N-(4-hydroxyphenyl)retinamide elevates ceramide in neuroblastoma cell lines by coordinate activation of serine palmitoyltransferase and ceramide synthase.
N-(4-hydroxyphenyl)retinamide elevates ceramide in neuroblastoma cell lines by coordinate activation of serine palmitoyltransferase and ceramide synthase.
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发表时间：
2001-07
期刊：
影响因子：
11.2
通讯作者：
Hongtao Wang;B. Maurer;Patrick Reynolds;M. Cabot
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文献类型：
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作者：
Hongtao Wang;B. Maurer;Patrick Reynolds;M. Cabot
类维甲酸N-(4-羟基苯基)维甲酰胺(4-HPR；fenretinide)对多种癌细胞系具有细胞毒性，我们先前已证明神经酰胺的产生与4-HPR对神经母细胞瘤细胞系的细胞毒性之间存在关联(B.J.Maurer等，J.Natl。癌症研究所。(贝塞斯达，91：1138-1146,1999)。在这里，我们确定4-HPR介导的CHLA-90人神经母细胞瘤细胞系神经酰胺的增加是否是神经酰胺从头合成的结果。在[(3)H]棕榈酸存在下，用4-HPR处理CHLA-90 2 h，可引起[(3)H]鞘氨醇(比对照高220%)和[(3)H]神经酰胺(比对照高160%)的顺序形成，鞘氨脂在4 h恢复到基线水平，神经酰胺继续增加(比对照高215%)。4-HPR处理不能加速神经鞘磷脂的细胞衰变。用丝氨酸棕榈酰转移酶(SPT)抑制剂L-环丝氨酸或神经酰胺合成酶抑制剂伏马菌素B(1)预先孵育细胞，可以抑制神经酰胺的形成，但在4-HPR和FB(1)存在的情况下仍能产生鞘氨醇。用微粒体进行体外酶分析的数据显示，4-HPR预先暴露于完整细胞后，SPT活性增加了一段时间(比对照增加175%；6小时)和神经酰胺合成酶活性增加了一段时间(比对照增加265%；10微米)，并呈剂量依赖性(比对照增加173%；10微米)。我们的结果表明，4-HPR介导的神经酰胺的产生来自SPT和神经酰胺合成酶的协同激活的从头合成途径。当使用神经酰胺代谢的下游调节剂来增强化疗的细胞毒性反应时，了解这些生化事件是有用的。
The retinoid N-(4-hydroxyphenyl)retinamide (4-HPR; fenretinide) is cytotoxic to a variety of cancer cell lines, and we previously showed an association between ceramide generation and 4-HPR cytotoxicity for neuroblastoma cell lines (B. J. Maurer et al., J. Natl. Cancer Inst. (Bethesda), 91: 1138-1146, 1999). Here we determine whether the increased ceramide mediated by 4-HPR in the CHLA-90 human neuroblastoma cell line results from de novo ceramide synthesis. Treatment of CHLA-90 with 4-HPR for 2 h, in the presence of [(3)H]palmitic acid, caused sequential formation of [(3)H]sphinganine (220% over control) and [(3)H]ceramide (160% over control), with sphinganine returning to baseline at 4 h, and ceramide continuing to increase (215% over control). 4-HPR treatment did not accelerate cellular decay of sphingomyelin. Preincubation of cells with either L-cycloserine, an inhibitor of serine palmitoyltransferase (SPT), or fumonisin B(1), an inhibitor of ceramide synthase, retarded ceramide formation in response to 4-HPR treatment, although sphinganine was still generated when 4-HPR and FB(1) were present. Data from in vitro enzyme assays using microsomes showed that preexposure of intact cells to 4-HPR resulted in a time (175% over control; 6 h)- and dose-dependent increase (173% over control; 10 microM) in SPT activity as well as a time (265% over control)- and dose-dependent increase (215% above control; 10 microM) in ceramide synthase activity. Our results show that 4-HPR-mediated ceramide generation is derived from the de novo synthetic pathway by coordinate activation of SPT and ceramide synthase. Knowledge of these biochemical events is of utility when downstream modulators of ceramide metabolism are used to heighten the cytotoxic response to chemotherapy.