Autophagy-Lysosome Pathway Dysfunction in Neurodegeneration and Cancer: Mechanisms and Therapeutic Opportunities

The autophagy-lysosome system is a master regulator of cellular homeostasis, integrating quality control, metabolism, and cell fate through the selective degradation of cytoplasmic components. Disruption of either autophagic flux or lysosomal function compromises this degradative pathway and leads to diverse pathological conditions. Emerging evidence identifies the autophagy-lysosome network as a central signaling hub that connects metabolic balance to disease progression, particularly in neurodegenerative disorders and cancer. Although cancer and neurodegenerative diseases exhibit seemingly opposite outcomes-uncontrolled proliferation versus progressive neuronal loss-both share common mechanistic foundations within the autophagy-lysosome axis. Here, we synthesize recent advances on the roles of autophagy and lysosomal mechanisms in neurodegenerative diseases and cancer, especially on how defects in lysosomal acidification, membrane integrity, and autophagosome-lysosome fusion contribute to toxic protein accumulation and organelle damage in Alzheimer's and Parkinson's diseases, while the same machinery is repurposed by tumor cells to sustain anabolic growth, stress tolerance, and therapy resistance. We also highlight emerging lysosome-centered therapeutic approaches, including small molecules that induce lysosomal membrane permeabilization, nanomedicine-based pH correction, and next-generation protein degradation technologies. Finally, we discuss the major challenges and future opportunities for translating these mechanistic insights into clinical interventions.