Chemokines in tumor development and progression

Integrating bulk RNA-seq and scRNA-seq analyses revealed the function and clinical value of thrombospondins in colon cancer

Background

Acting as mediators in cell-matrix and cell-cell communication, matricellular proteins play a crucial role in cancer progression. Thrombospondins (TSPs), a type of matricellular glycoproteins, are key regulators in cancer biology with multifaceted roles. Although TSPs have been implicated in anti-tumor immunity and epithelial-mesenchymal transition (EMT) in several malignancies, their specific roles to colon cancer remain elusive. Addressing this knowledge gap is essential, as understanding the function of TSPs in colon cancer could identify new therapeutic targets and prognostic markers.

Methods

Analyzing 1981 samples from 10 high-throughput datasets, including six bulk RNA-seq, three scRNA-seq, and one spatial transcriptome dataset, our study investigated the prognostic relevance, risk stratification value, immune heterogeneity, and cellular origin of TSPs, as well as their influence on cancer-associated fibroblasts (CAFs). Utilizing survival analysis, unsupervised clustering, and functional enrichment, along with multiple correlation analyses of the tumor-microenvironment (TME) via Gene Set Variation Analysis (GSVA), spatial localization, Monocle2, and CellPhoneDB, we provided insights into the clinical and cellular implications of TSPs.

Results

First, we observed significant upregulation of THBS2 and COMP in colon cancer, both of which displayed significant prognostic value. Additionally, we detected a significant positive correlation between TSPs and immune cells, as well as marker genes of EMT. Second, based on TSPs expression, patients were divided into two clusters with distinct prognoses: the high TSPs expression group (TSPs-H) was characterized by pronounced immune and stromal cell infiltration, and notably elevated T-cell exhaustion scores. Subsequently, we found that THBS2 and COMP may be associated with the differentiation of CAFs into pan-iCAFs and pan-dCAFs, which are known for their heightened matrix remodeling activities. Moreover, THBS2 enhanced CAFs communication with vascular endothelial cells and monocyte-macrophages. CAFs expressing THBS2 (THBS2+ CAFs) demonstrated higher scores across multiple signaling pathways, including angiogenic, EMT, Hedgehog, Notch, Wnt, and TGF-β, when compared to THBS2- CAFs. These observations suggest that THBS2 may be associated with stronger pro-carcinogenic activity in CAFs.

Conclusions

This study revealed the crucial role of TSPs and the significant correlation between THBS2 and CAFs interactions in colon cancer progression, providing valuable insights for targeting TSPs to mitigate cancer progression.

The multifaceted role of SOX2 in breast and lung cancer dynamics

Breast and lung cancers are leading causes of death among patients, with their global mortality and morbidity rates increasing. Conventional treatments often prove inadequate due to resistance development. The alteration of molecular interactions may accelerate cancer progression and treatment resistance. SOX2, known for its abnormal expression in various human cancers, can either accelerate or impede cancer progression. This review focuses on examining the role of SOX2 in breast and lung cancer development. An imbalance in SOX2 expression can promote the growth and dissemination of these cancers. SOX2 can also block programmed cell death, affecting autophagy and other cell death mechanisms. It plays a significant role in cancer metastasis, mainly by regulating the epithelial-to-mesenchymal transition (EMT). Additionally, an imbalanced SOX2 expression can cause resistance to chemotherapy and radiation therapy in these cancers. Genetic and epigenetic factors may affect SOX2 levels. Pharmacologically targeting SOX2 could improve the effectiveness of breast and lung cancer treatments.

Analyzing the Functional Roles and Immunological Features of Chemokines in COAD

Chemokines are key proteins that regulate cell migration and immune responses and are essential for modulating the tumor microenvironment. Despite their close association with colon cancer, the expression patterns, prognosis, immunity, and specific roles of chemokines in colon cancer are still not fully understood. In this study, we investigated the mutational features, differential expression, and immunological characteristics of chemokines in colon cancer (COAD) by analyzing the Tumor Genome Atlas (TCGA) database. We clarified the biological functions of these chemokines using Gene Ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. By univariate and multivariate COX regression analyses, we developed chemokine-based prognostic risk models. In addition, using Gene Set Enrichment Analysis (GSEA) and Gene Set Variant Analysis (GSVA), we analyzed the differences in immune responses and signaling pathways among different risk groups. The results showed that the mutation rate of chemokines was low in COAD, but 25 chemokines were significantly differentially expressed. These chemokines function in several immune-related biological processes and play key roles in signaling pathways including cytokine-cytokine receptor interactions, NF-kappa B, and IL-17. Prognostic risk models based on CCL22, CXCL1, CXCL8, CXCL9, and CXCL11 performed well. GSEA and GSVA analyses showed significant differences in immune responses and signaling pathways across risk groups. In conclusion, this study reveals the potential molecular mechanisms of chemokines in COAD and proposes a new prognostic risk model based on these insights.

Combination of Anti-Angiogenics and Immunotherapies in Renal Cell Carcinoma Show Their Limits: Targeting Fibrosis to Break through the Glass Ceiling?

This review explores treating metastatic clear cell renal cell carcinoma (ccRCC) through current therapeutic modalities-anti-angiogenic therapies and immunotherapies. While these approaches represent the forefront, their limitations and variable patient responses highlight the need to comprehend underlying resistance mechanisms. We specifically investigate the role of fibrosis, prevalent in chronic kidney disease, influencing tumour growth and treatment resistance. Our focus extends to unravelling the intricate interplay between fibrosis, immunotherapy resistance, and the tumour microenvironment for effective therapy development. The analysis centres on connective tissue growth factor (CTGF), revealing its multifaceted role in ccRCC-promoting fibrosis, angiogenesis, and cancer progression. We discuss the potential of targeting CTGF to address the problem of fibrosis in ccRCC. Emphasising the crucial relationship between fibrosis and the immune system in ccRCC, we propose that targeting CTGF holds promise for overcoming obstacles to cancer treatment. However, we recognise that an in-depth understanding of the mechanisms and potential limitations is imperative and, therefore, advocate for further research. This is an essential prerequisite for the successful integration of CTGF-targeted therapies into the clinical landscape.

Keras/TensorFlow in Drug Design for Immunity Disorders

Homeostasis of the host immune system is regulated by white blood cells with a variety of cell surface receptors for cytokines. Chemotactic cytokines (chemokines) activate their receptors to evoke the chemotaxis of immune cells in homeostatic migrations or inflammatory conditions towards inflamed tissue or pathogens. Dysregulation of the immune system leading to disorders such as allergies, autoimmune diseases, or cancer requires efficient, fast-acting drugs to minimize the long-term effects of chronic inflammation. Here, we performed structure-based virtual screening (SBVS) assisted by the Keras/TensorFlow neural network (NN) to find novel compound scaffolds acting on three chemokine receptors: CCR2, CCR3, and one CXC receptor, CXCR3. Keras/TensorFlow NN was used here not as a typically used binary classifier but as an efficient multi-class classifier that can discard not only inactive compounds but also low- or medium-activity compounds. Several compounds proposed by SBVS and NN were tested in 100 ns all-atom molecular dynamics simulations to confirm their binding affinity. To improve the basic binding affinity of the compounds, new chemical modifications were proposed. The modified compounds were compared with known antagonists of these three chemokine receptors. Known CXCR3 compounds were among the top predicted compounds; thus, the benefits of using Keras/TensorFlow in drug discovery have been shown in addition to structure-based approaches. Furthermore, we showed that Keras/TensorFlow NN can accurately predict the receptor subtype selectivity of compounds, for which SBVS often fails. We cross-tested chemokine receptor datasets retrieved from ChEMBL and curated datasets for cannabinoid receptors. The NN model trained on the cannabinoid receptor datasets retrieved from ChEMBL was the most accurate in the receptor subtype selectivity prediction. Among NN models trained on the chemokine receptor datasets, the CXCR3 model showed the highest accuracy in differentiating the receptor subtype for a given compound dataset.

