Zahra Orafa - Master of Science, Department of Molecular and Cellular Sciences, Pharmaceutical Sciences Branch,Islamic Azad University, Tehran, Iran
Mana Oloomi - Associate Professor, Department of Molecular Biology, Pasteur Institute of Iran, Tehran, Iran
Saeideh Keyvani - Master of Science, Department of Molecular Biology, Pasteur Institute of Iran, Tehran, Iran
Nasrin Karimi - Master of Science, Department of Molecular Biology, Pasteur Institute of Iran, Tehran, Iran

Cytokeratin19 (CK19) is a part of the cytoskeleton of epithelial cells. It is a sensitive and specific marker of epithelial cells that expressed in breast cancer cells. Immunofluorescence microscopy is a powerful technique that is widely used to assess both the localization and expression levels of proteins. On the other hand, T47D and MCF7 are two human hormone-dependent breast cancer cell lines, which are widely used as experimental models for breast cancer studies. Materials and methods: breast cancer cell lines (MCF7, T47D) were cultured in RPMI 1640 containing 10% fetal bovine serum (FBS) and penicillin-streptomycin antibiotic. Then, cells were fixed with 4% paraformaldehyde and permeabilized with ice-cold 100% methanol. The cells were blocked with 1% BSA and were stained with CK19 antibody. Finally, CK19 expression was elevated by mmunofluorescence microscopy.Results: Immunofluorescence microscopy was used to detect the CK19 expression in T47D and MCF7 cells. The result showed that T47D and MCF7 cells were CK19-immunoreactive cells and CK19 was mainly located in the cytoplasm of these cells.Conclusion: T47D and MCF7 cell lines belonged to luminal A subtype of breast cancer that CK19 expression correlated whit ER (Estrogen) marker. Expression of CK19 in the estrogen positive (ER+) breast cancer cell lines suggest that these cells have originated from luminal epithelial cells.CK19 is an epithelial marker that estrogen regulated its expression in luminal A subtype of breast cancer cell lines.

CK19, MCF7, T47D, Luminal A