Abstract A032: Uncovering the impact of current therapies on LUAD dormant metastasis

Abstract

Abstract Despite recent therapeutic advances, Lung Adenocarcinoma (LUAD) remains a leading cause of mortality worldwide, with most deaths attributed to metastasis. Metastasis is mediated by disseminated metastasis initiating cells (MICs) that can persist in a dormant state in distant sites for months to years and ultimately drive metastatic relapse, which is clinically incurable. Adjuvant therapy seeks to prevent cancer relapse, however, efforts to improve adjuvant treatments are hindered by an insufficient understanding of the molecular mechanisms supporting the long-term viability of dormant MICs. We have established that primitive LUAD cells characterized by the spontaneous expression of the pluripotency transcription factor SOX2 can enter an immune-evasive dormant state with downregulation of immune response mediators (STING, NK ligands, MHC-I) to evade immune surveillance during dormancy. Now, we hypothesize that dormant and immune evasive progenitor MICs may also escape therapies targeting growth pathways. We have generated latency competent cells (LCCs) that can remain in a latent state for months by isolating progenitor cells from the Kras LSL-G12D/+ ;Trp53 flox/flox mouse model and screening their metastatic potential and progenitor state in the B6 background. LCCs entering a slow-cycling state in response to dormancy signals remain sensitive to targeted KRAS inhibitors but contain a resistant subpopulation that survives. To specifically characterize the progenitor state in these LCC populations, we have developed and validated two strategies to fluorescently mark SOX2 expression and activity, respectively. As speculated, the resistant population is mostly composed of SOX2+ progenitor LCCs after treatment with KRAS inhibitor under dormancy signaling. Furthermore, induced-dormancy also drives an accumulation of cells in the SOX2+ progenitor state in these LCC-rich populations. Ongoing studies are focused on delineating the emergence of the SOX2+ progenitor state in LCCs during dormancy and the biological mechanisms driving their persistence and resistance to targeted therapies. We aim to define (1) the dependence of dormant LCCs on oncogenic signaling, the (2) effect of targeted therapy on MICs, and (3) strategies to overcome potential resistance mechanisms in dormant MICs. Our ultimate goal is to delineate strategies to clear latent MICs and prevent LUAD recurrence. Citation Format: Inês Godet, Zhenghan Wang, Joan Massagué. Uncovering the impact of current therapies on LUAD dormant metastasis [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr A032.