Main author: Qiong Wang
Institution or Company: University of Iceland
Co-Author, Institution or Company:
Óttar Rolfsson, University of Iceland.
Introduction: Epithelial–mesenchymal transition (EMT) which involves in cancer progression is a diverse and dynamic biological process. The proteomic changes that occur following EMT in breast gland and changes in cellular metabolism are incompletely understood at the molecular level.
Methods: To study metabolic reprogramming in different mesenchymal states, we analyzed proteomic changes following EMT in the cell model, D492, with single-shot LFQ supported by SILAC proteomic approach. D492 EMT cell model contains three isogenic breast cell lines: epithelial D492, mesenchymal D492M and tumorigenic partial mesenchymal D492HER2.
Results: The proteomic analysis positioned the epithelial D492 and D492M cells as basal-like while D492HER2 as claudin-low. Further comparison identified metabolic proteins that differentiate metabolic markers of migration from those associated with invasion. We identified glutamine-fructose-6-phosphate transaminase [isomerizing] 2 (GFPT2) to be the top dysregulated enzymes and increased GFPT2 expression was a characteristic of claudin-low breast cancer. GFPT2 influenced both cell growth and invasion in vitro and was accompanied by lowered hexosamine biosynthesis pathway (HBP) flux. GFPT2 has been reported to confer protection against oxidative stress, and we found knockdown of decreased cystathionine and sulfide:quinone oxidoreductase (SQOR) in the transsulfuration pathway which regulates H2S production. Moreover, GFPT2 expression was regulated by the level of reduced glutathione (GSH) and suppressed by the oxidative stress regulator, GSK3-β.
Conclusions: Our results demonstrate that GFPT2 is involved in oxidative stress regulation. It is upregulated and controls growth and invasion in the D492 EMT model and is associated with claudin-low and poor prognosis in breast cancer.
