(616h) Multimodal Imaging for Simultaneous Measurement of Melanocyte Mass and Pigmentation

Despite advances in treatment, the 5 year mortality rate for patients with advanced melanoma remains at 48%. Potentially effective targeted therapies, e.g. BRAF-inhibitors for patients harboring a BRAF mutation, exist for advanced melanoma. However, a key challenge to reducing melanoma mortality rates is that many patients’ tumors will eventually acquire resistance to these therapies. Predicting acquired resistance is, therefore, a major challenge that needs to be overcome to have an impact on patient outcomes in melanoma. We, and others, have previously shown that drug response of individual cells within large populations can be measured using quantitative phase imaging (QPI). QPI is a label-free microscopy method that measures the amount that light slows as it interacts with cell mass. QPI data can be used to measure total cell mass, or the rate of change of cell mass due to growth. Changes in growth rate during treatment with targeted therapies can then be used to monitor cell drug responses, and analyzed for signs of therapeutic resistance. Preliminary data also shows that increases in melanocyte pigmentation is associated with acquired drug resistance. We have, therefore, engineered a system for simultaneous quantification of cell mass, via QPI, and cell pigmentation, via dark field microscopy. In this work, we present the design and validation of this system as a high-throughput screening tool that can be used to study mechanisms of acquired drug resistance in melanoma.