Identification of CXCL5/ENA-78 as a factor involved in the interaction between cholangiocarcinoma cells and cancer-associated fibroblasts

CXCL5 expression is associated with active signals of macrophages in the microenvironment of papillary thyroid carcinoma

BACKGROUND

C-X-C motif chemokine ligand 5 (CXCL5) is a chemokine molecule that is secreted by immune cells in attracting granulocytes. Studies showed that CXCL5 was related to the progression of papillary thyroid carcinoma (PTC) tumor cells. However, the in vivo effects of CXCL5 on PTC tumor cells and their microenvironment have not been elucidated. The present study aimed to investigate the biological effects of CXCL5 on tumor cells, microenvironment, and clinical progression of PTC.

MATERIALS AND METHODS

The PTC patients from The Human Cancer Genome Atlas (TCGA) - thyroid carcinoma (THCA) were retrieved. There were a total of 500 patients who met the criteria of our study. Differential expression (DEA) and pathway analyses were used to explore the biological effects of CXCL5 gene expression.

RESULTS

In DEA, we found that CXCL5 was mostly associated with PBPP, SLC11A1, and MRC1 (adjusted p<0.001). Samples with CXCL5 FPKM≥1 were related to a different immune profile (p<0.001). In pathway analyses, samples with higher CXCL5 expression possessed higher activities of RAS-RAF, NF-kB, PRC2, IL2, IL5, and Wnt pathways (adjusted p<0.001). In microenvironment analysis, CXCL5 was highly correlated with the activity of macrophage (Rho=0.76; adjusted p<0.001). Clinically, high level of CXCL5 expression was an indicator of tumor stages (p<0.001), nodal metastasis (AUC=0.68), and prognosis (p=0.001).

CONCLUSION

CXCL5 was a significant biomarker of PTC. CXCL5 was highly associated with tumor immunology and microenvironment. Samples with higher CXCL5 expression had more advanced disease status and worse prognosis. CXCL5 target therapy is potentially helpful in advanced PTC.

Heterogeneity, crosstalk, and targeting of cancer-associated fibroblasts in cholangiocarcinoma

Cholangiocarcinoma (CCA) comprises diverse tumors of the biliary tree and is characterized by late diagnosis, short-term survival, and chemoresistance. CCAs are mainly classified according to their anatomical location and include diverse molecular subclasses harboring inter-tumoral and intratumoral heterogeneity. Besides the tumor cell component, CCA is also characterized by a complex and dynamic tumor microenvironment where tumor cells and stromal cells crosstalk in an intricate network of interactions. Cancer-associated fibroblasts, one of the most abundant cell types in the tumor stroma of CCA, are actively involved in cholangiocarcinogenesis by participating in multiple aspects of the disease including extracellular matrix remodeling, immunomodulation, neo-angiogenesis, and metastasis. Despite their overall tumor-promoting role, recent evidence indicates the presence of transcriptional and functional heterogeneous CAF subtypes with tumor-promoting and tumor-restricting properties. To elucidate the complexity and potentials of cancer-associated fibroblasts as therapeutic targets in CCA, this review will discuss the origin of cancer-associated fibroblasts, their heterogeneity, crosstalk, and role during tumorigenesis, providing an overall picture of the present and future perspectives toward cancer-associated fibroblasts targeting CCA.

Heterogeneity of Cholangiocarcinoma Immune Biology

Cholangiocarcinomas (CCAs) are aggressive tumors arising along the biliary tract epithelium, whose incidence and mortality are increasing. CCAs are highly desmoplastic cancers characterized by a dense tumor microenvironment (TME), in which each single component plays a fundamental role in shaping CCA initiation, progression and resistance to therapies. The crosstalk between cancer cells and TME can affect the recruitment, infiltration and differentiation of immune cells. According to the stage of the disease and to intra- and inter-patient heterogeneity, TME may contribute to either protumoral or antitumoral activities. Therefore, a better understanding of the effect of each immune cell subtype may open the path to new personalized immune therapeutic strategies for the management of CCA. In this review, we describe the role of immune cells in CCA initiation and progression, and their crosstalk with both cancer-associated fibroblasts (CAFs) and the cancer-stem-cell-like (CSC) niche.

Targeting CXCL5 in Pancreatic Cancer Cells Inhibits Cancer Xenograft Growth by Reducing Proliferation and Inhibiting EMT Progression

BACKGROUND

Pancreatic cancer (PC) is the most lethal malignant tumor, with average survival period of about 10 months. C-X-C ligand 5 (CXCL5), an important chemokine for immune cell accumulation in tumor tissues, has been reported to be involved in a variety of human cancers. However, the exact role of CXCL5 in PC progression has not been well defined.

METHODS

The expression of CXCL5 in PC was analyzed based on online databases and clinical specimens immunohistochemical staining, and Western blotting of CXCL5 in PC cell lines and patient samples. The correlation between CXCL5 expression and prognosis in PC was explored. The role of CXCL5 in PC was investigated through in vitro and in vivo experiments.

RESULTS

The expression of CXCL5 was significantly increased in PC tissues compared with that in pancreas tissues, and CXCL5 high expression predicts poor prognosis in PC patients. Further analyses demonstrated that overexpression of CXCL5 in PC cells was positively related to higher proliferation rate, higher migration ability, and higher EMT markers including SNAI2 and TWIST1 of tumor cells in vitro. Consistently, the knockdown of CXCL5 in PC cells harmed the proliferation rate, migration ability, and expression of EMT indexes of tumor cells in vitro. Importantly, knockdown of CXCL5 inhibited the growth of xenograft tumors in vivo.

CONCLUSION

CXCL5 high expression predicts poor prognosis in PC patients. CXCL5 promotes PC cell growth and EMT process. Inhibition of CXCL5 may be a potential therapeutic approach for PC.

Survival impact of immune cells infiltrating peritumoral area of hepatocellular carcinoma

Inflammatory and immune cells in the tumor microenvironment are reported to be associated with tumor progression in several cancers. In total, 225 patients who underwent initial and curative hepatectomy for hepatocellular carcinoma (HCC) from 2004 to 2013 were enrolled in this study. Tumor-associated neutrophils (TANs), M2 macrophages (TAMs; tumor-associated macrophages), CD8⁺ T cells, and regulatory T cells (Tregs) were evaluated by immunohistochemistry (IHC), and their relationships with patient clinicopathological characteristics and prognosis were evaluated. IHC was performed focusing on TANs first. We could not find a relationship between intratumoral and peritumoral TANs and clinicopathological features except for the fibrous capsule and infiltration of tumors into capsule. Next, TAMs, CD8⁺ cells and Tregs were evaluated by IHC. At the peritumoral area, TANs and TAMs (r = 0.36, p = 0.001) or Tregs (r = 0.16, p = 0.008) showed a positive correlation, whereas TANs and CD8⁺ cells showed a negative correlation (r = -0.16, p = 0.02). As for survival outcomes, at the peritumoral area, high TANs (p = 0.0398), low CD8⁺ cells (p = 0.0275), and high TAMs (p = 0.001) were significantly associated with worse overall survival (OS). In addition, high TANs (p = 0.010), and high TAMs (p = 0.00125) were significantly associated with worse disease-free survival (DFS). Finally, we established a risk signature model by combining the expression patterns of these cells. The high-risk signature group had significantly worse OS (p = 0.0277) and DFS (p = 0.0219) compared with those in the low-risk signature group. Our risk signature based on immune cells at the peritumoral area of the HCC can predict patient prognosis of HCC after curative hepatectomy.

Advances of cancer-associated fibroblasts in liver cancer

Liver cancer is one of the most common malignant tumors worldwide, it is ranked sixth in incidence and fourth in mortality. According to the distinct origin of malignant tumor cells, liver cancer is mainly divided into hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA). Since most cases are diagnosed at an advanced stage, the prognosis of liver cancer is poor. Tumor growth depends on the dynamic interaction of various cellular components in the tumor microenvironment (TME). As the most abundant components of tumor stroma, cancer-associated fibroblasts (CAFs) have been involved in the progression of liver cancer. The interplay between CAFs and tumor cells, immune cells, or vascular endothelial cells in the TME through direct cell-to-cell contact or indirect paracrine interaction, affects the initiation and development of tumors. Additionally, CAFs are not a homogeneous cell population in liver cancer. Recently, single-cell sequencing technology has been used to help better understand the diversity of CAFs in liver cancer. In this review, we mainly update the knowledge of CAFs both in HCC and CCA, including their cell origins, chemoresistance, tumor stemness induction, tumor immune microenvironment formation, and the role of tumor cells on CAFs. Understanding the context-dependent role of different CAFs subsets provides new strategies for precise liver cancer treatment.

