The present disclosure relates to inhibitors of mitochondrial function. Methods of treating hypoxic cancer cells using anti-angiogenic agents and mitochondrial biogenesis inhibitors are disclosed. Tetracyclines, such as doxycycline, may serve as mitochondrial biogenesis inhibitors. Also described are methods of sensitizing hypoxic cancer cells to one or more chemotherapies by administering a mitochondrial biogenesis inhibitor with the chemotherapy.