Extracellular matrix (ECM) stimulation and gene expression analysis

For the siRNA-mediated knockdown of uPAR, 48 hours post-transfection with siRNA, cells were harvested with 2 mM NaEDTA in PBS, washed with serum-free medium and plated for 30 minutes on culture dishes that were left uncoated or coated with the appropriate ECM. For gene expression analysis, cells were grown on the indicated ECM-coated or uncoated dishes for 18 hours prior to RNA extraction. For the rescue of plaur/fosl1 knockdowns, cells were first transfected with siRNA then, 24 hours later, transfected with the indicated expression plasmid: 24 hours later, these cells were plated for 18 hours on VN-coated dishes prior to RNA extraction. RNA was extracted using RNeasy kits (Qiagen Inc, Toronto, ON Canada) according to the manufacturer’s protocol and reverse transcribed using a high-capacity cDNA reverse transcription kit (ThermoScientific Inc, Waltham, MA, USA). Gene expression analysis was performed using the LightCycler 480 and associated software using Advanced Relative Gene Expression Analysis (Roche Diagnostics, Laval, Quebec, Canada). The sequences used for qPCR primers are listed in Additional file 1: Table S1.