High Expression of Bloom Syndrome Helicase is a Key Factor for Poor Prognosis and Advanced Malignancy in Patients with Pancreatic Cancer: A Retrospective Study

BACKGROUND

Bloom syndrome helicase (BLM) is overexpressed in multiple types of cancers and its overexpression may induce genomic instability. This study aimed to determine the function of BLM expression in pancreatic cancer.

METHODS

BLM messenger RNA (mRNA) expression was analyzed using public datasets to determine its relationship with pancreatic cancer prognosis. Overall, 182 patients with pancreatic cancer who underwent radical resection at our institution were enrolled. BLM expression was evaluated by immunohistochemistry (IHC). We explored the effect of BLM on the proliferation, invasion, migration, and chemoresistance of pancreatic cancer cells via small-interfering RNAs and performed pathway analysis using gene set enrichment analysis.

RESULTS

BLM mRNA expression was higher in tumor tissue than in normal tissue and had a prognostic effect on overall survival (OS) and recurrence-free survival. The same results were validated by IHC. Multivariate analysis showed that high BLM expression was an independent poor prognostic factor for OS (hazard ratio [HR] 1.678, p = 0.029). In subgroup analysis, the effect of high BLM expression was more significant on OS in patients with younger age (HR 2.27, p = 0.006), male sex (HR 2.39, p = 0.002), high cancer antigen 19-9 level (HR 2.44, p = 0.001), advanced tumor stage (HR 2.25, p = 0.001), lymph node metastasis (HR 2.51, p = 0.001), nerve invasion (HR 2.07, p = 0.002), and adjuvant chemotherapy (HR 2.66, p < 0.001). In vitro, BLM suppression resulted in reduced tumor proliferation, invasion, migration, and chemoresistance. Mechanistically, BLM expression may be associated with E2F1 and E2F2.

CONCLUSION

BLM expression is a prognostic factor for patients with pancreatic cancer, especially in those with advanced malignancies and receiving chemotherapy.

Molecular Subgroups of Intrahepatic Cholangiocarcinoma Discovered by Single-Cell RNA Sequencing-Assisted Multi-Omics Analysis

Intrahepatic cholangiocarcinoma (ICC) is a relatively rare but highly aggressive tumor type that responds poorly to chemotherapy and immunotherapy. Comprehensive molecular characterization of ICC is essential for the development of novel therapeutics. Here, we constructed two independent cohorts from two clinic centers. A comprehensive multi-omics analysis of ICC via proteomic, whole-exome sequencing (WES), and single-cell RNA sequencing (scRNA-seq) was performed. Novel ICC tumor subtypes were derived in the training cohort (n=110) using proteomic signatures and their associated activated pathways, which was further validated in a validation cohort (n=41). Three molecular subtypes, chromatin remodeling, metabolism, and chronic inflammation, with distinct prognoses in ICC were identified. The chronic inflammation subtype associated with a poor prognosis. Our random forest algorithm revealed that mutation of lysine methyltransferase 2D (KMT2D) frequently occurred in the metabolism subtype and associated with lower inflammatory activity. scRNA-seq further identified an APOE+C1QB+ macrophage subtype, which showed the capacity to reshape the chronic inflammation subtype and contribute to a poor prognosis in ICC. Altogether, with single-cell transcriptome-assisted multi-omics analysis, we identified novel molecular subtypes of ICC and validated APOE+C1QB+ tumor-associated macrophages (TAMs) as potential immunotherapy targets against ICC.

CXCR2 signaling might have a tumor-suppressive role in patients with cholangiocarcinoma

BACKGROUND

We reported that chemokine C-X-C motif receptor 2 (CXCR2) signaling appears to play an important role in the pathogenic signaling of gastric cancer (GC), and although CXCR2 may have a role in other solid cancers, the significance of CXCR2 in cholangiocarcinoma (CCA) has not been evaluated. Herein, we determined the clinicopathologic significance of CXCL1-CXCR2 signaling in CCA.

MATERIALS AND METHODS

Two human CCA cell lines, OCUG-1 and HuCCT1, were used. CXCR2 expression was examined by western blotting. We investigated the effects of CXCL1 on the proliferation (by MTT assay) and migration activity (by a wound-healing assay) of each cell line. Our immunohistochemical study of the cases of 178 CCA patients examined the expression levels of CXCR2 and CXCL1, and we analyzed the relationship between these expression levels and the patients' clinicopathologic features.

RESULTS

CXCR2 was expressed on both CCA cell lines. CXCL1 significantly inhibited both the proliferative activity and migratory activity of both cell lines. CXCL1 and CXCR2 were immunohistochemically expressed in 73% and 18% of the CCA cases, respectively. The CXCL1-positive group was significantly associated with negative lymph node metastasis (p = 0.043). The CXCR2-positive group showed significantly better survival (p = 0.042, Kaplan-Meier). A multivariate logistic regression analysis revealed that CXCR2 expression (p = 0.031) and lymph node metastasis (p = 0.004) were significantly correlated with the CCA patients' overall survival.

CONCLUSION

CXCR2 signaling might exert a tumor-suppressive effect on CCA cells. CXCR2 might be a useful independent prognostic marker for CCA patients after surgical resection.

Inflammatory pathways and cholangiocarcinoma risk mechanisms and prevention

Cholangiocarcinoma (CCA), a neoplasm burdened by a poor prognosis and currently lacking adequate therapeutic treatments, can originate at different levels of the biliary tree, in the intrahepatic, hilar, or extrahepatic area. The main risk factors for the development of CCA are the presence of chronic cholangiopathies of various etiology. To date, the most studied prodromal diseases of CCA are primary sclerosing cholangitis, Caroli's disease and fluke infestations, but other conditions, such as metabolic syndrome, nonalcoholic fatty liver disease and obesity, are emerging as associated with an increased risk of CCA development. In this review, we focused on the analysis of the pro-inflammatory mechanisms that induce the development of CCA and on the role of cells of the immune response in cholangiocarcinogenesis. In very recent times, these cellular mechanisms have been the subject of emerging studies aimed at verifying how the modulation of the inflammatory and immunological responses can have a therapeutic significance and how these can be used as therapeutic targets.

CXCL5/NF-κB Pathway as a Therapeutic Target in Hepatocellular Carcinoma Treatment

Background

Hepatocellular carcinoma (HCC) is a common malignant cancer worldwide. CXCL5 has a role in inhibiting cell viability and metastasis in many tumors. In the present study, we investigated the role of CXCL5 in HCC and explored the underlying mechanism. Material and Methods. RT-qPCR and western blot were performed to evaluate the mRNA and protein levels of CXCL5. CCK-8 and transwell assay were applied to measure the proliferative and invasive abilities. Meanwhile, the Kaplan–Meier method was used to assess the survival of HCC patients.

Results

CXCL5 was upregulated in HCC tissues, which predicted a shorter overall survival in HCC. CXCL5 was a target gene of miR-577, and its expression was mediated by miR-577 in HCC. Knockdown of CXCL5 suppressed HuH-7 cell proliferation, invasion, and EMT and inhibited the NF-κB signaling pathway in cells. Moreover, knockdown of CXCL5 inhibited the xenograft growth of HuH-7 cells.

Conclusion

Overexpression of CXCL5 predicts poor prognosis in HCC patients. Knockdown of CXCL5 inhibits cell proliferation and invasion through the NF-κB signaling pathway in HCC. The newly identified role of the CXCL5/miR-577/NF-κB axis provides novel insights into the targeted therapy of HCC.

CD40-mediated immune cell activation enhances response to anti-PD-1 in murine intrahepatic cholangiocarcinoma

BACKGROUND & AIMS

While cholangiocarcinomas (CCAs) commonly express programmed cell death 1 (PD-1) and its ligand (PD-L1), they respond poorly to immune checkpoint inhibitors (ICIs). We aimed to determine whether stimulating antigen-presenting cells, including macrophages and dendritic cells, using a CD40 agonist could improve this response.

METHODS

We compared treatment responses in subcutaneous, orthotopic, and 2 plasmid-based murine intrahepatic CCA (iCCA) models. Mice were treated for 4 weeks with weekly IgG control, a CD40 agonistic antibody, anti-PD-1, or the combination of both (anti-CD40/PD-1). Flow cytometric (FACS) analysis of lymphocytes and myeloid cell populations (including activation status) was performed. We used dendritic cell knockout mice, and macrophage, CD4⁺ and CD8⁺ T cell depletion models to identify effector cells. Anti-CD40/PD-1 was combined with chemotherapy (gemcitabine/cisplatin) to test for improved therapeutic efficacy.

