Abstract A001: Pre-existing non-genetic cellular states determine susceptibility to oncogenic transformation

Abstract Normal somatic cells possess innate defense mechanisms that confer resistance to cancer-driving mutations, including cellular senescence activation upon oncogene overexpression. However, oncogenic mutations are detected in normal somatic tissues, suggesting that some cells are able to escape these defense mechanisms. We investigated whether all cells become senescent upon overexpressing oncogenic KRAS G12D in primary human keratinocytes and found that while most cells entered a non-dividing state consistent with oncogene-induced senescence, 10-30% escaped these defenses and continued dividing. Cellular barcoding revealed that sister cells typically shared the same fate upon oncogene overexpression, suggesting heritable, non-genetic differences determine a cell’s ability to escape senescence programs. Using single-cell RNA sequencing prior to oncogene overexpression, we identified transcriptional states associated with cells that ultimately escape senescence, thus marking a subpopulation of cells most susceptible to cancer-driving mutations. We also observed transcriptional variation amongst escaper cells that may interact with subsequent mutational events. Our work demonstrates that a cell's initial transcriptional state influences its response to cancer-driving mutations and suggests that non-genetic variation interacts with genetic mutations to drive somatic evolution and cancer progression, challenging the genetics-only paradigm of cancer initiation. Citation Format: Grant Kinsler, Arjun Raj. Pre-existing non-genetic cellular states determine susceptibility to oncogenic transformation [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Cancer Evolution: The Dynamics of Progression and Persistence; 2025 Dec 4-6; Albuquerque, NM. Philadelphia (PA): AACR; Cancer Res 2025;85(23_Suppl):Abstract nr A001.