Infliximab Inhibits Colitis Associated Cancer in Model Mice by Downregulating Genes Associated with Mast Cells and Decreasing Their Accumulation

Inflammatory bowel diseases (IBDs), such as Crohn’s disease or ulcerative colitis, can be treated with anti TNF-alpha (TNF-α) antibodies (Abs), but they also put patients with IBDs at risk of cancer. We aimed to determine whether the anti TNF-α Ab induces colon cancer development in vitro and in vivo, and to identify the genes involved in colitis-associated cancer. We found that TNF-α (50 ng/mL) inhibited the proliferation, migration, and invasion of HCT8 and COLO205 colon cancer cell lines and that anti TNF-α Ab neutralized TNF-α inhibition in vitro. The effects of anti TNF-α Ab, infliximab (10 mg/kg) were investigated in mouse models of colitis-associated cancer induced by intraperitoneally injected azoxymethane (AOM: 10 mg/kg)/orally administered dextran sodium sulfate (DSS: 2.5%) (AOM/DSS) in vivo. Infliximab significantly attenuated the development of colon cancer in these mice. Microarray analyses and RT-qPCR revealed that mast cell protease 1, mast cell protease 2, and chymase 1 were up-regulated in cancer tissue of AOM/DSS mice; however, those mast cell related genes were downregulated in cancer tissue of AOM/DSS mice with infliximab. These results suggested that mast cells play a pivotal role in the development of cancer associated with colitis in AOM/DSS mice.

Identification and validation of a novel prognostic model of inflammation-related gene signature of lung adenocarcinoma

Previous literatures have suggested the importance of inflammatory response during lung adenocarcinoma (LUAD) development. This study aimed at exploring the inflammation-related genes and developing a prognostic signature for predicting the prognosis of LUAD. Survival‑associated inflammation-related genes were identified by univariate Cox regression analysis in the dataset of The Cancer Genome Atlas (TCGA). The least absolute shrinkage and selection operator (LASSO) penalized Cox regression model was used to derive a risk signature which is significantly negatively correlated with OS and divide samples into high-, medium- and low-risk group. Univariate and multivariate Cox analyses suggested that the level of risk group was an independent prognostic factor of the overall survival (OS). Time-dependent receiver operating characteristic (ROC) curve indicated the AUC of 1-, 3- and 5-years of the risk signature was 0.715, 0.719, 0.699 respectively. A prognostic nomogram was constructed by integrating risk group and clinical features. The independent dataset GSE30219 of Gene Expression Omnibus (GEO) was used for verification. We further explored the differences among risk groups in Gene set enrichment analysis (GSEA), tumor mutation and tumor microenvironment. Furthermore, Single Sample Gene Set Enrichment Analysis (ssGSEA) and the results of Cell-type Identification By Estimating Relative Subsets Of RNA Transcripts (CIBERSORT) suggested the status of immune cell infiltration was highly associated with risk groups. We demonstrated the prediction effect of CTLA-4 and PD-1/PD-L1 inhibitors in the low-risk group was better than that in the high-risk group using two methods of immune score include immunophenoscore from The Cancer Immunome Atlas (TCIA) and TIDE score from Tumor Immune Dysfunction and Exclusion (TIDE). In addition, partial targeted drugs and chemotherapy drugs for lung cancer had higher drug sensitivity in the high-risk group. Our findings provide a foundation for future research targeting inflammation-related genes to predictive prognosis and some reference significance for the selection of immunotherapy and drug regimen for lung adenocarcinoma.

The Exploration of Chemokines Importance in the Pathogenesis and Development of Endometrial Cancer

Endometrial cancer (EC) is one of the most frequent female malignancies. Because of a characteristic symptom, vaginal bleeding, EC is often diagnosed in an early stage. Despite that, some EC cases present an atypical course with rapid progression and poor prognosis. There have been multiple studies conducted on molecular profiling of EC in order to improve diagnostics and introduce personalized treatment. Chemokines-a protein family that contributes to inflammatory processes that may promote carcinogenesis-constitute an area of interest. Some chemokines and their receptors present alterations in expression in tumor microenvironment. CXCL12, which binds the receptors CXCR4 and CXCR7, is known for its impact on neoplastic cell proliferation, neovascularization and promotion of epidermal-mesenchymal transition. The CCL2-CCR2 axis additionally plays a pivotal role in EC with mutations in the LKB1 gene and activates tumor-associated macrophages. CCL20 and CCR6 are influenced by the RANK/RANKL pathway and alter the function of lymphocytes and dendritic cells. Another axis, CXCL10-CXCR3, affects the function of NK-cells and, interestingly, presents different roles in various types of tumors. This review article consists of analysis of studies that included the roles of the aforementioned chemokines in EC pathogenesis. Alterations in chemokine expression are described, and possible applications of drugs targeting chemokines are reviewed.

Role of the CCL2-CCR2 signalling axis in cancer: Mechanisms and therapeutic targeting

The chemokine ligand CCL2 and its receptor CCR2 are implicated in the initiation and progression of various cancers. CCL2 can activate tumour cell growth and proliferation through a variety of mechanisms. By interacting with CCR2, CCL2 promotes cancer cell migration and recruits immunosuppressive cells to the tumour microenvironment, favouring cancer development. Over the last several decades, a series of studies have been conducted to explore the CCL2-CCR2 signalling axis function in malignancies. Therapeutic strategies targeting the CCL2- CCR2 axis have also shown promising effects, enriching our approaches for fighting against cancer. In this review, we summarize the role of the CCL2-CCR2 signalling axis in tumorigenesis and highlight recent studies on CCL2-CCR2 targeted therapy, focusing on preclinical studies and clinical trials.

Association of gene and protein expression and genetic polymorphism of CC chemokine ligand 4 in colorectal cancer

BACKGROUND

Leukocytes, such as T cells and macrophages, play an important role in tumorigenesis. CC chemokine ligand (CCL) 4, which is produced by lymphocytes and macrophages, has been found to be expressed in the mucosa of the gastrointestinal tract and is a potent chemoattractant for various leukocytes.

AIM

To examine CCL4 expression and its genetic polymorphism rs10491121 in patients with colorectal cancer (CRC) and evaluate their prognostic significance.

METHODS

Luminex technology was used to determine CCL4 Levels in CRC tissue (n = 98), compared with paired normal tissue, and in plasma from patients with CRC (n = 103), compared with healthy controls (n = 97). Included patients had undergone surgical resection for primary colorectal adenocarcinomas between 1996 and 2019 at the Department of Surgery, Ryhov County Hospital, Jönköping, Sweden. Reverse transcription quantitative PCR was used to investigate the CCL4 gene expression in CRC tissue (n = 101). Paired normal tissue and TaqMan single nucleotide polymorphism assays were used for the CCL4 rs10491121 polymorphism in 610 CRC patients and 409 healthy controls.

RESULTS

The CCL4 protein and messenger RNA expression levels were higher in CRC tissue than in normal paired tissue (90%, P < 0.001 and 45%, P < 0.05, respectively). CRC tissue from patients with localized disease had 2.8-fold higher protein expression levels than that from patients with disseminated disease. Low CCL4 protein expression levels in CRC tissue were associated with a 30% lower cancer-specific survival rate in patients (P < 0.01). The level of plasma CCL4 was 11% higher in CRC patients than in healthy controls (P < 0.05) and was positively correlated (r = 0.56, P < 0.01) with the CCL4 protein level in CRC tissue. The analysis of CCL4 gene polymorphism rs10491121 showed a difference (P < 0.05) between localized disease and disseminated disease in the right colon, with a dominance of allele A in localized disease. Moreover, the rate of the A allele was higher among CRC patients with mucinous cancer than among those with non-mucinous cancer.