RESULTS

In all 4 models, anti-PD-1 alone was minimally efficacious. Mice exhibited a moderate response to CD40 agonist monotherapy. Combination anti-CD40/PD-1 therapy led to a significantly greater reduction in tumor burden. FACS demonstrated increased number and activation of CD4⁺ and CD8⁺ T cells, natural killer cells, and myeloid cells in tumor and non-tumor liver tissue of tumor-bearing mice treated with anti-CD40/PD-1. Depletion of macrophages, dendritic cells, CD4+ T cells, or CD8+ T cells abrogated treatment efficacy. Combining anti-CD40/PD-1 with gemcitabine/cisplatin resulted in a significant survival benefit compared to gemcitabine/cisplatin alone.

CONCLUSION

CD40-mediated activation of macrophages and dendritic cells in iCCA significantly enhances response to anti-PD-1 therapy. This regimen may enhance the efficacy of first-line chemotherapy.

LAY SUMMARY

Checkpoint inhibition, a common form of immune therapy, is generally ineffective for the treatment of cholangiocarcinoma. These tumors suppress the infiltration and function of surrounding immune cells. Stimulating immune cells such as macrophages and dendritic cells via the CD40 receptor activates downstream immune cells and enhances the response to checkpoint inhibitors.

TWEAK/Fn14 signalling promotes cholangiocarcinoma niche formation and progression

BACKGROUND & AIMS

Cholangiocarcinoma (CCA) is a cancer of the hepatic bile ducts that is rarely resectable and is associated with poor prognosis. Tumour necrosis factor-like weak inducer of apoptosis (TWEAK) is known to signal via its receptor fibroblast growth factor-inducible 14 (Fn14) and induce cholangiocyte and myofibroblast proliferation in liver injury. We aimed to characterise its role in CCA.

METHODS

The expression of the TWEAK ligand and Fn14 receptor was assessed immunohistochemically and by bulk RNA and single cell transcriptomics of human liver tissue. Spatiotemporal dynamics of pathway regulation were comprehensively analysed in rat and mouse models of thioacetamide (TAA)-mediated CCA. Flow cytometry, qPCR and proteomic analyses of CCA cell lines and conditioned medium experiments with primary macrophages were performed to evaluate the downstream functions of TWEAK/Fn14. In vivo pathway manipulation was assessed via TWEAK overexpression in NICD/AKT-induced CCA or genetic Fn14 knockout during TAA-mediated carcinogenesis.

RESULTS

Our data reveal TWEAK and Fn14 overexpression in multiple human CCA cohorts, and Fn14 upregulation in early TAA-induced carcinogenesis. TWEAK regulated the secretion of factors from CC-SW-1 and SNU-1079 CCA cells, inducing polarisation of proinflammatory CD206+ macrophages. Pharmacological blocking of the TWEAK downstream target chemokine monocyte chemoattractant protein 1 (MCP-1 or CCL2) significantly reduced CCA xenograft growth, while TWEAK overexpression drove cancer-associated fibroblast proliferation and collagen deposition in the tumour niche. Genetic Fn14 ablation significantly reduced inflammatory, fibrogenic and ductular responses during carcinogenic TAA-mediated injury.

CONCLUSION

These novel data provide evidence for the action of TWEAK/Fn14 on macrophage recruitment and phenotype, and cancer-associated fibroblast proliferation in CCA. Targeting TWEAK/Fn14 and its downstream signals may provide a means to inhibit CCA niche development and tumour growth.

LAY SUMMARY

Cholangiocarcinoma is an aggressive, chemotherapy-resistant liver cancer. Interactions between tumour cells and cells that form a supportive environment for the tumour to grow are a source of this aggressiveness and resistance to chemotherapy. Herein, we describe interactions between tumour cells and their supportive environment via a chemical messenger, TWEAK and its receptor Fn14. TWEAK/Fn14 alters the recruitment and type of immune cells in tumours, increases the growth of cancer-associated fibroblasts in the tumour environment, and is a potential target to reduce tumour formation.

CXCL5/CXCR2 axis in tumor microenvironment as potential diagnostic biomarker and therapeutic target

The components of the tumor microenvironment (TME) in solid tumors, especially chemokines, are currently attracting much attention from scientists. C-X-C motif chemokine ligand 5 (CXCL5) is one of the important chemokines in TME. Overexpression of CXCL5 is closely related to the survival time, recurrence and metastasis of cancer patients. In TME, CXCL5 binds to its receptors, such as C-X-C motif chemokine receptor 2 (CXCR2), to participate in the recruitment of immune cells and promote angiogenesis, tumor growth, and metastasis. The CXCL5/CXCR2 axis can act as a bridge between tumor cells and host cells in TME. Blocking the transmission of CXCL5/CXCR2 signals can increase the sensitivity and effectiveness of immunotherapy and slow down tumor progression. CXCL5 and CXCR2 are also regarded as biomarkers for predicting prognosis and molecular targets for customizing the treatment. In this review, we summarized the current literature regarding the biological functions and clinical significance of CXCL5/CXCR2 axis in TME. The possibility to use CXCL5 and CXCR2 as potential prognostic biomarkers and therapeutic targets in cancer is also discussed.

High ARHGEF2 (GEF-H1) Expression is Associated with Poor Prognosis Via Cell Cycle Regulation in Patients with Pancreatic Cancer

BACKGROUND

Pancreatic cancer has an extremely poor prognosis, even after curative resection. Treatment options for pancreatic cancer remain limited, therefore new therapeutic targets are urgently needed. We searched for genes predictive of poor prognosis in pancreatic cancer using a public database and validated the survival impact of the selected gene in a patient cohort.

METHODS

We used a public database to search for genes associated with early pancreatic cancer recurrence. As a validation cohort, 201 patients who underwent radical resection in our institution were enrolled. Expression of the target gene was evaluated using immunohistochemistry (IHC). We evaluated growth and invasiveness using small interfering RNAs, then performed pathway analysis using gene set enrichment analysis.

RESULTS

We extracted ARHGEF2 from GSE21501 as a gene with a high hazard ratio (HR) for early recurrence within 1 year. The high ARHGEF2 expression group had significantly poorer recurrence-free survival (RFS) and poorer overall survival (OS) than the low ARHGEF2 expression group. Multivariate analysis demonstrated that high ARHGEF2 expression was an independent poor prognostic factor for RFS (HR 1.92) and OS (HR 1.63). In vitro, ARHGEF2 suppression resulted in reduced cell growth and invasiveness. Bioinformatic analysis revealed that ARHGEF2 expression was associated with MYC, G2M, E2F, and CDC25A expression, suggesting that c-Myc and cell cycle genes are associated with high ARHGEF2 expression. IHC revealed a positive correlation between ARHGEF2 and c-Myc expression.

CONCLUSIONS

High ARHGEF2 expression is associated with cell cycle progression, and predicts early recurrence and poor survival in patients with pancreatic cancer.

CXCL5 expression in tumor tissues is associated with poor prognosis in patients with pancreatic cancer

Immunotherapy based on the tumor microenvironment is a feasible method for treating cancer; therefore, it is necessary to investigate the immune microenvironment of pancreatic cancer and the influencing factors of the immune microenvironment. Chemokines are an important factor affecting the tumor immune microenvironment. In the present study, chemokines or chemokine receptors were screened to identify those differentially expressed in pancreatic cancer compared with normal controls and associated with patient prognosis. Chemokines or chemokine receptors that are differentially expressed in pancreatic cancer tumor tissues were initially screened using the Gene Expression Omnibus database. Next, survival analysis was performed using GEPIA, a website based on The Cancer Genome Atlas (TCGA) database. Immunohistochemical staining of CXCL5 was performed in tissue microarrays (TMAs) containing 119 cases of pancreatic cancer. Histochemistry score (H-SCORE) was used to evaluate the expression of CXCL5. Next, association analysis of the H-SCORE of CXCL5 and the clinical characteristics of patients was performed, as well as Kaplan-Meier survival and Cox multivariate regression analyses. The results of the bioinformatics analysis demonstrated that CXCL5 was highly expressed in pancreatic cancer tissues. High expression of CXCL5 in pancreatic cancer tissues was associated with a poor prognosis in patients in TCGA cohort. The expression level of CXCL5 in tumor tissues was significantly higher compared with that in adjacent peritumoral normal tissues in the immunohistochemical analysis. There was no significant association between CXCL5 expression in pancreatic cancer tumor tissues and clinicopathological factors. Patients with pancreatic cancer with high CXCL5 expression had a poor prognosis, as determined by Kaplan-Meier survival analysis based on the TMA dataset. The results of Cox multivariate regression analysis showed that CXCL5 was an independent factor for a poor prognosis in patients with pancreatic cancer. In conclusion, the results of the present study revealed that the chemokine CXCL5 was highly expressed in pancreatic cancer tissues; high CXCL5 expression was associated with a poor prognosis in patients with pancreatic cancer.

