McLaughlin W H, Thramann W M, Lambrecht R M, Milius R A, Bloomer W D
Department of Radiotherapy, Mount Sinai School of Medicine, New York.
J Surg Oncol. 1988 Mar;37(3):192-7. doi: 10.1002/jso.2930370312.
A strategy for cancer therapy using astatine-211-labeled alpha-methyltyrosine (211At-AMT) was studied in cultured B16 melanoma cells and compared to the radiotoxicity of iodine-125-labeled iododeoxyuridine (125IUdR), a thymidine analogue. Both 125I and 211At deliver lethal doses of irradiation to melanoma cells when administered as 125IUdR and 211At-AMT. The alpha decay of astatine-211 is more effective however, needing only a fraction of the cellular radioactivity of 125IUdR to effect comparable clonogenic survival. Compared with 125IUdR, 125I-AMT is not cytotoxic because the range of the low energy electrons released does not interact with DNA. Uptake of radiolabeled AMT by melanotic cells is enhanced by theophylline. This preliminary evidence suggests that 211At-labeled melanin precursors may be exquisitely cytotoxic to B16 melanoma cells.
在培养的B16黑色素瘤细胞中研究了使用砹 - 211标记的α - 甲基酪氨酸（211At - AMT）进行癌症治疗的策略，并将其与胸腺嘧啶类似物碘 - 125标记的碘脱氧尿苷（125IUdR）的放射毒性进行了比较。当以125IUdR和211At - AMT形式给药时，125I和211At都会向黑色素瘤细胞传递致死剂量的辐射。然而，砹 - 211的α衰变更有效，仅需要125IUdR细胞放射性的一小部分就能产生相当的克隆存活效果。与125IUdR相比，125I - AMT没有细胞毒性，因为释放的低能电子的射程不会与DNA相互作用。茶碱可增强黑色素细胞对放射性标记的AMT的摄取。这一初步证据表明，211At标记的黑色素前体可能对B16黑色素瘤细胞具有极强的细胞毒性。
