A GAPDH serotonylation system couples CD8+ T cell glycolytic metabolism to antitumor immunity.

Apart from the canonical serotonin (5-hydroxytryptamine [5-HT])-receptor signaling transduction pattern, 5-HT-involved post-translational serotonylation has recently been noted. Here, we report a glyceraldehyde-3-phosphate dehydrogenase (GAPDH) serotonylation system that promotes the glycolytic metabolism and antitumor immune activity of CD8+ T cells. Tissue transglutaminase 2 (TGM2) transfers 5-HT to GAPDH glutamine 262 and catalyzes the serotonylation reaction. Serotonylation supports the cytoplasmic localization of GAPDH, which induces a glycolytic metabolic shift in CD8+ T cells and contributes to antitumor immunity. CD8+ T cells accumulate intracellular 5-HT for serotonylation through both synthesis by tryptophan hydroxylase 1 (TPH1) and uptake from the extracellular compartment via serotonin transporter (SERT). Monoamine oxidase A (MAOA) degrades 5-HT and acts as an intrinsic negative regulator of CD8+ T cells. The adoptive transfer of 5-HT-producing TPH1-overexpressing chimeric antigen receptor T (CAR-T) cells induced a robust antitumor response. Our findings expand the known range of neuroimmune interaction patterns by providing evidence of receptor-independent serotonylation post-translational modification.

Terbinafine prevents colorectal cancer growth by inducing dNTP starvation and reducing immune suppression.

Existing evidence indicates that gut fungal dysbiosis might play a key role in the pathogenesis of colorectal cancer (CRC). We sought to explore whether reversing the fungal dysbiosis by terbinafine, an approved antifungal drug, might inhibit the development of CRC. A population-based study from Sweden identified a total of 185 patients who received terbinafine after their CRC diagnosis and found that they had a decreased risk of death (hazard ratio = 0.50) and metastasis (hazard ratio = 0.44) compared with patients without terbinafine administration. In multiple mouse models of CRC, administration of terbinafine decreased the fungal load, the fungus-induced myeloid-derived suppressor cell (MDSC) expansion, and the tumor burden. Fecal microbiota transplantation from mice without terbinafine treatment reversed MDSC infiltration and partially restored tumor proliferation. Mechanistically, terbinafine directly impaired tumor cell proliferation by reducing the ratio of nicotinamide adenine dinucleotide phosphate (NADP+) to reduced form of nicotinamide adenine dinucleotide phosphate (NADPH), suppressing the activity of glucose-6-phosphate dehydrogenase (G6PD), resulting in nucleotide synthesis disruption, deoxyribonucleotide (dNTP) starvation, and cell-cycle arrest. Collectively, terbinafine can inhibit CRC by reversing fungal dysbiosis, suppressing tumor cell proliferation, inhibiting fungus-induced MDSC infiltration, and restoring antitumor immune response.

Exogenous carbon monoxide suppresses Escherichia coli vitality and improves survival in an Escherichia coli-induced murine sepsis model.

AIM: Endogenous carbon monoxide (CO) has been shown to modulate inflammation and inhibit cytokine production both in vivo and in vitro. The aim of this study was to examine whether exogenous carbon monoxide could suppress the vitality of Escherichia coli (E coli) and improve the survival rate in an E coli-induced murine sepsis model. METHODS: ICR mice were infected with E coli, and immediately injected intravenously with carbon monoxide releasing molecule-2 (CORM-2, 8 mg/kg) or inactive CORM-2 (8 mg/kg). The survival rate was monitored 6 times daily for up to 36 h. The blood samples, liver and lung tissues were collected at 6 h after the infection. Bacteria in peritoneal lavage fluid, blood and tissues were enumerated following culture. Tissue iNOS mRNA expression was detected using RT-PCR. NF-κB expression was detected with Western blotting. RESULTS: Addition of CORM-2 (200 and 400 µmol/L) into culture medium concentration-dependently suppressed the growth of E coli and decreased the colony numbers, but inactive CORM-2 had no effect. Treatment of the infected mice with CORM-2 significantly increased the survival rate to 55%, while all the infected mice treated with inactive CORM-2 died within 36 h. E coli infection caused severe pathological changes in liver and lungs, and significantly increased serum transaminases, lipopolysaccharide, TNF-α and IL-1ß levels, as well as myeloperoxidase activity, TNF-α and IL-1ß levels in the major organs. Meanwhile, E coli infection significantly increased the number of colonies and the expression of iNOS mRNA and NF-κB in the major organs. All these abnormalities were significantly attenuated by CORM-2 treatment, while inactive CORM-2 was ineffective. CONCLUSION: In addition directly suppressing E coli, CORM-2 protects the liver and lungs against E coli-induced sepsis in mice, thus improving their survival.

