BackgroundAccumulating studies suggest that targeting epigenetic modifications could improve the efficacy of tumor immunotherapy; however, the mechanisms underlying this phenomenon remain largely ...unknown. Here, we investigated the ability of the epigenetic modifier, enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2), to regulate the expression of immune checkpoint inhibitor, programmed death-1 ligand 1 (PD-L1) in hepatocellular carcinoma (HCC).MethodsImmunohistochemistry and multiplex immunofluorescence staining were performed to analyze the expression and correlation of EZH2 and PD-L1 in HCC tissues. Immunoblotting, quantitative real-time PCR, flow cytometry, chromatin immunoprecipitation, and dual-luciferase reporter gene assays were performed to evaluate the regulatory roles of EZH2 on PD-L1 expression.ResultsIn vitro cell experiments revealed that EZH2 negatively regulated the PD-L1 expression of hepatoma cell lines in IFNγ-dependent manner. Mechanistic studies demonstrated that EZH2 could suppress PD-L1 expression by upregulating the H3K27me3 levels on the promoters of CD274 (encoding PD-L1) and interferon regulatory factor 1 (IRF1), an essential transcription factor for PD-L1 expression, without affecting the activation of the IFNγ-signal transducer and activator of transcription 1 (STAT1) pathway. Clinical samples from HCC patients with immune-activated microenvironments showed negative correlations between EZH2 and PD-L1 expression in hepatoma cells. Multivariate Cox analysis demonstrated that the combination of EZH2 and PD-L1 was an independent prognostic factor for both OS and RFS for patients with HCC.ConclusionsThe epigenetic modificator EZH2 can suppress the expression of immune checkpoint inhibitor PD-L1 by directly upregulating the promoter H3K27me3 levels of CD274 and IRF1 in hepatoma cells, and might serve as a potential therapeutic target for combination of immunotherapy for immune-activated HCC.
Neutrophils constitute a major component in human hepatocellular carcinoma (HCC) and can facilitate disease progression via poorly understood mechanisms. Here, we show that neutrophil extracellular ...traps (NETs) formation was increased in human HCC tumor tissues than in paired non-tumor liver tissues. Mechanism study revealed that tumor-induced metabolic switch toward glycolysis and pentose phosphate pathway in tumor infiltrating neutrophils promoted NETs formation in a reactive oxygen species dependent-manner. NETs subsequently induced the migration of cancer cells and down-regulation of tight junction molecules on adjacent endothelial cells, thus facilitating tumor intravasation and metastasis. Accordingly, NETs depletion could inhibit tumor metastasis in mice in vivo, and the infiltration levels of NETs-releasing neutrophils were negatively associated with patient survival and positively correlated with tumor metastasis potential of HCC patients. Our results unveiled a pro-metastatic role of NETs in the milieu of human HCC, and pointed to the importance of metabolic reprogramming in shaping their characteristics, thus providing an applicable efficient target for anti-cancer therapies.
Soil salinity is an important abiotic stress factor that seriously affects the crop growth and yield. Use of plant-derived microorganisms is a promising strategy to alleviate salt stress. In a ...previous study, the endophytic strain
Bacillus altitudinis
WR10 isolated from wheat roots showed high salt resistance. In this study, we investigated the efficacy of WR10 in improving the salt tolerance of wheat and its potential mechanisms using a hydroponic test. Under salt stress, WR10 inoculation significantly increased the lengths and dry weights of the roots and shoots, indicating that WR10 improves wheat salt tolerance at the seedling stage. WR10 inoculation significantly reduced Na
+
accumulation and enhanced K
+
, P, and Ca
2+
uptake in salt-stressed plants, which can be attributed to the upregulated gene expression of H
+
-ATPase as well as the P-solubilizing and biofilm-producing characteristics of WR10. At the transcriptional level,
L
-ascorbate peroxidase (APX), glutathione (GSH) synthetase related to GSH biosynthesis, and phenylpropanoid biosynthesis genes (CYP73A, 4CL, and CAD) were significantly upregulated, whereas those of GSH metabolism genes (glutathione S-transferase and gamma-glutamyltranspeptidase) were significantly downregulated in WR10-applied wheat roots under salt stress. These changes increased the APX activity and GSH levels and resulted in a decrease in hydrogen peroxide levels. Additionally, a decrease in proline content was observed in WR10-inoculated plants under salt stress because of WR10-induced upregulation of proline dehydrogenase gene expression. These results provide supporting evidence that WR10 improves wheat salt tolerance via more than one mechanism and open a window of opportunity for WR10 application in salinized soil.
Common sensitizing mutations in epidermal growth factor receptor (cEGFR), including exon 19 deletions (19-Del) and exon 21 L858R substitution, are associated with high sensitivity to EGFR-TKIs in ...NSCLC patients. The treatment for NSCLC patients with uncommon EGFR (uEGFR) mutations remains a subject of debate due to heterogeneity in treatment responses. In this manuscript, the targeted next-generation sequencing (NGS) data of a large cohort of EGFR-mutated NSCLC patients was assessed to elucidate genomic profiles of tumors carrying cEGFR or uEGFR mutations. The results showed that NSCLC patients with uEGFR mutations were more likely to harbor co-occurring genetic alterations in the Hippo pathway and a higher TMB compared with cEGFR-positive patients. Smoking-related mutations were found to significantly enriched in uEGFR-positive patients. Subgroup analyses were performed to identify potential prognostic biomarkers in patients harboring various EGFR subtype mutations. L858R-positive patients with co-existing ARID2 mutations had shorter progression-free survival (PFS) than those who were L858R- or 19-Del-positive but ARID2-negative (median: 2.3 vs. 12.0 vs. 8.0 months, P = 0.038). Furthermore, mutational profiles, such as top frequently mutated genes and mutational signatures of patients with various EGFR subtype mutations were significantly different. Our study analyzed the mutational landscape of NSCLC patients harboring cEGFR and uEGFR mutations, revealing specific genomic characteristics associated with uEGFR mutations that might explain the poor prognosis of first-generation EGFR-TKIs.
