Study on expression upregulation of LRP16 induced by estrogen

Objective: To explore and identify the regulatory way of LRP16 gene expression. Methods: Cis-elements of LRP16gene promoter region and SAGE(Serial Analysis of Gene Expression)pattern of LRP16were analysed，the results suggested that 17β-estradiol(β-E₂) may upregulate its expression.To prove the hypothesis，the human LRP16gene promoter， with 2.6kb of 5'-flanking DNA， was cloned upstream of the Luciferase gene (pS₀) and tested for estrogen regulation by transient cotransfection with estrogen receptor α or β(ERα，ERβ)gene expression vector in COS-7 and MCF-7cells.The relative Luciferase activity was detected by Luciferase Assay.Results: The relative luciferase activity was significantly increased in MCF-7 and COS-7cells cotransfected with pS₀ and ERβexpression vector than those with pS₀transfection and pS₀ and ERβ expression vector cotransfection， and the increased extent in MCF-7 and COS-7cells was nearly consistent.Conclusion: LRP16 is a novelly identified target gene regulated by estrogen.The regulatory approach is mediated by ERα.The potential clinical significance of expression upregulation of LRP16 gene induced by estrogen in breast cancer cell line MCF-7is valuable to be further investigated.