Human T47D-ERβ breast cancer cells with tetracycline-dependent ERβ expression reflect ERα/ERβ ratios in rat and human breast tissue

Abstract

T47D-ERβ breast cancer cells with tetracycline-dependent ERβ expression and constant ERα expression can be used to investigate effects of varying ERα/ERβ ratios on estrogen-induced cellular responses. This study defines conditions at which ERα/ERβ ratios in T47D-ERβ cells best mimic ERα/ERβ ratios in breast and other estrogen-sensitive tissues in vivo in rat as well as in human. Protein and mRNA levels of ERα and ERβ were analyzed in T47D-ERβ cells exposed to a range of tetracycline concentrations and compared to ERα and ERβ levels found in breast, prostate, and uterus from rat and human origin. The ERα/ERβ ratio in T47D-ERβ cells exposed to >150ng/ml tetracycline is comparable to the ratio found in rat mammary gland and in human breast tissue. The ERα/ERβ ratio of other estrogen-sensitive rat and human tissues can also be mimicked in T47D-ERβ cells. The ERα/ERβ ratio found in MCF-7 and native T47D breast cancer cell lines did not reflect ratios in analyzed rat and human tissues, which further supports the use of T47D-ERβ cells as model for estrogen-responsive tissues. Using 17β-estradiol and the T47D-ERβ cells under the conditions defined to mimic various tissues it could be demonstrated how these different tissues vary in their proliferative response.

Keywords: BPH; Breast tissue; DCC-FCS; DL; DMEM; DNA; Dulbecco’s modified Eagle’s medium; EC(50); EDTA; ER; ERα/ERβ ratio; Estrogen receptors; Estrogen-sensitive tissue; FCS; HE staining; HP1; IgG; In vitro–in vivo comparison; M-MLV; MCF-7 cells; MSD; Merck, Sharp & Dohme; Moloney Murine Leukemia Virus; PBS; PVDF; RT; SDS; T47D cells; T47D human ductal breast epithelial tumor cells with tetracycline-dependent ERβ expression; T47D-ERβ calibration standard, the T47D-ERβ cells without tetracycline; T47D-ERβ cells; T47D-ERβ cells with tetracycline dependent ERβ expression; T47D-ERβ-CS; benign prostatic hyperplasia; cDNA; complementary deoxyribonucleic acid; dNTP; deoxynucleotide triphosphate; deoxyribonucleic acid; detection limit; dextran-coated charcoal-treated fetal calf serum; estrogen receptor; ethylenediaminetetraacetic acid; fetal calf serum; half maximal effective concentration; hematoxylin and eosin staining; heterochromatin protein 1; human breast adenocarcinoma cells; human ductal breast epithelial tumor cells; immunoglobulin G; mRNA; messenger ribonucleic acid; phosphate buffered saline; polyvinylideenfluoride; qPCR; quantitative polymerase chain reaction; reverse transcriptase; sodium dodecyl sulfate.