Cellular response to glutamine and/or glucose deprivation in in�vitro transformed human fibroblasts

Abstract

Neoplastic transformation is characterized by metabolic rewiring to sustain the elevated biosynthetic demands of highly proliferative cancer cells. To obtain the precursors for macromolecule biosynthesis, cancer cells avidly uptake and metabolize glucose and glutamine. Thus, targeting the availability or metabolism of these nutrients is an attractive anticancer therapeutic strategy. To improve our knowledge concerning how cancer cells respond to nutrient withdrawal, the response to glutamine and/or glucose starvation was studied in human in vitro transformed fibroblasts, deeply characterized at the cellular and molecular level. Concomitant starvation of both nutrients led to rapid loss of cellular adhesion (~16 h after starvation), followed by cell death. Deprivation of glucose alone had the same effect, although at a later time (~48 h after starvation), suggesting that glucose plays a key role in enabling cell attachment to the extracellular matrix. Glutamine deprivation did not induce rapid cell death, but caused a prolonged arrest of cellular proliferation; the cells started dying only 96 h after starvation. Before massive cell death occurred, the effects of all the starvation conditions were reversible. Autophagy activation was observed in cells incubated in the absence of glucose for more than 48 h, while autophagy was not detected under the other starvation conditions. Markers of apoptotic cell death, such as caspase 3, caspase 9 and poly(ADP-ribose) polymerase 1 (PARP-1) proteolytic fragments, were not observed under any growth condition. Glucose and/or glutamine deprivation caused very rapid PARP-1 activation, with marked PARP-1 (poly-ADP) ribosylation and protein (poly-ADP) ribosylation. This activation was not due to starvation-induced DNA double-strand breaks, which appeared at the late stages of deprivation, when most cells died. Collectively, these results highlight a broad range of consequences of glucose and glutamine starvation, which may be taken into account when nutrient availability is used as a target for anticancer therapies.

Nutritional Stress in Head and Neck Cancer Originating Cell Lines: The Sensitivity of the NRF2-NQO1 Axis

“…A possible explanation for this effect may be the nuclear retention of TP53 due to its poly(ADP-ribosyl)ation that prevents TP53 interaction with the nuclear export receptor CRM1 [69]. Chiodi et al recently reported that glucose and/or glutamine deprivation causes very rapid PARP-1 activation and protein poly(ADP-ribosyl)ation [70]. This is consistent with the intracellular distribution of TP53 that was observed in all the tested cells grown in a low glucose medium (NC2) or glucose- and glutamine-free medium (NC3) (Figure 10C).…”

Optical Control of Cellular ATP Levels with a Photocaged Adenylate Kinase

“…The change of GFP fluorescence intensity, normalized to the first timepoint of imaging of each cell (ΔF/F), was used to represent the fluctuation of cellular ATP levels. However, as deprivation of glucose only indirectly influences ATP concentrations and can impact other physiological responses, [31] we co-expressed photocaged Adk and the iATPSnFR sensor in HEK293T cells for the direct, non-invasive, and rapid depletion of cellular ATP. Genetically encoded Adk K13HCK was able to reduce ATP level upon optical triggering (10 s, microscope DAPI filter) to a greater extent than glucose deprivation, showing advantages in both specificity and dynamic capability (Figure 4c).…”

Nematode surface functionalization with hydrogel sheaths tailored in situ

“…S13 ). Depletion of glucose as a cancer cell energy source can cause cancer cells to die, whereas the generated H 2 O 2 can kill cancer cells as an oxidant [ 60 , 62 , 63 ]. Oxidation of glucose by GOX also affects the tumor environment in the form of enhanced hypoxia due to the consumption of O 2 and increased acidity by the production of d -gluconic acid [ 64 ].…”