The lack of three-dimensional (3-D) high-throughput (HT) screening assays designed to identify anti-
cancer invasion drugs is a major hurdle in reducing
cancer-related mortality, with the key challenge being assay standardization. Presented is the development of a novel 3-D invasion assay with HT potential that involves surrounding cell-
collagen spheres within
collagen to create a 3-D environment through which cells can invade. Standardization was achieved by designing a tooled 96-well plate to create a precisely designated location for the cell-
collagen spheres and by using
dialdehyde dextran to inhibit
collagen contraction, maintaining uniform size and shape. This permits automated readout for determination of the effect of inhibitory compounds on
cancer cell invasion. Sensitivity was demonstrated by the ability to distinguish varying levels of invasiveness of
cancer cell lines, and robustness was determined by calculating the Z-factor. A Z-factor of 0.65 was obtained by comparing the effects of
DMSO and anti-β1-integrin antibody, an inhibitory
reagent, on the invasion of Du145
cancer cells, suggesting this novel assay is suitable for large scale
drug discovery. As proof of principle, the NCI Diversity Compound Library was screened against human invasive
cancer cells. Nine compounds exhibiting high potency and low toxicity were identified, including
DX-52-1, a compound previously reported to inhibit cell migration, a critical determinant of
cancer invasion. The results indicate that this innovative HT platform is a simple, precise, and easy to replicate 3-D invasion assay for anti-
cancer drug discovery.