Organellar pH as an emerging vulnerability to exploit in cancer

Cancer cells undergo metabolic reprogramming to sustain their energy demands, and favor glycolysis despite the presence of functional mitochondria. This metabolic shift leads to the rapid production of lactate and protons. If not managed, this accumulation of acidic byproducts would lower the intracellular pH (pH_i). To counteract this, cancer cells employ diverse mechanisms to extrude excess protons through membrane transporters, and also sequester them within acidic organelles. Consequently, an alkaline pH_i provides cancer cells with a survival advantage by promoting their proliferation, migration, and resistance to cell death. Given the role of organellar acidification in sustaining this altered pH balance, targeting this process represents a potential therapeutic vulnerability in cancer. We explore the mechanisms by which cancer cells maintain pH homeostasis, with a particular focus on organellar pH and its impact on tumor progression. In addition, we assess inhibitors of the key transporters involved in organellar acidification and discuss their therapeutic potential in cancer.