Bcl-XL siRNA sensitisizes cisplatin-resistant human lung adenocarcinoma cells A549 to cisplatin

Abstract

Abstract: AIM: To investigate the effect of Bcl-XL siRNA on apoptosis and drug sensitization in cisplatin-resistance human lung adenocarcinoma cell line A549/DDP and to determine the inhibitory effect of the Bcl-XL siRNA on the expression of Bcl-XL gene in cells A549/DDP. METHODS: Bcl-XL siRNA and negative siRNA plasmid vector were stably transfected into A549/DDP cells.Drug sensitivity of the cells to cisplatin ( DDP) was analyzed with MTT and flow cytometry.Spontaneous apoptosis of cells was detected by AO/EB dyeing.RT-PCR and Western-blot were used to detect the target gene expression. RESULTS: MTT results showed that Bcl-XL siRNA transfectants had a higher cell inhibition rate than negative siRNA or untreated cells after treated with 0.2, 2, 20, 200 μg/mL DDP.Moreover, flow cytometry results demonstrated that Bcl-XL siRNA cells had increased apoptosis rate after addition of 20 μg/mL DDP.Spontaneous apoptosis of cells were significantly increased in Bcl-XL siRNA stable transfectants.The mRNA and protein expression level of Bcl-XL in Bcl-XL siRNA stable transfectants were obviously reduced compared with negative siRNA transfectants or untreated cells, moreover, Bcl-XL siRNA increased the activity of active caspase-3. CONCLUSION: siRNA targeting Bcl-XL gene can specifically down-regulate Bcl-XL expression in A549 DDP cells, increase cell spontaneous apoptosis and sensitize cells to DDP.Bcl-XL siRNA may be a potential therapy agent against human lung adenocarcinoma.

Key words: siRNA, Bcl-XL, A549/DDP, apoptosis, cisplatin

CLC Number:

R966

HUANG Ze-xiang, LIU Li-juan, YAO Shu-qiong, LEI Xiao-yong, ZHU Bing-yang, TANG Sheng-song, LIAO Duan-fang. Bcl-XL siRNA sensitisizes cisplatin-resistant human lung adenocarcinoma cells A549 to cisplatin[J]. Chinese Journal of Clinical Pharmacology and Therapeutics, 2007, 12(1): 57-61.

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