Figure 3

Immunostaining of original tumor, low passage, and high passage KCI-MENG1 cells. The original patient-derived tumor (top row) showed moderate and patchy immunoreactivity for epithelial membrane antigen (EMA); strong and diffuse immunostaining for progesterone receptor (PR); and a Ki-67 proliferative index of 2–3%. There was also strong immunostaining for N-cadherin and vimentin. KCI-MENG1-LP cells (middle row) and KCI-MENG1-HP cells (bottom row) maintained expression of EMA, N-cadherin, and vimentin but had significantly reduced PR expression compared to the original tumor. Whereas Ki-67 labeling was found in only a small number of cells in the original tumor and low passage cells, it was positive in virtually all P84 cells. Scale bar 50 µm.