Role of Chemokines in the Biology of Cholangiocarcinoma

Cholangiocarcinoma (CCA), a heterogeneous tumor with poor prognosis, can arise at any level in the biliary tree. It may derive from epithelial cells in the biliary tracts and peribiliary glands and possibly from progenitor cells or even hepatocytes. Several risk factors are responsible for CCA onset, however an inflammatory milieu nearby the biliary tree represents the most common condition favoring CCA development. Chemokines play a key role in driving the immunological response upon liver injury and may sustain tumor initiation and development. Chemokine receptor-dependent pathways influence the interplay among various cellular components, resulting in remodeling of the hepatic microenvironment towards a pro-inflammatory, pro-fibrogenic, pro-angiogenic and pre-neoplastic setting. Moreover, once tumor develops, chemokine signaling may influence its progression. Here we review the role of chemokines in the regulation of CCA development and progression, and the modulation of angiogenesis, metastasis and immune control. The potential role of chemokines and their receptors as possible biomarkers and/or therapeutic targets for hepatobiliary cancer is also discussed.

The use of tissue-engineered skin to demonstrate the negative effect of CXCL5 on epidermal ultraviolet radiation-induced cyclobutane pyrimidine dimer repair efficiency

BACKGROUND

Ultraviolet radiation (UVR) is responsible for keratinocyte cancers through the induction of mutagenic cyclobutane pyrimidine dimers (CPDs). Many factors influence CPD repair in epidermal keratinocytes, and a better understanding of those factors might lead to prevention strategies against skin cancer.

OBJECTIVES

To evaluate the impact of dermal components on epidermal CPD repair efficiency and to investigate potential factors responsible for the dermal-epidermal crosstalk modulating UVR-induced DNA damage repair in keratinocytes.

METHODS

A model of self-assembled tissue-engineered skin containing human primary keratinocytes and fibroblasts was used in this study.

RESULTS

We showed that CPD repair in keratinocytes is positively influenced by the presence of a dermis. We investigated the secretome and found that the cytokine CXCL5 is virtually absent from the culture medium of reconstructed skin, compared with media from fibroblasts and keratinocytes alone. By modulating CXCL5 levels in culture media of keratinocytes, we have shown that CXCL5 is an inhibitor of CPD repair.

CONCLUSIONS

This work outlines the impact of the secreted dermal components on epidermal UVR-induced DNA damage repair and sheds light on a novel role of CXCL5 in CPD repair.

CXCL5 overexpression predicts a poor prognosis in pancreatic ductal adenocarcinoma and is correlated with immune cell infiltration

Background: C-X-C motif chemokine 5 (CXCL5) is an important attractant for immune cell accumulation in tumor tissues. Recent evidence has shown that CXCL5 could promote carcinogenesis and cancer progression in a variety of cancer types. However, the relationships between CXCL5, immune cell infiltration and pancreatic ductal adenocarcinoma (PDAC) remain largely unknown. This study aimed to explore the role and regulative mechanism of CXCL5 in PDAC carcinogenesis.

Materials and Methods: The expression of CXCL5 in PDAC was analyzed based on online databases and tissue microarray staining, and Western blotting of CXCL5 in PDAC cell lines and patient samples. The correlation between CXCL5 expression and clinicopathological features, prognosis and immune cell infiltration in tumor tissues was analyzed.

Results: High expression of CXCL5 was observed both in PDAC tumor tissue and PDAC cell lines, compared to normal pancreas tissues and normal ductal epithelium cells. High CXCL5 expression in tumor tissues was positively correlated with an advanced T stage (p=0.036), a positive tumor lymph node metastasis (p=0.014), a poor differentiation status (p=0.003) and a poor prognosis (p=0.001). Combination of CA242 and CXCL5 expression (p<0.0001) served as a better prognostic factor than CA242 alone (p=0.006). In addition, PDAC patients with high CXCL5 expression had more intratumoral M2 polarized macrophages (p=0.0248), neutrophils (p=0.0068) and IgG⁺ plasma cells (p=0.0133) than patients with low CXCL5 expression.

Conclusions: The expression of CXCL5 is elevated in pancreatic cancer cells. High CXCL5 expression is positively correlated with poor survival and the increased infiltration of several types of immune suppressive cells. Thus, CXCL5 could be a promising therapeutic target for PDAC immunotherapy.

Inflammation and Progression of Cholangiocarcinoma: Role of Angiogenic and Lymphangiogenic Mechanisms

Cholangiocarcinoma (CCA), or cancer of the biliary epithelium is a relatively rare but aggressive form of biliary duct cancer which has a 5-year survival rate post metastasis of 2%. Although a number of risk factors are established for CCA growth and progression, a careful evaluation of the existing literature on CCA reveals that an inflammatory environment near the biliary tree is the most common causal link between the risk factors and the development of CCA. The fact that inflammation predisposes affected individuals to CCA is further bolstered by multiple observations where the presence and maintenance of an inflammatory microenvironment at the site of the primary tumor plays a significant role in the development and metastasis of CCA. In addition, mechanisms activating the tumor vasculature and enhancing angiogenesis and lymphangiogenesis significantly contribute to CCA aggressiveness and metastasis. This review aims to address the role of an inflammatory microenvironment-CCA crosstalk and will present the basic concepts, observations, and current perspectives from recent research studies in the field of tumor stroma of CCA.

Clinical Significance of PD-L1 Expression in Both Cancer and Stroma Cells of Cholangiocarcinoma Patients

BACKGROUND

The clinical significance of programmed death 1 and its ligand (PD-L1) as therapeutic targets has been reported previously. This study aimed to investigate the clinical impact of PD-L1 expression in cancer and stroma cells in cholangiocarcinoma (CCA).

METHODS

The study enrolled 177 consecutive CCA patients who underwent curative resection between 2005 and 2014. Expression of PD-L1 in CCA and stroma cells was assayed by immunohistochemistry, and their relationships with patient clinicopathologic characteristics and prognoses were evaluated. Tumor-infiltrating immune cells (CD66b⁺ neutrophils [TANs] and CD163⁺ M2 macrophages [TAMs]) also were assayed by immunohistochemistry, and their relationship with PD-L1 expression in cancer and stroma cells was evaluated.

RESULTS

Among the 177 analyzed CCA cases, PD-L1 expression was identified in cancer cells in 54 cases (30.5%) and in stroma cells in 77 cases (43.5%). The patients with positive PD-L1 expression in cancer and stroma cells had worse overall survival rates than those negative for PD-L1 (cancer cells: hazard ratio [HR] 2.08; P = 0.0004; stroma cells: HR 1.84; P = 0.003). Moreover, the patients with PD-L1-positive cancer cells had higher rates of PD-L1 expression in stroma cells (P < 0.0001) and higher numbers of TANs (P = 0.0003) and TAMs (P = 0.004) than those with low PD-L1 expression. In the multivariate analysis, PD-L1 expression in both cancer and stroma cells (HR 2.20; P = 0.002) was an independent predictor of poor overall survival.

CONCLUSIONS

The study showed PD-L1 expressed in both CCA and stromal cells and demonstrated that its expression may affect numbers of TANs and TAMs and play a pivotal role in CCA outcomes.

Lysyl oxidase induces epithelial-mesenchymal transition and predicts intrahepatic metastasis of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) has high recurrence rates even after curative hepatectomy. Drug therapy for recurrence of HCC is still limited; therefore, identifying new therapeutic targets is urgently needed. We searched for genes that would predict HCC recurrence from intrahepatic metastasis in an exhaustive DNA microarray database by searching genes associated with high early recurrence rate and having higher expression in the tumor area compared to background liver. We detected lysyl oxidase (LOX) and validated the clinical significance of LOX in 358 patients who underwent hepatectomy. Expression of LOX was evaluated by qRT‐ PCR, and immunohistochemical (IHC) staining. High LOX expression group had a significantly higher recurrence rate than the low LOX expression group (2‐year recurrence rate was 64.0% vs 24.2%, P < .0001 for IHC) and poorer survival rate (5‐year rate was 60.1% vs 86.2%, P < .0001 for IHC). Multivariate analysis showed that high LOX expression was an independent risk factor for early recurrence (IHC: HR, 2.52; P < .0001). Bioinformatic analysis showed that LOX expression was associated with hypoxia‐inducible factor‐1α (HIF‐1α) and the hypoxia cascade, suggesting that HIF‐1α or hypoxia regulates LOX expression and induces epithelial‐mesenchymal transition (EMT). In vitro, LOX and HIF‐1α were involved in migration and invasion capability. High LOX expression is associated with EMT markers and predicts early recurrence and poor survival in patients with HCC. These findings indicate that lysyl oxidase could be a potential therapeutic target for early recurrence of HCC.

