Primary screening using the developed 3-D invasion assay.

<p>A) The NCI Diversity Set II Compound Library was screened using the 3-D invasion assay and MDA-MB-231 cells, resulting in 24 positive hits, 9 of which were inhibitory but not cytotoxic. B) A quinocarmycin analog, DX-52-1 was positively identified as an anti-invasive compound. Representative images are shown for DMSO control and DX-52-1 (10 μM) after 18 hours incubation. Abrogated cell invasion and low cytotoxicity were observed in cells treated with DX-52-1. Numbers in the top right corners represent the total number of invasive cells within the field. Scale bar = 100 μm. C) Transwell chamber migration was performed with MDA-MB-231 cells treated with DMSO or DX-52-1 for 18 hours. Representative images of membranes (8 μm pore size) are shown in left panel. Quantification of cell migration is shown in right panel. DX-52-1 treated cells had decreased migratory ability. Bars represent the mean <u>+</u> SD. D) Fluorescent Protease Detection assay (Sigma) performed with cell lysates from MDA-MB-231 cells treated with DMSO or DX-52-1 for 18 hours. No effect on proteolytic activity was observed upon treatment with DX-52-1. Bars represent the mean <u>+</u> SD. ** refers to <i>p</i><.01.