HER2 surface protein expression in established and primary ovarian cell lines.

HER2 is expressed in the cell surface of all ascites and solid tumor-derived tumor cells. HER2 expression was assessed using flow cytometry in a large panel of clinical ascites and solid tumor specimens. A breast cancer cell line (MDA 468) and a leukemia cell line (CEM) which do not express any HER2 were used as negative controls. HER2 was found to be expressed in all tested ascites and solid tumor specimens albeit at different levels. HER2 cell surface levels are expressed as specific MFI. P = 0.03 when comparing percentage of HER2 protein-expressing cells in established vs. short-term lines. P = 0.43 when comparing MFI of HER2 protein detection in established vs. to short-term cell lines. P values were calculated using student’s unpaired t-test analysis.