Methotrexate analogs. 22. Synthesis, dihydrofolate reductase affinity, cytotoxicity, and in vivo antitumor activity of some putative degradation products of methotrexate-poly(L-lysine) conjugates
作者:Andre Rosowsky、Ronald A. Forsch、James H. Freisheim、John Galivan、Michael Wick
DOI:10.1021/jm00373a014
日期:1984.7
and their antitumor activity in vivo. These small lysine derivatives of MTX are of interest as putative breakdown products of MTX-poly(L-lysine). Inhibition of DHFR in a cell-free assay was decreased only 3-fold relative to MTX, indicating that gamma-substitution by up to three lysines is well tolerated for binding. On the other hand, toxicity toward L1210 murine leukemia cells in culture decreased up
分别将γ-羧基与L-赖氨酸,L-赖氨酰-L-赖氨酸或L-赖氨酰-L-赖氨酰-L-赖氨酸的ε-氨基连接的甲氨蝶呤(MTX)衍生物为评估它们的二氢叶酸还原酶(DHFR)亲和力,它们在培养中抑制细胞生长的能力以及它们在体内的抗肿瘤活性而制备的。这些MTX的小赖氨酸衍生物作为MTX-poly(L-赖氨酸)的推定分解产物而受到关注。相对于MTX,在无细胞测定中DHFR的抑制作用仅降低了3倍,表明对多达3个赖氨酸的γ取代具有良好的结合耐受性。另一方面,随着赖氨酸数量从一增加到三,对培养物中的L1210鼠白血病细胞的毒性相对于MTX降低了120倍,这表明当带正电荷的赖氨酸位于γ位置时,很难跨细胞膜吸收。相对于MTX,H35大鼠肝癌细胞的生长抑制作用降低了40至60倍,但是在具有正常DHFR含量但由于运输缺陷而对MTX具有180倍抗性的H35R0.3细胞中,赖氨酸衍生物仅毒性比MTX低3至7倍。当每天两次