Figure 6. Effects of trastuzumab and LY294002 on the Aldefluor-positive population in breast cancer cell lines.
A. Trastuzumab reduced the proportion of Aldefluor-positive cells by as much as 80% in SUM159-HER2 and HCC1954 cells. In contrast, trastuzumab had no effect on the Aldefluor-positive population in MDA-MB-453 and JIMT-1 trastuzumab resistant cell lines. In contrast, LY294002 reduced the proportion of Aldefluor-positive cells in all cell lines. (B) Trastuzumab reduced phospho-HER2 and phospho-AKT expression in Sum159-HER2 cells but has no effect on expression of these proteins in trastuzumab resistant MDA-MB-453 cells.