Centers for Cancer Pharmacology, Pharmacogenetics, and Excellence in Environmental Toxicology, Department of Pharmacology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6160, USA.
Eur J Pharmacol. 2012 Dec 5;696(1-3):12-7. doi: 10.1016/j.ejphar.2012.08.008. Epub 2012 Sep 5.
Elevated homocysteine is a risk marker for several major human pathologies. Emerging evidence suggests that perturbations of folate/homocysteine metabolism can directly modify production of inflammatory mediators. Pemetrexed acts by inhibiting thymidylate synthetase (TYMS), dihydrofolate reductase (DHFR), and glycinamide ribonucleotide formyltransferase (GARFT). EA.hy 926 cells grown under low ("Lo") and high ("Hi") folate conditions were treated with pemetrexed. The concentrations of several intracellular folate derivatives were measured using LC-MRM/MS. Lo cells had lower total folate concentrations and a different distribution of the intracellular folate derivatives than Hi cells. Treatment with pemetrexed caused a decrease in individual folate analytes. Microarray analysis showed that several genes were significantly up or down-regulated in pemetrexed treated Lo cells. Several of the significantly up-regulated transcripts were inflammatory. Changes in transcript levels of selected targets, including C3, IL-8, and DHFR, were confirmed by quantitative RT-PCR. C3 and IL-8 transcript levels were increased in pemetrexed-treated Lo cells relative to Lo controls; DHFR transcript levels were decreased. In Lo cells, IL-8 and C3 protein concentrations were increased following pemetrexed treatment. Pemetrexed drug treatment was shown in this study to have effects that lead to an increase in pro-inflammatory mediators in Lo cells. No such changes were observed in Hi cells, suggesting that pemetrexed could not modify the inflammatory profile in the context of cellular folate sufficiency.
同型半胱氨酸升高是几种人类主要病理的风险标志物。新出现的证据表明，叶酸/同型半胱氨酸代谢的紊乱可以直接改变炎症介质的产生。培美曲塞通过抑制胸苷酸合成酶（TYMS）、二氢叶酸还原酶（DHFR）和甘氨酰胺核苷酸甲酰基转移酶（GARFT）发挥作用。在低（“Lo”）和高（“Hi”）叶酸条件下生长的 EA.hy 926 细胞用培美曲塞处理。使用 LC-MRM/MS 测量几种细胞内叶酸衍生物的浓度。Lo 细胞的总叶酸浓度较低，细胞内叶酸衍生物的分布也与 Hi 细胞不同。培美曲塞处理导致个别叶酸分析物的减少。微阵列分析显示，培美曲塞处理的 Lo 细胞中有几个基因显著上调或下调。几个显著上调的转录本是炎症的。通过定量 RT-PCR 证实了选定靶标（包括 C3、IL-8 和 DHFR）的转录水平变化。与 Lo 对照相比，培美曲塞处理的 Lo 细胞中 C3 和 IL-8 的转录水平增加；DHFR 转录水平降低。在 Lo 细胞中，培美曲塞处理后 IL-8 和 C3 蛋白浓度增加。本研究表明，培美曲塞药物治疗会导致 Lo 细胞中促炎介质的增加。在 Hi 细胞中未观察到这种变化，表明在细胞叶酸充足的情况下，培美曲塞不能改变炎症特征。
