J Korean Cancer Assoc.  1999 Dec;31(6):1129-1139.

Multiparametric Flow Cytometry in Breast Cancer Cell Line (MCF-7) Stained with Fluorescein Isothiocyanate, Phycoerythrin, and Propidium Iodide

• Han KT
• Ryu KS
• Han SH
• In K
• Song JM
• Kim JH
• Lee JK
• Rha JG
• Kim SP
• Lee HY

Abstract

PURPOSE: Multiparametric flow cytometry is a powerful tool for analyzing the phenotypic, cell kinetic and ploidy heterogeneity of tumor cell populations. But there are major problems such as inaccurate results by the contribution of non-neoplastic cell contamination and the substantial spectral overlap of PI (propidium iodide) into PE (phycoery- thrin) fluorescent emissions on a standard flow cytometer. Recent studies suggested that the emission spectral overlap from PI into PE could be sufficiently compensated electrically and the cytokeratin, a marker for epithelial tumor cells, are successfully used in conjunction with DNA specific dye so as to obtain DNA profiles selectively for cytokeratin-positive tumor cells. The aim of this study was to investigate the feasibility that multiparametric analysis in heterogeneous cell populations of cell lines like solid tumors, which were stained triply with PE, fluorescein isothiocyanate FITC, and PI, can be done without any influences by the contaminated normal diploid cell populations and without spectral overlap between fluorochromes on a standard flow cytometer.
MATERIALS AND METHODS
MCF-7 cell lines and heterogeneous cell populations mixed with MCF-7 cells and human peripheral blood lymphocytes were fixed with 1% paraformal- dehyde and permeabilized with 100% methanol. Cytokeratin was labeled with PE and some proliferat!on-associated markers were labeled with FITC, which were followed by DNA staining by PI. These triply stained cells were measured on a standard FACScan flow cytometer equipped with 488 nm single laser and those acquired data were analyzed with WinList 3.0 and ModFit LT software programs on personal computor.
RESULTS
Coefficient of variation (CV) of GoG1> peak of MCF-7 cells alone was 4.3. GoG1, S, and G2M phase fractions were 44.9%, 45.9%, and 9.2% respectively. FITC, PE and PI fluorochromes could be detected without any interference between them. CVs of GoG1 peak of PBL and MCF-7 cells in those heterogeneous population were 2.3 and 4.2 respectively. The DNA index of MCF-7 cells was 1.7. MCF-7 cells expressed the cyto- keratin, PCNA, p53, c-erbB/2 and c-myc antigen and in contrast, PBL did not express cytokeratin. The cell cycle phase fractions and oncoprotein expressions could be detected separately in diploid PBL and aneuploid MCF-7 cells in the mixed cell population without any influences by each other.
CONCLUSION
These results suggested that the cellular antigen expressions of the malignant cells can be analyzed selectively without influences of fluorescent signals from nonneo- plastic cells. The neoplastic tumor subpopulations are clearly identified on the basis of both ploidy status and antigen expressions. The positive cytokeratin expressions indicate that they were derived from the epithelium, providing objective evidence of the tissue of origin and more precise analysis of DNA contents, ploidy, and oncogene expressions selectively with possible correlation between them. Thus, this method offers new possibilities for multiparameter flow cytometric analysis in the heterogeneous solid tumor cell populations.

Keyword

Multiparametric flow cytometry; Cytoketratin; Cellular antigens; MCF-7 cells

MeSH Terms

Aneuploidy
Breast Neoplasms*
Breast*
Cell Cycle
Cell Line*
Diploidy
DNA
Epithelium
Flow Cytometry*
Fluorescein*
Fluorescein-5-isothiocyanate
Fluorescent Dyes
Humans
Keratins
Lymphocytes
MCF-7 Cells
Methanol
Oncogenes
Phycoerythrin*
Plastics
Ploidies
Population Characteristics
Proliferating Cell Nuclear Antigen
Propidium*
DNA
Fluorescein
Fluorescein-5-isothiocyanate
Fluorescent Dyes
Keratins
Methanol
Phycoerythrin
Plastics
Proliferating Cell Nuclear Antigen
Propidium