In the evolving field of cancer immunotherapy, EGFR-mutated non-small cell lung cancer (NSCLC) poses a significant obstacle due to its inherent resistance to conventional treatments. The development of an effective strategy to overcome this resistance remains a challenge. Here we have identified glutamine fructose-6-phosphate transaminase 2 (GFPT2) as a prime architect in the immune evasion phenotype induced by EGFR mutations. Mechanistically, in the presence of EGFR mutations, the expression of GFPT2, typically low in normal tissues, is significantly upregulated via the EGFR/IRE1α/Xbp1s signaling pathway. This results in a significant increase in intracellular UDP-GlcNAc levels, altering N-glycosylation profiles extensively. GFPT2 escalates the expression and glycosylation of PD-L1, PVR and CD276, bolstering their interactions with CD8+T cells, and also amplifies CD73 glycosylation to intensify adenosine-mediated suppression of CD8+T cells. These actions collectively reduce tumor cell vulnerability to CD8+T cell-mediated death. Moreover, GFPT2 also hinders the infiltration of CD8+T cells into tumors by regulating EGFR glycosylation and subsequent secretion of CXCL10 and VEGF. The validation of this GFPT2-mediated immune evasion phenotype is substantiated by compelling clinical evidence. We further identified a GFPT2 isoform-specific inhibitor that can enhance the efficacy of PD-1 blockade therapy beyond current strategies, as evidenced by results in xenograft models and patient-derived organoids. Taken together, our results highlight the potential of GFPT2 as a metabolic checkpoint in controlling immune escape in EGFR-mutated NSCLC, offering an innovative and druggable target to bolster immunotherapy outcomes in NSCLC with EGFR mutations.
In the evolving field of cancer immunotherapy, EGFR-mutated NSCLC presents a significant challenge, demonstrating marked innate resistance to established treatments. An effective method to counter this resistance remains elusive. Through comprehensive genetic and pharmacological analyses across various models, we have identified glutamine fructose-6-phosphate transaminase 2 (GFPT2) as a key facilitator of immune evasion in EGFR-mutated NSCLC. Mechanistically, under EGFR mutation condition, GFPT2 expression, which is typically low in normal tissues, is highly induced via EGFR/IRE1α/Xbp1s signaling axis, leading to a significant increase in intracellular UDP-GlcNAc and consequently, an altered N-glycosylation profile. GFPT2 escalates the expression and glycosylation of PD-L1, PVR and CD276, bolstering their interactions with CD8+T cells, and amplifies CD73 glycosylation, thereby intensifying adenosine-mediated CD8+T cells suppression. These actions collectively reduce tumor cell vulnerability to CD8+T cell-mediated death. Moreover, GFPT2 regulates EGFR glycosylation, which consequentially modulates the EGFR-dependent secretion of CXCL10 and VEGF, thus impeding CD8+T cell infiltration within tumors. We further identified a GFPT2 isoform-specific inhibitor that potentiates PD-1 blockade therapy beyond that of existing strategy, corroborated by results in xenografts and patient-derived organoids. Together, these findings illuminate the promising therapeutic potential of GFPT2 as a metabolic checkpoint, offering an innovative approach to invigorate immunotherapy in NSCLC with EGFR mutations.### Competing Interest StatementThe authors have declared no competing interest.
Nephrotoxicity is the dose-limiting factor of cisplatin treatment. Magnesium isoglycyrrhizinate (MgIG) has been reported to ameliorate renal ischemia–reperfusion injury. This study aimed to investigate the protective effect and possible mechanisms of MgIG against cisplatin-induced nephrotoxicity from the perspective of cellular pharmacokinetics. We found that cisplatin predominantly accumulated in mitochondria of renal tubular epithelial cells, and the amount of binding with mitochondrial DNA (mtDNA) was more than twice that with nuclear DNA (nDNA). MgIG significantly lowered the accumulation of cisplatin in mitochondria and, in particular, the degree of target-binding to mtDNA. MgIG notably ameliorated cisplatin-induced changes in mitochondrial membrane potential, morphology, function, and cell viability, while the magnesium donor drugs failed to work. In a mouse model, MgIG significantly alleviated cisplatin-caused renal dysfunction, pathological changes of renal tubules, mitochondrial ultrastructure variations, and disturbed energy metabolism. Both in vitro and in vivo data showed that MgIG recovered the reduction of NAD+-related substances and NAD+-dependent deacetylase sirtuin-3 (SIRT3) level caused by cisplatin. Furthermore, SIRT3 knockdown weakened the protective effect of MgIG on mitochondria, while SIRT3 agonist protected HK-2 cells from cisplatin and specifically reduced platinum-binding activity with mtDNA. In conclusion, MgIG reduces the target-binding amount of platinum to mtDNA and exerts a protective effect on cisplatin-induced renal injury through SIRT3, which may provide a new strategy for the treatment of cisplatin-induced nephrotoxicity.
