ERBB-2 overexpression and cyclooxygenase-2 up-regulation in human cholangiocarcinoma and risk conditions

Unveil Intrahepatic Cholangiocarcinoma Heterogeneity through the Lens of Omics and Multi-Omics Approaches

Intrahepatic cholangiocarcinoma (iCCA) is recognized worldwide as the second leading cause of morbidity and mortality among primary liver cancers, showing a continuously increasing incidence rate in recent years. iCCA aggressiveness is revealed through its rapid and silent intrahepatic expansion and spread through the lymphatic system leading to late diagnosis and poor prognoses. Multi-omics studies have aggregated information derived from single-omics data, providing a more comprehensive understanding of the phenomena being studied. These approaches are gradually becoming powerful tools for investigating the intricate pathobiology of iCCA, facilitating the correlation between molecular signature and phenotypic manifestation. Consequently, preliminary stratifications of iCCA patients have been proposed according to their "omics" features opening the possibility of identifying potential biomarkers for early diagnosis and developing new therapies based on personalized medicine (PM). The focus of this review is to provide new and advanced insight into the molecular pathobiology of the iCCA, starting from single- to the latest multi-omics approaches, paving the way for translating new basic research into therapeutic practices.

BiliQML: a supervised machine-learning model to quantify biliary forms from digitized whole slide liver histopathological images

The progress of research focused on cholangiocytes and the biliary tree during development and following injury is hindered by limited available quantitative methodologies. Current techniques include two-dimensional standard histological cell-counting approaches, which are rapidly performed, error prone, and lack architectural context or three-dimensional analysis of the biliary tree in opacified livers, which introduce technical issues along with minimal quantitation. The present study aims to fill these quantitative gaps with a supervised machine-learning model (BiliQML) able to quantify biliary forms in the liver of anti-keratin 19 antibody-stained whole slide images. Training utilized 5,019 researcher-labeled biliary forms, which following feature selection, and algorithm optimization, generated an F score of 0.87. Application of BiliQML on seven separate cholangiopathy models [genetic (Afp-CRE;Pkd1l1null/Fl, Alb-CRE;Rbp-jkfl/fl, and Albumin-CRE;ROSANICD), surgical (bile duct ligation), toxicological (3,5-diethoxycarbonyl-1,4-dihydrocollidine), and therapeutic (Cyp2c70-/- with ileal bile acid transporter inhibition)] allowed for a means to validate the capabilities and utility of this platform. The results from BiliQML quantification revealed biological and pathological differences across these seven diverse models, indicating a highly sensitive, robust, and scalable methodology for the quantification of distinct biliary forms. BiliQML is the first comprehensive machine-learning platform for biliary form analysis, adding much-needed morphologic context to standard immunofluorescence-based histology, and provides clinical and basic science researchers with a novel tool for the characterization of cholangiopathies.NEW & NOTEWORTHY BiliQML is the first comprehensive machine-learning platform for biliary form analysis in whole slide histopathological images. This platform provides clinical and basic science researchers with a novel tool for the improved quantification and characterization of biliary tract disorders.

Smad4 restricts injury-provoked biliary proliferation and carcinogenesis

Cholangiocarcinoma (CCA) is a deadly and heterogeneous type of cancer characterized by a spectrum of epidemiologic associations as well as genetic and epigenetic alterations. We seek to understand how these features inter-relate in the earliest phase of cancer development and through the course of disease progression. For this, we studied murine models of liver injury integrating the most commonly occurring gene mutations of CCA - including Kras, Tp53, Arid1a and Smad4 - as well as murine hepatobiliary cancer models and derived primary cell lines based on these mutations. Among commonly mutated genes in CCA, we found that Smad4 functions uniquely to restrict reactive cholangiocyte expansion to liver injury through restraint of the proliferative response. Inactivation of Smad4 accelerates carcinogenesis, provoking pre-neoplastic biliary lesions and CCA development in an injury setting. Expression analyses of Smad4-perturbed reactive cholangiocytes and CCA lines demonstrated shared enriched pathways, including cell-cycle regulation, MYC signaling and oxidative phosphorylation, suggesting that Smad4 may act via these mechanisms to regulate cholangiocyte proliferation and progression to CCA. Overall, we showed that TGFβ/SMAD4 signaling serves as a critical barrier restraining cholangiocyte expansion and malignant transformation in states of biliary injury.

LiverQuant: An Improved Method for Quantitative Analysis of Liver Pathology

Current means to quantify cells, gene expression, and fibrosis of liver histological slides are not standardized in the research community and typically rely upon data acquired from a selection of random regions identified in each slide. As such, analyses are subject to selection bias as well as limited subsets of available data elements throughout the slide. A whole-slide analysis of cells and fibrosis would provide for a more accurate and complete quantitative analysis, along with minimization of intra- and inter-experimental variables. Herein, we present LiverQuant, a method for quantifying whole-slide scans of digitized histologic images to render a more comprehensive analysis of presented data elements. After loading images and preparing the project in the QuPath program, researchers are provided with one to two scripts per analysis that generate an average intensity threshold for their staining, automated tissue annotation, and downstream detection of their anticipated cellular matrices. When compared with two standard methodologies for histological quantification, LiverQuant had two significant advantages: increased speed and a 50-fold greater tissue area coverage. Using publicly available open-source code (GitHub), LiverQuant improves the reliability and reproducibility of experimental results while reducing the time scientists require to perform bulk analysis of liver histology. This analytical process is readily adaptable by most laboratories, requires minimal optimization, and its principles and code can be optimized for use in other organs. Graphical overview.

Primary sclerosing cholangitis and pancreatic cancer: A retrospective cohort study of United States veterans

Primary sclerosing cholangitis (PSC) is associated with hepatobiliary and colorectal cancers, but it remains uncertain if PSC increases the risk for pancreatic cancer. While some European studies have suggested an increased risk of pancreatic cancer in PSC patients, other studies have not. And these studies did not well account for presence or absence of concomitant inflammatory bowel disease (IBD). The purpose of this study is to investigate the prevalence of pancreatic cancer in United States veterans with PSC both with and without IBD.