Identification of Cytosolic DNA Sensor cGAS-STING as Immune-Related Risk Factor in Renal Carcinoma following Pan-Cancer Analysis.

Background: The cytosolic DNA sensor cyclic GMP-AMP synthase (cGAS) plays critical functions in innate immune responses via the production of the second messenger cyclic guanosine monophosphate-adenosine monophosphate (cGAMP), which stimulates the adaptor stimulator of interferon genes (STING). However, the clinical relevance and prognostic value of the cGAS-STING pathway in human cancers remains largely unexplored. Methods: A gene signature related to the cGAS-STING score was identified. The pan-cancer landscape of cGAS-STING expression was calculated using the RNAseq data acquired from the TCGA cohort. Tumor-infiltrating immune cells (TIICs) were determined by the ssGSEA method. Kaplan-Meier curves, Cox regression analyses, and the area under the curve (AUC) were employed to decipher the predictive value of cGAS-STING risk score and TIICs across several human cancers. Results: Most tumor tissues displayed a higher cGAS-STING score compared with their corresponding nontumor tissues, except for prostate adenocarcinoma (PRAD) and uterine corpus endometrial carcinoma (UCEC). Higher cGAS-STING score was closely associated with poor clinical outcome of kidney renal clear cell carcinoma (KIRC) and kidney renal papillary cell carcinoma (KIRP), whereas the cGAS-STING score predicted a better prognosis in pheochromocytoma and paraganglioma (PCPG). Enrichment analysis showed that cGAS-STING was profoundly implicated in diverse immune-related pathways in KIRC, KIRP, and PCPG. Significant positive correlations were noticed between cGAS-STING score and TIICs, including activated CD8+ T cells, activated CD4+ T cells, monocytes, and mast cells. Finally, the cGAS-STING score was revealed to be an independent prognostic factor for KIRC patients and possessed a strong predictive power for the prognostic evaluation of KIRC and KIRP patients. Conclusions: We constructed a cGAS-STING gene signature to predict survival and tumor immunity across human cancers, which can serve as a novel prognostic indicator and therapeutic target, especially in KIRC and KIRP.

The predictive value of peripheral blood cells and lymphocyte subsets in oesophageal squamous cell cancer patients with neoadjuvant chemoradiotherapy.

Purpose: Neoadjuvant chemoradiotherapy (nCRT) is a standard treatment option for patients with stage III oesophageal cancer. Approximately 30% of oesophageal cancer patients will have a pathological complete response (pCR) after nCRT. However, available clinical methods cannot accurately predict pCR for patients. We aimed to find more indicators that could be used to predict the pathological response to nCRT. Method: A total of 84 patients with stage III oesophageal squamous cell cancer were enrolled in this study. Ten patients failed to have surgery as a result of progressive disease (PD). Among the patients who underwent surgery, 32 patients had a pathologic complete response (pCR), whereas 42 patients showed no or partial response (npCR) after nCRT. Routine blood test results and lymphocyte subset assessments before and after nCRT were retrospectively analysed. Univariate and multivariate analyses were used to identify independent predictors of the clinical curative effect of nCRT. Eventually, nomograms were established for predicting the PD and pCR rates. Results: The numbers of lymphocytes, B lymphocytes, T lymphocytes, Th lymphocytes, Ts lymphocytes, and NK cells and the percentages of B lymphocytes and NK cells were decreased significantly after nCRT (P < 0.0001), whereas the percentages of T lymphocytes and Ts lymphocytes increased (P < 0.0001). Univariate analysis showed that age, the length of the lesion, the level of haemoglobin before nCRT, and the amount of change in haemoglobin were related to PD, and the percentage of NK cells after nCRT was related to pCR. Multivariate logistic analysis demonstrated that the length of the lesion, the neutrophil-to-lymphocyte ratio (NLR) before nCRT, and the amount of change in haemoglobin were independent predictors of PD, whereas the percentage of NK cells after nCRT was an independent predictor of pCR. Conclusion: Lymphocyte subsets changed dramatically during nCRT, and these changes together with baseline and posttreatment lymphocyte subsets have predictive value in determining the response to nCRT for oesophageal cancer.