CONCLUSION

The present study indicates that the CRC tissue levels of CCL4 and CCL4 gene polymorphism rs10491121, particularly in the right colon, are associated with clinical outcome in CRC patients.

Generating CAR T cells from tumor-infiltrating lymphocytes

Background: Tumor-infiltrating lymphocytes (TILs) and chimeric antigen receptor (CAR) T-cell therapies have demonstrated promising, though limited, efficacy against melanoma. Methods: We designed a model system to explore the efficacy of dual specific T cells derived from melanoma patient TILs by transduction with a Her2-specific CAR. Results: Metastatic melanoma cells in our biobank constitutively expressed Her2 antigen. CAR-TIL produced greater amounts of IFN compared with parental TIL, when co-cultured with Her2 expressing tumor lines, including autologous melanoma tumor lines, although no consistent increase in cytotoxicity by TIL was afforded by expression of a CAR. Results of an in vivo study in NSG mice demonstrated tumor shrinkage when CAR-TILs were used in an adoptive cell therapy protocol. Conclusion: Potential limitations of transduced TIL in our study included limited proliferative potential and a terminally differentiated phenotype, which would need addressing in further work before consideration of clinical translation.

Global analysis of lysine acetylome reveals the potential role of CCL18 in non-small cell lung cancer

C-C motif chemokine 18 (CCL18) belongs to the chemokine CC family and is predominantly secreted by M2-tumor-associated macrophages. It has been reported to be associated with various diseases and malignancies. Previous studies showed that CCL18 promotes metastasis by activating downstream kinases. However, it remains unknown whether CCL18 regulates post-translational modifications, other than phosphorylation, during tumorigenesis. Here, we demonstrate that CCL18 is up-regulated in non-small cell lung cancer (NSCLC) and is involved in regulating the lysine acetylome in A549 cells. Using the combination of SILAC labeling and high-efficiency acetylation enrichment methods, we identified 1372 lysine acetylation (Kac) sites on 796 proteins in CCL18-treated A549 cells. Among the identified Kac sites, 147 from 126 proteins were down-regulated and seven from five proteins were up-regulated with fold changes more than two and the p-value less than 0.05. Bioinformatics analysis further showed that the proteins with down-regulated acetylation play critical roles in glycolysis, oxidative phosphorylation, tricarboxylic acid cycle, and pentose phosphate pathway in A549 cells. These results suggest that CCL18 may be involved in the development of NSCLC by regulating acetylation of the proteins in many fundamental cellular processes, especially the metabolic reprogramming of tumor cells.

Exploration of the relationship between tumor mutation burden and immune infiltrates in colon adenocarcinoma

Background: Tumor mutation burden (TMB) was correlated with the immunotherapeutic response in various malignancies. We aimed to evaluate the TMB immune signature in colon adenocarcinoma (COAD). Methods: Gene expression profile, mutation and clinical data of COAD patients were obtained from The Cancer Genome Atlas (TCGA) database. The samples were divided into high and low TMB level groups to identify differentially expressed genes (DEGs). Functional enrichments analyzes were performed to identify the biological functions of the DEGs. Then, immune cell infiltration signatures were calculated by the CIBERSORT algorithm. Finally, Cox proportional hazard model was constructed to estimate the prognostic value of the identified immune-related genes. Results: Gene set enrichment analysis in the high-TMB level group showed that DEGS were enriched in immune-related pathways, such as antigen processing and presentation, Toll-like receptor signaling and natural killer cell-mediated cytotoxicity. A higher infiltration level of CD8+ T cells, CD4+ T cells, activated NK cells , M1 Macrophages and T follicular helper cells was observed in the high-TMB level group. Furthermore, a Cox regression model combined with survival analysis based on the expression level of four identified prognostic genes was constructed, validated anf revealed that higher risk-score levels conferred poor survival outcomes in COAD patients. Conclusions: Our data demonstrate that the high TMB levels are associated with an immune signature in COAD and deepen the molecular understanding of TMB function in tumor immunotherapy.

Prevention of CaCl2-induced aortic inflammation and subsequent aneurysm formation by the CCL3-CCR5 axis

Inflammatory mediators such as cytokines and chemokines are crucially involved in the development of abdominal aortic aneurysm (AAA). Here we report that CaCl₂ application into abdominal aorta induces AAA with intra-aortic infiltration of macrophages as well as enhanced expression of chemokine (C-C motif) ligand 3 (CCL3) and MMP-9. Moreover, infiltrating macrophages express C-C chemokine receptor 5 (CCR5, a specific receptor for CCL3) and MMP-9. Both Ccl3^−/− mice and Ccr5^−/− but not Ccr1^−/− mice exhibit exaggerated CaCl₂-inducced AAA with augmented macrophage infiltration and MMP-9 expression. Similar observations are also obtained on an angiotensin II-induced AAA model. Immunoneutralization of CCL3 mimics the phenotypes observed in CaCl₂-treated Ccl3^−/− mice. On the contrary, CCL3 treatment attenuates CaCl₂-induced AAA in both wild-type and Ccl3^−/− mice. Consistently, we find that the CCL3–CCR5 axis suppresses PMA-induced enhancement of MMP-9 expression in macrophages. Thus, CCL3 can be effective to prevent the development of CaCl₂-induced AAA by suppressing MMP-9 expression.

Inflammatory cytokines and chemokines are involved in the development of abdominal aortic aneurysm (AAA). Here the authors show that CCL3 prevents the development of CaCl₂-induced AAA by suppressing MMP-9 expression.

Cytoplasmic CCR7 (CCR7c) immunoexpression is associated with local tumor recurrence in triple-negative breast cancer

BACKGROUND

Triple-negative breast cancer (TNBC) is a subtype of cancer, which tests negative for estrogen receptors, progesterone receptors, and lacks overexpression of the human epidermal growth factor 2 (C-erbB2, HER2/neu) gene. The expression of chemokines and their receptors, including CCR7, has been described in several types of cancer, contributing to tumor progression.

AIM OF THE STUDY

This study investigated the association between the membrane and cytoplasmic CCR7 expression and the prognosis of TNBC.

MATERIALS AND METHODS

Surgical paraffin histopathology blocks and clinico-pathological data were assessed from 133 patients. Samples were analyzed by immunohistochemistry and immunofluorescence using the Tissue Microarray technique for scoring the intensity of CCR7 expression.

RESULTS

TNBC patients in which the CCR7 labeling was predominantly in the cytoplasm of tumor cells presented increased local tumor recurrence (P = 0.033). Conversely, there was no statistical difference in five-year overall survival between the patients with low (77%) versus high (80%) cytoplasmic CCR7 expression (P = 0.7104). Additionally, the risk of death between these groups was 1.19 (95% CI = 0.48-2.91).

CONCLUSION

The cytoplasmic CCR7 expression associates with an increased incidence of tumor relapse in TNBC, not affecting patients survival. Consequently, the cell compartment in which the CCR7 localizes could serve as a prognostic marker in this cancer subtype.

Identification of Prognostic Immune-Related Genes in Pancreatic Adenocarcinoma and Establishment of a Prognostic Nomogram: A Bioinformatic Study

BACKGROUND

The prognosis of pancreatic adenocarcinoma (PAAD) is extremely poor and has not been improved. Thus, an effective method to assess the prognosis of patients must be established to improve their survival rate.

METHOD

This study investigated immune-related genes that could be used as potential therapeutic targets for PAAD. Level 3 gene expression data from the PAAD cohort and the relevant clinical information were obtained from The Cancer Genome Atlas (TCGA) database. For validation, other PAAD datasets (DSE62452) were downloaded from the Gene Expression Omnibus (GEO) database. The PAAD datasets from TCGA and GEO were used to screen immune-related genes through the Molecular Signatures Database using gene set enrichment analysis. Then, the overlapping immune-related genes of the two datasets were identified. Coexpression networks of the immune-related genes were constructed.

