Figure 1: Resistance to glutamine withdrawal or glutaminase inhibition causes cellular asparagine dependence.
From: Asparagine promotes cancer cell proliferation through use as an amino acid exchange factor
(a–d) Proliferation curves of LPS2 parental, LPS2 glutamine (Q)-independent, SUM159PT parental and SUM159PT CB-839-resistant cells in the presence or absence of 0.1 mM asparagine (N) in the medium. (e) Percentages of intracellular 13C-labelled asparagine in LPS2 parental and glutamine-independent, as well as SUM159PT parental and CB-839-resistant cells labelled with U-13C-asparagine in the medium for 24 h, as determined by LC-MS. (f) The per cent change in medium asparagine levels as determined by LC-MS after 24-h incubation time for the indicated cells or for medium in an empty tissue culture plate (blank). Error bars denote s.d. of the mean (n=3). P values were calculated by the Student’s t-test: *P<0.05; **P<0.01; ***P<0.001; NS, not significant.