Acquired drug resistance and epithelial-mesenchymal transition (EMT) mediated metastasis are two highly interacting determinants for non-small-cell lung cancer (NSCLC) prognosis. This study investigated the common mechanisms of drug resistance and EMT from the perspective of metabolic reprogramming, which may offer new ideas to improve anticancer therapy. Acquired resistant cells were found to grow faster and have a greater migratory and invasive capacity than their parent cells. Metabolomics analysis revealed that acquired resistant cells highly relied on glutamine utilization and mainly fluxed into oxidative phosphorylation energy production. Further mechanistic studies screened out glutamate dehydrogenase 1 (GLUD1) as the determinant of glutamine addiction in acquired resistant NSCLC cells, and provided evidence that GLUD1-mediated α-KG production and the accompanying reactive oxygen species (ROS) accumulation primarily triggered migration and invasion by inducing Snail. Pharmacological and genetic interference with GLUD1 in vitro significantly reversed drug resistance and decreased cell migration and invasion capability. Lastly, the successful application of R162, a selective GLUD1 inhibitor, to overcome both acquired resistance and EMT-induced metastasis in vivo, identified GLUD1 as a promising and druggable therapeutic target for malignant progression of NSCLC. Collectively, our study offers a potential strategy for NSCLC therapy, especially for drug-resistant patients with highly expressed GLUD1.
Diabetic kidney disease (DKD) is a major feature of the final stage of nearly all cause types of diabetes mellitus (DM). To date, few safe and effective drugs are available to treat. Peroxisome proliferator-activated receptors (PPARs), comprised of three members: PPAR-α, PPAR-δ and PPAR-γ, play a protective role in the DKD through glycemic control and lipid metabolism, whereas systemic activation of PPAR-γ causes serious side-effects in clinical trials. GFT505 is a dual PPAR-α/δ agonist, and the selectivity against PPAR-γ is still to be improved. Sulfuretin has been shown to suppress the expression of PPAR-γ and improve the pathogenesis of diabetic complications. In this study, by hybridizing the carboxylic acid of GFT505 and the parent nucleus of sulfuretin, we pioneeringly designed and synthetized a series of novel dual PPAR-α/δ agonists, expecting to provide a better benefit/risk ratio for PPARs. Of all the synthesized compounds, compound 12 was identified with highly activity on PPAR-α/δ and higher selectivity against PPAR-γ than that of GFT505 (EC50: hPPAR-α: 0.26 μM vs.0.76 μM; hPPAR-δ: 0.50 μM vs.0.73 μM; hPPAR-γ: 4.22 μM vs.2.79 μM). The molecular docking studies also depicted good binding affinity of compound 12 for PPAR-α and PPAR-δ compared to GFT505. Furthermore, compound 12 exhibited an evidently renoprotective effect on the DKD through inhibiting inflammatory process, which might at least partly via JNK/NF-κB pathways in vivo and in vitro. Overall, compound 12 hold therapeutic promise for DKD.
Activation of AMPK emerges as a potential therapeutic approach to metabolic diseases. AdipoRon is claimed to be an adiponectin receptor agonist that activates AMPK through adiponectin receptor 1 (AdipoR1). However, AdipoRon also exhibits moderate inhibition of mitochondrial complex I, leading to increased risk of lactic acidosis. In order to find novel AdipoRon analogues that activate AMPK without inhibition of complex I, 27 analogues of AdipoRon were designed, synthesized and biologically evaluated. As results, benzyloxy arylamide B10 was identified as a potent AMPK activator without inhibition of complex I. B10 dose-dependently improved glucose tolerance in normal mice, and significantly lowered fasting blood glucose level and ameliorated insulin resistance in db/db diabetic mice. More importantly, unlike the pan-AMPK activator MK-8722, B10 did not cause cardiac hypertrophy, probably owing to its selective activation of AMPK in the muscle tissue but not in the heart tissue. Together, B10 represents a novel class of AMPK activators with promising therapeutic potential against metabolic disease.