Increased Nuclear Transporter KPNA2 Contributes to Tumor Immune Evasion by Enhancing PD-L1 Expression in PDAC.

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest malignancies and is known for its high resistance and low response to treatment. Tumor immune evasion is a major stumbling block in designing effective anticancer therapeutic strategies. Karyopherin alpha 2 (KPNA2), a member of the nuclear transporter family, is elevated in multiple human cancers and accelerates carcinogenesis. However, the specific role of KPNA2 in PDAC remains unclear. In this study, we found that expression of KPNA2 was significantly upregulated in PDAC compared to adjacent nontumor tissue and its high expression was correlated with poor survival outcome by analyzing the GEO datasets. Similar KPNA2 expression pattern was also found in both human patient samples and KPC mouse models through IHC staining. Although KPNA2 knockdown failed to impair the vitality and migration ability of PDAC cells in vitro, the in vivo tumor growth was significantly impeded and the expression of immune checkpoint ligand PD-L1 was reduced by silencing KPNA2. Furthermore, we uncovered that KPNA2 modulated the expression of PD-L1 by mediating nuclear translocation of STAT3. Collectively, our data suggested that KPNA2 has the potential to serve as a promising biomarker for diagnosis in PDAC.

Deciphering the genomic and lncRNA landscapes of aerobic glycolysis identifies potential therapeutic targets in pancreatic cancer.

Aerobic glycolysis, also known as the Warburg effect, is emerged as a hallmark of most cancer cells. Increased aerobic glycolysis is closely associated with tumor aggressiveness and predicts a poor prognosis. Pancreatic ductal adenocarcinoma (PDAC) is characterized by prominent genomic aberrations and increased glycolytic phenotype. However, the detailed molecular events implicated in aerobic glycolysis of PDAC are not well understood. In this study, we performed a comprehensive molecular characterization using multidimensional ''omic'' data from The Cancer Genome Atlas (TCGA). Detailed analysis of 89 informative PDAC tumors identified substantial copy number variations (MYC, GATA6, FGFR1, IDO1, and SMAD4) and mutations (KRAS, SMAD4, and RNF43) related to aerobic glycolysis. Moreover, integrated analysis of transcriptional profiles revealed many differentially expressed long non-coding RNAs involved in PDAC aerobic glycolysis. Loss-of-function studies showed that LINC01559 and UNC5B-AS1 knockdown significantly inhibited the glycolytic capacity of PDAC cells as revealed by reduced glucose uptake, lactate production, and extracellular acidification rate. Moreover, genetic silencing of LINC01559 and UNC5B-AS1 suppressed tumor growth and resulted in alterations in several signaling pathways, such as TNF signaling pathway, IL-17 signaling pathway, and transcriptional misregulation in cancer. Notably, high expression of LINC01559 and UNC5B-AS1 predicted poor patient prognosis and correlated with the maximum standard uptakevalue (SUVmax) in PDAC patients who received preoperative 18F-FDG PET/CT. Taken together, our results decipher the glycolysis-associated copy number variations, mutations, and lncRNA landscapes in PDAC. These findings improve our knowledge of the molecular mechanism of PDAC aerobic glycolysis and may have practical implications for precision cancer therapy.

