Abstract A038: A targetable tumor-induced wound-healing response is essential for osteosarcoma lung metastasis
Authors: Reinecke James B. , Garcia Leyre Jimenez , Gross Amy C. , Cannon Matthew V. , Budhathoki Yogesh , Roberts Ryan D. 
Published: November 2024

Abstract
Lung metastasis is responsible for nearly all deaths in children and teenagers affected by osteosarcoma, the most common pediatric sarcoma. The mechanisms by which malignant bone cells manipulate the lung microenvironment to promote the colonization and growth of metastatic tumor cells remain unclear but represent a potential therapeutic opportunity for preventing and treating metastasis. In this study, we sought to understand how osteosarcoma cells educate the lung microenvironment during metastatic progression. To address this gap, we generated several time series datasets of niche-labeled, single-cell RNA-seq of developing metastatic lesions and then used these to characterize the changes occurring in tumor and tumor-associated stromal cells during colonization. After identifying candidate mechanisms, we tested several therapeutic interventions to evaluate their effects on metastasis development in vitro using a tumor-on-lung co-culture system and in vivo using our animal models. Osteosarcoma cells induced acute epithelial injury upon lung dissemination. Shortly after dissemination, a paracrine loop established between a hyper-secretory, hypo-proliferative subpopulation of tumor cells and alveolar epithelial cells triggers the adoption of a chronic, non-resolving wound phenotype within the surrounding tissues that culminates in extensive tissue fibrosis with persistent extracellular matrix deposition, especially fibronectin. Cellular changes observed during this process include the proliferation of type 2 alveolar epithelial cells, the accumulation of highly fibrogenic epithelial intermediates (analogous to those observed in pulmonary fibrosis), and the emergence of a large population of scar-promoting macrophages. The formation of this matrix seems essential for lesion formation—disruption of the matrix-tumor cell interaction eliminated pseudonodules in vivo. Inhibition of pro-fibrotic pathways using nintedanib, an FDA- approved drug used to treat pulmonary fibrosis, or of tumor-epithelial paracrine signals with anakinra, an antagonist of IL1 signaling, effectively blocked metastatic lesion growth in both murine and human xenograft models, showing evidence of microenvironment reprogramming in the single cell data. Combining these therapies, which target primarily the hyper-secretory, hypo-proliferative “anchor” cells, with conventional therapies, which target proliferating tumor cells, proved highly effective in eliminating established metastatic lesions. Our work demonstrates that disseminated osteosarcoma cells trigger an aberrant, non-resolving wound-healing response in tumor-associated lung tissues, similar to that observed in non-malignant pulmonary fibrosis, and that this pathologic wound-healing response promotes metastatic growth. Therapeutic disruption of fibrosis-associated signaling prevents metastasis and treats established metastatic disease in multiple osteosarcoma models.
Citation Format: James B. Reinecke, Leyre Jimenez Garcia, Amy C. Gross, Matthew V. Cannon, Yogesh Budhathoki, Ryan D. Roberts. A targetable tumor-induced wound-healing response is essential for osteosarcoma lung 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 A038.