Fig. 6
From: 13C tracer analysis suggests extensive recycling of endogenous CO2 in vivo
13CO2 contributes to serine biosynthesis. A Schematic of 13C incorporation into serine via the serine biosynthesis pathway. B 13C labeling pattern of 2PG/3PG and serine from sarcoma cells fed with [U-13C]-glutamine in vitro for 3 h and labeling patterns of 2PG/3PG and serine in sarcomas from sarcoma-bearing mice receiving [U-13C]-glutamine infusion in vivo for 3 h. Data are presented as mean ± SD n = 5 for animals and n = 3 for cultured cells. PEP, phosphoenolpyruvate; PEPCK-C, phosphoenolpyruvate carboxykinase; 2PG, 2-phosphoglyceric acid; 3PG, 3-phosphoglyceric acid; PGM, 2,3-bisphosphoglycerate-dependent phosphoglycerate mutase. Data in this figure was after natural abundance correction