PDK1 increases anchorage-dependent and -independent cell growth and ECM invasion. A, Top panel, Cell growth on a plastic substrate was determined after 24–72 hr by SRB staining as described in Methods. Results are expressed as the OD560 at each time point. Lower panel, Anchorage-independent growth was determined by seeding cells in siliconized plates and determining growth after 72 hr by assay for ATP using luciferase as described in Methods. Results are expressed in units of luciferase activity. B, Cells were grown for 7 days on collagen-coated plates. Magnification 50×. C, Cells were grown on Matrigel in a Boyden chamber and cells invading through Matrigel were determined. Results are expressed as a percentage of MDA-MB-231 cells invading Matrigel run in parallel as a positive control, and represent the mean ± S.E. of three independent experiments.