Figure 7

Inhibitory effects of PD98059 and LY294002 blocking HRG-mediated tumor cell proliferation. The indicated breast cancer cells (5 × 10³) in 0.1 ml culture media were plated onto 96-well plates. After 24 h incubation, cells were grown in either 0.1 ml fresh medium with 0.5% FBS as control, or 0.1 ml same medium containing PD98059 (6.7 μM for 78617 and 85815, 5 μM for 85819), or LY294002 (3.3 μM for 78617 and 85815, 2.5 μM for 85819), or 25 ng/ml HRG alone or in combination of the same concentrations of HRG and PD98059, or HRG and LY294002. Cells were incubated at 37°C with 5% CO₂ for another 72 h, and the percentages of surviving cells from each group relative to controls, defined as 100% survival, were determined by reduction of MTS. Data reflect the means of at least three independent experiments.