Real-time cell viability monitoring for high-throughput drug screening using tumor xenograft-derived cells.

Patient-derived tumor xenografts (PDTXs) recapitulate the molecular and phenotypic heterogeneity of human cancers, making them valuable pre-clinical models for cancer drug development. However, high-throughput drug screening (HTDS) using ex vivo short-term cultures of PDTX-derived tumor cells (PDTCs) is hindered by endpoint viability assays that provide only static measures of drug response. Here, we establish an optimized a screening platform by validating the RealTime-Glo (RTG) bioluminescent assay for dynamic, real-time measurements of PDTC viability. We further introduce an analytical metric to quantify drug responses independent of cell growth rate. Using this approach, we screened 67 compounds across 43 breast cancer PDTCs and revealed model-specific pharmacodynamic heterogeneity. Our PDTC-based HTDS pipeline improves assay robustness and offers an enhanced platform for leveraging patient-derived xenograft models in precision medicine.