Allelic variation in the ATP7B gene promoter. Implications for phenotype variability, neurodegeneration and Pt resistance in tumor diseases
摘要
Wilson's disease (WD) is a rare genetic disorder of copper transport due to mutations in the ATP7B gene. This results in copper overload and tissue damage that is most evident in the liver and brain. Over 1000 pathogenic mutations have been found in WD patients, and of these, mutations within the ATP7B coding region predominate. In this study, we perform functional analyses of 7 rare sequence variations in the promoter region of the ATP7B gene. We performed dual luciferase reporter assays in HepG2 and SH-SY5Y cell lines under basal conditions and after the addition of 10 μM or 40 μM concentrations of CuSO4. The results showed that promoter activity varied both according to the haplotype and the cell line used. Our results suggest a potential role of promoter polymorphisms in the variation of ATP7B gene expression with probable implications in copper accumulation in the organism and consequent phenotype variation in WD. In addition, given the association of copper concentration and ATP7B expression in the brain, promoter polymorphisms could act as susceptibility determinants of neurodegeneration in the most common late-onset nervous system diseases. Finally, promoter involvement in ATP7B overexpression and platinum resistance presents new mechanisms of great importance that need to be better understood. Further experimental and clinical studies are necessary to further explore the role of the ATP7B promoter in copper and platinum management. These studies will offer new insights for the development of molecular therapies for brain degenerative and tumor diseases.