RESULTS

A signature of three immune-related genes (CKLF, ERAP2, and EREG) was identified in patients with PAAD. The signature could be used to divide the patients with PAAD into high- and low-risk groups based on their median risk score. Multivariate Cox regression analysis was performed to determine the independent prognostic factors of PAAD. Time-dependent receiver operating characteristic (ROC) curve analysis was conducted to assess the prediction accuracy of the prognostic signature. Last, a nomogram was established to assess the individualized prognosis prediction model based on the clinical characteristics and risk score of the TCGA PAAD dataset. The accuracy of the prognostic signature was further evaluated through functional evaluation and principal component analysis.

CONCLUSIONS

The results indicated that the signature of three immune-related genes had excellent predictive value for PAAD. These findings might help improve personalized treatment and medical decisions.

CCL4 Signaling in the Tumor Microenvironment

CCL4, a CC chemokine, previously known as macrophage inflammatory protein (MIP)-1β, has diverse effects on various types of immune and nonimmune cells by the virtue of its interaction with its specific receptor, CCR5, in collaboration with related but distinct CC chemokines such as CCL3 and CCL5, which can also bind CCR5. Several lines of evidence indicate that CCL4 can promote tumor development and progression by recruiting regulatory T cells and pro-tumorigenic macrophages, and acting on other resident cells present in the tumor microenvironment, such as fibroblasts and endothelial cells, to facilitate their pro-tumorigenic capacities. These observations suggest the potential efficacy of CCR5 antagonists for cancer treatment. On the contrary, under some situations, CCL4 can enhance tumor immunity by recruiting cytolytic lymphocytes and macrophages with phagocytic ability. Thus, presently, the clinical application of CCR5 antagonists warrants more detailed analysis of the role of CCL4 and other CCR5-binding chemokines in the tumor microenvironment.

Optimization of the process for purifying icariin from Herba Epimedii by macroporous resin and the regulatory role of icariin in the tumor immune microenvironment

Pancreatic cancer is a digestive tract malignancy that poses a serious threat to human health. Compounds derived from traditional Chinese medicines have been an important source of anticancer drugs and adjuvant agents to regulate the tumor immune microenvironment in patients with pancreatic cancer. In this study, icariin was purified from Herba Epimedii using macropores, and its bioactivity against pancreatic cancer was also investigated. We found that icariin has direct inhibitory and immunomodulatory effects on tumor cells. In vitro experiments showed that icariin can inhibit the migration and proliferation of Panc02 pancreatic cancer cells and induce apoptosis. Our in vivo experiments show that icariin inhibits the development of mouse pancreatic cancer by inhibiting tumor-infiltrating M2 macrophages and polymorphonuclear myeloid-derived suppressor cells (MDSCs) (PMN-MDSCs). In addition, icariin inhibits the polarization of RAW 264.7 cells into M2 macrophages by inhibiting the expression of ARG1 and MRC1 and downregulating the IL4-STAT6 signaling pathway. In conclusion, the inhibitory effect of icariin on pancreatic cancer can not only directly affect tumor cells but also inhibit tumor development by regulating the tumor immune microenvironment.

CXC chemokine ligand 1 mediates adiponectin-induced angiogenesis in ovarian cancer

OBJECTIVES

Adiponectin is a cytokine secreted from adipose tissue that regulates energy homeostasis, inflammation, and cell proliferation. Obesity is associated with increased risk of various cancers, including ovarian cancer. Adipokines, including adiponectin, have been implicated as a factor linking obesity and carcinogenesis. The oncogenic role of adiponectin is not known with regard to various cancer types. We sought to determine the role of adiponectin in angiogenesis in ovarian cancer in vitro.

METHODS

We transfected SKOV3 cells with vascular endothelial growth factor small interfering RNA in order to identify the independent angiogenic role of adiponectin in ovarian cancer. The vascular endothelial growth factor knockdown SKOV3 cell lines were treated with adiponectin for 48 h. The cytokines involved in adiponectin-mediated angiogenesis were explored using the human angiogenesis cytokine array and were verified with the enzyme-linked immunosorbent assay. The angiogenic effect of adiponectin was evaluated using the human umbilical vein endothelial cell tube formation assay. We also investigated the effects of adiponectin treatment on the migration and invasion of SKOV3 cells.

RESULTS

The number of tubes formed by human umbilical vein endothelial cell decreased significantly after knockdown of vascular endothelial growth factor (via transfection of vascular endothelial growth factor small interfering RNA into SKOV3 cells). When these vascular endothelial growth factor knockdown SKOV3 cells were treated with adiponectin, there was an increase in the number of tubes in a tube formation assay. Following adiponectin treatment, the CXC chemokine ligand 1 secretion increased in a cytokine array. This was confirmed by both enzyme-linked immunosorbent assay and Western blot. The increased secretion of CXC chemokine ligand 1 by adiponectin occurred regardless of vascular endothelial growth factor knockdown. In addition, the induction of migration and invasion of SKOV3 cells were significantly stronger with adiponectin treatment than they were without.

CONCLUSION

Adiponectin treatment of ovarian cancer cells induces angiogenesis via CXC chemokine ligand 1 independently of vascular endothelial growth factor. These findings suggest that adiponectin may serve as a novel therapeutic target for ovarian cancer.

Regulation of Chemokines and Cytokines by Histone Deacetylases and an Update on Histone Decetylase Inhibitors in Human Diseases

Histone acetyltransferases (HATs) and histone deacetylases (HDACs) counteract with each other to regulate gene expression by altering chromatin structure. Aberrant HDAC activity was reported in many human diseases including wide range of cancers, viral infections, cardiovascular complications, auto-immune diseases and kidney diseases. HDAC inhibitors are small molecules designed to block the malignant activity of HDACs. Chemokines and cytokines control inflammation, immunological and other key biological processes and are shown to be involved in various malignancies. Various HDACs and HDAC inhibitors were reported to regulate chemokines and cytokines. Even though HDAC inhibitors have remarkable anti-tumor activity in hematological cancers, they are not effective in treating many diseases and many patients relapse after treatment. However, the role of HDACs and cytokines in regulating these diseases still remain unclear. Therefore, understanding exact mechanisms and effector functions of HDACs are urgently needed to selectively inhibit them and to establish better a platform to combat various malignancies. In this review, we address regulation of chemokines and cytokines by HDACs and HDAC inhibitors and update on HDAC inhibitors in human diseases.

Targeting CXCL12/CXCR4 Axis in Tumor Immunotherapy

Chemokines, which have chemotactic abilities, are comprised of a family of small cytokines with 8-10 kilodaltons. Chemokines work in immune cells by trafficking and regulating cell proliferation, migration, activation, differentiation, and homing. CXCR-4 is an alpha-chemokine receptor specific for stromal-derived-factor-1 (SDF-1, also known as CXCL12), which has been found to be expressed in more than 23 different types of cancers. Recently, the SDF-1/CXCR-4 signaling pathway has emerged as a potential therapeutic target for human tumor because of its critical role in tumor initiation and progression by activating multiple signaling pathways, such as ERK1/2, ras, p38 MAPK, PLC/ MAPK, and SAPK/ JNK, as well as regulating cancer stem cells. CXCL12/CXCR4 antagonists have been produced, which have shown encouraging results in anti-cancer activity. Here, we provide a brief overview of the CXCL12/CXCR4 axis as a molecular target for cancer treatment. We also review the potential utility of targeting CXCL12/CXCR4 axis in combination of immunotherapy and/or chemotherapy based on up-to-date literature and ongoing research progress.

