Project description:The deficiency of LKB1 in tumor cells impairs their ability to sense metabolic stress appropriately,ultimately leading to redox imbalance. LKB1-deficient NSCLC cells predominantly take up ascorbic acid. Inflammatory PCD, including necroptosis, pyroptosis and PANoptosis, could release inflammatory mediators and switch the inflammatory state of TIME. Previous study demonstrated that high-dose AA could promote lung cancer cell death, but the modality of cell death still remained unclear. To further investigated the precise modality of the above inflammatory PCD, we performed RNA sequencing on cells with deficient or intact LKB1 pretreated with high-dose AA or not and then analyzed the established different forms of programmed cell death signaling gene.
Project description:Mutations in STK11/LKB1 in non-small cell lung cancer (NSCLC) are associated with poor patient responses to immune checkpoint blockade (ICB) and introduction of a Stk11/Lkb1 (L) mutation into murine lung adenocarcinomas driven by mutant Kras and Trp53 loss (KP) resulted in an ICB refractory syngeneic KPL tumor. Mechanistically this occurred because KPL mutant NSCLCs lacked TCF1-expressing CD8 T cells, a phenotype recapitulated in human STK11/LKB1 mutant NSCLCs. Systemic inhibition of Axl results in increased type I interferon secretion from dendritic cells that expanded tumor-associated TCF1+ PD-1+ CD8 T cells, restoring therapeutic response to PD-1 ICB for KPL tumors. This was observed in syngeneic immunocompetent mouse models and in humanized mice bearing STK11/LKB1 mutant NSCLC human tumor xenografts. NSCLC patients with identified STK11/LKB1 mutations receiving bemcentinib and pembrolizumab demonstrated objective clinical response to combination therapy. We conclude that AXL is a critical targetable driver of immune suppression in STK11/LKB1 mutant NSCLC.
Project description:Aplastic anaemia (AA) is a disease that shows complex pathogenesis involving multiple immune factors. While immunosuppressive therapies such as cyclosporine can effectively control AA, they may be ineffective in certain patients or those with relapse. Therefore, new treatments are needed. Among the targets for these treatments, the Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway regulates inflammatory cytokines and immune activation. Ruxolitinib, a JAK1/2 inhibitor, reduces T-cell activation and the associated inflammatory response and improves AA disease status in mice. However, its mechanism of action is unclear; thus, further research is needed before its clinical use. We previously showed increased pyroptosis in patients with severe AA (SAA) and that macrophage pyroptosis is an important factor in immune activation. The current study investigated the interaction of ruxolitinib with macrophages and whether the drug could treat SAA by improving pyroptosis levels. We induced differentiation of the THP-1 human monocyte cell line into macrophages in vitro and then induced pyroptosis. After constructing a macrophage pyroptosis model, treatment with different concentrations of ruxolitinib was administered. The results showed that ruxolitinib reduced the levels of pyroptosis and inflammatory-related factors. A mouse model of SAA was validated. In conclusion, ruxolitinib may treatment affects SAA by reducing the level of macrophage pyroptosis.
Project description:Inactivating mutations in LKB1/STK11 are present in ~20% of non-small cell lung cancers (NSCLC) and portend poor response to anti-PD-1 immunotherapy in patients and genetically engineered mouse model (GEMMs). Here, we sought to uncover the basis for immunotherapy resistance of these tumors and to define strategies that overcome this barrier. Whereas high tumor mutational burden (TMB) often correlates with response to anti-PD1 treatment, we found that LKB1-deficient NSCLCs from non-smokers and GEMMs exhibited striking elevations in nonsynonymous mutations compared to LKB1 wildtype tumors. Correspondingly, LKB1 mutant NSCLC cell lines showed defects in both replication dependent and independent double-strand DNA break (DSB) repair, which were reversed upon LKB1 re-expression.
Project description:Inactivating mutations in LKB1/STK11 are present in ~20% of non-small cell lung cancers (NSCLC) and portend poor response to anti-PD-1 immunotherapy in patients and genetically engineered mouse model (GEMMs). Here, we sought to uncover the basis for immunotherapy resistance of these tumors and to define strategies that overcome this barrier. Whereas high tumor mutational burden (TMB) often correlates with response to anti-PD1 treatment, we found that LKB1-deficient NSCLCs from non-smokers and GEMMs exhibited striking elevations in nonsynonymous mutations compared to LKB1 wildtype tumors. Correspondingly, LKB1 mutant NSCLC cell lines showed defects in both replication dependent and independent double-strand DNA break (DSB) repair, which were reversed upon LKB1 re-expression.
Project description:Deubiquitinases (DUBs), frequently overactivated in cancers, are associated with tumorigenesis and regarded as promising therapeutic targets. However, the underlying mechanism of DUBs promoting non-small cell lung cancer (NSCLC) are poorly understood. Through a global analysis of the contribution of 97 DUBs in NSCLC survival possibilities by The Cancer Genome Atlas (TCGA) database, we found that high expression of Josephin Domain-containing protein 2 (JOSD2) predicted the poor prognosis of patients. Depletion of JOSD2 significantly impeded NSCLC growth in vivo in both cell/patient-derived xenografts. Mechanistically, JOSD2 inhibits LKB1 kinase activity by removing K6-linked polyubiquitination, which was critical for maintaining LKB1-STRAD-MO25 complex integrity. Furthermore, we identified the first small molecule inhibitor of JOSD2 and the pharmacological inhibition of JOSD2 significantly arrested NSCLC proliferation in vitro/in vivo. Notably, our findings demonstrate a crucial role of JOSD2 in hindering LKB1 activity, highlighting JOSD2 as a potential therapeutic target in NSCLC and providing its inhibitors as a promising strategy for NSCLC treatment.