Osteosarcoma chemosensitivity signatures from BETi with holographic dynamic-contrast OCT

Patient-derived xenograft (PDX) models are often used to screen for drug-sensitive patients. The procedure involves disaggregating human tumor tissue and implanting it into immunocompromised mice. The method of growing the tumors, implanting them and conducting chemotherapy testing can take months. Additionally, the PDX model has an altered microenvironment as the cells are regrown in an alien species with different genetic and physical characteristics. Holographic Dynamic-Contrast Optical Coherence Tomography (OCT), also called biodynamic imaging (BDI), measures the intracellular dynamics of tissues responding to chemotherapeutics with the potential to provide a chemotherapy assay result within 48 hours performed on tumor biopsies from the patient. A key question is how a PDX drug response compares to a primary biopsy drug response. As a first step to answering this question, we perform BDI on osteosarcoma PDX samples to test the effect of BET inhibitors, a class of novel anticancer drugs.