Juranka P, Chan V L
Cancer Res. 1980 Nov;40(11):4123-6.
The relative cytotoxicity of 9-beta-D-arabinofuranosyladenine and 9-beta-D-arabinofuranosyladenine 5'-monophosphate (ara-AMP) were compared using wild-type and adenosine kinase (AK)-deficient baby hamster kidney somatic cell mutants. The cytotoxicity of ara-AMP to baby hamster kidney cells was dependent on the presence of AK activity since AK-deficient mutants were resistant to ara-AMP. On an equimolar basis, ara-AMP was consistently less cytotoxic than was 9-beta-D-arabinofuranosyladenine to wild-type and AK-deficient baby hamster kidney mutant cells. These findings are consistent with the common view that ara-AMP molecules do not enter mammalian cells as an intact nucleotide. Presumably, ara-AMP molecules were hydrolyzed by the nonspecific phosphatases and 5'-nucleotidase found in the serum or by the ecto-5'-nucleotidase on the outer surface of the membrane and only enter the mammalian cells as 9-beta-D-arabinofuranosyladenine.
使用野生型和腺苷激酶（AK）缺陷的幼仓鼠肾体细胞突变体比较了9-β-D-阿拉伯呋喃糖基腺嘌呤和9-β-D-阿拉伯呋喃糖基腺嘌呤5'-单磷酸酯（ara-AMP）的相对细胞毒性。ara-AMP对幼仓鼠肾细胞的细胞毒性取决于AK活性的存在，因为AK缺陷突变体对ara-AMP具有抗性。在等摩尔基础上，ara-AMP对野生型和AK缺陷的幼仓鼠肾突变体细胞的细胞毒性始终低于9-β-D-阿拉伯呋喃糖基腺嘌呤。这些发现与普遍观点一致，即ara-AMP分子不会作为完整核苷酸进入哺乳动物细胞。据推测，ara-AMP分子被血清中发现的非特异性磷酸酶和5'-核苷酸酶或膜外表面的ecto-5'-核苷酸酶水解，仅作为9-β-D-阿拉伯呋喃糖基腺嘌呤进入哺乳动物细胞。