CXCL16/CXCR6 Axis Drives Microglia/Macrophages Phenotype in Physiological Conditions and Plays a Crucial Role in Glioma

Microglia are patrolling cells that sense changes in the brain microenvironment and respond acquiring distinct phenotypes that can be either beneficial or detrimental for brain homeostasis. Anti-inflammatory microglia release soluble factors that might promote brain repair; however, in glioma, anti-inflammatory microglia dampen immune response and promote a brain microenvironment that foster tumor growth and invasion. The chemokine CXCL16 is expressed in the brain, where it is neuroprotective against brain ischemia, and it has been found to be over-expressed in glioblastoma (GBM). Considering that CXCL16 specific receptor CXCR6 is diffusely expressed in the brain including in microglia cells, we wanted to investigate the role of CXCL16 in the modulation of microglia cell activity and phenotype, and in the progression of glioma. Here we report that CXCL16 drives microglia polarization toward an anti-inflammatory phenotype, also restraining microglia polarization toward an inflammatory phenotype upon LPS and IFNγ stimulation. In the context of glioma, we demonstrate that CXCL16 released by tumor cells is determinant in promoting glioma associated microglia/macrophages (GAMs) modulation toward an anti-inflammatory/pro-tumor phenotype, and that cxcr6ko mice, orthotopically implanted into the brain with GL261 glioma cells,survive longer compared to wild-type mice. We also describe that CXCL16/CXCR6 signaling acts directly on mouse glioma cells, as well as human primary GBM cells, promoting tumor cell growth, migration and invasion. All together these data suggest that CXCL16 signaling could represent a good target to modulate microglia phenotype in order to restrain inflammation or to limit glioma progression.

Expression of the Chemokine Receptor CXCR3 Correlates with Dendritic Cell Recruitment and Prognosis in Gastric Cancer

AIM

The aim of this study was to investigate whether CXCR3 expression is associated with: infiltration of dendritic cells (DCs) and CD4+ and CD8+ tumor-infiltrating lymphocytes (TILs); various clinical features; and overall survival (OS) of patients diagnosed with gastric cancer (GC).

MATERIALS AND METHODS

The study included 169 GC specimens and 91 corresponding paracancerous tissues. Immunohistochemistry was conducted to determine the expression of CXCR3 and the presence of DCs and CD4+ and CD8+ TILs. Statistical analyses were done using SPSS 17.0 software.

RESULTS

CXCR3 expression in GC tissues was significantly higher than in paracancerous tissues (p < 0.001). Higher CXCR3 expression was associated with increased DC and both CD8+ and CD4+ TIL infiltration (p = 0.003, p = 0.008, and p = 0.016, respectively). In contrast, low CXCR3 expression was correlated with greater tumor invasion depth, III/IV TNM stage, lymph node metastasis, and more poorly differentiated tumor cells in GC patients (p = 0.001, p = 0.005, p = 0.037, and p = 0.004, respectively). Univariate analysis indicated that patients with high CXCR3 expression and high DC and CD8+ TIL infiltration had longer OS (log-rank test, p < 0.001, p = 0.018, and p = 0.001, respectively). Univariate and multivariate analyses indicated that CXCR3 expression was an independent prognostic factor for OS (p < 0.001, in both cases).

CONCLUSION

The results of this study indicate that CXCR3 overexpression in GC is associated with increased DC and TIL infiltration and improved OS, and thus could be further exploited as a biomarker of favorable prognosis and a therapeutic target in GC.

Chemokines and their receptors in lung cancer progression and metastasis

Lung cancer is the leading cause of cancer-related mortality around the world. Despite advancements in diagnosis, surgical techniques, and neoadjuvant chemoradiotherapy over the last decade, the mortality rate is still high and the 5-year survival is a dismal 15%. Fortunately, early detection by low-dose computed tomography (LDCT) scans has reduced mortality by 20%; yet, overall, 5-year-survival remains low at less than 20%. Therefore, in order to ameliorate this situation, a thorough understanding of the underlying molecular mechanisms is urgently needed. Chemokines and their receptors, crucial microenvironmental factors, play important roles in lung tumor genesis, progression, and metastasis, and exploring the mechanisms of this might bring new insights into early diagnosis and precisely targeted treatment. Consequently, this review will mainly focus on recent advancements on the axes of chemokines and their receptors of lung cancer.

Chemokine (C‑C motif) ligand 21/C‑C chemokine receptor type 7 triggers migration and invasion of human lung cancer cells by epithelial‑mesenchymal transition via the extracellular signal‑regulated kinase signaling pathway

C-C chemokine receptor type 7 (CCR7) has been implicated in lymph node metastasis of various cancers. Previous studies have revealed that epithelial-mesenchymal transition (EMT) is involved in the chemotactic process mediated by CCR7 and its ligands in various types of carcinoma. However, the underlying mechanism of this process remains to be fully elucidated. The present study investigated whether chemokine (C-C motif) ligand 21 (CCL21)/CCR7 may activate EMT of lung cancer cells and their associated signaling pathways. A549 and H520 lung cancer cell lines were examined in vitro in the present study. The results indicated that A549 and H520 expressed CCR7, but reduced levels of CCL21. Following stimulation of lung cancer cell lines with CCL21, the expression of the epithelial marker E-cadherin was downregulated, and the mesenchymal markers Vimentin/Slug and extracellular signal-regulated kinase (ERK) were upregulated. In addition, the ERK inhibitor PD98059 may inhibit EMT caused by CCL21, and decreased cell migration and invasion initiated by CCL21. Furthermore, lung adenocarcinoma tissues from 50 patients who underwent lung cancer operations were investigated by immunohistochemistry. The findings revealed that CCR7, Slug and Vimentin were highly expressed in lung carcinoma tissues, and were significantly associated with lymph node metastasis and clinical pathological stages, respectively. CCR7 expression was correlated positively with expression levels of Slug and Vimentin. CCL21 was expressed positively in the endothelium of lymphatic vessels adjacent to cancer cells, and weakly in lung cancer cells. Collectively, these results demonstrated that CCL21/CCR7 may activate EMT in lung cancer cells via the ERK1/2 signaling pathway. The current study provides evidence that a close interaction exists between CCL21/CCR7chemotaxis and EMT procedures in lung cancer metastasis, providing a basis for the development of therapeutic targets.

CCL2/CCR2 signaling pathway in glioblastoma multiforme

Glioblastoma multiform (GBM) is described as one of the most frequent primary brain tumors. These types of malignancies constitute only 15% of all primary brain tumors. Despite, extensive developments on effective therapeutic methods during the 20th century as well as the first decade of the present century (21st), the median survival rate for patients suffering from GBM is only approximately 15 months, even in response to multi-modal therapy. numerous types of reticuloendothelial system cells such as macrophages and microglial cells occupied within both GBM and also normal surrounding tissues. These immune cells acquire an otherwise activated phenotype with potent tumor-tropic functions that contribute to the glioma growth and invasion. The CC chemokine, CCL2 (previously named MCP-1) is of the most important CC chemokines family member involving in regulation of oriented migration and penetrative infiltration of mainly reticuloendothelial system cells specifically monocyte/macrophage phenotypes. Fundamental parts are played by CCL2 and its related receptor (the CCR2) in brain tumors and obviously in migration of monocytes from the bloodstream through the vascular endothelium. Therefore, CCL2/CCR2 axis is required for the routine immunological surveillance of tissues, in accordance with response to inflammation. Briefly, in this review, we have tried our best to collect the latest, straightened and summarize literature reports exist within data base regarding the interaction between microglia/macrophages and CCL2/CCR2 axis in GBM. We aimed to discuss potential application of this chemokine/receptor interaction axis for the expansion of future anti-glioma therapies as well.