Cellular Senescence, Represented by Expression of Caveolin-1, in Cancer-Associated Fibroblasts Promotes Tumor Invasion in Pancreatic Cancer

BACKGROUND

The role of senescence of cancer-associated fibroblasts (CAFs) in the development of cancer is controversial. In this study, we investigated whether cellular senescence of CAFs, represented by CAV1 expression, affects tumor progression in pancreatic cancers (PC).

METHODS

Because CAV1 plays a major role in cellular senescence, we used CAV1 expression to monitor cellular senescence. A total of 157 consecutive patients with PC who underwent curative resection were enrolled in the study. Patients were divided into two groups according to CAV1 expression in CAFs by immunohistochemistry. We investigated the relationship between the CAV1 expression in CAFs and the patients' clinicopathological characteristics, including survival. We also established ten CAFs cell lines using PC clinical samples and chose one of them to knock down CAV1 expression. Finally, we cultured a PC cell line (MIAPaCa-2) in CAF-conditioned medium (CM).

RESULTS

Regarding patients' clinicopathological characteristics, the serum levels of carbohydrate antigen 19-9 and the rate of advanced tumor stage (pT2, 3, and 4) were significantly higher in the high-CAV1 group. The high-CAV1 group had significantly worse outcomes in both overall and disease-free survival (p < 0.01). Additionally, in co-culture assays using CAFs-CM and MIAPaCa-2 cells, we found that knockdown of CAV1 in CAFs negatively affected the invasion of PC cells.

CONCLUSIONS

In PC, CAV1 expression in CAFs is associated with patients' poor prognosis and the downregulation of CAV1 in CAFs reduces the invasiveness of PC cells. Therefore, CAV1 of CAFs might be a new target for the treatment of PC.

Attenuation of CD47-SIRPα Signal in Cholangiocarcinoma Potentiates Tumor-Associated Macrophage-Mediated Phagocytosis and Suppresses Intrahepatic Metastasis

The involvement of chronic inflammation in cholangiocarcinoma (CCA) progression is well established. Cluster of differentiation 47 (CD47) is mutually expressed in various cancers and serves as a protective signal for phagocytic elimination. CD47 signaling blockage is a recent treatment strategy; however, little is known regarding CD47 in CCA. Therefore, the potential use of CD47 targeting in CCA was focused. CD47 was highly expressed in CCA compared to hepatocellular carcinoma (HCC). Disturbance of CD47-signal regulatory protein-α (SIRPα) interaction by blocking antibodies promoted the macrophage phagocytosis. The therapeutic potential of anti-CD47 therapy was demonstrated in liver metastatic model; alleviation of cancer colonization together with dense macrophage infiltrations was observed. The usefulness of anti-CD47 was emphasized by its universal facilitating macrophage activities. Moreover, increased production of inflammatory cytokines, such as IL-6 and IL-10, in macrophage exposed to CCA-conditioned media suggested that CCA alters macrophages toward cancer promotion. Taken together, interfering of CD47-SIRPα interaction promotes macrophage phagocytosis in all macrophage subtypes and consequently suppresses CCA growth and metastasis. The unique overexpression of CD47 in CCA but not HCC offers an exceptional opportunity for a targeted therapy. CD47 is therefore a novel target for CCA treatment.

The role of tumour microenvironment: a new vision for cholangiocarcinoma

Cholangiocarcinoma (CCA) is a relatively rare malignant and lethal tumour derived from bile duct epithelium and the morbidity is now increasing worldwide. This disease is difficult to diagnose at its inchoate stage and has poor prognosis. Therefore, a clear understanding of pathogenesis and major influencing factors is the key to develop effective therapeutic methods for CCA. In previous studies, canonical correlation analysis has demonstrated that tumour microenvironment plays an intricate role in the progression of various types of cancers including CCA. CCA tumour microenvironment is a dynamic environment consisting of authoritative tumour stromal cells and extracellular matrix where tumour stromal cells and cancer cells can thrive. CCA stromal cells include immune and non‐immune cells, such as inflammatory cells, endothelial cells, fibroblasts, and macrophages. Likewise, CCA tumour microenvironment contains abundant proliferative factors and can significantly impact the behaviour of cancer cells. Through abominably intricate interactions with CCA cells, CCA tumour microenvironment plays an important role in promoting tumour proliferation, accelerating neovascularization, facilitating tumour invasion, and preventing tumour cells from organismal immune reactions and apoptosis. This review summarizes the recent research progress regarding the connection between tumour behaviours and tumour stromal cells in CCA, as well as the mechanism underlying the effect of tumour stromal cells on the growth of CCA. A thorough understanding of the relationship between CCA and tumour stromal cells can shed some light on the development of new therapeutic methods for treating CCA.

The Role of Stroma in Cholangiocarcinoma: The Intriguing Interplay between Fibroblastic Component, Immune Cell Subsets and Tumor Epithelium

Cholangiocarcinoma (CCA) is a severe and mostly intractable adenocarcinoma of biliary epithelial cells. A typical feature of CCA is its highly desmoplastic microenvironment containing fibrogenic connective tissue and an abundance of immune cells (T lymphocytes, Natural Killer (NK) cells, and macrophages) infiltrating tumor epithelium. This strong desmoplasia is orchestrated by various soluble factors and signals, suggesting a critical role in shaping a tumor growth-permissive microenvironment that is responsible for CCA poor clinical outcome. Indeed stroma not only provides an abundance of factors that facilitate CCA initiation, growth and progression, but also a prejudicial impact on therapeutic outcome. This review will give an overview of tumor-stroma signaling in a microenvironment critically regulating CCA development and progression. Identification of CCA secreted factors by both the fibroblast component and immune cell subsets might provide ample opportunities for pharmacological targeting of this type of cancer.

CXCL5, the upregulated chemokine in patients with uterine cervix cancer, in vivo and in vitro contributes to oncogenic potential of Hela uterine cervix cancer cells

CXCL5 is showed a surprisingly elevated profile and implicated in tumorigenesis in several tumors. However, the expression and function of CXCL5 in uterine cervix cancer (UCC) remain largely unknown. The current study aimed to elucidate the expression pattern of CXCL5 in human UCC tissues and Hela cervix cancer cell, as well as its functions in Hela cells. Our data showed that CXCL5 and its receptor CXCR2 were expressed by Hela uterine cervix cancer cells. CXCL5 was upregulated in UCC tissues, and its overexpression was positively correlated with age, but did not correlate with clinical stages and tumor infiltration. Exogenous administration of CXCL5 and CXCL5 overexpression contributed to proliferation and migration activities of Hela cells in vitro, consistent with this, CXCL5 overexpression also promoted growth of Hela cells in a nude mouse xenograft model. At the gene level, CXCL5 overexpression regulated the expression of tumor-related genes including ERK, p-ERK, AKT, p-AKT, DIABOL, NUMB, NDRG3 and CXCR2. Taken together, CXCL5 may contribute to a dominant role in UCC progression and sever as a potential molecular therapeutic target for UCC.

Prognostic significance of CXCL5 expression in cancer patients: a meta-analysis

Background

CXCL5 is a member of the CXC-type chemokine family, which has been found to play important roles in tumorigenesis and cancer progression. Recent studies have demonstrated that CXCL5 could serve as a potential prognostic biomarker for cancer patients. However, the prognostic value of CXCL5 is still controversial.

Methods

We systematically searched PubMed, Embase and Web of Science to obtain all relevant articles investigating the prognostic significance of CXCL5 expression in cancer patients. Hazards ratios (HR) with corresponding 95% confidence intervals (CI) were pooled to estimate the association between CXCL5 expression levels with survival of cancer patients.