Methods

This retrospective study used International Classification of Diseases, Tenth Revision (ICD-10) codes to identify patients with PSC, IBD, and pancreatic cancer from the Veterans Affairs (VA) Corporate Data Warehouse. The prevalence of pancreatic cancer in patients with PSC only, IBD only, PSC with IBD, and neither PSC nor IBD were compared. Logistic regression was used to control for age, gender, chronic pancreatitis, diabetes mellitus, and tobacco and alcohol use.

Results

A total of 946 patients with PSC were identified from a population of over 9 million veterans. 486 (51.4%) of these had concurrent IBD. Additionally 112,653 patients with IBD without PSC were identified. When adjusted for confounding factors, patients with PSC had a significantly higher prevalence of pancreatic cancer compared to the general population and those with IBD without PSC (2.4% vs. 0.2% and 0.5%, respectively).

Conclusions

Veterans with PSC, particularly those without concomitant IBD, have a high prevalence of pancreatic cancer compared to the general veteran population. Our findings support the need for multicenter prospective studies investigating the benefits of screening for pancreatic cancer in patients with PSC.

Genomic alterations in cholangiocarcinoma: clinical significance and relevance to therapy

Improving the survival of patients with cholangiocarcinoma (CCA) has long proved challenging, although the treatment of this disease nowadays is on advancement. The historical invariability of survival outcomes and the limited number of agents known to be effective in the treatment of this disease has increased the number of studies designed to identify genetic targetable hits that can be efficacious for novel therapies. In this respect, the increasing feasibility of molecular profiling starting either from tumor tissue or circulating cell-free DNA (cfDNA) has led to an increased understanding of CCA biology. Intrahepatic CCA (iCCA) and extrahepatic CCA (eCCA) display different and typical patterns of actionable genomic alterations, which offer opportunity for therapeutic intervention. This review article will summarize the current knowledge on the genomic alterations of iCCA and eCCA, provide information on the main technologies for genomic profiling using either tumor tissue or cfDNA, and briefly discuss the main clinical trials with targeted agents in this disease.

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.

Promotion of the inflammatory response in mid colon of complement component 3 knockout mice

To determine whether complement component 3 (C3) deficiency affects its receptor downstream-mediated inflammatory response, the current study was undertaken to measure alterations in the inducible nitric oxide synthase (iNOS)‑mediated cyclooxygenase‑2 (COX‑2) induction pathway, inflammasome pathway, nuclear factor-κB (NF-κB) activation, and inflammatory cytokine expressions in the mid colon of C3 knockout (KO) mice. Significant enhancement was observed in expressions of key components of the iNOS‑mediated COX‑2 induction pathway, and in the phosphorylation of mitogen‑activated protein (MAP) kinase members. A similar pattern of increase was also observed in the expression levels of inflammasome proteins in C3 KO mice. Moreover, compared to WT mice, C3 KO mice showed remarkably enhanced phosphorylation of NF-κB and Inhibitor of κB-α (IκB-α), which was reflected in entirety as increased expressions of Tumor necrosis factor (TNF), IL-6 and IL-1α. However, the levels of E-cadherin, tight junction channels and ion channels expressions were lower in the C3 KO mice, although myeloperoxidase (MPO) activity for neutrophils was slightly increased. Taken together, results of the current study indicate that C3 deficiency promotes inflammatory responses in the mid colon of C3 KO mice through activation of the iNOS‑mediated COX‑2 induction pathway, Apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC)-inflammasome pathway and NF-κB signaling pathway, and the enhancement of inflammatory cytokine expressions.

Epigenetic Silencing of 15-Hydroxyprostaglandin Dehydrogenase by Histone Methyltransferase EHMT2/G9a in Cholangiocarcinoma

Cholangiocarcinoma (CCA) is a lethal malignancy with few therapeutic options. NAD+-dependent 15-hydroxyprostaglandin dehydrogenase (15-PGDH) has been shown to inhibit CCA cell growth in vitro and in xenograft models. However, the role of 15-PGDH in CCA development has not been investigated and the mechanism for 15-PGDH gene regulation remains unclear. Here, we evaluated the role of 15-PGDH in CCA development by using a mouse model with hydrodynamic tail vein injection of transposase-based plasmids expressing Notch1 intracellular domain and myr-Akt, with or without co-injection of 15-PGDH expression plasmids. Our results reveal that 15-PGDH overexpression effectively prevents CCA development. Through patient data mining and experimental approaches, we provide novel evidences that 15-PGDH is epigenetically silenced by histone methyltransferase G9a. We observe that 15-PGDH and G9a expressions are inversely correlated in both human and mouse CCAs. By using CCA cells and mouse models, we show that G9a inhibition restores 15-PGDH expression and inhibited CCA in vitro and in vivo. Mechanistically, our data indicate that G9a is recruited to 15-PGDH gene promoter via protein-protein interaction with the E-box binding Myc/Max heterodimer. The recruited G9a then silences 15-PGDH gene through enhanced methylation of H3K9. Our further experiments have led to the identification of STAT4 as a key transcription factor involved in the regulation of 15-PGDH by G9a. Collectively, our findings disclose a novel G9a-15PGDH signaling axis which is importantly implicated in CCA development and progression. Implications: The current study describes a novel G9a-15PGDH signaling axis which is importantly implicated in cholangiocarcinoma (CCA) development and progression.

In vivo impact assessment of orally administered polystyrene nanoplastics: biodistribution, toxicity, and inflammatory response in mice

To assess the in vivo impact of nanoplastics (NP) and coagulation-based purified NP (PurNP), this study analyzed for alterations in the biodistribution, toxicity and inflammatory response in ICR mice exposed to three different doses of NP (5, 25, and 50 mg/kg) and PurNP for 2 weeks. Except water consumption, which was dose-dependently and significantly increased in all NP-treated groups, most factors assessed for feeding behaviors and excretions remained constant, without any significant change. Orally administered NP was detected in the intestine, kidneys, and liver at all concentrations, although the accumulation was higher in the intestine than in the kidneys and liver. No significant alterations were detected in the levels of serum biochemical markers and histopathological structures. However, compared to the vehicle group, expressions of the inflammatory response proteins (iNOS and COX-2) and mRNA levels of the inflammatory cytokines were remarkably increased in the liver, kidneys, and intestine of NP-treated mice. A similar increase was detected in the oxidative stress responses, including ROS concentration, SOD activity, and Nrf2 expression. Furthermore, similar inflammatory responses were observed in the PurNP-treated group, as compared to the vehicle-treated group. The results presented in this study provide the first strong evidence that oral administration of NP for 2 weeks results in high accumulation in the liver, kidneys, and intestine of ICR mice, and induces severe inflammatory and oxidative stress responses. These results additionally confirm the efficacy of water purification using the tannic acid-mediated coagulation removal technique.

