Estrogen receptors (ERs), ERα and ERβ, mediate estrogen actions in a broad range of target tissues. With the introduction of microarray techniques, a significant understanding has been gained regarding the interplay between the ERα and ERβ in breast cancer cell lines. To gain a more comprehensive understanding of ERβ-dependent gene regulation independent of ERα, we performed microarray analysis on HEK293/mock and HEK293/ERβ cells. A total of 332 genes was identified as ERβ-upregulated genes and 210 identified as ERβ-downregulated genes. ERβ-induced and ERβ-repressed genes were involved in cell-cell signaling, morphogenesis, and cell proliferation. The ERβ repressive effect on genes related to proliferation was further studied by proliferation assays, where ERβ expression resulted in a significant decrease in cell proliferation. To identify primary ERβ target genes, we examined a number of ERβ-regulated genes using chromatin immunoprecipitation assays for regions bound by ERβ. Our results showed that ERβ recruitment was significant to regions associated with 12 genes (IL1RAP, TMSB4X, COLEC12, ENPP2, KLRC1, RERG, RGS16, TNNT2, CYR61, FER1L3, FAM108A1, and CYP4X1), suggesting that these genes are likely to be ERβ primary target genes. This study has provided novel information on the gene regulatory function of ERβ independent of ERα and identified a number of ERβ primary target genes. The results of Gene Ontology analysis and proliferation assays are consistent with an antiproliferative role of ERβ independent of ERα.
- Chromatin immunoprecipitation
- Target gene
ASJC Scopus subject areas
- Endocrinology, Diabetes and Metabolism