Background: The purpose of the study was to test the feasibility of laser scanning cytometry (LSC) to simultaneously measure estrogen receptor (ER) and nucleolin (NU) expression in the nuclei of the same individual breast cancer cells.
Materials and methods: Cancer cells from 64 breast tumors were labeled with anti-NU and biotinylated anti-ER antibodies, then with secondary FITC-conjugated antibody and streptavidin-APC conjugate, respectively, and measured by LSC. The expression of NU in the nucleus and NU aggregates (NUA), number of NUA, nuclear and NUA areas and ER expression were assessed for aspiration each cell.
Results: ER-bound APC fluorescence correlated with nuclear NU (r=0.65; p<0.001) and NUA-bound FITC fluorescence (r=0.59; p<0.001). Good correlation was found between percentages of ER-positive cells in LSC and by image analysis in paraffin-embedded sections (r=0.59, p<0.001).
Conclusion: ER and NU expression can be measured simultaneously in the same nuclei of breast cancer cells.