Primary sclerosing cholangitis and the risk of cancer, cardiovascular disease, and all-cause mortality: a systematic review and meta-analysis of cohort studies

A diagnosis of primary sclerosing cholangitis (PSC) has been associated with increased risk of hepatobiliary cancers, colorectal cancer and all-cause mortality in several studies, while associations with cardiovascular disease have been inconsistent. We conducted a systematic review and meta-analysis of published cohort studies on the topic to summarize these associations. PubMed and Embase databases were searched up to January 13th, 2020. Cohort studies on PSC and risk of cancer, cardiovascular disease, or mortality were included. Summary relative risks (RRs) and 95% confidence intervals (95% CIs) were estimated using random effects models. The summary RR (95% CI) comparing persons with PSC to persons without PSC was 584.37 (269.42-1267.51, I² = 89%, n = 4) for cholangiocarcinoma (CCA), 155.54 (125.34-193.02, I² = 0%, n = 3) for hepatobiliary cancer, 30.22 (11.99-76.17, I² = 0%, n = 2) for liver cancer, 16.92 (8.73-32.78, I² = 88%, n = 4) for gastrointestinal cancer, 7.56 (2.42-23.62, I² = 0%, n = 3) for pancreatic cancer, 6.10 (4.19-8.87, I² = 14%, n = 7) for colorectal cancer (CRC), 4.13 (2.99-5.71, I² = 80%, n = 5) for total cancer, 3.55 (2.94-4.28, I² = 46%, n = 5) for all-cause mortality, and 1.57 (0.25-9.69, I² = 79%, n = 2) for cardiovascular disease. Strong positive associations were observed between PSC and risk of CCA, hepatobiliary cancer, liver cancer, gastrointestinal cancer, pancreatic cancer, CRC, total cancer, and all-cause mortality, but not for cardiovascular disease.

Inhibition of T-cell-mediated immune response via the PD-1/ PD-L1 axis in cholangiocarcinoma cells

Cholangiocarcinoma (CCA) is a malignant biliary tract epithelium tumor. The programmed death-1 (PD-1)/programmed receptor-ligand 1 (PD-L1) signaling pathway has been implicated as an immune escape mechanism in several cancers. The present study aimed to assess the expression of PD-L1 on human CCA cell lines and its potential role in suppressing CD8⁺ T- cell function. A panel of intrahepatic CCA cell lines was evaluated for immune regulatory checkpoint ligands and inflammation markers. Effects of pro-inflammatory cytokine, interferon gamma (IFN-γ), on the expression of immune regulatory checkpoint ligands and inflammation markers were determined. The PD-L1 function was measured by co-culturing CCA cells with lymphocytes. Most of the selected Thai CCA cell lines, including HuCCA-1, RMCCA-1, KKU-100, and KKU-213, expressed higher PD-L1 than normal cholangiocyte MMNK-1 and ANK-1 cells. Both PD-L1 and cyclooxygenase-2 (COX-2) expressions were highest in HuCCA-1 cells. A 48 h treatment with IFN-γ increased the expression of PD-L1 and COX-2 in CCA cells. The expression of CTLA-4 ligands, including H7-1 and H7-2, did not change after IFN-γ treatment. Rofecoxib, a specific COX-2 inhibitor, mitigated IFN-γ-induced PD-L1 expression. After 48 h co-incubation, CD8⁺ T-cell apoptosis was increased as compared to the control group. Pretreatment of CCA cells with IFN-γ further increased CD8⁺ T-cell apoptosis. Pembrolizumab, an anti-PD-1 antibody, mitigated CCA cell escape phenomenon. The inhibition of T-cell-mediated immune response via the PD-L1/PD-1 axis are evidenced in intrahepatic CCA. Immunotherapy with checkpoint inhibitor offers a potentially therapeutic strategy for CCA patients; however, further in vivo and clinical studies are required.

Inhibitory effect of isomorellin on cholangiocarcinoma cells via suppression of NF-κB translocation, the phosphorylated p38 MAPK pathway and MMP-2 and uPA expression

Evidence indicates that most cancer deaths are caused by tumor invasion and metastasis. Cholangiocarcinoma (CCA) is a tumor of the bile duct epithelium characterized by slow growth, rapid metastasis and poor prognosis. Caged xanthones are extracted from gamboge, a dry resin exuded by Garcinia hanbury. These compounds have been reported to be cytotoxic to several types of cancer cells, without affecting normal cells. The aim of the present study was to determine the effect of isomorellin on the inhibition of CCA cell (KKU-100) viability, migration, invasion and the expression of invasion-regulated proteins. Cytotoxicity of isomorellin was evaluated using a sulforhodamine B assay. The anti-migratory and anti-invasive effects of isomorellin on KKU-100 cells were assessed using wound healing and chamber invasion assays, respectively. Furthermore, the activities of matrix metalloproteinases (MMPs)-2 and -9, and urokinase-type plasminogen activator (uPA) were also investigated. The expression levels of proteins regulating invasion were determined via western blot analysis. The cell viability of KKU-100 cells was decreased following treatment with isomorellin in a dose-dependent manner, with IC50 values at 24, 48 and 72 h of 3.46±0.19, 3.78±0.02 and 4.01±0.01 µM, respectively. Wound healing and chamber invasion assays indicated that isomorellin significantly inhibited KKU-100 cell migration and invasion in a dose-dependent manner. In addition, isomorellin significantly inhibited cancer cell migration and invasion abilities via focal adhesion kinase (FAK), protein kinase C (PKC), the phosphorylated (p)-p38 mitogen-activated protein kinase (MAPK) pathway, and nuclear factor (NF)-κB expression and translocation to the nucleus, thus resulting in downregulation of MMP-2, uPA and cyclooxygenase-2 (COX-2) expression. Therefore, inhibition of MMP-2, uPA and COX-2 expression may result in decreased CCA cell invasion ability. These data demonstrated for the first time that the suppression of KKU-100 cell viability, invasion and migration, and downregulation of NF-κB, MMP-2, uPA and the p-p38 MAPK pathway, may result in isomorellin-mediated anti-invasiveness.

