Messikommer Alessandra, Seipel Katja, Byrne Stephen, Valk Peter J M, Pabst Thomas, Luedtke Nathan W
Department of Chemistry, University of Zurich, CH-8057 Zurich, Switzerland.
Department of Medical Oncology, University Hospital Inselspital and University of Bern, CH-3010 Bern, Switzerland.
ACS Pharmacol Transl Sci. 2020 Oct 12;3(6):1225-1232. doi: 10.1021/acsptsci.0c00120. eCollection 2020 Dec 11.
Nucleosides and their analogues constitute an essential family of anticancer drugs. DNA has been the presumptive target of the front-line prodrug for acute myeloid leukemia (AML), cytarabine (ara-C), since the 1980s. Here, the biomolecular targeting of ara-C was evaluated in primary white blood cells using the ara-C mimic "AzC" and azide-alkyne "click" reactions. Fluorescent staining and microscopy revealed that metabolic incorporation of AzC into primary white blood cells was unexpectedly enhanced by the DNA polymerase inhibitor aphidicholine. According to RNaseH digestion and pull-down-and-release experiments, AzC was incorporated into short RNA fragments bound to DNA in peripheral blood monocytes (PBMCs) collected from all six healthy human donors tested. Samples from 22 AML patients (French-American-British classes M4 and M5) exhibited much more heterogeneity, with 27% incorporating AzC into RNA and 55% into DNA. The overall survival of AML patients whose samples incorporated AzC into RNA was approximately 3-fold higher as compared to that of the DNA cohort ( ≤ 0.056, χ = 3.65). These results suggest that the RNA primers of DNA synthesis are clinically favorable targets of ara-C, and that variable incorporation of nucleoside drugs into DNA versus RNA may enable future patient stratification into treatment-specific subgroups.
核苷及其类似物是抗癌药物的一个重要类别。自20世纪80年代以来，DNA一直被认为是急性髓系白血病（AML）一线前体药物阿糖胞苷（ara-C）的作用靶点。在此，使用阿糖胞苷模拟物“AzC”和叠氮化物-炔烃“点击”反应，在原代白细胞中评估了阿糖胞苷的生物分子靶向作用。荧光染色和显微镜检查显示，DNA聚合酶抑制剂蚜虫胆碱意外增强了AzC在原代白细胞中的代谢掺入。根据核糖核酸酶H消化以及下拉和释放实验，AzC被掺入到从所有6名受试健康人类供体采集的外周血单核细胞（PBMC）中与DNA结合的短RNA片段中。来自22例AML患者（法美英分型M4和M5）的样本表现出更多的异质性，27%的样本将AzC掺入RNA，55%的样本将AzC掺入DNA。与DNA组相比，样本将AzC掺入RNA的AML患者的总生存期高出约3倍（≤0.056，χ=3.65）。这些结果表明，DNA合成的RNA引物是阿糖胞苷临床上有利的靶点，并且核苷药物在DNA和RNA中的可变掺入可能使未来能够将患者分层到特定治疗亚组中。
