Increased N‐Acetylglucosamine‐l‐phosphotransferase Activity in Sera from Patients with Leukemia

In human cancer, lysosomal hydrolases contain increased amounts of phosphorylated sugar chains. Sugar chains of the hydrolases undergo post‐translational processing which is catalyzed by N‐acetyl‐glucosamine‐1‐phosphotransferase (GIcNAc‐phosphotransferase) at the first step. In the present study we estimated serum GlcNAc‐phosphotransferase in 50 adults suffering from leukemia and myelo‐dysplastic syndrome. The serum GlcNAc‐phosphotransferase was increased to moderate or high levels in patients with acute nonlymphocytic leukemia (ANLL), acute lymphoblastic leukemia and chronic myelogenous leukemia, suggesting that the serum transferase is released from leukemic cells. In many cases of ANLL examined,activity of the transferase was decreased concomitantly with reduction of peripheral blastic cells by effective chemotherapy.