Exploiting Lysosomal Vulnerabilities: A Novel Therapeutic Strategy to Induce Immunogenic Cell Death in Oncogene-Addicted Cancers

Abstract

Background: A significant challenge in oncology is the development of therapies that selectively eliminate cancer cells while engaging the immune system for durable protection. Oncogene-driven transformation has been shown to rewire cellular metabolism and organelle function, creating unique dependencies. Lysosomes, traditionally considered mere degradative centers, are emerging as critical regulators of cell survival and death. We hypothesized that oncogenic transformation, particularly by drivers like Her2, creates a lysosomal "Achilles' heel," priming these organelles for permeabilization and offering a novel therapeutic target. Methods: Using the MCF-10A-neoT model of oncogene-driven transformation, we first characterized lysosomal alterations. We then conducted a high-throughput screen for compounds inducing Lysosomal Membrane Permeabilization (LMP), focusing on Reactive Oxygen Species (ROS) inducers. Lead compounds were evaluated for their ability to trigger established markers of Immunogenic Cell Death (ICD), including surface calreticulin (CRT), ATP release, and HMGB1 release. Selectivity and efficacy were further validated in co-culture models and immunocompetent mouse models. Results: Oncogene-transformed cells exhibited significantly enlarged lysosomes, altered subcellular distribution, and increased cathepsin B/L activity compared to their non-transformed counterparts. Our screen identified several ROS-generating compounds that selectively induced LMP in cancer cells. Treatment with these lead compounds resulted in the robust exposure of CRT, and the extracellular release of ATP and HMGB1, confirming the induction of ICD. In co-culture, the compounds demonstrated a clear therapeutic window, preferentially killing cancer cells. In vivo studies in immunocompetent mice confirmed tumor regression and the establishment of a protective anti-tumor immune memory. Conclusion: Our findings validate that targeted LMP induction is a viable strategy for selectively killing oncogene-addicted cancer cells. Moreover, by triggering ICD, this approach not only directly eliminates tumor cells but also stimulates a systemic immune response, addressing the critical need for therapies that provide long-term anti-cancer immunity.