Boritzki T J, Barlett C A, Zhang C, Howland E F
Agouron Pharmaceuticals Inc., San Diego, CA 92121, USA.
Invest New Drugs. 1996;14(3):295-303. doi: 10.1007/BF00194533.
The glycinamide ribonucleotide formyltransferase (GARFT) inhibitor, 4-[2-(2-amino-4-oxo-4,6,7,8-tetrahydro-3H-pyrimidino[5,4-6] [1,4]thiazin-6-yl)-(S)-ethyl]-2,5-thienoyl-L-glutamic acid (AG2034), was designed from the X-ray structure of the GARFT domain of the human tri functional enzyme. AG2034 inhibits human GARFT (Ki = 28 nM), has a high affinity for the folate receptor (Kd = 0.0042 nM), and is a substrate for rat liver folylpolyglutamate synthetase (K(m) = 6.4 microM, Vmax = 0.48 nmole/hr/mg). The IC50 for growth inhibition was 4 nM against L1210 cells and 2.9 nM for CCRF-CEM cells in culture. In vitro growth inhibition can be reversed by addition of either hypoxanthine or AICA (5-aminoimidazole-4-carboxamide) to the culture medium. A cell line with impaired transport of reduced folates, L1210/C1920, was resistant to AG2034 indicating that this compound can enter cells by utilizing the reduced folate carrier. AG2034 showed in vivo antitumor activity against the 6C3HED, C3HBA, and B-16 murine tumors and in the HxGC3, KM20L2, LX-1, and H460 human xenograft models, and has been selected for preclinical development towards clinical trials.
甘氨酰胺核糖核苷酸甲酰基转移酶（GARFT）抑制剂4-[2-(2-氨基-4-氧代-4,6,7,8-四氢-3H-嘧啶并[5,4-b][1,4]噻嗪-6-基)-(S)-乙基]-2,5-噻吩甲酰-L-谷氨酸（AG2034）是根据人类三功能酶GARFT结构域的X射线结构设计的。AG2034抑制人GARFT（Ki = 28 nM），对叶酸受体具有高亲和力（Kd = 0.0042 nM），并且是大鼠肝脏叶酰聚谷氨酸合成酶的底物（K(m)= 6.4 microM，Vmax = 0.48 nmole/小时/毫克）。在培养中，对L1210细胞生长抑制的IC50为4 nM，对CCRF-CEM细胞为2.9 nM。通过向培养基中添加次黄嘌呤或AICA（5-氨基咪唑-4-甲酰胺）可逆转体外生长抑制。具有还原型叶酸转运受损的细胞系L1210/C1920对AG2034具有抗性，表明该化合物可通过利用还原型叶酸载体进入细胞。AG2034在体内对6C3HED、C3HBA和B-16小鼠肿瘤以及HxGC3、KM20L2、LX-1和H460人异种移植模型显示出抗肿瘤活性，并且已被选用于朝着临床试验进行临床前开发。
