Nasrin Karimi - Master of Sciences, Department of Molecular Biology, Pasteur Institute of Iran, Tehran-Iran
Mana Oloomi - Associate Professor, Department of Molecular Biology, Pasteur Institute of Iran, Tehran-Iran
Zohreh Orafa - Master of Sciences, Department of Molecular Biology, Pasteur Institute of Iran, Tehran-Iran

Background :Circulating tumor cells (CTCs) detection in peripheral blood of epithelial cancer patients is a recognized indicator for the presence of primary tumors and/or metastasis. Cytokeratin19 (CK19) has been used as a marker for detecting CTCs in blood.Methods: A total of 50 blood samples including 25 healthy and 25 patients with breast cancer were tested by flow cytometry to quantify the expression of CK19. Briefly, 1 ml blood and 5 ml RBC lysis buffer were mixed and kept on ice for 15 min. Subsequently, the cells were fixed with 4%paraformaldehyde for 20 min at room temperature. They were permeabilized with methanol for 30 min on ice. Then the cells were incubated with FITC conjugated CK19 antibody or FITC-mouse IgG2a isotype antibody as negative control. Results: CK19 was positive in the peripheral blood cells of breast cancer patients at stages II to IV, but not in the patients at stage I and healthy controls. CK19 was detected in 48% of breast cancer patients. The CK19 gene expression in different stages was statistically significant with P Value= 0.037. Conclusion: The detection of CK19 in peripheral blood by flow cytometry is a specific and feasible method to monitor CTCs in breast cancer patients.

CK19, CTCs, Flow cytometry