Results

A total of 15 eligible studies including 19 cohorts and 5070 patients were enrolled in the current meta-analysis. Our results demonstrated that elevated expression level of CXCL5 was significantly associated with poor overall survival (OS) (pooled HR 1.70; 95% CI 1.36–2.12), progression-free survival (pooled HR 1.65; 95% CI 1.09–2.49) and recurrence-free survival (pooled HR 1.49; 95% CI 1.15–1.93) in cancer patients. However, high or low expression of CXCL5 made no difference in predicting the disease-free survival (pooled HR 0.63; 95% CI 0.11–3.49) of cancer patients. Furthermore, we found that high CXCL5 expression was associated with reduced OS in intrahepatic cholangiocarcinoma (HR 1.91; 95% CI 1.31–2.78) and hepatocellular carcinoma (HR 1.87; 95% CI 1.55–2.27). However, there was no significant association between expression level of CXCL5 with the OS in lung cancer (HR 1.25; 95% CI 0.79–1.99) and colorectal cancer (HR 1.16; 95% CI 0.32–4.22, p = 0.826) in current meta-analysis.

Conclusions

In conclusion, our meta-analysis suggested that elevated CXCL5 expression might be an adverse prognostic marker for cancer patients, which could help the clinical decision making process.

Desmoplastic Tumor Microenvironment and Immunotherapy in Cholangiocarcinoma

Cholangiocarcinoma (CCA) is a dismal disease which often is diagnosed at a late stage where the tumor is locally advanced, metastatic, and, as a result, is associated with low resectability. The heterogeneity of this cancer type is a major reason why the majority of patients fail to respond to therapy, and surgery remains their only curative option. Among patients who undergo surgical intervention, such tumors typically recur in 50% of cases within 1year. Thus, CCA is among the most aggressive and chemoresistant malignancies. CCA is characterized by marked tumor reactive stroma, a fibrogenic connective tissue which surrounds and infiltrates the tumor epithelium. This desmoplastic environment presents a clinical challenge, limiting drug delivery and supporting the growth of the tumor mass. In this review we attempt to highlight key pathways involved in cell to cell communication between the tumor epithelium and stroma, the immune components, and opportunities for novel strategies to improve patient outcome.

The Correlation Between Serum Chemokines and Clinical Outcome in Patients with Advanced Biliary Tract Cancer

BACKGROUND

Biliary tract cancers (BTCs) are known to have a dismal prognosis. A number of chemokines play important roles in the progress of BTCs. However, the serum levels of chemokines in BTCs have not yet been explored.

METHODS

The sera of healthy donors (n = 8) and patients with BTCs who were enrolled in second line sunitinib trials (n = 27) were collected. The concentrations of three kinds of chemokines (CXCL5, CXCL8 and CXCL12) were measured using ELISA assay. The median concentrations of chemokines were compared between healthy donors and BTC patients and the role of chemokines as a prognostic biomarker was examined.

RESULTS

BTC patients generally had higher serum levels of CXCL5 and CXCL12 compared to healthy donors. Patients with cholangiocarcinoma showed significantly higher levels of serum CXCL12 than patients with gallbladder cancer. In survival analysis, only CXCL12 level showed a prognostic impact on overall survival (median OS: 6.9 vs. 0.9 months in low CXCL12 vs. high CXCL12, respectively; P = .008). High CXCL5 levels were also correlated with poor survival without statistical insignificance (median OS: 6.2 vs. 2.0 months in low CXCL5 vs. high CXCL5, respectively; P = .070).

CONCLUSIONS

There was a significant difference in OS according to the level of CXCL12, suggesting that serum CXCL12 levels may be a useful surrogate marker for clinical outcome in advanced BTCs.

CXCL5 secreted from adipose tissue-derived stem cells promotes cancer cell proliferation

Accumulating data suggest that adipose tissue facilitates breast tumor initiation and progression through paracrine and endocrine pathways, and that adipose tissue-derived stem cell (ASC) is likely the major cell type responsible for tumorigenesis and tumor development. However, it remains unknown how ASCs exert their effects. In the present study, in cultured breast cancer cell lines, including estrogen receptor (ER)-positive MCF-7 cells and ER-negative MDA-MB-231 cells, the effects on tumor proliferation of isolated ASCs from human breasts were examined. The expression of 174 cytokines was additionally identified in this medium. With an anti-human C-X-C motif ligand 5 (CXCL5) monoclonal antibody, the effects of neutralization of CXCL5 on the actions of ASCs in a co-culture medium of ASCs and tumor cells were studied The results demonstrated that ASCs significantly increased the number of breast cancer cells compared with controls. Similarly, the co-culture medium of ASCs with breast cancer cells exhibited potent effects on tumor cell proliferation. In the co-culture medium of ASCs with breast cancer cells, CXCL5 levels were significantly increased. In addition, depletion of CXCL5 with its specific antibody in ASC-conditioned medium blocked the stimulatory effect of ASCs on the proliferation of breast cancer cells. To the best of our knowledge, these results indicate for the first time that ASC-secreted CXCL5 is a key factor promoting breast tumor cell proliferation.

The clinical significance of CXCL5 in non-small cell lung cancer

As a CXC-type chemokine, ENA78/CXCL5 is an important attractant for granulocytes by binding to its receptor CXCR2. Recent studies proved that CXCL5/CXCR2 axis plays an oncogenic role in many human cancers. However, the exact clinical significance of CXCL5 in lung cancer has not been well defined. Here, we found that the serum protein expression of CXCL5 was significantly increased in non-small cell lung cancer (NSCLC) compared with that in healthy volunteers. Immunohistochemistry staining revealed that CXCL5 protein was higher in various lung cancer tissues compared with normal tissues. Moreover, CXCL5 expression correlated with histological grade, tumor size, and TNM stage in NSCLC. Elevated CXCL5 protein abundance predicted poor overall survival in adenocarcinoma patients. Further meta-analysis demonstrated that CXCL5 mRNA expression was also positively associated with tumor stage, lymph node metastasis, and worse survival. Kaplan–Meier plot analyses indicated high CXCL5 was associated with short overall survival and progression-free survival. Together, these results indicated that CXCL5 may be a potential biomarker for NSCLC.

Tumour-infiltrating inflammatory and immune cells in patients with extrahepatic cholangiocarcinoma

Background:

Inflammation and immune characteristics of the tumour microenvironment have therapeutic significance. The aim of this study was to investigate the clinical impact on disease progression in human extrahepatic cholangiocarcinoma (ECC).

Methods:

A total of 114 consecutive ECC patients with curative resection between 2000 and 2014 were enrolled. Tumour infiltrating CD66b⁺ neutrophils (TANs; tumour associated neutrophils), CD163⁺ M2 macrophages (TAMs; tumour associated macrophages), CD8⁺ T cells, and FOXP3⁺ regulatory T cells (Tregs) were assayed by immunohistochemistry, and their relationships with patient clinicopathological characteristics and prognosis were evaluated.

Results:

Tumour associated neutrophils were inversely correlated with CD8⁺ T cells (P=0.0001) and positively correlated with Tregs (P=0.001). High TANs (P=0.01), low CD8⁺ T cells (P=0.02), and high Tregs (P=0.04) were significantly associated with poor overall survival (OS). A high-risk signature, derived from integration of intratumoural inflammatory and immune cells, was significantly associated with poor recurrence-free survival (P=0.01) and OS (P=0.0008). A high-risk signature was correlated with postoperative distant metastases. Furthermore, a high-risk signature was related to the resistance to gemcitabine-based chemotherapy used after recurrence.

Conclusions:

Our data showed that tumour infiltrating inflammatory and immune cells may play a pivotal role in ECC progression and a high-risk signature predicted poor prognosis in ECC patients.

Understanding liver regeneration to bring new insights to the mechanisms driving cholangiocarcinoma

Cancer frequently arises in epithelial tissues subjected to repeated cycles of injury and repair. Improving our understanding of tissue regeneration is, therefore, likely to reveal novel processes with inherent potential for aberration that can lead to carcinoma. These highly conserved regenerative mechanisms are increasingly understood and in the liver are associated with special characteristics that underlie the organ's legendary capacity for restoration of size and function following even severe or chronic injury. The nature of the injury can determine the cellular source of epithelial regeneration and the signalling mechanisms brought to play. These observations are shaping how we understand and experimentally investigate primary liver cancer, in particular cholangiocarcinoma; a highly invasive malignancy of the bile ducts, resistant to chemotherapy and whose pathogenesis has hitherto been poorly understood. Interestingly, signals that drive liver development become activated in the formation of cholangiocarcinoma, such as Notch and Wnt and may be potential future therapeutic targets. In this review, we summarise the work which has led to the current understanding of the cellular source of cholangiocarcinoma, how the tumour recruits, sustains and is educated by its supporting stromal environment, and the tumour-derived signals that drive the progression and invasion of the cancer. With few current treatments of any true efficacy, advances that will improve our understanding of the mechanisms driving this aggressive malignancy are welcome and may help drive therapeutic developments.