ERBB2 Pathway in Biliary Tract Carcinoma: Clinical Implications of a Targetable Pathway

BACKGROUND/AIMS

Current chemotherapy regimens for cholangiocarcinoma (CCA) yield poor outcomes, with a median overall survival of <12 months. Recent data on the genomic landscape of CCAs have created opportunities for targeted therapy. Yet, data regarding its efficacy are scarce. We aimed to describe the genomic landscape of a CCA patient cohort using next-generation sequencing (NGS), focusing on the ERBB/EFGR pathway and assessing response to anti-HER2 agents.

METHODS

Tissue samples of intrahepatic CCA (IHCC) and extrahepatic CCA (EHCC) underwent NGS for somatic aberrations. The clinical outcomes for patients treated with anti-HER2 agents were evaluated.

RESULTS

A total of 1,863 CCA cases (1,615 IHCCs and 248 EHCCs) underwent NGS, and they revealed a high prevalence of ERBB alterations (IHCC, 4.2%; EHCC, 9.7%). Among these, 23.8% of the IHCCs and 53.6% of the EHCCs had a point mutation in ERBB2, and 66.6% of the IHCCs and 41.2% of the EHCCs had ERBB copy number amplification. Three EHCC patients were diagnosed at our institute with ERBB/EGFR aberrations; 2 patients were treated with neratinib and 1 patient with a chemotherapy-trastuzumab combination. All 3 achieved disease stabilization and a clinical benefit. One patient underwent a liquid biopsy before and after 3 months of treatment, demonstrating disappearance of the ERBB2 clone and emergence of a Myc-mutated clone after treatment.

CONCLUSIONS

The genomic landscape of CCAs may harbor targetable alterations, especially in the ERBB/EGFR pathway. These alterations may have clinical significance in everyday practice.

Pathogenesis of Cholangiocarcinoma

Cholangiocarcinoma (CCA) encompasses a group of malignancies that can arise at any point in the biliary tree. Although considered a rare cancer, the incidence of CCA is increasing globally. The silent and asymptomatic nature of these tumors, particularly in their early stages, in combination with their high aggressiveness, intra- and intertumor heterogeneity, and chemoresistance, significantly compromises the efficacy of current therapeutic options, contributing to a dismal prognosis. During the last few years, increasing efforts have been made to unveil the etiologies and pathogenesis of these tumors and to develop more effective therapies. In this review, we summarize current findings in the field of CCA, mainly focusing on the mechanisms of pathogenesis, cells of origin, genomic and epigenetic abnormalities, molecular alterations, chemoresistance, and therapies.

Multifaceted Aspects of Metabolic Plasticity in Human Cholangiocarcinoma: An Overview of Current Perspectives

Cholangiocarcinoma (CCA) is a deadly tumor without an effective therapy. Unique metabolic and bioenergetics features are important hallmarks of tumor cells. Metabolic plasticity allows cancer cells to survive in poor nutrient environments and maximize cell growth by sustaining survival, proliferation, and metastasis. In recent years, an increasing number of studies have shown that specific signaling networks contribute to malignant tumor onset by reprogramming metabolic traits. Several evidences demonstrate that numerous metabolic mediators represent key-players of CCA progression by regulating many signaling pathways. Besides the well-known Warburg effect, several other different pathways involving carbohydrates, proteins, lipids, and nucleic acids metabolism are altered in CCA. The goal of this review is to highlight the main metabolic processes involved in the cholangio-carcinogeneis that might be considered as potential novel druggable candidates for this disease.

Mitogen-Activated Protein Kinases (MAPKs) and Cholangiocarcinoma: The Missing Link

In recent years, the incidence of both liver and biliary tract cancer has increased. Hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA) are the two most common types of hepatic malignancies. Whereas HCC is the fifth most common malignant tumor in Western countries, the prevalence of CCA has taken an alarming increase from 0.3 to 2.1 cases per 100,000 people. The lack of specific biomarkers makes diagnosis very difficult in the early stages of this fatal cancer. Thus, the prognosis of CCA is dismal and surgery is the only effective treatment, whilst recurrence after resection is common. Even though chemotherapy and radiotherapy may prolong survival in patients with CCA, the 5-year survival rate is still very low—a significant global problem in clinical diagnosis and therapy. The mitogen-activated protein kinase (MAPK) pathway plays an important role in signal transduction by converting extracellular stimuli into a wide range of cellular responses including inflammatory response, stress response, differentiation, survival, and tumorigenesis. Dysregulation of the MAPK cascade involves key signaling components and phosphorylation events that play an important role in tumorigenesis. In this review, we discuss the pathophysiological role of MAPK, current therapeutic options, and the current situation of MAPK-targeted therapies in CCA.

Aspirin use is associated with a reduced risk of cholangiocarcinoma: a systematic review and meta-analysis

Background

Aspirin has been revealed to probably decrease the risk of cholangiocarcinoma (CCC), which, nevertheless, is of controversy. To this end, a systematic review and meta-analysis was performed to investigate the above-described association.

Methods

We thoroughly searched PubMed, EMBASE, and ISI Web of Science for relevant studies published prior to October 2017, followed by random-effects model for calculation of pooled ORs and corresponding 95% CIs. Additionally, subgroup and sensitivity analyses were carried out to confirm whether the outcomes were stable.

