[Expression of Bcl-w protein in human small intestinal adenocarcinoma and effect of Bcl-w siRNA on apoptosis in intestinal adenocarcinoma HuTu-80 cells].
OBJECTIVE
To investigate the expression of apoptosis-related protein Bcl-w in adenocarcinoma of the small intestine, and the apoptotic effect of Bcl-w siRNA on small intestinal adenocarcinoma cells HuTu-80.


METHODS
Forty-two tissue samples were examined in our study, including 7 cases from human small intestinal adenocarcinoma, and 35 cases from normal small intestine served as control. The expression of Bcl-w was detected by immunohistochemistry (IHC). Western blot analysis was performed to confirm whether Bcl-w siRNA could effectively down-regulate Bcl-w protein after HuTu-80 cells were transfected with Bcl-w siRNA. The cells were treated with chemotherapeutic agent 5-Fu to observe whether Bcl-w protein-silecing affects the pro-apoptotic effect of 5-Fu. Flow cytometry analysis was used for assessment of apoptotic rate of HuTu-80 cells cultured with Bcl-w siRNA alone, with 5-Fu alone, and with combination of Bcl-w siRNA and 5-Fu, using untreated HuTu-80 cells as control.


RESULTS
The positive rate of Bcl-w expression was significantly higher in small intestinal adenocarcinoma than that in normal tissue (85.7% vs. 25.7%, P=0.005). Compared with the control group, Bcl-w siRNA transfection effectively down-regulated the expression of Bcl-w protein (P<0.05). The apoptosis in HuTu-80 cells was not increased significantly in Bcl-w-/-cells compared with that of control group (12.4±2.2)% vs. (8.6±1.7)% (P>0.05). However, compared with the 5-Fu group, the apoptosis in HuTu-80 cells was effectively enhanced after combination treatment with Bcl-w siRNA and 5-Fu (45.7±2.1)% vs. (71.6±3.2)% (P<0.05).


CONCLUSIONS
Bcl-w protein plays a significant role in the carcinogenesis of human small intestinal adenocarcinoma. Down-regulation of Bcl-w protein in small intestine adenocarcinoma HuTu-80 cells leads them susceptible to 5-Fu.
Department of Gastroenterology, the Third Hospital of Peking University, Beijing 100191, China.
Wen-juan
WJ
Guo
Zhu
Z
Jin
Ai-ying
AY
Wang
D000230:Adenocarcinoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology; D017209:Apoptosis; D051017:Apoptosis Regulatory Proteins / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D015536:Down-Regulation; D005472:Fluorouracil / Q000494:pharmacology*; D015972:Gene Expression Regulation, Neoplastic; D020868:Gene Silencing; D006801:Humans; D007414:Intestinal Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D007421:Intestine, Small; D034741:RNA, Small Interfering / Q000235:genetics; D014162:Transfection
D000964:Antimetabolites, Antineoplastic; D051017:Apoptosis Regulatory Proteins; C491073:BCL2L2 protein, human; D034741:RNA, Small Interfering; D005472:Fluorouracil