Tumor reactive stroma in cholangiocarcinoma: The fuel behind cancer aggressiveness

Cholangiocarcinoma (CCA) is a highly aggressive epithelial malignancy still carrying a dismal prognosis, owing to early lymph node metastatic dissemination and striking resistance to conventional chemotherapy. Although mechanisms underpinning CCA progression are still a conundrum, it is now increasingly recognized that the desmoplastic microenvironment developing in conjunction with biliary carcinogenesis, recently renamed tumor reactive stroma (TRS), behaves as a paramount tumor-promoting driver. Indeed, once being recruited, activated and dangerously co-opted by neoplastic cells, the cellular components of the TRS (myofibroblasts, macrophages, endothelial cells and mesenchymal stem cells) continuously rekindle malignancy by secreting a huge variety of soluble factors (cyto/chemokines, growth factors, morphogens and proteinases). Furthermore, these factors are long-term stored within an abnormally remodeled extracellular matrix (ECM), which in turn can deleteriously mold cancer cell behavior. In this review, we will highlight evidence for the active role played by reactive stromal cells (as well as by the TRS-associated ECM) in CCA progression, including an overview of the most relevant TRS-derived signals possibly fueling CCA cell aggressiveness. Hopefully, a deeper knowledge of the paracrine communications reciprocally exchanged between cancer and stromal cells will steer the development of innovative, combinatorial therapies, which can finally hinder the progression of CCA, as well as of other cancer types with abundant TRS, such as pancreatic and breast carcinomas.

CXCL5 Plays a Promoting Role in Osteosarcoma Cell Migration and Invasion in Autocrine- and Paracrine-Dependent Manners

CXCL5, a CXC-type chemokine, is an important attractant for granulocytic immune cells by binding to its receptor CXCR2. Recently, CXCL5/CXCR2 has been found to play an oncogenic role in many human cancers. However, the exact role of CXCL5 in osteosarcoma cell migration and invasion has not been revealed. Here we found that the protein expression of CXCL5 was significantly increased in osteosarcoma tissues compared with that in matched adjacent nontumor tissues. Moreover, the expression of CXCL5 was significantly associated with advanced clinical stage and metastasis. Further investigation showed that the CXCL5 expression levels were also significantly increased in osteosarcoma cell lines, including Saos-2, MG63, U2OS, and SW1353, when compared with those in normal osteoblast hFoB1.19 cells. U2OS cells were further transfected with CXCL5-specific siRNA or overexpression plasmid. Knockdown of CXCL5 significantly suppressed U2OS cell migration and invasion. On the contrary, overexpression of CXLC5 remarkably promoted the migration and invasion of U2OS cells. Interestingly, both exogenous CXCL5 treatment and the conditioned medium of CXCL5-overexpressing hFoB1.19 cells could also enhance the migration and invasion of U2OS cells, suggesting that the promoting role of CXCL5 in U2OS cell migration and invasion is also in a paracrine-dependent manner. According to these data, our study demonstrates that CXCL5 is upregulated in osteosarcoma and may play an oncogenic role in osteosarcoma metastasis. Therefore, CXCL5 may become a potential therapeutic target for osteosarcoma treatment.

Extracellular vesicles carry microRNA-195 to intrahepatic cholangiocarcinoma and improve survival in a rat model

The cancer microenvironment plays a central role in cancer development, growth, and homeostasis. This paradigm suggests that cancer fibroblasts support cancers, probably in response to stimuli received from the cancer cells. We aimed at investigating whether extracellular vesicles (EVs) can shuttle microRNA (miR) species between cancer-associated fibroblasts (CAFs) and cancer cells. To this end, we extracted EVs according to published protocols. EVs were studied for their miR content by quantitative reverse-transcription polymerase chain reaction. EVs were transfected with select miR species and utilized in vitro as well as in vivo in a rat model of cholangiocarcinoma (CCA). We found that miR-195 is down-regulated in CCA cells, as well as in adjoining fibroblasts. Furthermore, we report that EVs shuttle miR-195 from fibroblasts to cancer cells. Last, we show that fibroblast-derived EVs, loaded with miR-195, can be administered in a rat model of CCA, concentrate within the tumor, decrease the size of cancers, and improve survival of treated rats.

CONCLUSION

EVs play a salient role in trafficking miR species between cancer cells and CAFs in human CCA. Understanding of these mechanisms may allow devising of novel therapeutics. (Hepatology 2017;65:501-514).

The Role of Cancer-Associated Fibroblasts and Fibrosis in Liver Cancer

Liver cancer is the second leading cause of cancer mortality worldwide, causing more than 700,000 deaths annually. Because of the wide landscape of genomic alterations and limited therapeutic success of targeting tumor cells, a recent focus has been on better understanding and possibly targeting the microenvironment in which liver tumors develop. A unique feature of liver cancer is its close association with liver fibrosis. More than 80% of hepatocellular carcinomas (HCCs) develop in fibrotic or cirrhotic livers, suggesting an important role of liver fibrosis in the premalignant environment (PME) of the liver. Cholangiocarcinoma (CCA), in contrast, is characterized by a strong desmoplasia that typically occurs in response to the tumor, suggesting a key role of cancer-associated fibroblasts (CAFs) and fibrosis in its tumor microenvironment (TME). Here, we discuss the functional contributions of myofibroblasts, CAFs, and fibrosis to the development of HCC and CCA in the hepatic PME and TME, focusing on myofibroblast- and extracellular matrix-associated growth factors, fibrosis-associated immunosuppressive pathways, as well as mechanosensitive signaling cascades that are activated by increased tissue stiffness. Better understanding of the role of myofibroblasts in HCC and CCA development and progression may provide the basis to target these cells for tumor prevention or therapy.

Neutrophil infiltration mediated by CXCL5 accumulation in the laryngeal squamous cell carcinoma microenvironment: A mechanism by which tumour cells escape immune surveillance

The CXCL5 chemokine is important for neutrophil accumulation in tumour tissues. In this report, we attempted to clarify whether and how infiltrating tumour-associated neutrophils (TANs) in laryngeal squamous cell carcinoma (LSCC) affect the proliferation and activation of T cells. We examined chemokine expression by real-time PCR (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) and performed an immunohistochemical analysis of LSCC microarrays. The relationship between CXCL5 and CD66b (a neutrophil marker) was investigated by immunofluorescence staining. We found that CXCL5 was upregulated in LSCC tissues, whereas CXCL5 levels were decreased in LSCC patient serum. Furthermore, high levels of CXCL5 were significantly correlated with intratumoural neutrophil infiltration. Compared with peripheral blood neutrophils (PBNs), TANs significantly inhibited T cell proliferation and decreased IFN-γ and TNF-α secretion. These data suggest that excessive neutrophil infiltration is associated with advanced clinical stages of LSCC (T3 or T4, III or IV, and N1 or N2).

Increased plasma levels of epithelial neutrophil-activating peptide 78/CXCL5 during the remission of Neuromyelitis optica

BACKGROUND

In neuromyelitis optica (NMO), one of the underlying pathogenic mechanisms is the formation of antigen-antibody complexes which can trigger an inflammatory response by inducing the infiltration of neutrophils in lesions. Epithelial neutrophil-activating peptide 78 (ENA 78), known as Chemokine (C-X-C motif) ligand 5 (CXCL5), belongs to the ELR-CXCL family. It recruits and activates neutrophils. The aim of this study was to evaluate ENA 78, IL-1β and TNF-α plasma levels in multiple sclerosis (MS) and neuromyelitis optica (NMO) patients.

METHODS

ENA 78, IL-1β and TNF-α plasma levels were detected in 20 healthy controls (HC), 25 MS and 25 NMO patients using MILLIPLEX® map Human High Sensitivity Cytokine/Chemokine Panels.

RESULTS

Plasma levels of ENA 78 were significantly higher in NMO patients than in HC (P < 0.001) and MS patients (P < 0.05). The NMO patients showed higher plasma levels of IL-1β compared with HC (P < 0.01). Further, increased plasma levels of TNF-α were found in the MS (P < 0.05) and NMO patients (P < 0.001). In addition, NMO patients had higher Expanded Disability Status Scale (EDSS) scores compared with MS patients (P < 0.05). EDSS scores were correlated with plasma levels of ENA 78 in NMO patients (P < 0.05). There were no significant correlations between EDSS scores and plasma levels of ENA 78 in MS patients (P > 0.05).