Results

Nine articles, consisting of 12,535 CCC patients and 92,97,450 healthy controls, were enrolled in this study. We demonstrated a significantly decreased risk of CCC in those using aspirin, with studies being heterogeneous (OR=0.69; CI=0.43–0.94; I2=97.4%). Moreover, this relationship was detected only in case-control studies (OR=0.65; 95% CI=0.38–0.93), rather than cohort studies (OR=0.94; 95% CI=0.70–1.27). Besides, in separated analysis of intrahepatic CCC and extrahepatic CCC, aspirin was more strongly correlated with a declined risk of intrahepatic CCC (OR=0.33, 95% CI=0.26–0.39; I2=93.6%) than the risk of extrahepatic CCC (OR=0.56, 95% CI=0.41–0.73; I2=0%).

Conclusion

Collectively, the aspirin administration was correlated with a significant 31% decreased risk of CCC, particularly in the intrahepatic CCC.

Potential candidate treatment agents for targeting of cholangiocarcinoma identified by gene expression profile analysis

Cholangiocarcinoma (CCA) remains to be a major health problem in several Asian countries including Thailand. The molecular mechanism of CCA is poorly understood. Early diagnosis is difficult, and at present, no effective therapeutic drug is available. The present study aimed to identify the molecular mechanism of CCA by gene expression profile analysis and to search for current approved drugs which may interact with the upregulated genes in CCA. Gene Expression Omnibus (GEO) was used to analyze the gene expression profiles of CCA patients and normal subjects. Using the Kyoto Encyclopedia of Genes and Genomes (KEGG), gene ontology enrichment analysis was also performed, with the KEGG pathway analysis indicating that pancreatic secretion, protein digestion and absorption, fat digestion and absorption, and glycerolipid metabolism may serve important roles in CCA oncogenesis. The drug signature database (DsigDB) was used to search for US Food and Drug Administration (FDA)-approved drugs potentially capable of reversing the effects of the upregulated gene expression in CCA. A total of 61 antineoplastic and 86 non-antineoplastic drugs were identified. Checkpoint kinase 1 was the most interacting with drug signatures. Many of the targeted protein inhibitors that were identified have been approved by the US-FDA as therapeutic agents for non-antineoplastic diseases, including cimetidine, valproic acid and lovastatin. The current study demonstrated an application for bioinformatics analysis in assessing the potential efficacy of currently approved drugs for novel use. The present results suggest novel indications regarding existing drugs useful for CCA treatment. However, further in vitro and in vivo studies are required to support the current predictions.

Role of ErbB/HER family of receptor tyrosine kinases in cholangiocyte biology

The ErbB/HER family comprises four distinct tyrosine kinase receptors, EGFR/ErbB1/HER1, ErbB2/HER2, ErbB3/HER3, and ErbB4/HER4, which trigger intracellular signals at the origin of essential cellular functions, including differentiation, proliferation, survival, and migration. Epithelial cells, named cholangiocytes, that line intrahepatic and extrahepatic bile ducts, contribute substantially to biliary secretory functions and bile transport. Although ErbB receptors have been widely studied in cholangiocarcinoma (CCA), a malignancy of the biliary tract, knowledge of these receptors in biliary epithelium physiology and in non-malignant cholangiopathies is far from complete. Current knowledge suggests a role for epidermal growth factor receptor (EGFR) in cholangiocyte specification and proliferation, and in hepatocyte transdifferentiation into cholangiocytes during liver regeneration to restore biliary epithelium integrity. High expression and activation of EGFR and/or ErbB2 were recently demonstrated in biliary lithiasis and primary sclerosing cholangitis, two cholangiopathies regarded as risk factors for CCA. In CCA, ErbB receptors are frequently overexpressed, leading to tumor progression and low prognosis. Anti-ErbB therapies were efficient only in preclinical trials and have suggested the existence of resistance mechanisms with the need to identify predictive factors of therapy response. This review aims to compile the current knowledge on the functions of ErbB receptors in physiology and physiopathology of the biliary epithelium. (Hepatology 2018;67:762-773).

Intrahepatic cholangiocarcinoma: Role of metabolism in pathogenesis, clinical diagnosis, and treatment

Recent studies demonstrated that metabolism plays an important role in the pathogenesis, clinical diagnosis, and treatment of intrahepatic cholangiocarcinoma (ICC). The mechanisms of several metabolic enzymes associated with ICC, including pyruvate kinase M2 (PKM2), thymidine synthase (TS), thymidine phosphorylase (TP), dihydropyrimidine dehydrogenase (DPD), isocitric acid dehydrogenase 1/2 (IDH1/2), and cyclo-oxygenase-2 (COX-2), have been gradually clarified and hopefully transformed into clinical application in the future. Besides, ICC patients always have concomitant abnormal lipid metabolism, which has attracted the attention of clinicians and researchers. Metabolites in serum and bile have potential diagnostic utility, which has yet to be verified by prospective clinical research. ¹⁸F-FDG PET/CT based on metabolism presents application value in many aspects of ICC, such as diagnosis, staging, evaluation of therapeutic effect, and monitoring prognosis. In this article, we review the recent progress in the understanding of the role of metabolism in ICC from both basic and clinical perspectives, with an aim to highlight the further research directions and accelerate the clinical transformation.

Molecular alterations and clinical prognostic factors for cholangiocarcinoma in Thai population

This study explores genomic alterations in cholangiocarcinoma (CCC) tissues in Thai patients. We identified and reviewed the records of patients who had been diagnosed with CCC and for whom sufficient tumor samples for DNA and RNA extraction were available in our database. The specimens were explored for EGFR, KRAS, BRAF, and PIK3CA mutations and ROS1 translocation in 81 samples. Immunohistochemistry staining for HER2, ALK, and Ki-67 expression was tested in 74 samples. Prevalence of EGFR, KRAS, and PIK3CA mutations in this study was 21%, 12%, and 16%, respectively. No BRAF V600 mutation or ROS1 translocation was found. Patients with T790M mutation had a significantly longer overall survival (18.84 months) than those with the other types of EGFR mutations (4.08 months; hazard ratio [HR]: 0.26, P=0.038) and also had a significantly lower median Ki-67 (22.5% vs 80%, P=0.025). Furthermore, patients with PIK3CA mutations had a significantly longer median progression-free survival (15.87 vs 7.01 months; HR: 0.46, P=0.043). Strongly positive HER2 expression was found in only 1 patient, whereas ALK expression was not found. The presence of EGFR and/or PIK3CA mutations implies that targeted drugs may provide a feasible CCC treatment in the future.

