High-Throughput Cell Deformability Screening to Identify Novel Anti-Cancer Compounds

Cell mechanical phenotype, or mechanotype, is emerging as a valuable label-free biomarker for cancer diagnosis, prognosis, and treatment response. To advance mechanotype as a marker for screening requires a method to simultaneously measure the deformability of 102 cell samples that interfaces with existing high throughput screening facilities. Here we present the high throughput parallel microfiltration (HT-PMF) method, which enables parallel measurements of cell deformability. HT-PMF relies on the pressure-driven filtration of cells through a porous membrane with micron-scale pores. More deformable cells passage through the pores or interpillar gaps more quickly than less deformable cells, resulting in a smaller retention volume and larger filtrate volume, which are quantified using a plate reader. To demonstrate the ability of HT-PMF to screen cells based on cell deformability, we show the differential filtration of human ovarian cancer cells that have acquired drug resistance, that overexpress transcription factors (Snail, Slug) that are implicated in epithelial-to-mesenchymal transition; as well as cells treated with the common anti-cancer agent, paclitaxel, and cytoskeleton perturbing drugs. We also use HT-PMF for deformability-based screening of cisplatin-resistant ovarian cancer cells treated with the library of pharmacologically active compounds (LOPAC1280) to identify lead compounds that reverse their more deformable phenotype. We validate the lead compounds using secondary, orthogonal assays including invasion and dose response assays. To further advance HT-PMF for automated screening, we also demonstrate the use of an easy-to-fabricate polydimethylsiloxane (PDMS) membrane, which consists of an array of 96 individual filtration devices, each with an array of micropillars with micron-scale gaps that are fabricated using soft lithography. Taken together, our results demonstrate a simple and scalable mechanotyping method that interfaces with commercial equipment such as multichannel pipettes, multiwell plates, and plate readers for HT screening of cells to identify novel anti-cancer agents.