Figure 1
Tolerance of varying cell types of glutamine depletion and ammonia utilisation as an alternative nitrogen source. Cells in the control group were fixed in 4% formaldehyde 24 h after plating (n = 6). This represents the starting number of cells grown in normal media (DMEM containing high glucose, 10% FBS and 8 mM glutamine). Cells in the other groups (n = 6) were washed with DPBS and fresh media with or without glutamine or 0.8 mM NH4Cl was added. After 3 days, cells in all groups were fixed and stained with 0.5% crystal violet solution in 4% formaldehyde and colorimetric (OD) measurement was quantified using spectrophotometer. SH-SY5Y, HCT116, HT29, HACAT and A549 cells can survive in glutamine-depleted culture, but cannot utilise NH4Cl to proliferate (A). LNCAP and MCF10A cells displayed cell loss in glutamine-depleted media that was worsen by NH4Cl supplementation (B). MCF7 and T47D cells can survive in glutamine-depleted culture and they can utilise NH4Cl as alternative nitrogen source to support proliferation (C). Huh7 and HEK293 cells can proliferate in glutamine-depleted culture and proliferation was enhanced in the presence of NH4Cl (D). *p ≤ 0.05, **p ≤ 0.01, ***p ≤ 0.001.