HER2/HER3 pathway in biliary tract malignancies; systematic review and meta-analysis: a potential therapeutic target?

Human epidermal growth factor receptor 2 (HER2) overexpression and amplification have been reported as predictive markers for HER2-targeted therapy in breast and gastric cancer, whereas human epidermal growth factor receptor 3 (HER3) is emerging as a potential resistance factor. The aim of this study was to perform a systematic review and meta-analysis of the HER2 and HER3 overexpression and amplification in biliary tract cancers (BTCs). An electronic search of MEDLINE, American Society of Clinical Oncology (ASCO), European Society of Medical Oncology Congress (ESMO), and American Association for Cancer Research (AACR) was performed to identify studies reporting HER2 and/or HER3 membrane protein expression by immunohistochemistry (IHC) and/or gene amplification by in situ hybridization (ISH) in BTCs. Studies were classified as "high quality" (HQ) if IHC overexpression was defined as presence of moderate/strong staining or "low quality" (LQ) where "any" expression was considered positive. Of 440 studies screened, 40 met the inclusion criteria. Globally, HER2 expression rate was 26.5 % (95 % CI 18.9-34.1 %). When HQ studies were analyzed (n = 27 studies), extrahepatic BTCs showed a higher HER2 overexpression rate compared to intrahepatic cholangiocarcinoma: 19.9 % (95 % CI 12.8-27.1 %) vs. 4.8 % (95 % CI 0-14.5 %), respectively, p value 0.0049. HER2 amplification rate was higher in patients selected by HER2 overexpression compared to "unselected" patients: 57.6 % (95 % CI 16.2-99 %) vs. 17.9 % (95 % CI 0.1-35.4 %), respectively, p value 0.0072. HER3 overexpression (4/4 HQ studies) and amplification rates were 27.9 % (95 % CI 9.7-46.1 %) and 26.5 % (one study), respectively. Up to 20 % of extrahepatic BTCs appear to be HER2 overexpressed; of these, close to 60 % appear to be HER2 amplified, while HER3 is overexpressed or amplified in about 25 % of patients. Clinical relevance for targeted therapy should be tested in prospective clinical trials.

Butanol extracts of Asparagus cochinchinensis fermented with Weissella cibaria inhibit iNOS-mediated COX-2 induction pathway and inflammatory cytokines in LPS-stimulated RAW264.7 macrophage cells

Roots of Asparagus cochinchinesis have been widely used to treat fever, cough, kidney disease, breast cancer, inflammatory and brain disease, although the effects of their fermented products have not been assessed until now. To investigate the anti-inflammatory effects on macrophages of a butanol extract from A. cochinchinensis roots fermented with Weissella cibaria (BAW), alterations in the inducible nitric oxide synthase (iNOS)-mediated cyclooxygenase-2 (COX-2) induction pathway and inflammatory cytokine expression were measured in lipopolysaccharide (LPS)-activated RAW264.7 cells following pretreatment with BAW. Briefly, W. cibaria was selected from two bacterial strains for the fermentation of A. cochinchinensis roots based on its hyaluronidase inhibition and NO suppression rates. Following fermentation with W. cibaria, the level of various key components including total phenols and protodioscin were significantly enhanced in BAW. In addition, BAW exhibited high free radical scavenging activity (IC₅₀=31.62 µg/ml) and induced a decrease of intracellular ROS production in RAW264.7 cells following DCFH-DA staining. Significant suppressions in the expression level of important members of the iNOS-mediated COX-2 induction pathway and the phosphorylation of mitogen-activated protein kinase members were detected. The expressions of pro-inflammatory and anti-inflammatory cytokines were recovered in BAW pretreated RAW264.7 cells. Overall, these results suggest that BAW may suppress inflammatory responses through differential regulation of the iNOS-mediated COX-2 induction pathway and inflammatory cytokine expressions in LPS-activated RAW264.7 cells.

MicroRNA-191 acts as a tumor promoter by modulating the TET1-p53 pathway in intrahepatic cholangiocarcinoma

Current treatment of intrahepatic cholangiocarcinoma (ICC) remains ineffective because knowledge of ICC carcinogenesis is unclear. Increasing evidence suggests that microRNAs (miRNAs), including miR-191, play an important role in tumorigenesis; but expression and biological functions of miR-191 in ICC remain to be established. This study investigated the functions and underlying mechanisms of miR-191 in ICC. ICC miRNA profiles were generated in five pairs of ICC and matched to normal bile duct tissues by next-generation sequencing technology; ICC miRNA profiles were verified in 18 pairs of ICC tissues and normal bile duct tissues by quantitative RT-PCR. The miR-191-associated mechanisms in ICC were investigated in vitro and in vivo, and clinical outcomes associated with miR-191 were correlated in 84 patients. Our results showed that miR-191 expression was significantly increased in ICC compared with the adjacent normal bile duct tissues (P < 0.001). Overexpression of miR-191 promoted proliferation, invasion, and migration of cholangiocarcinoma cells in vitro and in vivo. The elevated miR-191 expression reduced the expression level of ten-eleven translocation 1 (TET1)-a direct target gene of miR-191 in ICC, which catalyzes demethylation. The reduced TET1 expression level allowed the methylated CpG-rich regions at the p53 gene transcription start site stay methylated, leading to reduced p53 expression level, which compromises p53's anticancer vigor. Finally, miR-191 was found to be an independent risk factor for poor prognosis in patients with ICC (overall survival, hazard ratio = 3.742, 95% confidence interval 2.080-6.733, P < 0.001; disease-free survival, hazard ratio = 2.331, 95% confidence interval 1.346-4.037, P = 0.003).

CONCLUSION

Our results suggest that overexpressed miR-191 is associated with ICC progression through the miR-191/TET1/p53 pathway. (Hepatology 2017;66:136-151).

