FIGURE 6.

Cysteine is directly used by ES2 cells in the main metabolic pathways. (A) Highlight of the lactate methyl group resonance on the ¹³C-NMR spectra of 48 h culture media incubated with U-¹³C-cysteine. On the left panel, ES2 cells under normoxia (upper spectra) and under hypoxia (lower spectra); on the right panel, OVCAR3 cells under normoxia (upper spectra) and under hypoxia (lower spectra). (B) Production of lactate by ES2 cells in culture media at different time points (12, 24, 36, and 48 h). (C) Glucose consumption in ES2 and OVCAR3 cells. (D) Resonances areas of the ¹³C-1H-HSQC projection on ¹³C spectra normalized by TSP area in the cell extracts. (E) Highlight of ¹³C-1H-HSQC spectra of the growth media at 48 h incubation in the presence of U-¹³C-cysteine under normoxia and hypoxia conditions. NC, normoxia with cysteine; HC, hypoxia with cysteine. (B–D) Results are shown as mean ± SD. Assays were performed in biological triplicates.