Aim and Background: Cytokeratins (CKs) constitute the largest intermediate filamentous protein that during the development of malignancy, the original CK profile of the cell is frequently variable. Cytokeratin 19 (CK19) is known as an epithelial cell marker and CK19 expression was seen in more than 90% of breast cancers. In this study, CK19 mRNA expression by the real-time PCR (Polymerase Chain Reaction) in luminal A cell lines was assessed.

Materials and Methods: MCF7 and T47D breast cancer cell lines were purchased and cultured according to the recommended protocols. The cells were collected, counted and RNA was extracted from cell lines. The mRNA of CK19 as the target gene and GAPDH (Glyceraldehyde 3-phosphate Dehydrogenase) as a reference gene by real-time PCR was amplified. Quantitative CK19 expression was calculated using the ∆∆C_t method. The average ∆C_t of CK19 and GAPDH was calculated in each cell line as well as the ∆C_t of GAPDH as a calibrator in different cell lines was quantitatively reported.

Results: This method can be used for detection of CK19 tumor marker expression, in the cells. On the other hand, the same expression in the MCF7 and T47D breast cancer cell lines was shown.

Conclusions: Expression of CK19 is the same, in the luminal A breast cancer cell lines. Molecular markers could be used for cell Lines classification which is significant in breast cancer research and it is helpful in detection and treatment of the disease.