The Clinical Impact of c-MET Over-Expression in Advanced Biliary Tract Cancer (BTC)

Background: c-MET is a proto-oncogene that encodes the tyrosine kinase receptor for hepatocyte growth factor (HGF). Activation of HGF-c-MET signaling involves cell invasiveness and evokes metastasis through direct involvement of tumor angiogenesis. However, the value of c-MET overexpression is still unknown in metastatic biliary tract cancer (BTC).

Methods: We analyzed the incidence and clinicopathologic characteristics of c-MET overexpression in advanced BTC. Moreover, we investigated the value of c-MET overexpression in predicting response to gemicitabine plus cisplatin (GC), a first line standard regimen, and as a prognostic marker in metastatic BTC.

Results: The BTC subtype distribution (N=44) was as follows: intrahepatic cholangiocarcinoma (IHCC, n=7), extrahepatic cholangiocarcinoma (EHCC, n=25) and gallbladder cancer (GBC, n=12). Liver (52.3%) was the predominant metastatic site, followed by lymph nodes (36.4%) and bone (15.9%). Among the 44 patients analyzed for c-MET expression, 15 (34.1%) exhibited c-MET overexpression in tumor tissues. There was no significant difference in the prevalence of c-MET overexpression among primary sites in EHCC (7/25, 28.0%), IHCC (3/7, 42.9%), and GBC (5/12, 41.7%). There was also no significant correlation between specific clinicopathologic variables and c-MET expression. Comparing the tumor-response to GC according to c-MET expression (overexpression vs. non-overexpression), there was no significant difference in either RR or DCR (p=0.394 and p >0.999, respectively). The median PFS for all 44 patients was 9.00 months (95% CI, 7.5-10.5 months) and there was no significant difference for PFS between patients with c-MET overexpression and those without (p=0.917). The median OS was 14.4 months (95% CI, 11.9-16.9 months). There was no significant difference in OS between patients with c-MET overexpression compared to those without (13.7 vs. 14.4 months, respectively; p=0.708).

Conclusions: c-MET overexpression was detected in 34.1% of advanced BTC patients irrespective of tumor location. c-MET overexpression did not predict response to GC or survival. Further studies are needed to fully elucidate the value of c-MET overexpression as a novel biomarker in these patients.

Screening of potential biomarkers for cholangiocarcinoma by integrated analysis of microarray data sets

Cholangiocarcinoma (CCA) continues to harbor a difficult prognosis and it is difficult to diagnose in its early stages. The molecular mechanisms of CCA oncogenesis and progression are poorly understood. This study aimed to identify candidate biomarkers for CCA. Integrated analysis of microarray data sets was performed to identify differentially expressed genes (DEGs) between CCA and normal tissues. Gene Ontology enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were then performed to identify the functions of DEGs. Furthermore, the protein-protein interaction (PPI) network of DEGs was constructed. The expressions of DEGs were validated in human CCA tissues by qRT-PCR. A set of 712 DEGs were identified in CCA compared with normal tissues, including 306 upregulated and 406 downregulated DEGs. It can be shown from the KEGG pathway analysis that some pathways may have important roles in pathology of CCA, including peroxisome proliferator-activated receptor signaling pathway, bile secretion, cell cycle, fat digestion and absorption. PPI network indicated that the significant hub proteins were PKM, SPP1 and TPM1. The abnormally overexpression PKM, SPP1 and TPM1 were closely related to oncogenesis and progression of CCA. PKM, SPP1, TPM1, COL1A1 and COL1A2 may serve as candidate biomarkers for diagnosis and prognosis of CCA.

Hepatolithiasis and intrahepatic cholangiocarcinoma: A review

Although the incidence of hepatolithiasis is decreasing as the pattern of gallstone disease changes in Asia, the prevalence of hepatolithiasis is persistently high, especially in Far Eastern countries. Hepatolithiasis is an established risk factor for cholangiocarcinoma (CCA), and chronic proliferative inflammation may be involved in biliary carcinogenesis and in inducing the upregulation of cell-proliferating factors. With the use of advanced imaging modalities, there has been much improvement in the management of hepatolithiasis and the diagnosis of hepatolithiasis-associated CCA (HL-CCA). However, there are many problems in managing the strictures in hepatolithiasis and differentiating them from infiltrating types of CCA. Surgical resection is recommended in cases of single lobe hepatolithiasis with atrophy, uncontrolled stricture, symptom duration of more than 10 years, and long history of biliary-enteric anastomosis. Even after resection, patients should be followed with caution for development of HL-CCA, because HL-CCA is an independent prognostic factor for survival. It is not yet clear whether hepatic resection can reduce the occurrence of subsequent HL-CCA. Furthermore, there are no consistent findings regarding prediction of subsequent HL-CCA in patients with hepatolithiasis. In the management of hepatolithiasis, important factors are the reduction of recurrence of cholangitis and suspicion of unrecognized HL-CCA.

Is c-Met oncoprotein expression an adverse prognosticator in extrahepatic bile duct cancer treated with curative resection followed by adjuvant chemoradiotherapy?

PURPOSE

To analyze the expression of c-Met, and to investigate correlations between the expression of c-Met, clinicopathologic variables, and survival in patients undergoing curative surgery followed by adjuvant chemoradiotherapy for extrahepatic bile duct (EHBD) cancer.

METHODS

Ninety EHBD cancer patients who underwent curative resection followed by adjuvant chemoradiotherapy were enrolled. Expression of c-Met was assessed with immunohistochemical staining on tissue microarray. The correlation between clinicopathologic variables and survival outcomes was evaluated using Kaplan-Meier method and Cox proportional hazard model.

RESULTS

On univariate analysis, 66 patients (76.7 %) showed c-Met expression. c-Met expression had a significant impact on 5-year overall survival (OS) (43.0 % in c-Met(+) vs. 25.0 % in c-Met(-), p = 0.0324), but not on loco-regional relapse-free survival or distant metastasis-free survival (DMFS). However, on multivariate analysis incorporating tumor location and nodal involvement, survival difference was not maintained (p = 0.2940). Tumor location was the only independent prognostic factor predicting OS (p = 0.0089). Hilar location tumors, nodal involvement, and poorly differentiated tumors were all identified as independent prognostic factors predicting inferior DMFS (p = 0.0030, 0.0013, and 0.0037, respectively).

