5-Fluorouracil induces apoptosis in human colon cancer cell lines with modulation of Bcl-2 family proteins.
5-Fluorouracil induces apoptosis in human colon cancer cell lines with modulation of Bcl-2 family proteins.
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DOI：
10.1038/bjc.1998.617
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发表时间：
1998-10
影响因子：
8.8
通讯作者：
Muto T
中科院分区：
文献类型：
--
作者：
Nita ME;Nagawa H;Tominaga O;Tsuno N;Fujii S;Sasaki S;Fu CG;Takenoue T;Tsuruo T;Muto T
最近，细胞凋亡已被认为是暴露于化疗药物的细胞的终点之一。p53和Bcl-2蛋白家族参与化疗诱导的细胞凋亡，但以细胞类型依赖的方式。我们试图确定p53和Bcl-2蛋白家族在5-氟尿嘧啶（5-FU）诱导的人结肠癌细胞系凋亡中所起的作用。我们首先研究了p53的遗传和功能状态，然后使用50%抑制浓度（IC 50）的5-FU诱导凋亡，通过形态学分析和酶联免疫吸附试验（ELISA）证实。Western blotting检测Bcl-2、Bcl-X（L）、Bax、Bad、巴克和p53蛋白表达。使用5个人结肠癌细胞系，我们发现等毒性（IC 50）剂量的5-FU诱导野生型p53和突变型p53细胞凋亡。Bcl-2家族蛋白的稳态水平的分析显示，除了Colo 320之外，所有细胞系中Bcl-X（L）的高表达。Bcl-2在其中2例中表达。Bax基础表达最低，Bad表达均匀。另一方面，这些细胞中巴克的表达变化超过5倍。在含有野生型p53的细胞（如LoVo）中，5-FU诱导的细胞凋亡伴随Bax和巴克的表达增加，而没有其他bcl-2家族蛋白的一致调节。相反，在含有突变型p53（例如DLD 1）的细胞中，巴克表达显著增加。化疗敏感性与Bcl-X（L）/Bax比值相关，而与Bcl-2/Bax比值无关。总之，这些结果表明，在人结肠癌细胞系中，Bcl-2蛋白家族的一些成员受到5-FU的调节，并且Bcl-X（L）与Bax的比率可能与对5-FU的化学敏感性有关。
Recently, apoptosis has been implicated as one of the end points of cells exposed to chemotherapeutic agents. The p53 and Bcl-2 family of proteins are involved in chemotherapy-induced apoptosis, but in a cell type-dependent manner. We sought to determine the roles played by the p53 and Bcl-2 family of proteins in 5-fluorouracil (5-FU)-induced apoptosis of human colon cancer cell lines. We first studied the p53 genetic and functional status, and then 5-FU, at inhibitory concentration of 50% (IC50) doses, was used to induce apoptosis, which was confirmed by morphological analysis and enzyme-linked immunosorbent assay (ELISA). Bcl-2, Bcl-X(L), Bax, Bad, Bak and p53 protein expression was analysed by Western blotting. Using five human colon cancer cell lines, we found that equitoxic (IC50) doses of 5-FU induced apoptosis in both wild-type p53 and mutant p53 cells. Analysis of the steady-state levels of Bcl-2 family proteins showed high expression of Bcl-X(L) in all of the cell lines except Colo320. Bcl-2 was expressed in two of them. Bax presented with the lowest basal expression and Bad showed homogeneous expression. On the other hand, Bak expression varied more than fivefold among these cells. In cells containing wild-type p53 (e.g. LoVo), 5-FU-induced apoptosis was accompanied by increased expression of Bax and Bak without consistent modulation of other bcl-2 family proteins. In contrast in cells containing mutant p53 (e.g. DLD1), Bak expression was remarkably increased. There was a significant correlation between chemosensitivity and Bcl-X(L) to Bax ratio, rather than Bcl-2 to Bax. In conclusion, these results suggest that some members of the Bcl-2 family of proteins, in human colon cancer cell lines, are modulated by 5-FU and that the ratio of Bcl-X(L) to Bax may be related to chemosensitivity to 5-FU.