Cooperative STAT/NF-κB signaling regulates lymphoma metabolic reprogramming and aberrant GOT2 expression

Abstract

Knowledge of stromal factors that have a role in the transcriptional regulation of metabolic pathways aside from c-Myc is fundamental to improvements in lymphoma therapy. Using a MYC-inducible human B-cell line, we observed the cooperative activation of STAT3 and NF-κB by IL10 and CpG stimulation. We show that IL10 + CpG-mediated cell proliferation of MYClow cells depends on glutaminolysis. By 13C- and 15N-tracing of glutamine metabolism and metabolite rescue experiments, we demonstrate that GOT2 provides aspartate and nucleotides to cells with activated or aberrant Jak/STAT and NF-κB signaling. A model of GOT2 transcriptional regulation is proposed, in which the cooperative phosphorylation of STAT3 and direct joint binding of STAT3 and p65/NF-κB to the proximal GOT2 promoter are important. Furthermore, high aberrant GOT2 expression is prognostic in diffuse large B-cell lymphoma underscoring the current findings and importance of stromal factors in lymphoma biology.

Restricting Glycolysis Preserves T Cell Effector Functions and Augments Checkpoint Therapy

“…Metabolite extraction was performed with 80% methanol. Amino acids isotopologues were analyzed by high performance liquid chromatography (HPLC)-electrospray ionization (ESI)-tandem MS (MS/MS) after propyl chloroformate derivatization and intermediates of glycolysis and TCA cycle by GC-MS after derivatization using methoximation and silylation (Feist et al, 2018;Loftus et al, 2018). All raw data were corrected for natural stable isotope abundance and tracer impurity using IsoCorrectoR .…”

Double genetic disruption of lactate dehydrogenases A and B is required to ablate the “Warburg effect” restricting tumor growth to oxidative metabolism

“…Analyses of amino acids and organic acids from stable isotope tracer experiments were performed using HPLC-MS/MS and GC-MS after derivatization, respectively, as described recently (55). All expected isotopologs were analyzed.…”

Preventing BRCA1/ZBRK1 repressor complex binding to the GOT2 promoter results in accelerated aspartate biosynthesis and promotion of cell proliferation

“…The potential feed-forward loop of BRCA1/ZBRK1/GOT2 may be a crucial metabolic driver signaling BC progression. Recently, GOT2 was shown to activate transcriptionally STAT3/NF-jB in IL-10 responsiveness (Feist et al, 2018). One may propose that GOT2 is fine-tuned with different cell metabolic status and different stimuli in the tumor microenvironment.…”

“…Actually, aspartate metabolism reprogramming exists in many cancers, including hepatocellular carcinoma (Darpolor et al, 2014), pancreatic cancer (Yang et al, 2015(Yang et al, , 2018, leukemia (Sullivan et al, 2015), lung cancer, cervical cancer, osteosarcoma and glioblastoma (Sullivan et al, 2015). GOT2 converts glutamate and oxaloacetate to generate aspartate and a-KG, which is the critical enzyme for maintaining the aspartate pool (Feist et al, 2018). Previous studies have revealed that a crucial role of cellular respiration is to maintain redox homeostasis to support aspartate and therefore biomass production and rapid proliferation (Birsoy et al, 2015;Sullivan et al, 2015).…”

“…Here, we found that GOT2 overexpression sensitized breast cancer cells to MTX. GOT2 is a key enzyme providing aspartate for nucleotide synthesis, which sustains rapid cell proliferation (Feist et al, 2018). It is considered that MTX treatment causes cancer cells death mainly by reducing the cellular pool of tetrahydrofolate (THF), which inhibits nucleotide synthesis (Hitchings and Burchall, 1965;Kanarek et al, 2018).…”