Metastasis is an inefficient process, but a consensus has not been reached as to which steps of metastasis are potentially rate-limiting. In this study, a microfluidic system was developed to mimic the physiological flow profile in the blood vessel to study how hemodynamic shear stress affects circulating tumor cells (CTCs). Breast cancer MDA-MB-231 cells transfected with a fluorescence resonance energy transfer (FRET)-based biosensor (231-C3) were circulated and recovered repeatedly to obtain series of fluid force-selected cell lines. These cells were shown to acquire enhanced survival ability. They also exhibit elongated cell morphology and greater drug resistance compared to parental 231-C3.