Morphological and Optical Characterization of NRAS-Mutant Melanoma Cells and Primary Melanocytes via Quantitative Phase Imaging With Digital Holographic Microscopy.

Early detection of melanoma, a highly variable and aggressive form of skin cancer, is crucial for improving patient outcomes. It is essential to distinguish malignant cells from normal melanocytes, and therefore, label-free imaging methods that can do so are needed. Given the genotoxic effect of UV radiation, these mutations are numerous and affect many genes, including NRAS; therefore, therapeutic strategies can be directed toward these recurrent mutations. The aggressive nature of NRAS-mutant melanoma contributes to poor patient prognosis, highlighting the need for early diagnosis. This study utilizes quantitative phase imaging (QPI) with digital holographic microscopy (DHM) to differentiate the morphology of NRAS-mutant SK-MEL-2 cells from melanocytes using holographic microscopy; dimensionality reduction techniques, including Principal Component Analysis (PCA),t-distributed stochastic neighbor embedding (t-SNE); and clustering techniques, including K-Means Elbow Plots and Hierarchical Clustering Dendrograms. The results demonstrated distinct morphologies and geometries between melanocytes and SK-MEL-2 cells, indicating that QPI with DHM can serve as a label-free tool for identifying optical biomarkers in melanoma.