The multifaceted roles of lysosomes in cancer

Cancer cells proliferate rapidly and require sustained supplies of nutrients and biosynthetic precursors. Lysosomes are more than terminal degradation sites: they recycle amino acids, sugars, lipids, nucleosides and ions, while also coordinating nutrient sensing, organelle communication and immune regulation. Consequently, lysosomal capacity can become selectively advantageous in tumours by linking nutrient salvage with growth control, organelle communication and inflammatory signalling. Enhanced lysosomal function can support tumour growth, invasion and therapy resistance. Here, we review four cancer‐relevant dimensions of lysosomal capacity: catabolism and transport; mTORC1‐ and AMPK‐linked nutrient sensing; membrane contact sites with the ER, mitochondria, and Golgi; and immune regulation spanning innate and adaptive responses and inflammatory control. These functions are context dependent: lysosomal quality control can restrain tumour initiation, whereas established cancers often exploit increased lysosomal capacity to support proliferation, invasion, metastasis and therapy resistance. Finally, we discuss lysosome‐state biomarkers and lysosome‐targeted strategies for patient stratification and rational combination therapy.