Vitamin K3 and K5 are inhibitors of tumor pyruvate kinase M2

Pyruvate kinase M2 (PKM2) is a rate-limiting enzyme of aerobic glycolysis in cancer cells and plays important roles in cancer metabolism and growth. Here we show that vitamin K3 and K5 (VK3 and VK5) are relatively specific PKM2 inhibitors. VK3 and VK5 showed a significantly stronger potency to inhibit PKM2 than to inhibit PKM1 and PKL, 2 other isoforms of PK dominantly expressed in most adult tissues and liver. This study combined with previous reports supports that VK3 and VK5 have potential as adjuvant for cancer chemotherapy.