Cytotoxic effects of pemetrexed in gastric cancer cells
Cytotoxic effects of pemetrexed in gastric cancer cells
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DOI：
10.1111/j.1349-7006.2005.00058.x
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发表时间：
2005-06-01
期刊：
影响因子：
5.7
通讯作者：
Bang, YJ
中科院分区：
文献类型：
--
作者：
Kim, JH;Lee, KW;Bang, YJ
培美曲塞是一种新型的多靶点叶酸拮抗剂，对包括胃癌在内的多种实体瘤具有良好的临床疗效。本研究的目的是评价培美曲塞的细胞毒性及其与顺铂在胃癌细胞系中的相互作用模式，并鉴定与培美曲塞敏感性相关的基因。采用四唑蓝比色法（MTT法）评价培美曲塞的细胞毒活性，采用等效线图法评价培美曲塞与顺铂的相互作用。对胸苷酸合成酶（TS）、叶酸聚-γ-谷氨酸合成酶（FPGS）和还原型叶酸载体（RFC 1）进行Western免疫印迹和真实的实时RT-PCR分析，以确定是否可以通过蛋白或mRNA表达水平预测对培美曲塞的敏感性。培美曲塞的细胞毒性高于5-氟尿嘧啶，在大多数检测的胃癌细胞系中，IC 50为17 - 310 nM，培美曲塞/顺铂联合给药可产生相加或协同相互作用。TS、FPGS和RFC 1的蛋白表达与5-氟尿嘧啶的IC 50显著相关，但与培美曲塞化疗敏感性无关。RFC 1、FPGS等靶基因和耐药相关基因的mRNA表达与培美曲塞敏感性无显著相关性。总之，培美曲塞对胃癌细胞系具有活性，培美曲塞/顺铂联合用药显示出协同或相加的相互作用，支持其在胃癌中的临床应用。培美曲塞的药物敏感性不能通过TS、RFC 1或FPGS的表达来预测，我们认为它是由多个基因之间的相互作用决定的。
Pemetrexed is a newly developed multitargeted antifolate with promising clinical activity in many solid tumors including gastric cancer. The aim of the present study was to evaluate the cytotoxicity of pemetrexed and its mode of interaction with cisplatin in gastric cancer cell lines, and to identify genes associated with sensitivity to pemetrexed. The cytotoxic activity of pemetrexed was assessed by tetrazolium-based colorimetric assay (MTT assay) and the interaction between pemetrexed and cisplatin was evaluated by the isobologram method. Western immunoblotting and real time RT-PCR analysis of thymidylate synthase (TS), folylpoly-gamma-glutamate synthetase (FPGS) and reduced folate carrier (RFC1) were performed in order to determine whether sensitivity to pemetrexed would be predictable by protein or mRNA expression levels. Pemetrexed was more cytotoxic than 5-fluorouracil, with IC50 between 17 and 310 nM in most of the gastric cancer cell lines examined and the pemetrexed/cisplatin combination resulted in additive or synergistic interaction. The protein expressions of TS, FPGS, and RFC1 were significantly associated with IC50 for 5-fluorouracil, but no such association was found for pemetrexed chemosensitivity. The mRNA expressions of RFC1, FPGS and other target and resistance related genes revealed no significant association with pemetrexed sensitivity. In conclusion, pemetrexed is active against gastric cancer cell lines and the pemetrexed/cisplatin combination showed a synergistic or additive interaction, supporting its clinical use in gastric cancer. Drug sensitivity toward pemetrexed could not be predicted by the expressions of TS, RFC1, or FPGS and we suggest that it is determined by interactions between multiple genes.