RNA干扰沉默PI3K p85α基因促进5-氟尿嘧啶诱导的大肠癌细胞LoVo凋亡

[PI3K p85alpha gene silencing by RNA interference promotes 5-fluorouracil-induced apoptosis of colorectal cancer LoVo cells].

作者信息

Yang Hui, Ni Li, Ma Yu-qian, Song Yu-gang

机构信息

Department of Gastroenterology/Guangdong Provincial Key Laboratory of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China.

出版信息

Nan Fang Yi Ke Da Xue Xue Bao. 2010 May;30(5):1085-8.

PMID:20501401

Abstract

OBJECTIVE

To explore the effect of PI3K p85alpha gene silencing on the 5-fluorouracil (5-FU)-induced apoptosis of colorectal cancer cells.

METHODS

The PI3K p85alpha/RNAi transfected cells (PI3K p85alpha/RNAi-LoVo) were cultured in RPMI 1640 supplemented with 10% fetal calf serum and 500 microg/ml G418. The 50% inhibitory concentration (IC50) values of 5-FU (0.000625, 0.00125, 0.005, 0.01, 0.02, 0.04, 0.08, 0.16, 0.32 micromol/ml) were evaluated by MTT assay. Mitochondrial membrane potential was detected by JC-1 fluorescence, and Western blotting was used to analyze the expression of apoptotic proteins Bcl-6 and Bim.

RESULTS

Compared with the untransfected LoVo cells, PI3K p85alpha/RNAi-LoVo showed obviously decreased IC(50) of 5-FU (P=0.000). The mitochondrial membrane potential of PI3K p85alpha/RNAi-LoVo cells was significantly lower than that of LoVo cells, suggesting that silencing PI3K p85alpha expression increased the sensitivity of LoVo cells to 5-FU. The expression of apoptotic protein Bcl-6 and Bim were significantly higher in PI3K p85alpha/RNAi-LoVo cells treated with 5-FU than LoVo cells (P=0.000).

CONCLUSION

PI3Kp85alpha gene silencing can significantly promote 5-FU-induced apoptosis of colorectal LoVo cells.

摘要

目的

探讨PI3K p85α基因沉默对5-氟尿嘧啶（5-FU）诱导大肠癌细胞凋亡的影响。

方法

将PI3K p85α/RNAi转染细胞（PI3K p85α/RNAi-LoVo）培养于添加10%胎牛血清和500μg/ml G418的RPMI 1640培养基中。采用MTT法评估5-FU（0.000625、0.00125、0.005、0.01、0.02、0.04、0.08、0.16、0.32μmol/ml）的50%抑制浓度（IC50）值。通过JC-1荧光检测线粒体膜电位，并用蛋白质免疫印迹法分析凋亡蛋白Bcl-6和Bim的表达。

结果

与未转染的LoVo细胞相比，PI3K p85α/RNAi-LoVo的5-FU IC50明显降低（P = 0.000）。PI3K p85α/RNAi-LoVo细胞的线粒体膜电位显著低于LoVo细胞，提示沉默PI3K p85α表达可增加LoVo细胞对5-FU的敏感性。在用5-FU处理的PI3K p85α/RNAi-LoVo细胞中，凋亡蛋白Bcl-6和Bim的表达明显高于LoVo细胞（P = 0.000）。