Department of Structural and Cellular Biology, Tulane Cancer Center and Tulane University Health Sciences Center, 1430 Tulane Ave., SL-49, New Orleans, LA 70112, USA.
Steroids. 2010 Dec;75(12):944-51. doi: 10.1016/j.steroids.2010.06.002. Epub 2010 Jun 15.
Luciferase reporter constructs and transient co-transfection approaches demonstrate that elevated expression of RORalpha1 augments 17-beta-estradiol (E(2))-induced transcriptional activation of the full-length ERalpha, but not truncated ERalpha constructs (ABCD or CDEF), in MCF-7 breast cancer and HEK293 embryonic kidney cells, and that physiologic concentrations of MLT inhibit the individual and combined transcriptional activity of ERalpha by RORalpha1 and E(2). Gel mobility shift and co-immunoprecipitation (IP)/pull-down assays demonstrate that RORalpha1 and ERalpha do not interact directly at the DNA-binding level or as heterodimers, however, RORalpha1 augments E(2)-induced pS2 and cyclin D1 mRNA expression while MLT inhibits RORalpha1/E(2)-induced expression of pS2 and cyclin D1 in MCF-7 cells.
荧光素酶报告基因构建体和瞬时共转染方法表明，RORα1 的高表达增强了 17-β-雌二醇（E2）诱导的全长 ERα的转录激活，但不能增强截断的 ERα 构建体（ABCD 或 CDEF）在 MCF-7 乳腺癌和 HEK293 胚胎肾细胞中的转录激活，并且生理浓度的 MLT 通过 RORα1 和 E2 抑制 ERα 的单独和联合转录活性。凝胶迁移率变动和共免疫沉淀（IP）/下拉测定表明，RORα1 和 ERα 不会在 DNA 结合水平或异二聚体上直接相互作用，但是，RORα1 增强了 E2 诱导的 pS2 和细胞周期蛋白 D1 mRNA 的表达，而 MLT 抑制了 RORα1/E2 诱导的 MCF-7 细胞中 pS2 和细胞周期蛋白 D1 的表达。
