Down-regulation of mitochondrial F1F0-ATP synthase in human colon cancer cells with induced 5-fluorouracil resistance
Down-regulation of mitochondrial F1F0-ATP synthase in human colon cancer cells with induced 5-fluorouracil resistance
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DOI：
10.1158/0008-5472.can-04-3300
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发表时间：
2005-04-15
期刊：
影响因子：
11.2
通讯作者：
Park, JG
中科院分区：
文献类型：
--
作者：
Shin, YK;Yoo, BC;Park, JG
5-氟尿嘧啶（5-FU）广泛用于治疗晚期结直肠癌。然而，此类患者对5-FU产生耐药性是很常见的，这种耐药性成为化疗的关键问题。这种耐药性背后的机制很大程度上是未知的。为了筛选可能导致 5-FU 耐药性的蛋白质，从人结肠癌细胞系中提取出对 5-FU 耐药的细胞，并进行了基于二维凝胶电泳的比较蛋白质组学。二维凝胶电泳数据显示，与亲本细胞相比，5-FU耐药细胞中线粒体F1F0-ATP合酶（ATP合酶）α亚基的表达较低。蛋白质印迹显示，5-FU 抗性细胞系中其他 ATP 合酶复合物亚基的表达也较低，并且这些抗性细胞还表现出 ATP 合酶活性降低和细胞内 ATP 含量降低。 ATP 合酶抑制剂寡霉素 A 强烈拮抗 5-FU 诱导的细胞增殖抑制。当将六种不同的人类结肠癌细胞系中的 5-FU 敏感性与 ATP 合酶活性进行比较时，发现呈正相关。此外，通过 siRNA 转染抑制 ATP 合酶 d 亚基表达可增加 5-FU 存在下的细胞活力。据报道，线粒体生物能功能障碍是许多类型癌症的标志（即肝癌、肾癌、结肠癌、鳞状食管癌和肺癌以及乳腺癌和胃腺癌中 ATP 合成酶 β 亚基表达下调）。我们的研究结果表明，ATP 合酶下调可能不仅是结直肠癌的生物能特征，而且还可能导致导致 5-FU 耐药的细胞事件。
5-Fluorouracil (5-FU) is widely used for treatment of advanced colorectal cancer. However, it is common for such patients to develop resistance to 5-FU, and this drug resistance becomes a critical problem for chemotherapy. The mechanisms underlying this resistance are largely unknown. To screen for proteins possibly responsible for 5-FU resistance, cells resistant to 5-FU were derived from human colon cancer cell lines and two-dimensional gel electrophoresis-based comparative proteomics was done. Two-dimensional gel electrophoresis data showed there was lower expression of the alpha subunit of mitochondrial F1F0-ATP synthase (ATP synthase) in 5-FU-resistant cells compared with parent cells. Western blotting showed that expression of other ATP synthase complex subunits was also lower in 5-FU-resistant cell lines and that these resistant cells also showed decreased ATP synthase activity and reduced intracellular ATP content. The ATP synthase inhibitor, oligomycin A, strongly antagonized 5-FU-induced suppression of cell proliferation. When 5-FU sensitivity was compared with ATP synthase activity in six different human colon cancer cell lines, a positive correlation has been found. Furthermore, suppressed ATP synthase d-subunit expression by siRNA transfection increased cell viability in the presence of 5-FU. Bioenergetic dysfunction of mitochondria has been reported as a hallmark of many types of cancers (i.e., down-regulation of ATP synthase beta-subunit expression in liver, kidney, colon, squamous oesophageal, and lung carcinomas, as well as in breast and gastric adenocarcinomas). Our findings show that ATP synthase down-regulation may not only be a bioenergetic signature of colorectal carcinomas but may also lead to cellular events responsible for 5-FU resistance.