Abstract 3864: AOH1996: A multi-faceted inhibitor of metastasis via PCNA and tumor microenvironment targeting

Abstract Metastasis remains the leading cause of cancer-related mortality, emphasizing the urgent need for therapies to prevent and treat this process. AOH1996, a selective inhibitor of proliferating cell nuclear antigen (PCNA), has emerged as a promising agent with anti-metastatic properties. AOH1996 disrupts critical pathways such as angiogenesis, cancer cell migration, and tumor microenvironment modulation. Through bulk RNA-seq analysis of cancer cells, AOH1996 was found to downregulate genes involved in angiogenesis and migration, processes essential for metastasis. Functional assays using highly metastatic osteosarcoma cell lines revealed that AOH1996 inhibited cell proliferation and migration in both 2D monolayer and 3D spheroid models. In 3D cultures, which closely mimic the tumor microenvironment, AOH1996 significantly suppressed cell invasion and growth, demonstrating its efficacy in a more physiologically relevant context. The anti-metastatic potential of AOH1996 was further validated using an ex vivo Pulmonary Metastasis Assay (PuMA), where osteosarcoma cells implanted into mouse lungs were effectively killed by AOH1996. This highlights its ability to directly target metastatic cells in the lung. Complementary cell invasion assays using Matrigel showed that AOH1996 altered the morphology of invadopodia—structures critical for tissue invasion—rendering them non-functional and significantly reducing invasive capacity. Preliminary data from a Phase I clinical trial (NCT05227326) in patients with advanced, chemo-refractory solid tumors demonstrated AOH1996’s clinical potential. In one patient with pancreatic cancer, AOH1996 reduced the size of two liver metastases by 50%, underscoring its efficacy in a clinical setting. Tumor-associated macrophages (TAMs) facilitate immune evasion, angiogenesis, and metastasis. Oncogenic MYC influences the tumor microenvironment (TME) by recruiting TAMs to the TME. We have found that AOH1996 inhibits MYC expression in cancer cells, but not in non-malignant cells. We hypothesize that this suppression of MYC by AOH1996 disrupts the formation of a supportive metastatic niche through reduced TAM recruitment. Thus, AOH1996 may enhance immune responses and impede angiogenesis and metastasis. Together, these findings establish AOH1996 as a multi-faceted therapeutic with significant anti-metastatic potential. By targeting both PCNA-dependent processes and the tumor microenvironment, AOH1996 could provide a unique approach for combating metastatic cancers. Citation Format: Robert G. Lingeman, Robert Hickey, Linda Malkas, Mustafa Raoof, Jacob Cawley. AOH1996: A multi-faceted inhibitor of metastasis via PCNA and tumor microenvironment targeting [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 3864.