The metabolic bioactivation of caffeic acid phenethyl ester (CAPE) mediated by tyrosinase selectively inhibits glutathione S-transferase.
The metabolic bioactivation of caffeic acid phenethyl ester (CAPE) mediated by tyrosinase selectively inhibits glutathione S-transferase.
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DOI：
10.1016/j.cbi.2011.03.015
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发表时间：
2011-07-15
影响因子：
5.1
通讯作者：
Moridani, Majid Y.
中科院分区：
文献类型：
--
作者：
Kudugunti, Shashi K.;Thorsheim, Helen;Yousef, Mohammad S.;Guan, Lan;Moridani, Majid Y.
谷胱甘肽S-转移酶（GST）和多药耐药相关蛋白（MRP）在黑色素瘤耐药中起主要作用。在这项研究中，我们研究了咖啡酸苯乙酯（CAPE）作为一种选择性GST抑制剂的酪氨酸酶，这是丰富的黑色素瘤细胞的存在。酪氨酸酶将CAPE生物活化为邻醌，邻醌与谷胱甘肽反应形成CAPE-SG缀合物。我们的研究结果表明，90%的CAPE被酪氨酸酶代谢后，60分钟的孵育。LC-MS/MS分析确定CAPE-SG缀合物为主要代谢物。在存在酪氨酸酶的情况下，CAPE（10-25 µM）显示70-84%的GST抑制;而在不存在酪氨酸酶的情况下，CAPE不抑制GST。CAPE-SG结合物和CAPE-醌（25 µM）分别通过可逆和不可逆机制表现出≥85%的GST抑制。与CDNB和GSH相比，非底物CAPE在浓度>50 µM时作为弱的可逆GST抑制剂。此外，MK-571（一种选择性MRP抑制剂）和丙磺舒（一种非选择性MRP抑制剂）分别使CAPE（15 µM）的IC 50降低13%和21%，使人SK-MEL-28黑色素瘤细胞的凋亡细胞死亡降低3%和13%，使线粒体膜电位降低10%和56%。此外，计算对接分析表明，CAPE结合GST催化活性位点。咖啡酸（CAPE的水解产物）在酪氨酸酶存在下表现出类似的GST抑制作用。虽然，作为对照，4-羟基茴香醚和L-酪氨酸被酪氨酸酶代谢形成醌和谷胱甘肽结合物，但在酪氨酸酶存在和不存在的情况下，它们均未表现出GST抑制。总之，在酪氨酸酶存在下，CAPE和咖啡酸都选择性地抑制GST。我们的研究结果表明，细胞内形成的咖啡酸和CAPE的醌类和谷胱甘肽共轭物可能在选择性抑制GST在SK-MEL-28黑色素瘤细胞中发挥重要作用。此外，MRP的抑制增强了SK-MEL-28黑素瘤细胞中CAPE诱导的毒性。
Glutathione S-transferase (GST) and multidrug resistance-associated proteins (MRPs) play major roles in drug resistance in melanoma. In this study, we investigated caffeic acid phenethyl ester (CAPE) as a selective GST inhibitor in the presence of tyrosinase, which is abundant in melanoma cells. Tyrosinase bioactivates CAPE to an o-quinone, which reacts with glutathione to form CAPE-SG conjugate. Our findings indicate that 90% CAPE was metabolized by tyrosinase after a 60-min incubation. LC–MS/MS analyses identified a CAPE-SG conjugate as a major metabolite. In the presence of tyrosinase, CAPE (10–25 µM) showed 70–84% GST inhibition; whereas in the absence of tyrosinase, CAPE did not inhibit GST. CAPE-SG conjugate and CAPE-quinone (25 µM) demonstrated ≥85% GST inhibition via reversible and irreversible mechanisms, respectively. Comparing with CDNB and GSH, the non-substrate CAPE acted as a weak, reversible GST inhibitor at concentrations >50 µM. Furthermore, MK-571, a selective MRP inhibitor, and probenecid, a non-selective MRP inhibitor, decrease the IC50 of CAPE (15 µM) by 13% and 21%, apoptotic cell death by 3% and 13%, and mitochondrial membrane potential in human SK-MEL-28 melanoma cells by 10% and 56%, respectively. Moreover, computational docking analyses suggest that CAPE binds to the GST catalytic active site. Caffeic acid, a hydrolyzed product of CAPE, showed a similar GST inhibition in the presence of tyrosinase. Although, as controls, 4-hydroxyanisole and l-tyrosine were metabolized by tyrosinase to form quinones and glutathione conjugates, they exhibited no GST inhibition in the absence and presence of tyrosinase. In conclusion, both CAPE and caffeic acid selectively inhibited GST in the presence of tyrosinase. Our results suggest that intracellularly formed quinones and glutathione conjugates of caffeic acid and CAPE may play major roles in the selective inhibition of GST in SK-MEL-28 melanoma cells. Moreover, the inhibition of MRP enhances CAPE-induced toxicity in the SK-MEL-28 melanoma cells.
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影响因子：
8.8
作者：
通讯作者：
--
影响因子：
7.2
作者：
Asakura, Tadashi;Sasagawa, Atsuko;Ohkawa, Kiyoshi
通讯作者：
Ohkawa, Kiyoshi
影响因子：
4.7
作者：
Johansson, Katarina;Ahlen, Karin;Morgenstern, Ralf
通讯作者：
Morgenstern, Ralf
影响因子：
3.4
作者：
Kudugunti, Shashi K.;Vad, Nikhil M.;Moridani, Majid Y.
通讯作者：
Moridani, Majid Y.
DOI：
10.1016/0305-0491(92)90206-7
发表时间：
1992-12-01
影响因子：
2.2
作者：
KURATA, M;SUZUKI, M;TAKEDA, K
通讯作者：
TAKEDA, K