CONCLUSIONS

The overproduction of pro-inflammatory cytokines such as IL-1β and TNF-α during the remission of NMO activates ENA 78, which in turn leads to neutrophil infiltration in lesions. ENA 78 plasma levels were correlated with EDSS scores in NMO patients. Elevated secretion of ENA 78 may be a critical step in neutrophil recruitment during the remission of NMO.

Expert consensus document: Cholangiocarcinoma: current knowledge and future perspectives consensus statement from the European Network for the Study of Cholangiocarcinoma (ENS-CCA)

Cholangiocarcinoma (CCA) is a heterogeneous group of malignancies with features of biliary tract differentiation. CCA is the second most common primary liver tumour and the incidence is increasing worldwide. CCA has high mortality owing to its aggressiveness, late diagnosis and refractory nature. In May 2015, the "European Network for the Study of Cholangiocarcinoma" (ENS-CCA: www.enscca.org or www.cholangiocarcinoma.eu) was created to promote and boost international research collaboration on the study of CCA at basic, translational and clinical level. In this Consensus Statement, we aim to provide valuable information on classifications, pathological features, risk factors, cells of origin, genetic and epigenetic modifications and current therapies available for this cancer. Moreover, future directions on basic and clinical investigations and plans for the ENS-CCA are highlighted.

Diverse Basis of β-Catenin Activation in Human Hepatocellular Carcinoma: Implications in Biology and Prognosis

Aim

β-catenin signaling is a major oncogenic pathway in hepatocellular carcinoma (HCC). Since β-catenin phosphorylation by glycogen synthase kinase 3β (GSK3β) and casein kinase 1ε (CK1ε) results in its degradation, mutations affecting these phosphorylation sites cause β-catenin stabilization. However, the relevance of missense mutations in non-phosphorylation sites in exon 3 remains unclear. The current study explores significance of such mutations in addition to addressing the clinical and biological implications of β-catenin activation in human HCC.

Methods

Gene alteration in exon3 of CTNNB1, gene expression of β-catenin targets such as glutamate synthetase (GS), axin2, lect2 and regucalcin (RGN), and protein expression of β-catenin were examined in 125 human HCC tissues.

Results

Sixteen patients (12.8%) showed conventional missense mutations affecting codons 33, 37, 41, and 45. Fifteen additional patients (12.0%) had other missense mutations in codon 32, 34, and 35. Induction of exon3 mutation caused described β-catenin target gene upregulation in HCC cell line. Interestingly, conventional and non-phosphorylation site mutations were equally associated with upregulation of β-catenin target genes. Nuclear localization of β-catenin was associated with poor overall survival (p = 0.0461). Of these patients with nuclear β-catenin localization, loss of described β-catenin target gene upregulation showed significant poorer overall survival than others (p = 0.0001).

Conclusion

This study suggests that both conventional and other missense mutations in exon 3 of CTNNB1 lead to β-catenin activation in human HCC. Additionally, the mechanism of nuclear β-catenin localization without upregulation of described β-catenin target genes might be of clinical importance depending on distinct mechanism.

Neutrophils in Cancer: Two Sides of the Same Coin

Neutrophils are the most abundant leukocytes in blood and are considered to be the first line of defense during inflammation and infections. In addition, neutrophils are also found infiltrating many types of tumors. Tumor-associated neutrophils (TANs) have relevant roles in malignant disease. Indeed neutrophils may be potent antitumor effector cells. However, increasing clinical evidence shows TANs correlate with poor prognosis. The tumor microenvironment controls neutrophil recruitment and in turn TANs help tumor progression. Hence, TANs can be beneficial or detrimental to the host. It is the purpose of this review to highlight these two sides of the neutrophil coin in cancer and to describe recent studies that provide some light on the mechanisms for neutrophil recruitment to the tumor, for neutrophils supporting tumor progression, and for neutrophil activation to enhance their antitumor functions.

Skin telocytes versus fibroblasts: two distinct dermal cell populations

It is already accepted that telocytes (TCs) represent a new type of interstitial cells in human dermis. In normal skin, TCs have particular spatial relations with different dermal structures such as blood vessels, hair follicles, arrector pili muscles or segments of sebaceous and/or eccrine sweat glands. The distribution and the density of TCs is affected in various skin pathological conditions. Previous studies mentioned the particular (ultra)structure of TCs and also their immunophenotype, miR imprint or proteome, genome or secretome features. As fibroblast is the most common intersitital cell (also in human dermis), a dedicated comparison between human skin TCs and fibroblasts (Fbs) was required to be performed. In this study, using different techniques, we document several points of difference between human dermis TCs and Fbs. By transmission electron microscopy (TEM) and scanning electron microscopy (SEM), we demonstrated TCs with their hallmark cellular prolongations - telopodes. Thus, we showed their ultrastructural distinctiveness from Fbs. By RayBio Human Cytokine Antibody Array V analyses performed on the supernatant from separately cultured TCs and Fbs, we detected the cytokine profile of both cell types, individually. Two of 79 detected cytokines - epithelial-derived neutrophil-activating peptide 78 and granulocyte chemotactic protein-2 - were 1.5 times higher in the supernatant of TCs (comparing with Fbs). On the other hand, 37 cytokines were at least 1.5 higher in Fbs supernatant (comparing with TCs), and among them six cytokines - interleukin 5, monocyte chemotactic protein-3 (MCP-3), MCP-4, macrophage inflammatory protein-3, angiogenin, thrombopoietin - being 9.5 times higher (results also confirmed by ELISA testing). In summary, using different techniques, we showed that human dermal TCs and Fbs are different in terms of ultrastructure and cytokine profile.

Significance of P-cadherin overexpression and possible mechanism of its regulation in intrahepatic cholangiocarcinoma and pancreatic cancer

It has become evident that P-cadherin, one of the classical cadherins, contributes to the malignant behavior of several types of cancer. In this study, we analyzed the expression of P-cadherin and its clinicopathological and prognostic values in intrahepatic cholangiocarcinoma (ICC) and pancreatic cancer. Furthermore, we investigated the functional role of P-cadherin in these cancer cells by knockdown and overexpression in vitro and by analyzing the correlation between the P-cadherin expression and its promoter methylation status. Thirty of 59 ICC cases (51%) and 36 of 73 pancreatic cancer cases (49%) stained positive for P-cadherin with mainly membranous distribution in tumor cells by immunohistochemistry. P-cadherin expression was significantly correlated with several clinicopathological factors, which reflect tumor behavior, and was identified as an independent adverse prognostic factor for disease-free survival in patients with ICC (relative risk [RR] 2.93, P = 0.04) and pancreatic cancer (RR 2.68, P = 0.005) via multivariate analyses. P-cadherin downregulation by siRNA suppressed migration and invasion, and P-cadherin overexpression induced the opposite effects in both ICC and pancreatic cancer cells, without any effects on cell proliferation. P-cadherin expression was related to its promoter methylation status in both cell lines and cancer tissues. In summary, P-cadherin overexpression may serve as a useful biomarker of invasive phenotype and poor prognosis; P-cadherin expression was found to be regulated by its promoter methylation. These results suggest that P-cadherin represents a novel therapeutic target for the treatment of ICC and pancreatic cancer.

Role of chemokine pathways in hepatobiliary cancer

Persistent hepatic inflammation resulting from hepatitis B or C virus infections (HBV or HCV, respectively), obesity-associated non-alcoholic steatohepatitis (NASH) or alcohol abuse is a hallmark feature of chronic liver diseases and appears to be an essential prerequisite of hepatocarcinogenesis. The inflammatory processes in the liver are regulated by various chemokines, which orchestrate the interaction between parenchymal liver cells, Kupffer cells (resident macrophages), hepatic stellate cells (HSC), endothelial cells, and infiltrating immune cells. In consequence, these cellular interactions result in the re-modeling of the hepatic microenvironment toward a pro-inflammatory, pro-fibrotic, pro-angiogenic and thus pre-neoplastic milieu. Once developed, liver neoplasms provoke pro- and anti-tumor immune responses that are also critically regulated through differential activation of chemokine pathways. With respect to hepatobiliary cancers, including hepatocellular carcinoma (HCC), gallbladder cancer and cholangiocellular carcinoma (cholangiocarcinoma), together belonging to the highest causes of cancer-related deaths worldwide, this review article will give an overview of chemokine pathways involved in both the establishment of a pro-tumorigenic microenvironment as well as the development and progression of hepatobiliary cancer. Pharmaceutical targeting of chemokine pathways is a promising approach to treat or even prevent hepatobiliary cancer.