Single-cell RNA sequencing reveals that targeting HSP90 suppresses PDAC progression by restraining mitochondrial bioenergetics.

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers, which lacks effective treatment strategies. There is an urgent need for the development of new strategies for PDAC therapy. The genetic and phenotypic heterogeneity of PDAC cancer cell populations poses further challenges in the clinical management of PDAC. In this study, we performed single-cell RNA sequencing to characterize PDAC tumors from KPC mice. Functional studies and clinical analysis showed that PDAC cluster 2 cells with highly Hsp90 expression is much more aggressive than the other clusters. Genetic and pharmacologic inhibition of Hsp90 impaired tumor cell growth both in vitro and in vivo. Further mechanistic study revealed that HSP90 inhibition disrupted the interaction between HSP90 and OPA1, leading to a reduction in mitochondrial cristae amount and mitochondrial energy production. Collectively, our study reveals that HSP90 might be a potential therapeutic target for PDAC.

CTHRC1 promotes liver metastasis by reshaping infiltrated macrophages through physical interactions with TGF-ß receptors in colorectal cancer.

Metastasis is a major cause of cancer-related deaths. Tumor-intrinsic properties can determine whether tumor metastasis occurs or not. Here, by comparing the gene expression patterns in primary colorectal cancer (CRC) patients with or without metastasis, we found that Collagen Triple Helix Repeat Containing 1 (CTHRC1) in primary CRC served as a metastasis-associated gene. Animal experiments verified that CTHRC1 secreted by CRC cells promoted hepatic metastasis, which was closely correlated with macrophage infiltration. Depletion of macrophages by liposomal clodronate largely abolished the promoting effect of CTHRC1 on CRC liver metastasis. Furthermore, we demonstrated that CTHRC1 modulated macrophage polarization to M2 phenotypes through TGF-ß signaling. A mechanistic study revealed that CTHRC1 bound directly to TGF-ß receptor II and TGF-ß receptor III, stabilized the TGF-ß receptor complex, and activated TGF-ß signaling. The combination treatment of CTHRC1 monoclonal antibody and anti-PD-1 blocking antibody effectively suppressed CRC hepatic metastasis. Taken together, our data demonstrated that CTHRC1 is an intrinsic marker of CRC metastasis and further revealed that CTHRC1 promoted CRC liver metastasis by reshaping infiltrated macrophages through TGF-ß signaling, suggesting that CTHRC1 could be a potential biomarker for the early prediction of and a therapeutic target of CRC hepatic metastasis.

Identification of a subset of immunosuppressive P2RX1-negative neutrophils in pancreatic cancer liver metastasis.

The immunosuppressive microenvironment that is shaped by hepatic metastatic pancreatic ductal adenocarcinoma (PDAC) is essential for tumor cell evasion of immune destruction. Neutrophils are important components of the metastatic tumor microenvironment and exhibit heterogeneity. However, the specific phenotypes, functions and regulatory mechanisms of neutrophils in PDAC liver metastases remain unknown. Here, we show that a subset of P2RX1-negative neutrophils accumulate in clinical and murine PDAC liver metastases. RNA sequencing of murine PDAC liver metastasis-infiltrated neutrophils show that P2RX1-deficient neutrophils express increased levels of immunosuppressive molecules, including PD-L1, and have enhanced mitochondrial metabolism. Mechanistically, the transcription factor Nrf2 is upregulated in P2RX1-deficient neutrophils and associated with PD-L1 expression and metabolic reprogramming. An anti-PD-1 neutralizing antibody is sufficient to compromise the immunosuppressive effects of P2RX1-deficient neutrophils on OVA-activated OT1 CD8+ T cells. Therefore, our study uncovers a mechanism by which metastatic PDAC tumors evade antitumor immunity by accumulating a subset of immunosuppressive P2RX1-negative neutrophils.

