Treatment of breast and lung cancer cells with a N-7 benzyl guanosine monophosphate tryptamine phosphoramidate pronucleotide (4Ei-1) results in chemosensitization to gemcitabine and induced eIF4E proteasomal degradation.
Treatment of breast and lung cancer cells with a N-7 benzyl guanosine monophosphate tryptamine phosphoramidate pronucleotide (4Ei-1) results in chemosensitization to gemcitabine and induced eIF4E proteasomal degradation.
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DOI：
10.1021/mp300699d
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发表时间：
2013-02-04
影响因子：
4.9
通讯作者：
Wagner CR
中科院分区：
文献类型：
--
作者：
Li S;Jia Y;Jacobson B;McCauley J;Kratzke R;Bitterman PB;Wagner CR
癌症和纤维化疾病的发展已被证明高度依赖于帽依赖性翻译的失调。已发现结合蛋白eIF 4 E与N7-甲基化鸟苷加帽mRNA是控制翻译起始的限速步骤，因此代表了药物发现的有吸引力的靶标。本课题组发现7-苄基鸟苷一磷酸（7-benzyl guanosine monophosphate，7 Bn-GMP）是eIF 4 E cap结合的有效拮抗剂（Kd = 0.8 μ/M）。最近的X射线晶体学研究表明，帽依赖口袋经历了独特的结构变化，以适应苄基。不幸的是，7 Bn-GMP不是细胞可渗透的。最近，我们制备了7 Bn-GMP的色胺氨基磷酸酯前药4 Ei-1，并显示其是人组氨酸三联体核苷酸结合蛋白（hHINT 1）的底物，并抑制斑马鱼胚胎细胞的eIF 4 E启动的上皮-间质转化（EMT）。为了评估癌细胞对4 Ei-1的细胞内摄取和向7 Bn-GMP的转化，我们开发了一种使用LC-ESI-MS/MS的灵敏测定法用于4 Ei-1和7 Bn-GMP的细胞内定量。当与乳腺癌细胞系MDA-231或肺癌细胞系H460、H383和H2009孵育时，发现4 Ei-1被迅速内化并转化为7 Bn-GMP。由于预测致癌mRNA具有最高的eIF 4 E翻译要求，我们用4 Ei-1进行了化学增敏研究。发现该前体药物对乳腺癌和肺癌细胞都对无毒水平的吉西他滨具有化学增敏作用。进一步的机制研究表明，在用4 Ei-1处理的细胞中，eIF 4 E的表达水平以剂量依赖性方式显著降低。eI 4 E的水平可以通过蛋白酶体抑制剂MG-132的治疗来恢复。总之，我们的结果表明，4 Ei-1可能通过拮抗eIF 4 E帽结合和启动eIF 4 E蛋白酶体降解来抑制eIF 4 E帽结合的翻译起始。
The development of cancer and fibrotic diseases has been shown to be highly dependent on disregulation of cap-dependent translation. Binding protein eIF4E to N7-methylated guanosine capped mRNA has been found to be the rate-limiting step governing translation initiation, and therefore represents an attractive target for drug discovery. Our group has found that 7-benzyl guanosine monophosphate (7Bn-GMP) is a potent antagonist of eIF4E cap binding (Kd = 0.8 μ/M). Recent X-ray crystallographic studies have revealed that the cap-dependent pocket undergoes a unique structural change in order to accommodate the benzyl group. Unfortunately, 7Bn-GMP is not cell permeable. Recently, we have prepared a tryptamine phosphoramidate prodrug of 7Bn-GMP, 4Ei-1, and shown that it is a substrate for human histidine triad nucleotide binding protein (hHINT1) and inhibits eIF4E initiated epithelial–mesenchymal transition (EMT) by Zebra fish embryo cells. To assess the intracellular uptake of 4Ei-1 and conversion to 7Bn-GMP by cancer cells, we developed a sensitive assay using LC-ESI-MS/MS for the intracellular quantitation of 4Ei-1 and 7Bn-GMP. When incubated with the breast cancer cell line MDA-231 or lung cancer cell lines H460, H383 and H2009, 4Ei-1 was found to be rapidly internalized and converted to 7Bn-GMP. Since oncogenic mRNAs are predicted to have the highest eIF4E requirement for translation, we carried out chemosensitization studies with 4Ei-1. The prodrug was found to chemosensitize both breast and lung cancer cells to nontoxic levels of gemcitabine. Further mechanistic studies revealed that the expressed levels of eIF4E were substantially reduced in cells treated with 4Ei-1 in a dose-dependent manner. The levels of eI4E could be restored by treatment with the proteasome inhibitor MG-132. Taken together, our results demonstrate that 4Ei-1 is likely to inhibit translation initiation by eIF4E cap binding by both antagonizing eIF4E cap binding and initiating eIF4E proteasomal degradation.
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影响因子：
2.9
作者：
DARZYNKIEWICZ, E;STEPINSKI, J;TAHARA, SM
通讯作者：
TAHARA, SM
影响因子：
6.7
作者：
Jia, Yan;Chiu, Ting-Lan;Amin, Elizabeth A.;Polunovsky, Vitaly;Bitterman, Peter B.;Wagner, Carston R.
通讯作者：
Wagner, Carston R.
影响因子：
7.3
作者：
McGuigan, Christopher;Hassan-Abdallah, Alshaimaa;Balzarini, Jan
通讯作者：
Balzarini, Jan
影响因子：
3.2
作者：
Mehellou, Youcef;Balzarini, Jan;McGuigan, Christopher
通讯作者：
McGuigan, Christopher
影响因子：
5.6
作者：
Brown, Christopher J.;McNae, Iain;Walkinshaw, Malcolm D.
通讯作者：
Walkinshaw, Malcolm D.