Analysis of the prognostic role of an immune checkpoint score in resected non-small cell lung cancer patients

Tumors develop mechanisms to recruit tolerogenic immune cells and to induce the expression of molecules that act as immune checkpoints. This regulation of the immune microenvironment favors immune tolerance to the neoplastic cells. In this study, we have investigated the prognostic role of immune-checkpoint expression markers in a cohort of resectable non-small cell lung cancer (NSCLC) patients. RNA was isolated from fresh-frozen lung specimens (tumor and normal lung) (n = 178). RTqPCR was performed to analyze the relative expression of 20 immune-related genes that were normalized by the use of endogenous genes selected by GeNorm algorithm. Patients with higher expression levels of IL23A and LGALS2 presented better outcomes. In the clustering expression patterns, we observed that patients with higher expression of immunoregulatory genes had better survival rates. Additionally, these data were used to develop a gene expression score. Since CTLA4 and PD1 were associated with prognosis based on Cox regression analysis (Z-score > 1.5), a multivariate model including these two genes was created. Absolute regression coefficients from this analysis were used in order to calculate the immune-checkpoint score: (PD1×0.116) + (CTLA4×0.059) for each case. Kaplan-Meier survival analysis showed that patients with high immune-checkpoint score have longer overall survival (OS) [NR vs. 40.4 mo, p = 0.008] and longer relapse-free survival (RFS) [82.6 vs. 23 mo, p = 0.009]. Multivariate analysis in the entire cohort indicated that the immune-checkpoint score was an independent biomarker of prognosis for OS [HR: 0.308; 95% CI, 0.156-0.609; p = 0.001] and RFS [HR: 0.527; 95% CI, 0.298-0.933; p = 0.028] in early-stage NSCLC patients. In conclusion, this score provides relevant prognostic information for a better characterization of early stage NSCLS patients with strikingly different outcomes and who may be candidates for immune-based therapies.

CCL2 as a potential therapeutic target for clear cell renal cell carcinoma

We previously reported that the pVHL‐atypical PKC‐JunB pathway contributed to promotion of cell invasiveness and angiogenesis in clear cell renal cell carcinoma (ccRCC), and we detected chemokine (C‐C motif) ligand‐2 (CCL2) as one of downstream effectors of JunB. CCL2 plays a critical role in tumorigenesis in other types of cancer, but its role in ccRCC remains unclear. In this study, we investigated the roles and therapeutic potential of CCL2 in ccRCC. Immunohistochemical analysis of CCL2 expression for ccRCC specimens showed that upregulation of CCL2 expression correlated with clinical stage, overall survival, and macrophage infiltration. For functional analysis of CCL2 in ccRCC cells, we generated subclones of WT8 cells that overexpressed CCL2 and subclones 786‐O cells in which CCL2 expression was knocked down. Although CCL2 expression did not affect cell proliferation in vitro, CCL2 overexpression enhanced and CCL2 knockdown suppressed tumor growth, angiogenesis, and macrophage infiltration in vivo. We then depleted macrophages from tumor xenografts by administration of clodronate liposomes to confirm the role of macrophages in ccRCC. Depletion of macrophages suppressed tumor growth and angiogenesis. To examine the effect of inhibiting CCL2 activity in ccRCC, we administered CCL2 neutralizing antibody to primary RCC xenografts established from patient surgical specimens. Inhibition of CCL2 activity resulted in significant suppression of tumor growth, angiogenesis, and macrophage infiltration. These results suggest that CCL2 is involved in angiogenesis and macrophage infiltration in ccRCC, and that CCL2 could be a potential therapeutic target for ccRCC.

Proteomic-Based Approaches for the Study of Cytokines in Lung Cancer

Proteomic techniques are currently used to understand the biology of different human diseases, including studies of the cell signaling pathways implicated in cancer progression, which is important in knowing the roles of different proteins in tumor development. Due to its poor prognosis, proteomic approaches are focused on the identification of new biomarkers for the early diagnosis, prognosis, and targeted treatment of lung cancer. Cytokines are proteins involved in inflammatory processes and have been proposed as lung cancer biomarkers and therapeutic targets because it has been reported that some cytokines play important roles in tumor development, invasion, and metastasis. In this review, we aim to summarize the different proteomic techniques used to discover new lung cancer biomarkers and therapeutic targets. Several cytokines have been identified as important players in lung cancer using these techniques. We underline the most important cytokines that are useful as biomarkers and therapeutic targets. We also summarize some of the therapeutic strategies targeted for these cytokines in lung cancer.

Fibroblasts, an inconspicuous but essential player in colon cancer development and progression

Tumor microenvironments have a crucial role in cancer initiation and progression, and share many molecular and pathological features with wound healing process. Unless treated, tumors, however, do not heal in contrast to wounds that heal within a limited time framework. Wounds heal in coordination of a myriad of types of cells, particularly endothelial cells, leukocytes, and fibroblasts. Similar sets of cells also contribute to cancer initiation and progression, and as a consequence, anti-cancer treatment strategies have been proposed and tested by targeting endothelial cells and/or leukocytes. Compared with endothelial cells and leukocytes, less attention has been paid to the roles of cancer-associated fibroblasts (CAFs), fibroblasts present in tumor tissues, because their heterogeneity hinders the elucidation on them at cellular and molecular levels. Here, we will discuss the origin of CAFs and their crucial roles in cancer initiation and progression, and the possibility to develop a novel type of anti-cancer treatment by manipulating the migration and functions of CAFs.

Oncogenic roles and drug target of CXCR4/CXCL12 axis in lung cancer and cancer stem cell

Although the great progress has been made in diagnosis and therapeutic in lung cancer, it induces the most cancer death worldwide in both males and females. Chemokines, which have chemotactic abilities, contain up to 50 family members. By binding to G protein-coupled receptors (GPCR), holding seven-transmembrane domain, they function in immune cell trafficking and regulation of cell proliferation, differentiation, activation, and migration, homing under both physiologic and pathologic conditions. The alpha-chemokine receptor CXCR4 for the alpha-chemokine stromal cell-derived-factor-1 (SDF-1) is most widely expressed by tumors. In addition to human tissues of the bone marrow, liver, adrenal glands, and brain, the CXC chemokine SDF-1 or CXCL12 is also highly expressed in lung cancer tissues and is associated with lung metastasis. Lung cancer cells have the capabilities to utilize and manipulate the CXCL12/CXCR system to benefit growth and distant spread. CXCL12/CXCR4 axis is a major culprit for lung cancer and has a crucial role in lung cancer initiation and progression by activating cancer stem cell. This review provides an evaluation of CXCL12/CXCR4 as the potential therapeutic target for lung cancers; it also focuses on the synergistic effects of inhibition of CXCL12/CXCR4 axis and immunotherapy as well as chemotherapy. Together, CXCL12/CXCR4 axis can be a potential therapeutic target for lung cancers and has additive effects with immunotherapy.

CCR9 in cancer: oncogenic role and therapeutic targeting

Cancer is currently one of the leading causes of death worldwide and is one of the most challenging major public health problems. The main challenges faced by clinicians in the management and treatment of cancer mainly arise from difficulties in early diagnosis and the emergence of tumor chemoresistance and metastasis. The structures of chemokine receptor 9 (CCR9) and its specific ligand chemokine ligand 25 (CCL25) have been elucidated, and, interestingly, a number of studies have demonstrated that CCR9 is a potential tumor biomarker in diagnosis and therapy, as it has been found to be highly expressed in a wide range of cancers. This expression pattern suggests that CCR9 may participate in many important biological activities involved in cancer progression. Researchers have shown that CCR9 that has been activated by its specific ligand CCL25 can interact with many signaling pathways, especially those involved in tumor chemoresistance and metastasis. This review, therefore, focuses on CCR9 induction activity and summarizes what is currently known regarding its role in cancers and its potential application in tumor-targeted therapy.

Osteopontin-integrin interaction as a novel molecular target for antibody-mediated immunotherapy in adult T-cell leukemia

Background

Adult T-cell leukemia (ATL) is a CD4⁺ T-cell neoplasm with a poor prognosis. A previous study has shown that there is a strong correlation between the secreted matricellular protein osteopontin (OPN) level and disease severity in ATL patients. Here, we investigated the role of OPN in ATL pathogenesis and the possible application of anti-OPN monoclonal antibody (mAb) for ATL immunotherapy in NOD/Shi-scid,IL-2Rg^null (NOG) mice.

