Abstract LB-008: Mesofluidic platform for high throughput screening for inhibitors of metastasis

Abstract

Background: A fundamental limitation in the development of new therapies to prevent metastatic cancer is a lack of in vitro systems that can accurately recapitulate the steps of cancer cell metastasis. Currently, most assays for examining the steps of metastasis fail to incorporate the biophysical forces experienced by tumor cells due to blood flow, or are low throughput and therefore not amenable to drug screening and high throughput experimentation. Methods: We have developed a novel high throughput mesofluidic platform for assaying cell adhesion under flow in a 96-well format. This device functions like a cone and plate viscometer in each well by inducing shear stress on cells cultured in a standard 96-well plate. We validated the fluid flow and alignment of the device and studied the adhesion of cultured leukocytic monocytes (THP-1 cells) and multiple cancer cell lines (HCT116, MDA-MB-231 and MCF-7 cells) to purified extracellular matrix molecules (ECM), endothelial cells and immobilized platelets. All assays were carried out under flow (0.5 dynes/cm2 of shear stress) and static conditions. Results: Our studies show that adhesion assays performed under flow yield markedly different results from static adhesion assays, and are better at identifying both aggressive cancer cells lines and known pathways for circulating cancer and immune cell adhesion. Treatment of breast cancer cells with a small library of integrin inhibitors demonstrated that these compounds had minimal effect on cancer cell adhesion to endothelial cells under static conditions, whereas under shear conditions many of these compounds reduced adhesion of cancer cells. In addition, a static adhesion assay of breast cancer cells to various types of ECM showed higher adhesion of the less aggressive MCF-7 cell line in comparison to the more aggressive MDA-MB-231 cell line. In contrast, flow incorporating assays showed increased adhesion of the MDA-MB-231 in comparison to the MCF-7 cell line. Finally, we performed a high throughput screening experiment using a kinase inhibitor library with 80 compounds and found that the shear based assay yielded notably different results from a similar screen under static conditions for cancer cell adhesion to endothelial cells, immune cell adhesion to endothelial cells and cancer cell adhesion to platelets. Conclusions: Our studies show that adhesion assays performed under flow yield markedly different results from static adhesion assays, and are better at identifying both aggressive cancer cells lines and known pathways for circulating cancer and immune cell adhesion. Thus, this high-throughput screening platform may enable the development of novel compounds to inhibit cancer metastasis and facilitate the study of the systems level behavior of cancer-endothelium adhesion. Citation Format: Adrianne Shearer, Chris Spruell, Victoria Le, Mar Creixell, Seema Nandi, Aaron B. Baker. Mesofluidic platform for high throughput screening for inhibitors of metastasis. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-008. doi:10.1158/1538-7445.AM2015-LB-008