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Dendritic cells (DCs) are potent and specialized antigen presenting cells, which play a crucial role in initiating and amplifying both the innate and adaptive immune responses against cancer. Tumor cells can escape from immune attack by secreting suppressive cytokines that solely or cooperatively impair the immune function of DCs. However, the underlying mechanisms are not fully defined. Vascular endothelial growth factor (VEGF) has been identified as a major cytokine in the tumor microenvironment. To elucidate the effects of VEGF on the motility and immune function of mature DCs (mDCs), the cells were treated with 50 ng/mL VEGF and investigated by proteomics and molecular biological technologies. The results showed that VEGF can impair the migration capacity and immune function of mDCs through the RhoA‐cofilin1 pathway mediated by the VEGF receptor 2, suggesting impaired motility of mDCs by VEGF is one of the aspects of immune escape mechanisms of tumors. It is clinically important to understand the biological behavior of DCs and the immune escape mechanisms of tumor as well as how to improve the efficiency of antitumor therapy based on DCs.

Dendritic cells (DCs) are the most potent antigen-presenting cells. Upon maturation, DCs express costimulatory molecules and migrate to the lymph nodes to present antigens to T cells. The actin cytoskeleton plays key roles in multiple aspects of DC functions. However, little is known about the mechanisms and identities of actin-binding proteins that control DC maturation and maturation-associated functional changes. Tropomodulin1 (Tmod1), an actin-capping protein, controls actin depolymerization and nucleation. We found that Tmod1 was expressed in bone marrow-derived immature DCs and was significantly upregulated upon lipopolysaccharide (LPS)-induced DC maturation. By characterizing LPS-induced mature DCs (mDCs) from Tmod1 knockout mice, we found that compared with Tmod1+/+ mDCs, Tmod1-deficient mDCs exhibited lower surface expression of costimulatory molecules and chemokine receptors and reduced secretion of inflammatory cytokines, suggesting that Tmod1 deficiency retarded DC maturation. Tmod1-deficient mDCs also showed impaired random and chemotactic migration, deteriorated T-cell stimulatory ability, and reduced F-actin content and cell stiffness. Furthermore, Tmod1-deficient mDCs secreted high levels of IFN-β and IL-10 and induced immune tolerance in an experimental autoimmune encephalomyelitis (EAE) mouse model. Mechanistically, Tmod1 deficiency affected TLR4 signaling transduction, resulting in the decreased activity of MyD88-dependent NFκB and MAPK pathways but the increased activity of the TRIF/IRF3 pathway. Rescue with exogenous Tmod1 reversed the effect of Tmod1 deficiency on TLR4 signaling. Therefore, Tmod1 is critical in regulating DC maturation and immune functions by regulating TLR4 signaling and the actin cytoskeleton. Tmod1 may be a potential target for modulating DC functions, a strategy that would be beneficial for immunotherapy for several diseases.

The immune infiltration of tumors is closely related to clinical outcomes. The composition of tumor-infiltrating immune cells (TIICs) can serve as biomarkers for predicting response to treatment and survival in different patient subgroups in terms of chemotherapy and immunotherapy. This study is focused on investigating the clinical implications of TIICs in breast cancer patients. We performed several in silico analyses of gene expression profiles in 2976 nonmetastatic tumor samples. CIBERSORT was used to estimate the proportion of 22 immune cell types to analyze their correlation with overall survival (OS) and disease-free survival (DFS) in different breast cancer subtypes and stages. Our results showed that a higher fraction of plasma cells in estrogen receptor (ER)-positive breast cancer patients indicated an increase in DFS (hazard ratio [HR]=0.66, 95% confidence interval [CI] 0.54~0.82, p

Purpose: This study aimed to observe the feasibility and safety of addition of recombinant human endostatin injection to standard chemoradiation for the locally advanced nasopharyngeal carcinoma. Current follow-up results updated long-term efficacy and late toxicity of the trial. Methods: Between July 2012 and December 2013, we enrolled 114 patients that are older than 18 years with stage Ⅲ-Ⅳb nasopharyngeal carcinoma from 3 centers in Guizhou, China. Fifty six patients who received standard chemoradiation combined with recombinant human endostatin injection (Endostar) were included in the study group. Another 58 patients were randomly assigned to the control group without using Endostar. Patients in both groups received the same 2 cycles of induction chemotherapy (Docetaxel 75 mg/m2, cisplatin 80 mg/m2), followed by 2 cycles of concurrent intensity-modulated radiation therapy with cisplatin (DDP; 80 mg/m2 on days 1 and 22). The patients in the experimental group received 2 cycles Endostar (7.5 mg/m2 d8-d21 during induction chemotherapy and d1-d14 during concurrent chemoradiation). Results: There were no significant differences of toxicities between the 2 groups. Chemotherapy and radiotherapy compliance between the 2 groups was similar. No hemorrhage and coagulation dysfunction in the experimental group were observed. There was a median follow-up of 67.1 months. Comparing the short-time effect of 3 months to the completion of chemoradiotherapy, there was a little higher objective response rate in the experimental group. Compared with the control group, the experimental group improved in the complete remission rate of cervical lymph node metastasis (91.1% vs 72.4%, χ2 = 3.897, P = 0.048). However, there was no significant difference in the curative effect of nasopharyngeal lesions between the 2 groups. (78.6% vs 74.1%, χ2 = 0.310, P = 0.578). The 5-year overall survival, progression-free of survival, metastasis-free survival, and locoregional failure-free survival rates in the 2 groups were 69.6%, 67.8%, 78.75, and 83.0%, respectively, for the experimental group, these rates were 73.2%, 80.1%, 81.7%, and 91.0%, respectively, and for the control group, no significant difference was found (P > 0.05). Conclusions: Patients show good tolerance and compliance with a manageable toxicity profile to the regimen of chemoradiation plus Endostar. There was a little higher objective response rate in the study group. A phase 3 randomized study is needed to substantiate our findings.

