Effects of receptor proteins on cellular motility. (a) Wound-healing assay. Infected MDA-MB-231 or BT-549 cells were incubated in the presence (+) or absence (−) of 10−9 M E2 as indicated for 48h to allow cells to reach near confluence. A wound was then created and images were captured at 0h and at 24h intervals. Results, representing the mean ± s.e.m. of three independent experiments performed in duplicate, summarize the wound closure at 96h for MDA-MB-231 cells and 48h for BT-549 cells relative to 0h, which is set to 1. (b) Invasion assay. Cells were infected with recombinant adenoviruses with (+) or without (−) 10−9 M E2 for 48h as depicted. Cells were collected and counted. The same number of cells from each group was then seeded on the upper section of the invasion chamber membrane with the corresponding treatment. After 24h incubation, cells on the bottom of chamber membrane as an indication of invasiveness were stained and counted. Results, which represent the mean ± s.e.m. of three independent experiments performed in duplicate, are relative changes compared to cells infected with Ad5 in the absence of E2, which is set to 1. Asterisk (*) indicates significant change.