Retinoic Acid Synthesis Deficiency Fosters the Generation of Polymorphonuclear Myeloid-Derived Suppressor Cells in Colorectal Cancer.

Metabolism is reprogrammed in cancer to fulfill the demands of malignant cells for cancer initiation and progression. Apart from its effects within cancer cells, little is known about whether and how reprogramed metabolism regulates the surrounding tumor microenvironment (TME). Myeloid-derived suppressor cells (MDSC) are key regulators of the TME and greatly affect tumor progression and therapeutic responses. In this study, our results revealed that retinol metabolism-related genes and enzymes were significantly downregulated in human colorectal cancer compared with adjacent colonic tissues, and tumors exhibited a defect in retinoic acid (RA) synthesis. Reduced ADH1-mediated retinol metabolism was associated with attenuated RA signaling and accumulated MDSCs in colorectal cancer tumors. Using an in vitro model, generating MDSCs from CD34+ myeloid precursors, we found that exogenous RA could abrogate the generation of polymorphonuclear MDSCs (PMN-MDSC) with negligible impact on myeloid differentiation. Mechanistically, RA could restrain the glycolytic capacity of myeloid cells, which in turn activated the AMP-activated protein kinase (AMPK) pathway, further impairing the suppressive capacity of myeloid cells. Supplementation with RA could significantly delay tumor growth, with reduced arginase-1-expressing myeloid cells and increased CD8+ and granzyme B+ T cells in both colitis-associated and implanted MC38 mouse colorectal cancer models. Our results indicated that the defect in ADH1-mediated RA synthesis could provide a possible mechanism that fosters the generation of PMN-MDSCs in colorectal cancer and that restoring RA signaling in the TME could serve as a promising therapeutic strategy to abrogate the generation of PMN-MDSCs.

Targeting adenosinergic pathway enhances the anti-tumor efficacy of sorafenib in hepatocellular carcinoma.

BACKGROUND: Sorafenib is the most widely used first-line treatment for patients with advanced hepatocellular carcinoma (HCC), but such treatment provides only limited survival benefits that might be related to the immune status of distinct tumor microenvironments. A fundamental understanding of the distribution and phenotypes of T lymphocytes in tumors will undoubtedly lead to the development of novel immunotherapeutic strategies that could possibly enhance the efficacy of sorafenib treatments. METHODS: Flow cytometry, immunohistochemistry and immunofluorescence analyses were performed to detect the infiltration and distribution of various leukocyte populations, and the expression of different immune checkpoint molecules in fresh HCC tumor tissues. Correlations among indicating genes were calculated in 365 patients with HCC from The Cancer Genome Atlas (TCGA) data set, and the cumulative overall survival time was calculated using the Kaplan-Meier method. Moreover, role of adenosinergic pathway on sorafenib anti-tumor efficacy was investigated using both subcutaneous and orthotopic transplantation tumor model in immune competent C57BL/6 mice. RESULTS: We revealed that levels of CD3+ and CD8+ T cells were significantly downregulated in HCC tumor tissue, so were the infiltration of CD169+ cells (a Mφ subpopulation with T cell activation capacities) and their contact with CD8+ cells in tumor milieus. Moreover, levels of PD-1 and CD39 expression were significantly upregulated in human HCC-infiltrating CD4+ and CD8+ T cells, and CD39+CD8+ T cells exhibited a CD69+PD-1+perforinlowIFNγlow "exhausted" phenotype. Levels of both CD39+ T cells infiltration and adenosine receptor ADORA2B expression in tumor tissues were negatively correlated with overall survival of patients with HCC. Accordingly, mice treated with sorafenib in combination with adenosine A2B receptor blockage reagents exhibited significantly reduced tumor progression compared with control groups. CONCLUSIONS: These results suggest that adenosinergic pathway might represent an applicable target for sorafenib-combined-therapies in human HCC.

Vessels That Encapsulate Tumor Clusters (VETC) Pattern Is a Predictor of Sorafenib Benefit in Patients with Hepatocellular Carcinoma.

