Establishment of taylor-made therapy of acute leukemia by means of pharmacogenetics

通过药物遗传学研究了两种主要抗白血病药物阿糖胞苷（Ara-C）的泰勒治疗策略。(1)白血病细胞中ara-C的关键代谢物是dna结合的ara-C。在白血病细胞DNA水平上监测治疗药物可以优化急性白血病的化疗方案，改善临床疗效。我们目前开发了一种灵敏的新方法来监测体内DNA中ara-C的掺入。方法的准确度、精密度和变异系数均较好。该方法可测定经ara-C处理的HL60细胞DNA中ara-C的掺入量，其值与平行实验中用氚化ara-C进行闪烁计数的结果一致。我们的方法可以监测中剂量ara-C治疗期间dna结合的ara-C浓度，以及血浆ara-C和细胞内ara-C三磷酸浓度。ara-C并入DNA似乎与细胞内三磷酸ara-C的保留或血浆ara-C的持久性有关。因此，本方法是敏感、准确、精确的，并且可以在DNA水平上进行治疗药物监测，以更好地个性化抗白血病方案。(2)利用cDNA微阵列技术检测血液细胞系中与Ara-C抗性相关的基因的综合表达水平。我们从母体细胞株THP-1、K562、HL60、CEM、U937中分离出5株Ara-C耐药细胞株，并对其进行分子细胞遗传学分析。通过对这些Ara-C抗性细胞系中mRNA表达的定量分析，我们发现没有共同的基因表达来确定对Ara-C的抗性。尽管采用了常见的方法诱导对Ara-C的抗性，但每个细胞系表现出不同的交叉抗性。这些发现表明，血液学细胞系对Ara-C的耐药机制在不同细胞系之间是不同的，这为泰勒制造的Ara-C治疗提供了有用的信息。少

Two strategies for taylor-made therapy with a major antileukemic agent cytarabine (Ara-C) by means of pharmacogenetics were studied.(1) The crucial metabolite for ara-C is the DNA-incorporared ara-C in leukemic cells. Therapeutic drug monitoring at the DNA level in leukemic cells may optimize the chemotherapy for acute leukemia and improve clinical outcome. We presently developed a sensitive new method for monitoring ara-C incorporated into DNA in vivo. Accuracy, precision, and coefficient of variation of the method were excellent. The method was found to determine ara-C incorporation into DNA of ara-C-treated HL60 cells in vitro, the values of which were compatible with those measured by scintillation counting in parallel experiments using tritiated ara-C. Our method could monitor DNA-incorporated ara-C concentrations during intermediate-dose ara-C therapy, together with plasma ara-C and intracellular ara-C triphosphate concentrations. ara-C incorporation into DNA appeared to be assoc … More iated with the intracellular retention of ara-C triphosphate or persistence of the plasma ara-C. Thus, the present method is sensitive, accurate, precise, and may permit therapeutic drug monitoring at the DNA level for better individualization of antileukemic regimens.(2) cDNA microarray was used to examine the comprehensive expression levels of genes in hematologic cell lines in relation to resistance to Ara-C. We isolated five Ara-C resistant cell lines from its parent cell lines (THP-1, K562, HL60, CEM, U937), and conducted molecular cytogenetic analysis of them. Using a quantitative analysis of mRNA expression within these Ara-C reisistant cell lines, we showed no common gene expression to determine resistantce to Ara-C. Each cell lines demonstrated different cross-resistance, despite employment of the common method to induce resistance to Ara-C. These findings suggest the mechanism of resistance of hematological cell lines to Ara-C was varied among each cell lines, which was useful information for the taylor-made therapy with Ara-C. Less