Macrophages (Mφ) in most solid tumors exhibit a distinct immunosuppressive phenotype, but the mechanisms that allow tumor microenvironments to “educate” Mφ are incompletely understood. Here, we ...report that culture supernatants (TSNs) from several types of tumor cell lines can drive monocytes to become immunosuppressive Mφ. Kinetic experiments revealed that soon after exposure to these TSNs, monocytes began to provoke transient proinflammatory responses and then became refractory to subsequent stimulation. Other TSNs that failed to cause such temporary preactivation did not alter Mφ polarization. Consistent with these results, we observed that the monocytes/Mφ in different areas of human tumor samples exhibited distinct activation patterns. Moreover, we found that hyaluronan fragments constitute a common factor produced by various tumors to induce the formation of immunosuppressive Mφ, and also that upregulation of hyaluronan synthase-2 in tumor cells is correlated with the ability of the cells to cause Mφ dysfunction. These results indicate that soluble factors derived from tumor cells, including hyaluronan fragments, co-opt the normal development of Mφ to dynamically educate the recruited blood monocytes in different niches of a tumor. The malignant cells can thereby avoid initiation of potentially dangerous Mφ functions and create favorable conditions for tumor progression.
Abstract
Based on the perspective of corporate cash holdings, this paper explores whether the combination of an optimistic CEO and a pessimistic CFO creates the “best partners”. Taking the ...non-financial A-share listed firms in China from 2010 to 2018 as the sample, ordinary least squares (OLS) regression analysis was used as the baseline approach to empirically test, for the first time, the comprehensive influence of CEO optimism and CFO pessimism on corporate cash holdings. The empirical results show that firms with an optimistic CEO and a pessimistic CFO will hold less cash. Moreover, this negative compound effect is found to be more significant in regions with a strong gambling culture and in non-state-owned enterprises (non-SOEs). Further analysis reveals that whether the CFO sits on the board of directors and the educational level difference between the CEO and CFO are also essential factors restricting this negative compound effect. This study provides a new perspective for relevant research on upper echelons theory, and also enriches relevant research on the factors influencing corporate cash holdings.
C-reactive protein (CRP) is a widely used marker of systemic inflammation and predicts poor clinical outcomes in patients with hepatocellular carcinoma (HCC); however, its significance in the local ...immune response at the tumor site is not clear.
Serum CRP levels of 329 HCC patients were detected before resection. Paired paraffin-embedded tumor samples were used to quantify immune cell populations, such as CD11b
myeloid cells, CD68
macrophages (Mφs), CD15
neutrophils, CD8
T cells, and CD206
, CD204
, CD163
and CD169
Mφs, by immunohistochemistry. Enrichment scores for 34 types of immune cells based on transcriptome data from 24 HCC samples were calculated by xCell. Overall survival of patients was analyzed using the Kaplan-Meier method.
Serum CRP levels were correlated with liver functions and tumor stages in patients with HCC. The densities of CD68
tumor-associated macrophages (TAMs) and CD15
tumor-associated neutrophils (TANs) were significantly higher in patients with elevated serum CRP levels than in those with low CRP levels (both
0.0001). Further analysis of TAM subtypes revealed that serum CRP levels were associated with CD204
and CD163
Mφ densities (
< 0.0001 and
= 0.0003, respectively). Moreover, transcriptome data showed that CRP expression was associated with the expression of myeloid cell infiltration-related genes in HCC tumors. The combination of serum CRP with TAMs or TANs in both the nontumor and intratumor regions could represent a powerful criterion for predicting patient prognoses.
Serum CRP could serve as an indicator of an immunosuppressive TME in HCC, which could be of potential clinical application for treatment strategies targeting the TME.
B cells consistently represent abundant cellular components in tumors; however, direct evidence supporting a role for B cells in the immunopathogenesis of human cancers is lacking, as is specific ...knowledge of their trafficking mechanisms. Here, we demonstrate that chemokine (C‐X‐C motif) receptor 3–positive (CXCR3+) B cells constitute approximately 45% of B‐cell infiltrate in human hepatocellular carcinoma (HCC) and that their levels are positively correlated with early recurrence of HCC. These cells selectively accumulate at the invading edge of HCC and undergo further somatic hypermutation and immunoglobulin G–secreting plasma cell differentiation. Proinflammatory interleukin‐17+ cells are important for the induction of epithelial cell–derived CXCR3 ligands CXCL9, CXCL10, and CXCL11, which subsequently promote the sequential recruitment and further maturation of CXCR3+ B cells. More importantly, we provide evidence that CXCR3+ B cells, but not their CXCR3– counterparts, may operate in immunoglobulin G–dependent pathways to induce M2b macrophage polarization in human HCC. Depletion of B cells significantly suppresses M2b polarization and the protumorigenic activity of tumor‐associated macrophages and restores the production of antitumorigenic interleukin‐12 by those cells in vivo. Conclusion: Selective recruitment of CXCR3+ B cells bridges proinflammatory interleukin‐17 response and protumorigenic macrophage polarization in the tumor milieu, and blocking CXCR3+ B‐cell migration or function may help defeat HCC.(Hepatology 2015;62:1779–1790)
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