Sorafenib is the most recommended first-line systemic therapy for advanced hepatocellular carcinoma (HCC). Yet there is no clinically applied biomarker for predicting sorafenib response. We have demonstrated that a vascular pattern, named VETC (Vessels that Encapsulate Tumor Clusters), facilitates the release of whole tumor clusters into the bloodstream; VETC-mediated metastasis relies on vascular pattern, but not on migration and invasion of cancer cells. In this study, we aimed to explore whether vascular pattern could predict sorafenib benefit. Two cohorts of patients were recruited from four academic hospitals. The survival benefit of sorafenib treatment for patients with or without the VETC pattern (VETC+ /VETC- ) was investigated. Kaplan-Meier analyses revealed that sorafenib treatment significantly reduced death risk and prolonged overall survival (OS; in cohort 1/2, P = 0.004/0.005; hazard ratio [HR] = 0.567/0.408) and postrecurrence survival (PRS; in cohort 1/2, P = 0.001/0.002; HR = 0.506/0.384) in VETC+ patients. However, sorafenib therapy was not beneficial for VETC- patients (OS in cohort 1/2, P = 0.204/0.549; HR = 0.761/1.221; PRS in cohort 1/2, P = 0.121/0.644; HR = 0.728/1.161). Univariate and multivariate analyses confirmed that sorafenib treatment significantly improved OS/PRS in VETC+ , but not VETC- , patients. Further mechanistic investigations showed that VETC+ and VETC- HCCs displayed similar levels of light chain 3 (LC3) and phosphorylated extracellular signal-regulated kinase (ERK) in tumor tissues (pERK) or endothelial cells (EC-pERK), and greater sorafenib benefit was consistently observed in VETC+ HCC patients than VETC- irrespective of levels of pERK/EC-pERK/LC3, suggesting that the different sorafenib benefit between VETC+ and VETC- HCCs may not result from activation of Raf/mitogen-activated protein kinase kinase (MEK)/ERK and vascular endothelial growth factor (VEGF)A/VEGF receptor 2 (VEGFR2)/ERK signaling or induction of autophagy. Conclusion: Sorafenib is effective in prolonging the survival of VETC+ , but not VETC- , patients. VETC pattern may act as a predictor of sorafenib benefit for HCC.

Vascular CXCR4 Expression Promotes Vessel Sprouting and Sensitivity to Sorafenib Treatment in Hepatocellular Carcinoma.

Purpose: C-X-C chemokine receptor type 4 (CXCR4) is known to be involved in both developmental and adult angiogenesis; however, its role in tumor angiogenesis remains largely unknown. Here, the role of vascular CXCR4 in regulating vascular structure in hepatocellular carcinoma (HCC) was assessd, and the clinical value of CXCR4 was explored.Experimental Design: The expression of CXCR4 in HCC was determined by IHC and immunofluorescence. Characteristics of CXCR4+ cells were determined by in vitro and mice experiments. Kaplan-Meier survival analysis was used to determine the correlation of CXCR4 expression with prognosis.Results: We found that CXCR4 is selectively expressed on a fraction of tumor endothelial cells (TECs) in HCC tissues, but not on the hepatic endothelium in peritumoral area. High levels of CXCR4 on TECs tended to develop a sinusoidal vasculature in tumors and predicted poor prognosis for patients with HCC. CXCR4+ endothelial cells (EC) displayed the functional features of tip cells, with increased expression of tip cell-related markers. Functional studies revealed that CXCR4 could directly promote vessel sprouting in vitro and in vivo Interestingly, sorafenib treatment reduced the frequency of CXCR4+ ECs in culture and inhibited the formation of sinusoidal vasculature and growth of CXCR4High xenograft tumors. Moreover, high CXCR4 vascular density in resected tumor tissues before sorafenib treatment was associated with prolonged survival in patients with advanced HCC treated with sorafenib.Conclusions: These data revealed that CXCR4 is a novel HCC vascular marker for vessel sprouting and could serve as a potential therapeutic target and a predictive factor for sorafenib treatment in patients with HCC. Clin Cancer Res; 23(15); 4482-92. ©2017 AACR.

A supercritical-CO2 extract of Ganoderma lucidum spores inhibits cholangiocarcinoma cell migration by reversing the epithelial-mesenchymal transition.

BACKGROUND: Ganoderma lucidum (G. lucidum) is an oriental medical mushroom that has been widely used in Asian countries for centuries to prevent and treat different diseases, including cancer. HYPOTHESIS/PURPOSE: The objective of this study was to investigate the effect of A supercritical-CO2 extract of G. lucidum spores on the transforming growth factor beta 1 (TGF-ß1)-induced epithelial-mesenchymal transition (EMT) of cholangiocarcinoma cells. STUDY DESIGN: This was an in vitro study with human cholangiocarcinoma TFK-1 cells treated with varying concentrations of G. lucidum. METHODS: A supercritical-CO2 extract of G. lucidum spores (GLE) was obtained from completely sporoderm-broken germinating G. lucidum spores by supercritical fluid carbon dioxide (SCF-CO2) extraction. GLE pre-incubated with human cholangiocarcinoma TFK-1 cells prior to TGF-ß1 treatment (2ng/ml) for 48h. Changes in EMT markers were analyzed by western blotting and immunofluorescence. The formation of F-actin stress fibers was assessed via immunostaining with phalloidin and examined using confocal microscopy. Additionally, the effect of the GLE on TGF-ß1-induced migration was investigated by a Boyden chamber assay. RESULTS: TGF-ß1-induced reduction in E-cadherin expression was associated with a loss of epithelial morphology and cell-cell contact. Concomitant increases in N-cadherin and Fibronectin were evident in predominantly elongated fibroblast-like cells. The GLE suppressed the TGF-ß1-induced morphological changes and the changes in cadherin expression, and also inhibited the formation of F-actin stress fibers, which are a hallmark of EMT. The GLE also inhibited TGF-ß1-induced migration of TFK-1 cells. CONCLUSION: Our findings provide new evidence that GLE suppress cholangiocarcinoma migration in vitro through inhibition of TGF-ß1-induced EMT. The GLE may be clinically applied in the prevention and/or treatment of cancer metastasis.

