Abstract SY24-04: And by a sleep to say we end: Tumor dormancy, aging, and recurrent disease

Abstract

Abstract Disseminated cancer cells (DCCs) that escape the primary site can seed in distal tissues, but may take several years, or even decades to grow out into overt metastases, a phenomenon termed tumor dormancy. Despite its importance in metastasis and residual disease, few studies have been able to successfully model or characterize dormancy within melanoma. Here, we show that age-related changes in the lung microenvironment facilitate a permissive niche for efficient outgrowth of disseminated dormant tumor cells, in contrast to the aged skin, where age-related changes suppress melanoma growth but drive dissemination. A model of melanoma progression that addresses these microenvironmental complexities is the phenotype switching model, which argues that melanoma cells switch between a proliferative cell state and a slower-cycling, invasive state. We have previously shown that dermal fibroblasts are key orchestrators of promoting phenotype switching in primary melanoma tumors via changes in the secretion of soluble factors during aging. Our new data identify Wnt5A as a master regulator of activating melanoma DCC dormancy within the lung, which initially enables efficient dissemination and seeding of melanoma cells in metastatic niches. Age-induced reprogramming of lung fibroblasts increases their secretion of soluble Wnt factors enabling efficient metastatic outgrowth. Overall, we find that age-induced changes in distal metastatic microenvironments promotes efficient reactivation of dormant melanoma cells in the lung. Further these changes are also reflected in the response of tumor cells to therapy, linking dormancy to recurrent disease. Citation Format: Ashani T. Weeraratna. And by a sleep to say we end: Tumor dormancy, aging, and recurrent disease [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr SY24-04.