Single Cell Analysis on the Effects of Fluid Shear Stress on Cancer Cell Deformability and Migration | AIChE

Single Cell Analysis on the Effects of Fluid Shear Stress on Cancer Cell Deformability and Migration

Metastasis, the leading cause of cancer-related fatalities, is a complex biological process involving the transit of circulating tumor cells (CTCs) through the bloodstream. While transporting through the circulatory system, these cells are exposed to interstitial flow and chemical stimuli, potentially triggering significant phenotypic changes. Recently, it has been discovered that model CTC cell lines express significantly higher levels of EpCAM (an established CTC biomarker) after exposure to fluid shear stress (FSS). However, these prior studies have been limited to population-based studies with restricted ranges of FSS duration and magnitude. Additionally, changes in cell morphology and motility have not been quantified after exposure to FSS. This project presents a microfluidic approach for assessing the phenotypic response of cancer cells to the shear forces present in the circulatory system. A trapping device comprised of two inlets (cell suspension and media), a sheath-flow focusing region, and semicircular trap array was constructed for on-chip morphological studies. Within the device, isolated cells were challenged with hemodynamic shear stress at defined magnitudes (5, 10, 15, 30, 60 dyne/cm2) and durations (1, 5, 15, 30 minutes). Cell morphology data was acquired before, during, and after shear stress exposure. It was discovered that cellular deformability parameters (e.g., circularity, horizontal length, area) and trap retention rates responded heterogeneously with increasing values of FSS magnitude and duration. This heterogeneous response suggests the presence of distinct cell subpopulations with different gene expression, cytoskeleton integrity, or deformability attributes. Additionally, it was observed that exposure to FSS significantly increased cell motility. Further studies are underway involving both biomarker staining and the transfection of fluorescent vectors for CTC phenotype to further identify and characterize the various subpopulations observed during testing. This work demonstrates the utility of a microfluidic platform for high-throughput, single-cell phenotype analysis and provides valuable insight into the biophysics of cancer metastasis.