Figure 3. The Effect of LDH Isoform Reversal under Hypoxia.

(A and B) Adherent cell proliferation of vector control (vector) and LDH isoform-reversed (LDH-rev) mp53/Ras cells under 21 % oxygen (A) or 1 % oxygen (B). Data are means + SD. *p < 0.01 versus vector control by Student’s t test.

(C and D) Extracellular lactate secretion (C) and glucose consumption (D) at 1 % oxygen.

(E) Total intracellular NAD:NADH ratio at 1 % oxygen determined by LC-MS/MS.

(F) Schematic of the glycolytic pathway.

(G) Relative intracellular metabolite levels at 1 % oxygen determined by LC-MS/MS.

(B–E) Data are means + SE. *p < 0.01 versus vector control by Student’s t test.

(H) Cells were labeled with ¹³C-glucose for 90 min at 1% oxygen, and the relative abundance of ¹³C and ¹²C isoforms was determined by LC-MS/MS. Columns represent total relative abundance, and the ¹³C portion represents the sum of all detectable isotopologues of a given metabolite. *p < 0.01 for ¹³C isoform abundance of the indicated metabolite versus that metabolite’s ¹³C isoform abundance in vector control cells by Student’s t test. Data are means + SE.

(I) Measurement of fatty acid biosynthesis at 1 % oxygen. Data are means + SE. *p < 0.01 versus vector control by Student’s t test.

(C–I) All measurements were made following 8- to 10-hr cell culture in 1 % oxygen.

See also Figures S4 and S5 and Table S5.