Flavonoids were found to synergize anti-malaria and anti-cancer compounds in Artemisia annua, a very important economic crop in China. In order to discover the regulation mechanism of flavonoids in Artemisia annua, the full length cDNA of flavanone 3-hydroxylase (F3H) were isolated from Artemisia annua for the first time by using RACE (rapid amplification of cDNA ends). The completed open read frame of AaF3H was 1095 bp and it encoded a 364-amino acid protein with a predicted molecular mass of 41.18 kDa and a pI of 5.67. The recombinant protein of AaF3H was expressed in E. coli BL21(DE3) as His-tagged protein, purified by Ni-NTA agrose affinity chromatography, and functionally characterized in vitro. The results showed that the His-tagged protein (AaF3H) catalyzed naringenin to dihydrokaempferol in the present of Fe(2+). The Km for naringenin was 218.03 μM. The optimum pH for AaF3H reaction was determined to be pH 8.5, and the optimum temperature was determined to be 35 °C. The AaF3H transcripts were found to be accumulated in the cultivar with higher level of flavonoids than that with lower level of flavonoids, which implied that AaF3H was a potential target for regulation of flavonoids biosynthesis in Artemisia annua through metabolic engineering.

The regulatory mechanism of flavonoids, which synergise anti-malarial and anti-cancer compounds in Artemisia annua, is still unclear. In this study, an anthocyanidin-accumulating mutant callus was induced from A. annua and comparative transcriptomic analysis of wild-type and mutant calli performed, based on the next-generation Illumina/Solexa sequencing platform and de novo assembly. A total of 82,393 unigenes were obtained and 34,764 unigenes were annotated in the public database. Among these, 87 unigenes were assigned to 14 structural genes involved in the flavonoid biosynthetic pathway and 37 unigenes were assigned to 17 structural genes related to metabolism of flavonoids. More than 30 unigenes were assigned to regulatory genes, including R2R3-MYB, bHLH and WD40, which might regulate flavonoid biosynthesis. A further 29 unigenes encoding flavonoid biosynthetic enzymes or transcription factors were up-regulated in the mutant, while 19 unigenes were down-regulated, compared with the wild type. Expression levels of nine genes involved in the flavonoid pathway were compared using semi-quantitative RT-PCR, and results were consistent with comparative transcriptomic analysis. Finally, a putative flavonol synthase gene (AaFLS1) was identified from enzyme assay in vitro and in vivo through heterogeneous expression, and confirmed comparative transcriptomic analysis of wild-type and mutant callus. The present work has provided important target genes for the regulation of flavonoid biosynthesis in A. annua.

Dendritic cells (DCs), the most potent antigen-presenting cells, play a central role in the initiation, regulation, and maintenance of the immune responses. Vascular endothelial growth factor (VEGF) is one of the important cytokines in the tumor microenvironment (TME) and can inhibit the differentiation and functional maturation of DCs. To elucidate the potential mechanisms of DC dysfunction induced by VEGF, the effects of VEGF on the biophysical characteristics and motility of human mature DCs (mDCs) were investigated. The results showed that VEGF had a negative influence on the biophysical properties, including electrophoretic mobility, osmotic fragility, viscoelasticity, and transmigration. Further cytoskeleton structure analysis by confocal microscope and gene expression profile analyses by gene microarray and real-time PCR indicated that the abnormal remodeling of F-actin cytoskeleton may be the main reason for the deterioration of biophysical properties, motility, and stimulatory capability of VEGF-treated mDCs. This is significant for understanding the biological behavior of DCs and the immune escape mechanism of tumors. Simultaneously, the therapeutic efficacies may be improved by blocking the signaling pathway of VEGF in an appropriate manner before the deployment of DC-based vaccinations against tumors.

Interlukin-10 (IL-10) is an immunomodulatory cytokine which predominantly induces immune-tolerance. It has been also identified as a major cytokine in the tumor microenvironment that markedly mediates tumor immune escape. Previous studies on the roles of IL-10 in tumor immunosuppression mainly focus on its biochemical effects. But the effects of IL-10 on the biophysical characteristics of immune cells are ill-defined. Dendritic cells (DCs) are the most potent antigen-presenting cells and play a key role in the anti-tumor immune response. IL-10 can affect the immune regulatory functions of DCs in various ways. In this study, we aim to explore the effects of IL-10 on the biophysical functions of mature DCs (mDCs). mDCs were treated with different concentrations of IL-10 and their biophysical characteristics were identified. The results showed that the biophysical properties of mDCs, including electrophoresis mobility, osmotic fragility and deformability, as well as their motilities, were impaired by IL-10. Meanwhile, the cytoskeleton (F-actin) of mDCs was reorganized by IL-10. IL-10 caused the alternations in the expressions of fasin1 and profilin1 as well as the phosphorylation of cofilin1 in a concentration-dependent fashion. Moreover, Fourier transformed infrared resonance data showed that IL-10 made the status of gene transcription and metabolic turnover of mDCs more active. These results demonstrate a new aspect of IL-10’s actions on the immune system and represent one of the mechanisms for immune escape of tumors. It may provide a valuable clue to optimize and improve the efficiency of DC-based immunotherapy against cancer.