Clonal dynamics reveal cancer resistance arises from adaptive programs [CROP-Seq]

Rather than acquiring new mutations, resistance is driven by drug-tolerant persister cells (DTP) that enter a reversible drug-refractory state and sustain minimal residual disease2. Here, we developed MeRLin, a high-resolution barcoding platform combining single-cell RNA sequencing, RNA fluorescence in situ hybridization, and computational analyses to track clonal and transcriptional dynamics of melanoma cells during targeted therapy.

Clonal tracking reveals that dominant resistant clones arise from minor pre-treatment subpopulations. The pre-treatment melanoma populations diversify into phenotypically distinct DTP subpopulations, marked by stress-like, lipid metabolism, PI3K signaling, and extracellular matrix remodeling programs associated with adaptive resistance. Spatial transcriptomics revealed the co-localization of lipid metabolism and PI3K signaling programs near the tumor boundaries, and a complex network of autocrine and paracrine interactions among DTP subpopulations.