Role of GADD34 in modulation of cisplatin cytotoxicity
Role of GADD34 in modulation of cisplatin cytotoxicity
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DOI：
10.1016/j.bcp.2005.10.039
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发表时间：
2006-01-12
影响因子：
5.8
通讯作者：
Dolan, ME
中科院分区：
文献类型：
--
作者：
Fishel, ML;Rabik, CA;Dolan, ME
顺铂和卡铂是临床上广泛使用的化疗药物，尤其是针对睾丸癌、卵巢癌和头颈癌。O-6-苄基鸟嘌呤（BG）与顺铂和卡铂联合用于头颈癌细胞系时，已显示可增强细胞毒性、细胞凋亡和DNA铂化。微阵列表达数据表明，使用Affytek HG-U133 A基因芯片（R），与顺铂单独治疗相比，在SQ 20 b头颈癌细胞中，对BG顺铂联合治疗特异性的19个基因过表达和22个基因表达不足（p < 0.05）。在过表达的探针组中，有参与DNA损伤和凋亡的基因，包括GADD 34、DDIT 4、ATF 4和PTHLH。类似结构的类似物9-CH 3-BG不增强顺铂诱导的细胞毒性或细胞凋亡，与对照细胞相比，在顺铂或9-CH 3-BG顺铂处理的细胞中GADD 34的表达也没有增强。对暴露于9-CH 3-BG顺铂的细胞的分析使我们能够将我们的阵列列表集中在对BG +/-顺铂与顺铂特异的32个探针组上，排除了9-CH 3-BG +/-顺铂与顺铂共有的差异表达探针组。类似地，14个探针组对BG顺铂相对于BG是特异性的，排除了9-CH 3-BG顺铂相对于9-CH 3-BG共有的差异表达探针组。定量实时PCR显示暴露于BG顺铂的细胞中GADD 34表达的剂量依赖性增加，与单独的顺铂相比，暴露于BG +/-顺铂的细胞的水平约> 2倍。在伴随药物治疗和药物治疗后的几个不同时间点，用顺铂和BG +/-顺铂测定GADD 34转录物的水平。在所有时间点，与单独的顺铂相比，在用BG +顺铂处理的细胞中GADD 34转录物水平升高约两倍。此外，与对照相比，在用BG +/-顺铂处理后，SQ 20 b、SCC 3S和SCC 61细胞中GADD 34表达水平显著变化，表达分别增加约3倍、2倍和3.5倍。阐明这些分子途径将有助于我们合成更强大的调节剂，以提高铂剂的疗效的目标。(c)2005年爱思唯尔公司All rights reserved.
Cisplatin and carboplatin are widely used clinical chemotherapeutic agents, especially against testicular, ovarian, and head and neck cancers. O-6-Benzylguanine (BG) has been shown to result in enhanced cytotoxicity, apoptosis, and DNA platination when used in conjunction with cisplatin and carboplatin in head and neck cancer cell lines. Microarray expression data indicated overexpression of 19 genes and underexpression of 22 genes specific to treatment with the combination of BG cisplatin compared to cisplatin alone treatment in SQ20b head and neck cancer cells (p < 0.05) using the Affymetrix HG-U133A GeneChip (R). Among the overexpressed probe sets were genes involved in DNA damage and apoptosis, including GADD34, DDIT4, ATF4, and PTHLH. A similarly structured analog, 9-CH3-BG, does not enhance cisplatin-induced cytotoxicity or apoptosis nor is there enhanced expression of GADD34 in cisplatin or 9-CH3-BG cisplatin-treated cells compared to control cells. Analysis of cells exposed to 9-CH3-BG cisplatin allowed us to focus our array list on 32 probe sets specific to BG +/- cisplatin versus cisplatin, ruling out differentially expressed probe sets common to 9-CH3-BG +/- cisplatin versus cisplatin. Similarly, 14 probe sets were specific to BG cisplatin versus BG, ruling out differentially expressed probe sets common to 9-CH3-BG cisplatin versus 9-CH3-BG. Quantitative real-time PCR demonstrated a dose dependent increase in GADD34 expression in cells exposed to BG cisplatin with levels approximately > 2-fold for cells exposed to BG +/- cisplatin compared to cisplatin alone. Levels of GADD34 transcripts were determined with both cisplatin and BG +/- cisplatin at several different time points concomitant with and following drug treatment. At all timepoints, GADD34 transcript levels are approximately two-fold elevated in cells treated with BG + cisplatin compared to cisplatin alone. Furthermore, significant changes in GADD34 expression levels in SQ20b, SCC3S, and SCC61 cells, with approximately three-fold, two-fold, and 3.5fold increases in expression, respectively, upon treatment with BG +/- cisplatin compared with control. Elucidation of these molecular pathways will aid in our goal of synthesizing more powerful modulators to increase efficacy of platinum agents. (c) 2005 Elsevier Inc. All rights reserved.