Department of Pharmacology, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Pondicherry, 605006, India.
Mol Biol Rep. 2011 Aug;38(6):4171-9. doi: 10.1007/s11033-010-0537-9. Epub 2010 Dec 9.
CYP2C19 is an enzyme involved in the metabolism of several clinically important drugs. The variations in the CYP2C19 promoter region may alter the transcription of the gene by altering the interaction between the trans and cis-acting elements. In the present study, CYP2C19 promoter region with different variant alleles were cloned into a pGL-3 basic luciferase reporter vector and transfected into HepG2 cell lines. Subsequently, dual luciferase activity was measured to evaluate the activity of the promoter region. Gel shift assays with predicted binding sites for CCAAT displacement protein, activating transcription factor-2 and glucocorticoid receptor were performed. Results from this study indicate that few variations present in the putative cis-acting elements of the CYP2C19 promoter region such as -1442T>C, -779A>C and -98T>C -1498T>G and -828del>T alter the transcription of the gene. Specific binding with nuclear proteins was also observed in gel shift assays. This may account for the interindividual variations in gene expression and genotype dependant differences in gene transcription. The results also suggest the role of activating transcription factor-2 and CCAAT displacement repressor protein on CYP2C19 gene transcription.
CYP2C19 是一种参与多种临床重要药物代谢的酶。CYP2C19 启动子区域的变异可能通过改变顺式和反式作用元件之间的相互作用来改变基因的转录。在本研究中，将具有不同变异等位基因的 CYP2C19 启动子区域克隆到 pGL-3 基本荧光素酶报告载体中，并转染到 HepG2 细胞系中。随后，测量双荧光素酶活性以评估启动子区域的活性。进行凝胶阻滞实验，以评估预测的 CCAAT 位移蛋白、激活转录因子-2 和糖皮质激素受体结合位点的活性。本研究的结果表明，CYP2C19 启动子区域中存在的少数假定顺式作用元件的变异，如 -1442T>C、-779A>C 和 -98T>C-1498T>G 和 -828del>T，改变了基因的转录。凝胶阻滞实验中也观察到与核蛋白的特异性结合。这可能解释了基因表达的个体间差异和基因型依赖的基因转录差异。结果还表明激活转录因子-2 和 CCAAT 位移抑制蛋白在 CYP2C19 基因转录中的作用。
