5-aminosalicylic acid inhibits cell cycle progression in a phospholipase D dependent manner in colorectal cancer
5-aminosalicylic acid inhibits cell cycle progression in a phospholipase D dependent manner in colorectal cancer
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DOI：
10.1136/gutjnl-2011-301626
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发表时间：
2012-12-01
期刊：
影响因子：
24.5
通讯作者：
van den Brink, Gijs R.
中科院分区：
文献类型：
--
作者：
Baan, Bart;Dihal, Ashwin A.;van den Brink, Gijs R.
背景5-氨基水杨酸（5-ASA）可以预防炎症相关结直肠癌的发生。体外数据表明，在结直肠癌细胞中，5-ASA诱导细胞周期阻滞，但导致这种阻滞的分子机制仍有待确定。目的探讨5-ASA介导的结直肠癌细胞增殖抑制的信号转导事件，重点研究哺乳动物雷帕霉素靶点（mTOR），一种细胞周期进程的调节剂。方法在结直肠癌细胞系中检测5-ASA对mTOR信号传导的影响。在两种不同的结直肠癌细胞系中，利用western blot、siRNA、磷脂酶D （PLD）活性测定、增殖试验和细胞周期分析，详细研究了5-ASA对控制mTOR活性途径的影响。我们研究了局部5-ASA治疗前后结直肠癌中mTOR及其下游靶点核糖体蛋白S6的磷酸化状态。结果5-ASA治疗大肠癌可抑制体内外mTOR信号传导。5-ASA对调节结直肠癌细胞中结节硬化复合体活性的任何途径均无影响。增殖和mTOR活性都依赖于PLD，一种产生磷脂酸（PA）的酶。5-ASA处理抑制PLD活性和增殖；这些作用可以通过外源性PA恢复。结论5-ASA通过抑制pld依赖性PA的产生和mTOR信号通路的丧失来干扰结直肠癌细胞的增殖。
Background 5-aminosalicylic acid (5-ASA) may protect against the development of inflammation-associated colorectal cancer. In vitro data suggest that, in colorectal cancer cells, 5-ASA induces cell cycle arrest, but the molecular mechanism leading to this arrest remains to be determined.Aim To dissect the signal transduction events that lead to 5-ASA mediated inhibition of proliferation of colorectal cancer cells, focusing on mammalian target of rapamycin (mTOR), a regulator of cell cycle progression.Methods The influence of 5-ASA on mTOR signalling was examined in a panel of colorectal cancer cell lines. The effects of 5-ASA on the pathways that control mTOR activity were studied in detail in two different colorectal cancer cell lines, using western blot, siRNA, a phospholipase D (PLD) activity assay, proliferation assays and cell cycle analysis. The phosphorylation status of mTOR and its downstream target, ribosomal protein S6, was studied in colorectal cancers before and after topical 5-ASA treatment.Results Treatment of colorectal cancer with 5-ASA inhibited mTOR signalling in vitro and in vivo. 5-ASA had no effect on any of the pathways that regulate the activity of the tuberous sclerosis complex in colorectal cancer cells. Both proliferation and mTOR activity depended on PLD, an enzyme that generates phosphatidic acid (PA). 5-ASA treatment inhibited PLD activity and proliferation; these effects could be rescued with exogenous PA.Conclusion 5-ASA interferes with proliferation of colorectal cancer cells via inhibition of PLD-dependent generation of PA and loss of mTOR signalling.