Results

Subcutaneous inoculation of ATL cell lines into NOG mice increased the plasma level of OPN, which significantly correlated with metastasis of the inoculated cells and survival time. Administration of an SVVYGLR motif-recognizing anti-OPN mAb resulted in inhibition not only of tumor growth but also of tumor invasion and metastasis. The number of fibroblast activating protein-positive fibroblasts was also reduced by this mAb. We then co-inoculated mouse embryonic fibroblasts (MEFs) isolated from wild-type (WT) or OPN knockout mice together with ATL-derived TL-OmI cells into the NOG mice. The mice co-inoculated with WT MEFs displayed a significant decrease in survival relative to those injected with TL-OmI cells alone and the absence of OPN in MEFs markedly improved the survival rate of TL-OmI-inoculated mice. In addition, tumor volume and metastasis were also reduced in the absence of OPN.

Conclusion

We showed that the xenograft NOG mice model can be a useful system for assessment of the physiological role of OPN in ATL pathogenesis. Using this xenograft model, we found that fibroblast-derived OPN was involved in tumor growth and metastasis, and that this tumor growth and metastasis was significantly suppressed by administration of the anti-OPN mAbs. Our findings will lead to a novel mAb-mediated immunotherapeutic strategy targeting against the interaction of OPN with integrins on the tumor of ATL patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s12977-015-0225-x) contains supplementary material, which is available to authorized users.

TNF-α increases the membrane expression of the chemokine receptor CCR6 in thyroid tumor cells, but not in normal thyrocytes: potential role in the metastatic spread of thyroid cancer

The chemokine receptor CCR6, selectively bound by CCL20, is involved in the metastatic spread of cancer cells. Tumor necrosis factor-α (TNF-α) displays a complex pro-tumorigenic actions, but it is unknown whether this cytokine could modulate the expression of chemokine receptors in thyroid tumors. The membrane expression of CCR6 was assessed by flow cytometry and immunofluorescence, in primary cultures of normal human thyroid (NHT) cells and in thyroid cancer cell lines (TPC-1 and BCPAP), both in basal conditions and after stimulation with TNF-α. In basal conditions, CCR6+ cells were virtually absent in NHT cells (0.4 ± 0.4 %), while they were detected in TPC-1 (23.6 ± 6.6 %) and in BCPAP (12.9 ± 9.4 %) tumor cells (ANOVA F: 10.534; p < 0.005). The incubation with TNF-α significantly increased the percentage of CCR6+ cells in TPC-1 (23.6 ± 6.6 % vs. 33.1 ± 8.7; p < 0.033) and in BCPAP (12.9 ± 9.4 % vs. 18.1 ± 11.5; p < 0.030), but not in NHT (0.4 ± 0.4 % vs. 0.2 ± 0.3; NS) cells. The magnitude of the TNF-α effect was similar for TPC-1 and BCPAP (∼40 % vs. baseline) cells. TPC-1 cells were characterized by a greater amount of CCR6 per cell as compared with BCPAP cells, both in basal conditions (148.3 ± 33.7 fluorescence intensity vs. 102.5 ± 22.1 p < 0.016) and after TNF-α stimulation (147.8 ± 46.3 fluorescence intensity vs. 95.3 ± 18.5; p < 0.025). Cell migration assays showed that TNF-α treatment significantly increased the rate of migrated cells in those cells in which it also increased the membrane expression of CCR6 (TPC-1 and BCPAP) as compared to basal condition (p < 0.05 for both TPC-1 and BCPAP cells). No effect was observed in NHT cells in which TNF-α stimulation had no effect in terms of CCR6 expression. We first report that TNF-α enhances the expression of CCR6 in thyroid tumor cells, thus providing evidence that TNF-α increases the metastatic potential of thyroid tumors.

Overexpression of the chemokine receptor CXCR3 and its correlation with favorable prognosis in gastric cancer

Chemokine receptor, CXCR3, has been increasingly reported to be involved in tumorigenesis and tumor progression, but limited data are available regarding the expression of CXCR3 in gastric cancer (GC). In the present study, the expressions of CXCR3 and its variants were detected in 96 GC and corresponding nontumor gastric tissues by immunohistochemical staining, in 40 freshly frozen GC and nontumor gastric tissues by reverse-transcription polymerase chain reaction and quantitative real-time polymerase chain reaction, and in 10 freshly frozen GC and nontumor gastric tissues by Western blotting. Results revealed that an overexpression of CXCR3 occurs in GC tissues as compared to the nontumor gastric tissues. High level of CXCR3 expression was found to be inversely associated with invasion depth and metastasis (P = .030 and P = .019, respectively) and directly associated with improved overall survival (log-rank test, P < .001). Furthermore, multivariate analysis showed that high CXCR3 expression acts an independent prognostic factor for GC patients (hazard ratio, 0.379 [0.196-0.734]; P = .004). The messenger RNA expression of both the CXCR3 variants, CXCR3-A and CXCR3-B, were up-regulated in GC tissues (P = .006 and P = .002, respectively), although CXCR3-B messenger RNA expression was significantly higher than CXCR3-A, with an average CXCR3-B to CXCR3-A ratio of 1.80. CXCR3-B protein expression was also up-regulated in GC tissues (P = .023). In conclusion, our study suggested a potential use of CXCR3 overexpression as a prognostic marker for GC and involvement of the up-regulation of CXCR3-B in favorable prognosis of GC patients.

Role of Chemokines in Non-Small Cell Lung Cancer: Angiogenesis and Inflammation

Non-small cell lung cancer (NSCLC) is one of the most common types of aggressive cancer. The tumor tissue, which shows an active angiogenesis, is composed of neoplastic and stromal cells, and an abundant inflammatory infiltrate. Angiogenesis is important to support tumor growth, while infiltrating cells contribute to the tumor microenvironment through the secretion of growth factors, cytokines and chemokines, important molecules in the progression of the disease. Chemokines are important in development, activation of the immune response, and physiological angiogenesis. Chemokines have emerged as important regulators in the pathophysiology of cancer. These molecules are involved in the angiogenesis/angiostasis balance and in the recruitment of tumor infiltrating hematopoietic cells. In addition, chemokines promote tumor cell survival, as well as the directing and establishment of tumor cells to metastasis sites. The findings summarized here emphasize the central role of chemokines as modulators of tumor angiogenesis and their potential role as therapeutic targets in the inflammatory process of NSCLC angiogenesis.

Matrix metalloproteases as maestros for the dual role of LPS- and IL-10-stimulated macrophages in cancer cell behaviour

Background

The interactions established between macrophages and cancer cells are largely dependent on instructions from the tumour microenvironment. Macrophages may differentiate into populations with distinct inflammatory profiles, but knowledge on their role on cancer cell activities is still very scarce. In this work, we investigated the influence of pro-inflammatory (LPS-stimulated) and anti-inflammatory (IL-10-stimulated) macrophages on gastric and colorectal cancer cell invasion, motility/migration, angiogenesis and proteolysis, and the associated molecular mechanisms.

Methods

Following exposure of gastric and colon cancer cell lines to LPS- and IL-10-stimulated human macrophages, either by indirect contact or conditioned media, we analyzed the effect of the different macrophage populations on cancer cell invasion, migration, motility and phosphorylation status of EGFR and several interacting partners. Cancer-cell induced angiogenesis upon the influence of conditioned media from both macrophage populations was assessed using the chick embryo chorioallantoic membrane assay. MMP activities were evaluated by gelatin zymograhy.