Astragalus polysaccharide attenuates lipopolysaccharide-induced inflammatory responses in microglial cells: regulation of protein kinase B and nuclear factor-κB signaling.

OBJECTIVES AND DESIGN: Microglia play an important role in immune and inflammatory responses in the central nervous system. Astragalus polysaccharide (APS) has been reported as an immune stimulant for various inflammation-associated diseases in vivo. The present study investigated the effects of APS on lipopolysaccharide-stimulated inflammatory responses in microglial cells. MATERIALS AND METHODS: Cultured BV2 microglial cells were pre-treated with APS (0-200 µg/ml) prior to lipopolysaccharide (50 ng/ml) stimulation. The production of proinflammatory mediators including inducible nitric oxide synthase (iNOS)/nitric oxide (NO), cyclooxygenase-2 (COX-2)/prostaglandin E (PGE2), tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß) were evaluated. RESULTS: APS dose-dependently reduced lipopolysaccharide stimulated nitric oxide and PGE2 production, as well as iNOS and cyclooxygenase-2 gene expression. It also attenuated proinflammatory cytokines IL-1ß and TNF-α generation. In addition, APS inhibited nuclear factor-κB translocation by blockade of IκB degradation and suppressed protein kinase B phosphorylation in lipopolysaccharide-stimulated cells. CONCLUSIONS: The inhibitory effects of APS on lipopolysaccharide-stimulated inflammatory mediator production in microglia are associated with suppression of nuclear factor-κB and protein kinase B signaling pathways. APS may offer therapeutic potential for treating inflammatory and neurodegenerative diseases accompanied with microglial activation.

Phosphorus(V)-corrole: synthesis, spectroscopic properties, theoretical calculations, and potential utility for in vivo applications in living cells.

The synthesis and properties of phosphorus(V) 5,10,15-tris(4-methoxycarbonylphenyl)corrole (1) have been investigated, and its potential utility for bioimaging applications in living cells has been explored. As would normally be anticipated for corrole complexes, the intensity of the Q(0,0) bands of 1 is greater than those of comparable phosphorus(V) tetraphenylporphyrins, but the ΦF values (0.25 for 1) are found to be comparable. A detailed analysis of the electronic structure of the complex was carried out by comparing electronic absorption and MCD spectral data to the results of TD-DFT calculations. The meso-aryl substituents, which enhance the lipophilicity of 1 and hence result in its localization in intracellular membranes during HeLa cell experiments, are predicted to result in a narrowing of the HOMO-LUMO gap and hence a red shift of the Q(0,0) bands toward the optical window in biological tissues.

Synthesis and study of three novel macrocyclic selena[n]ferrocenophanes containing a naphthalene unit.

Three novel macrocyclic ligands, L1-L3, in which a ferrocene unit and a fluorescent moiety are linked to polyselena rings have been designed and prepared from 1,1'-bis(3-bromopropylseleno)ferrocene. Reaction of L with [M(NCMe)4](PF6)2 (M = Pd and Pt) led to complexes [ML](PF6)2 (M = Pd and Pt). Crystal structure analysis revealed that after complexation, the macrocyclic ligand adopts the unusual c,c,c conformation due to intramolecular C-H···π interactions from the hydrogen atoms of ferrocene moieties to the naphthalene ring. Electrochemical studies showed that in [ML](PF6)2 (M = Pd and Pt) the half-wave potential of the 1,1'-ferrocenediyl group shifts to much more positive potentials due to electron density withdrawn from Se donor atoms. Electrochemical and optical measurements were used to calculate HOMO and LUMO levels as well as HOMO-LUMO band gaps. Results were compared and correlated with the differences in molecular structures.

Lipid extract from completely sporoderm-broken germinating Ganoderma sinensis spores elicits potent antitumor immune responses in human macrophages.

Ganoderma sinensis has been used widely in Oriental countries for the prevention and treatment of various diseases including cancer. Previous studies have shown that the lipid extract from Ganoderma exhibits direct cytotoxicity against tumor cells. Here, it is reported that the lipid extract from germinating G. sinensis spores, at lower concentrations that have no direct tumoricidal activity, induce potent antitumor immune responses in human monocytes/macrophages. Upon stimulation with the lipid extract, monocytes/macrophages exhibited markedly increased production of proinflammatory cytokines and surface expression of costimulatory molecules. Conditioned medium from stimulated cells effectively suppressed the growth of tumor cells. Apparently, the lipid extract triggered macrophage activation via a mechanism different from that associated with LPS. Moreover, it was observed that the lipid extract could partially re-establish the antitumor activity of the immunosuppressive tumor-associated macrophages. These results indicated that in addition to its direct tumoricidal activity, the lipid extract from G. sinensis spores could exert antitumor activity by stimulating the activation of human monocytes/macrophages.