Houghton J A, Williams L G, de Graaf S S, Cheshire P J, Wainer I W, Jadaud P, Houghton P J
Department of Biochemical and Clinical Pharmacology, St. Jude Children's Research Hospital, Memphis, TN 38101.
Cancer Commun. 1989;1(3):167-74.
Four hr infusions i.v. of [6RS]5-formyltetrahydrofolate ([6RS]5-CHO-H4PteGlu; 500 mg/m2) and [6RS]5-methyltetrahydrofolate ([6RS]5-CH3-H4PteGlu; 500 mg/m2) were compared for their relative effects on expansion of pools of 5,10-methylenetetrahydrofolates (CH2-H4PteGlun) and tetrahydrofolates (H4PteGlun) in two human colon adenocarcinoma xenografts in mice. Expansion of these pools by 253-661% of control and increase in predominance of di-, tri-, and tetra-glutamate species were observed during [6RS]5-CHO-H4PteGlu infusion. In contrast, only modest pool size expansion (148-164% of control) and limited modulation of polyglutamate species were detected in four tumor lines during infusion with [6RS]5-CH3-H4PteGlu. The data suggest that [6RS]5-CH3-H4PteGlu is less effective than [6RS]5-CHO-H4PteGlu as a precursor for pools of CH2-H4PteGlun and H4PteGlun in colon tumors.
对[6RS]5-甲酰四氢叶酸（[6RS]5-CHO-H4PteGlu；500mg/m²）和[6RS]5-甲基四氢叶酸（[6RS]5-CH3-H4PteGlu；500mg/m²）进行4小时静脉输注，比较它们对小鼠体内两种人结肠腺癌异种移植瘤中5,10-亚甲基四氢叶酸（CH2-H4PteGlun）和四氢叶酸（H4PteGlun）池扩张的相对影响。在输注[6RS]5-CHO-H4PteGlu期间，观察到这些池扩张至对照的253 - 661%，并且二、三、四谷氨酸物种的优势度增加。相比之下，在输注[6RS]5-CH3-H4PteGlu期间，在四个肿瘤系中仅检测到适度的池大小扩张（对照的148 - 164%）和对多谷氨酸物种的有限调节。数据表明，作为结肠肿瘤中CH2-H4PteGlun和H4PteGlun池的前体，[6RS]5-CH3-H4PteGlu的效果不如[6RS]5-CHO-H4PteGlu。
