCL161 can inhibit proliferation and induce apoptosis in esophageal cancer cells by regulating the expression of IAP family members, suggesting that it has potential to be an effective treatment for esophageal squamous cell carcinoma.