Results

Our results show that IL-10-stimulated macrophages are more efficient in promoting in vitro cancer cell invasion and migration. In addition, soluble factors produced by these macrophages enhanced in vivo cancer cell-induced angiogenesis, as opposed to their LPS-stimulated counterparts. We further demonstrate that differences in the ability of these macrophage populations to stimulate invasion or angiogenesis cannot be explained by the EGFR-mediated signalling, since both LPS- and IL-10-stimulated macrophages similarly induce the phosphorylation of cancer cell EGFR, c-Src, Akt, ERK1/2, and p38. Interestingly, both populations exert distinct proteolytic activities, being the IL-10-stimulated macrophages the most efficient in inducing matrix metalloprotease (MMP)-2 and MMP-9 activities. Using a broad-spectrum MMP inhibitor, we demonstrated that proteolysis was essential for macrophage-mediated cancer cell invasion and angiogenesis.

Conclusions

We propose that IL-10- and LPS-stimulated macrophages distinctly modulate gastric and colorectal cancer cell behaviour, as result of distinct proteolytic profiles that impact cell invasion and angiogenesis.

p53-dependent expression of CXCR5 chemokine receptor in MCF-7 breast cancer cells

Elevated expression of chemokine receptors in tumors has been reported in many instances and is related to a number of survival advantages for tumor cells including abnormal activation of prosurvival intracellular pathways. In this work we demonstrated an inverse correlation between expression levels of p53 tumor suppressor and CXCR5 chemokine receptor in MCF-7 human breast cancer cell line. Lentiviral transduction of MCF-7 cells with p53 shRNA led to elevated CXCR5 at both mRNA and protein levels. Functional activity of CXCR5 in p53-knockdown MCF-7 cells was also increased as shown by activation of target gene expression and chemotaxis in response to B-lymphocyte chemoattractant CXCL13. Using deletion analysis and site-directed mutagenesis of the cxcr5 gene promoter and enhancer elements, we demonstrated that p53 appears to act upon cxcr5 promoter indirectly, by repressing the activity of NFκB transcription factors. Using chromatin immunoprecipitation and reporter gene analysis, we further demonstrated that p65/RelA was able to bind the cxcr5 promoter in p53-dependent manner and to directly transactivate it when overexpressed. Through the described mechanism, elevated CXCR5 expression may contribute to abnormal cell survival and migration in breast tumors that lack functional p53.

The Intricate Interplay between Mechanisms Underlying Aging and Cancer

Age is the major risk factor in the incidence of cancer, a hyperplastic disease associated with aging. Here, we discuss the complex interplay between mechanisms underlying aging and cancer as a reciprocal relationship. This relationship progresses with organismal age, follows the history of cell proliferation and senescence, is driven by common or antagonistic causes underlying aging and cancer in an age-dependent fashion, and is maintained via age-related convergent and divergent mechanisms. We summarize our knowledge of these mechanisms, outline the most important unanswered questions and suggest directions for future research.

Chemokine receptor-specific antibodies in cancer immunotherapy: achievements and challenges

The 1990s brought a burst of information regarding the structure, expression pattern, and role in leukocyte migration and adhesion of chemokines and their receptors. At that time, the FDA approved the first therapeutic antibodies for cancer treatment. A few years later, it was reported that the chemokine receptors CXCR4 and CCR7 were involved on directing metastases to liver, lung, bone marrow, or lymph nodes, and the over-expression of CCR4, CCR6, and CCR9 by certain tumors. The possibility of inhibiting the interaction of chemokine receptors present on the surface of tumor cells with their ligands emerged as a new therapeutic approach. Therefore, many research groups and companies began to develop small molecule antagonists and specific antibodies, aiming to neutralize signaling from these receptors. Despite great expectations, so far, only one anti-chemokine receptor antibody has been approved for its clinical use, mogamulizumab, an anti-CCR4 antibody, granted in Japan to treat refractory adult T-cell leukemia and lymphoma. Here, we review the main achievements obtained with anti-chemokine receptor antibodies for cancer immunotherapy, including discovery and clinical studies, proposed mechanisms of action, and therapeutic applications.

F-box protein FBXW7 inhibits cancer metastasis in a non-cell-autonomous manner

The gene encoding F-box protein FBXW7 is frequently mutated in many human cancers. Although most previous studies have focused on the tumor-suppressive capacity of FBXW7 in tumor cells themselves, we determined that FBXW7 in the host microenvironment also suppresses cancer metastasis. Deletion of Fbxw7 in murine BM-derived stromal cells induced accumulation of NOTCH and consequent transcriptional activation of Ccl2. FBXW7-deficient mice exhibited increased serum levels of the chemokine CCL2, which resulted in the recruitment of both monocytic myeloid-derived suppressor cells and macrophages, thereby promoting metastatic tumor growth. Administration of a CCL2 receptor antagonist blocked the enhancement of metastasis in FBXW7-deficient mice. Furthermore, in human breast cancer patients, FBXW7 expression in peripheral blood was associated with serum CCL2 concentration and disease prognosis. Together, these results suggest that FBXW7 antagonizes cancer development in not only a cell-autonomous manner, but also a non-cell-autonomous manner, and that modulation of the FBXW7/NOTCH/CCL2 axis may provide a potential approach to suppression of cancer metastasis.

CCL21/CCR7 axis activating chemotaxis accompanied with epithelial-mesenchymal transition in human breast carcinoma

Secondary lymphoid tissue chemokine (SLC/CCL21) and its receptor CCR7 have been implicated in lymph node metastasis, whereas the mechanism of which remains unclear. Epithelial-mesenchymal transition (EMT) plays an important role in invasion and migration of cancer cells. We presumed that CCL21/CCR7 axis activates EMT process to induce cancer cell invasion and metastasis. Firstly, the expressions of CCR7 and EMT markers were examined by immunohistochemical staining in the primary breast carcinoma tissues from 60 patients who underwent radical mastectomy. Then, we investigated whether CCL21/CCR7 induces EMT process during mediating cancer cell invasion or migration in vitro. By immunohistolochemistry, high expressions of CCR7, Slug and N-cadherin were seen in 60, 65, and 76.67 % of tumors, respectively, and significantly associated with lymph node metastases as well as clinical pathological stage. Furthermore, the CCR7 expression was significantly correlated to Slug and N-cadherin. In vitro, stimulating breast cancer cell lines 1428, MCF-7 and MDA-MB-231 with CCL21, the invasion and migration of tumor cells were promoted, and simultaneously, EMT phenotype of tumor cells was enhanced, including down-regulation of E-cadherin, up-regulation of Slug, Vimentin and N-cadherin at both protein and mRNA levels. Inversely, knockdown of CCR7 by shRNA suppressed tumor cell invasion, migration and EMT phenotype induced by CCL21. These results indicated that CCL21/CCR7 axis could activate EMT process during chemotaxis of breast carcinoma cells.

CCL20/CCR6 promotes the invasion and migration of thyroid cancer cells via NF-kappa B signaling-induced MMP-3 production

CCL20, an important member of the CC-chemokine family, is the only ligand that activates CCR6. The levels of CCL20 and CCR6 are elevated in many human cancers, and CCL20/CCR6 interaction participates in the development and progression of cancer. In this present study, we found that CCR6 was overexpressed in thyroid cancer cells. Activation of CCR6 by CCL20 promoted the invasion and migration of human thyroid cancer SW1736 cells, while knockdown of CCR6 repressed the effect of CCL20. Furthermore, CCL20/CCR6 interaction induced the activation of NF-κB, and stimulated the expression and secretion of MMP-3. In addition, BAY117082, a special inhibitor of NF-κB, suppressed the expression and secretion of MMP-3 stimulated by CCL20/CCR6. Together, these results suggest that CCL20/CCR6 enhances thyroid cancer cell invasion and migration. The possible molecular mechanisms involved NF-κB activation and NF-κB-dependent MMP-3 upregulation. Thus, molecular therapies that aim at CCL20 and CCR6 may offer promising intervention strategies for thyroid cancer.