Bax inhibitor-1 mediates apoptosis-resistance in human nasopharyngeal carcinoma cells.
Bax inhibitor-1 (BI-1), a newly identified apoptosis inhibitor, has recently been found to be overexpressed in several human carcinomas and its specific down-regulation by RNA interference (RNAi) could lead to cell death. The purpose of this study is to investigate the role of BI-1 in apoptosis-resistance and the underlying mechanisms in human nasopharyngeal carcinoma (NPC) cells. Our results showed that BI-1 was expressed in two different human NPC cell lines, CNE-2Z and CNE-1, and specific inhibition of BI-1 expression by siRNA caused a significant increase in spontaneous apoptosis in both cell lines. Mechanistically, we demonstrated that down-regulation of BI-1 protein expression decreased the ratio of Bcl-X(L)/Bcl-2 with Bax protein as determined by Western blot and increased the activity of caspase-3 by colorimetric analysis, thus leading to the activation of the associated cell death pathways. Taken together, these results have provided evidence that BI-1 could serve as an important molecular target gene for the development of new therapeutic strategy against human NPCs.
Zhang
Meihong
M
Institute of Biochemistry and Molecular Biology, Guangdong Medical College, Zhanjiang City, 524023, China.
Li
Xiangyong
X
Zhang
Yuefei
Y
Zhou
Keyuan
K
D017209:Apoptosis; D051017:Apoptosis Regulatory Proteins / Q000032:analysis / Q000235:genetics / Q000502:physiology*; D053148:Caspase 3 / Q000378:metabolism; D045744:Cell Line, Tumor; D015536:Down-Regulation / Q000187:drug effects; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics / Q000502:physiology*; D009303:Nasopharyngeal Neoplasms / Q000473:pathology*; D034741:RNA, Small Interfering / Q000494:pharmacology
D051017:Apoptosis Regulatory Proteins; D008565:Membrane Proteins; D034741:RNA, Small Interfering; C484209:TMBIM6 protein, human; D053148:Caspase 3