Ruschel L R, Schmitt V M, Silva A B, Oliveira C S A, Flach K, d'Avila D O, Thiesen F V
Programa de Pós-Graduação em Biotecnologia Farmacêutica, Faculdade de Farmácia, , , Brasil.
Departmento de Análises Clínicas e Toxicológicas, Faculdade de Farmácia, , , Brasil.
Genet Mol Res. 2017 May 31;16(2):gmr-16-02-gmr.16029598. doi: 10.4238/gmr16029598.
Mycophenolate mofetil (MMF) is a prodrug active only after its hydrolysis to mycophenolic acid (MPA). The UGT1A9 enzyme is of special interest since it is the main enzyme involved in the glucuronidation of MPA. Single nucleotide polymorphisms (SNPs) in the UGT1A9 gene may be responsible for individual differences in the pharmacokinetics of MMF. Expression levels and the activity of UGT1A9 may depend on the presence of some SNPs located in the gene promoter region (-2152C>T and -275T>A), as well as changes in the coding region (c.98T>C). The objective of this study was to evaluate the effect of allelic variants of the UGT1A9 c.98T>C polymorphism (rs72551330; g. 87289T>C) on MMF metabolism in renal transplant patients. MPA and MPA 7-O glucuronide (MPAG) levels were determined on plasma samples of kidney transplant patients (N = 39) by high-performance liquid chromatography using ultraviolet detection. DNA was isolated from leukocytes and stored at -20°C. The presence of SNPs was investigated using polymerase chain reaction, followed by amplicon sequencing. The analysis of the UGT1A9 c.98T>C polymorphism revealed that all study patients presented the TT genotype. Diverse MPA and MPAG plasma concentrations were detected, including therapeutic, subtherapeutic, and toxic levels. A standardized molecular method permitted identification of UGT1A9 c.98T>C polymorphism genotypes in the examined renal transplant patients. All individuals of the study group presented the same genotype (c.98TT) for that polymorphism. Thereby, no association between the c.98T>C polymorphism and MPA and MPAG plasma levels could be evaluated, despite different levels of these compounds being observed.
霉酚酸酯（MMF）是一种前体药物，只有在水解为霉酚酸（MPA）后才具有活性。UGT1A9酶特别值得关注，因为它是参与MPA葡萄糖醛酸化的主要酶。UGT1A9基因中的单核苷酸多态性（SNP）可能是MMF药代动力学个体差异的原因。UGT1A9的表达水平和活性可能取决于位于基因启动子区域（-2152C>T和-275T>A）的一些SNP的存在，以及编码区域（c.98T>C）的变化。本研究的目的是评估UGT1A9 c.98T>C多态性（rs72551330；g. 87289T>C）的等位基因变体对肾移植患者MMF代谢的影响。通过使用紫外检测的高效液相色谱法测定肾移植患者（N = 39）血浆样本中的MPA和MPA 7 - O葡萄糖醛酸苷（MPAG）水平。从白细胞中分离DNA并储存在-20°C。使用聚合酶链反应，随后进行扩增子测序来研究SNP的存在。对UGT1A9 c.98T>C多态性的分析表明，所有研究患者均呈现TT基因型。检测到不同的MPA和MPAG血浆浓度，包括治疗水平、亚治疗水平和毒性水平。一种标准化的分子方法能够鉴定所检查的肾移植患者中UGT1A9 c.98T>C多态性的基因型。研究组的所有个体对于该多态性均呈现相同的基因型（c.98TT）。因此，尽管观察到这些化合物的水平不同，但无法评估c.98T>C多态性与MPA和MPAG血浆水平之间的关联。