A novel role of kukoamine B: Inhibition of the inflammatory response in the livers of lipopolysaccharide-induced septic mice via its unique property of combining with lipopolysaccharide.

Kukoamine B (KB), derived from the traditional Chinese herb cortex Lycii, exerts anti-inflammatory effects due to its potent affinity with lipopolysaccharide (LPS) and CpG DNA; however, little is known regarding whether the in vivo administration of KB can effectively inhibit inflammation in septic mice. The present study thus aimed to investigate the inhibitory effects of KB on the inflammatory response in the livers of LPS-induced septic mice. KB treatment in the LPS-induced septic mice significantly decreased the plasma level of LPS. In addition, KB protected against liver injury, as confirmed by improved histology and decreased aminotransferase levels in the serum. Further experiments revealed that KB attenuated liver myeloperoxidase activity and reduced the expression of vascular cell adhesion molecule-1 and intercellular adhesion molecule-1. These effects were accompanied by decreases in the levels of tumor necrosis factor α and interleukin-1ß in the liver tissue. In parallel, the activity of nuclear factor-κ-gene binding (NF-κB) in the livers of LPS-induced septic mice was markedly inhibited with KB treatment. In combination, these results demonstrate that KB inhibits inflammation in septic mice by reducing the concentrations of plasma LPS, decreasing leukocyte sequestration and interfering with NF-κB activation, and, therefore, suppressing the pro-adhesive phenotype of endothelial cells.

Regulatory effect and mechanisms of carbon monoxide-releasing molecule II on hepatic energy metabolism in septic mice.

AIM: To investigate the possible mechanisms of exogenous carbon monoxide-releasing molecule II (CORM-2) intervention on hepatic energy metabolism in experimental sepsis. METHODS: Forty-eight C57BL/6 mice were randomly divided into four groups (n = 12): sham group; cecal ligation and puncture (CLP) group; CLP + CORM-2 group and CLP + iCORM-2 (inactive CORM-2) group. Survival rates were determined after 72 h. Twenty-four similarly treated mice (n = 6 in each group) were assayed for post-operative continuous blood glucose in the first 36 h. Thirty-six similarly treated mice (n = 9 in each group) underwent micro-positron emission tomography (PET) scanning after tail vein injection of (18)F-fluorodeoxyglucose (FDG) 24 h after operation. Plasma and liver specimens were collected for assay of liver pathology, alanine transaminase (ALT) and aspartate transaminase (AST) activities. Hepatic glucokinase activity, lactic acid levels and mitochondrial swelling were also determined. RESULTS: Improved survival was observed in CORM-2 treated mice. Both the CLP and CLP + CORM-2 groups had sustained low blood glucose levels within the first post-operative 36 h. (18)F-FDG micro-PET images showed abnormally high levels of hepatic glucose metabolism (standardized uptake value) in the CLP group (2.76 ± 0.39 vs 0.84 ± 0.14, P < 0.01), which declined to normal levels after CORM-2 intervention (1.29 ± 0.32 vs 2.76 ± 0.39, P < 0.05). glucokinase activity was markedly increased in the CLP group (6.38 ± 0.56 U/g vs 4.60 ± 0.21 U/g, P < 0.01), but was normal after CORM-2 intervention (4.74 ± 0.14 U/g vs 6.38 ± 0.56 U/g, P < 0.05). CORM-2 suppressed plasma lactic acid levels (4.02 ± 0.02 mmol/L vs 7.72 ± 2.37 mmol/L, P < 0.05) and protected hepatic mitochondria in CLP mice. CORM-2 intervention also reduced elevated plasma AST (199.67 ± 11.08 U/L vs 379.67 ± 16.34 U/L, P < 0.05) and ALT (63.67 ± 12.23 U/L vs 112.67 ± 9.74 U/L, P < 0.05) activities in CLP mice. CONCLUSION: The release of CO molecules by CORM-2 protects mitochondria and maintains a stable level of hepatic glucose metabolism. Thus, CORM-2 improves liver function and survival in septic mice.