Background
Human breast cancer cell (BCC) lines are used extensively in biomedical research and are classified as estrogen receptor (ER)-positive or ER-negative. We used flow cytometry (FCM), reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting (WB) to assess ER expression in human BCC lines reported as being ER-positive (MCF7, T-47D, ZR-75-1) or ER-negative (MDA-MB-231, SK-BR-3, MDA-MB-453, HCC1954) to determine the validity of this classification. Materials and
Conclusion
These results demonstrate the importance of reassessing the ER status of human BCC lines that are used widely in biomedical research.
Methods
ER was assessed in permeablized, fixed cells by FCM using two monoclonal anti-ERα antibodies and a polyclonal anti-ERβ antibody, in parallel with RT-PCR and WB.
Results
All of the cell lines expressed ERα and ERβ. Indirect immunofluorescence indicated that it was membrane and cytoplasmic ER that was being detected by FCM. Down-regulation by fulvestrant confirmed it was ER.