Sphingoid bases and ceramide induce apoptosis in HT-29 and HCT-116 human colon cancer cells
Sphingoid bases and ceramide induce apoptosis in HT-29 and HCT-116 human colon cancer cells
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DOI：
10.1177/153537020222700507
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发表时间：
2002-05-01
影响因子：
3.2
通讯作者：
Schroeder, JJ
中科院分区：
文献类型：
--
作者：
Ahn, EH;Schroeder, JJ
据报道，复合膳食鞘脂如鞘磷脂和鞘脂糖可抑制结肠癌的发生。这种保护作用可能是生物活性代谢物转化的结果，这些代谢物包括鞘碱（鞘氨酸和鞘氨酸）和神经酰胺，它们抑制增殖和刺激细胞凋亡。本研究旨在探讨鞘碱和神经酰胺对人结肠癌细胞HT-29和HCT-116生长、死亡和细胞周期的影响。通过比较鞘氨酸和c -2-神经酰胺（神经酰胺的短链类似物）与鞘氨酸和c -2-二氢神经酰胺（二氢神经酰胺的短链类似物）脂质的作用，评估了鞘氨酸和c -2-二氢神经酰胺缺乏这种结构特征的重要性。鞘氨醇、鞘氨氨酸和c -2-神经酰胺对结肠癌细胞的生长和死亡均呈时间和浓度依赖性，而c -2-二氢神经酰胺对结肠癌细胞的生长和死亡没有影响。这些发现表明，4,5-反式双键对c -2神经酰胺的抑制作用是必需的，而不是对鞘碱的抑制作用。通过荧光显微镜对细胞形态的评估和使用二苯胺测定对碎片化低分子量DNA的定量分析表明，鞘碱和c -2神经酰胺导致染色质和核凝聚以及DNA的碎片化，这表明这些脂质通过诱导细胞凋亡杀死结肠癌细胞。流式细胞分析证实，鞘碱和c -2神经酰胺增加了指示细胞凋亡的An峰的细胞数量，并表明鞘碱在G(2)/M期阻止细胞周期，并在S期引起积累。这些发现表明鞘鞘碱和神经酰胺诱导结肠癌细胞凋亡，并暗示它们可能是更复杂的膳食鞘鞘脂在结肠癌发生中的保护作用的潜在介质。
Complex dietary sphingolipids such as sphingomyelin and glycosphingolipids have been reported to inhibit development of colon cancer. This protective role may be the result of turnover to bioactive metabolites including sphingoid bases (sphingosine and sphinganine) and ceramide, which inhibit proliferation and stimulate apoptosis. The purpose of the present study was to investigate the effects of sphingoid bases and ceramides on the growth, death, and cell cycle of HT-29 and HCT-116 human colon cancer cells. The importance of the 4,5-trans double bond present in both sphingosine and C-2-ceramide (a short chain analog of ceramide) was evaluated by comparing the effects of these lipids with those of sphinganine and C-2-dihydroceramide (a short chain analog of dihydroceramide), which lack this structural feature. Sphingosine, sphinganine, and C-2-ceramide inhibited growth and caused death of colon cancer cells in time- and concentration-dependent manners, whereas C-2-dihydroceramide had no effect. These findings suggest that the 4,5-trans double bond is necessary for the inhibitory effects of C-2-ceramide, but not for sphingoid bases. Evaluation of cellular morphology via fluorescence microscopy and quantitation of fragmented low-molecular weight DNA using the diphenylamine assay demonstrated that sphingoid bases and C-2-ceramide cause chromatin and nuclear condensation as well as fragmentation of DNA, suggesting these lipids kill colon cancer cells by inducing apoptosis. Flow cytometric analyses confirmed that sphingoid bases and C-2-ceramide increased the number of cells in the An peak indicative of apoptosis and demonstrated that sphingoid bases arrest the cell cycle at G(2)/M phase and cause accumulation in the S phase. These findings establish that sphingoid bases and ceramide induce apoptosis in colon cancer cells and implicate them as potential mediators of the protective role of more complex dietary sphingolipids in colon carcinogenesis.