CONCLUSIONS

This study showed that c-Met expression was not associated with survival outcomes in EHBD cancer patients undergoing curative resection followed by adjuvant chemoradiotherapy. Further studies are needed to fully elucidate the prognostic value of c-Met expression in these patients.

Metastasis-associated in colon cancer 1 is an independent prognostic biomarker for survival in Klatskin tumor patients

Curative treatment of intrahepatic cholangiocarcinoma (ICC) and hilar cholangiocarcinoma (Klatskin tumors) is limited to surgical resection or orthotopic liver transplantation. However, not all patients benefit from a surgical approach and suffer from early tumor recurrence. Response to chemotherapy is generally poor and, until today, no targeted therapy could be established. Metastasis-associated in colon cancer 1 (MACC1) is a recently discovered regulator of the hepatocyte growth factor (HGF)/Met/mitogen-activated protein kinase pathway, which induces proliferation, migration, and invasion in cell culture, as well as metastasis in mice. MACC1 expression shows a significant correlation with Met expression in colon cancer tissue and is highly prognostic for occurrence of distant metastasis and survival in colon cancer patients. Thus, we aimed to measure the expression of MACC1, Met, and HGF messenger RNA in microdissected tumor tissue and corresponding normal liver tissue of 156 patients with Klatskin tumors (n = 76) and ICC (n = 80) using real-time quantitative reverse-transcriptase polymerase chain reaction. We used immunohistochemical staining to validate the results. MACC1 expression in tumor tissue of both tumor entities was significantly higher than in corresponding normal liver tissue (P < 0.001). Klatskin tumor patients with a history of tumor recurrence had significantly higher MACC1 expression than those without tumor recurrence (P = 0.005). Uni- und multivariate survival analysis showed that Klatskin tumor patients with high MACC1 had a significantly shorter overall (OS) and disease-free survival (DFS; P = 0.001 and P < 0.001, respectively). The multivariate analysis confirmed MACC1 to be an independent factor for overall survival in Klatskin tumor patients (hazard ratio: 2.777; 95% confidence interval: 1.389-5.555; P = 0.004).

CONCLUSION

Our study identified MACC1 as a highly prognostic biomarker for OS and DFS in Klatskin tumor patients. MACC1 expression could become an important diagnostic tool and might be a candidate for targeted therapy.

Omega-3 Polyunsaturated Fatty Acids Upregulate 15-PGDH Expression in Cholangiocarcinoma Cells by Inhibiting miR-26a/b Expression

Prostaglandin E2 (PGE2) is a proinflammatory lipid mediator that promotes cancer growth. The 15-hydroxyprostaglandin dehydrogenase (15-PGDH) catalyzes oxidation of the 15(S)-hydroxyl group of PGE2, leading to its inactivation. Therefore, 15-PGDH induction may offer a strategy to treat cancers that are driven by PGE2, such as human cholangiocarcinoma. Here, we report that omega-3 polyunsaturated fatty acids (ω-3 PUFA) upregulate 15-PGDH expression by inhibiting miR-26a and miR-26b, thereby contributing to ω-3 PUFA-induced inhibition of human cholangiocarcinoma cell growth. Treatment of human cholangiocarcinoma cells (CCLP1 and TFK-1) with ω-3 PUFA (DHA) or transfection of these cells with the Fat-1 gene (encoding Caenorhabditis elegans desaturase, which converts ω-6 PUFA to ω-3 PUFA) significantly increased 15-PGDH enzymes levels, but with little effect on the activity of the 15-PGDH gene promoter. Mechanistic investigations revealed that this increase in 15-PGDH levels in cells was mediated by a reduction in the expression of miR-26a and miR-26b, which target 15-PGDH mRNA and inhibit 15-PGDH translation. These findings were extended by the demonstration that overexpressing miR-26a or miR-26b decreased 15-PGDH protein levels, reversed ω-3 PUFA-induced accumulation of 15-PGDH protein, and prevented ω-3 PUFA-induced inhibition of cholangiocarcinoma cell growth. We further observed that ω-3 PUFA suppressed miR-26a and miR-26b by inhibiting c-myc, a transcription factor that regulates miR-26a/b. Accordingly, c-myc overexpression enhanced expression of miR-26a/b and ablated the ability of ω-3 PUFA to inhibit cell growth. Taken together, our results reveal a novel mechanism for ω-3 PUFA-induced expression of 15-PGDH in human cholangiocarcinoma and provide a preclinical rationale for the evaluation of ω-3 PUFA in treatment of this malignancy.

Prognostıc value of increased HER2 expression in cancers of pancreas and biliary tree

Increased HER2 expression has a prognostic, and predictive value in many solid cancer types, predominantly in breast cancer. However the effects of HER2 on survival from cancers of pancreas, gall bladder, cholangiocellular, and ampullary region are not known. In this study, the effects of increased HER2 expression on these types of cancer have been analyzed. Immunohistochemical HER2 staining was performed in 31 (44.9 %) female, and 38 (55.1 %) male patients with a mean age of 65 ± 10 years, and various parameters, mostly survival rates of patients with pancreas (n = 30; 43.5 %), gall bladder (n = 17; 24.6 %), cholangiocellular (n = 12; 17.4 %), and ampullary region (n = 10; 14.5 %) carcinomas were evaluated. Strong (3 +) membranous staining for HER2 was observed in 2 patients with gall bladder cancers (11.76 % of all gall bladder cancers). In 2.90 % of all cases strong membranous staining (2+ or 3+) was observed. Weak (1+) membranous staining was noted in one (3.33 %) pancreatic, and one cholangiocellular (8.33 %) cancer patient, and in none of the ampullary region patient membranous staining for HER2 was observed. Since only scarce number of patients demonstrated membranous staining for HER2, survival analysis was not performed on these patients. Based on cytoplasmic HER2 staining scores, the patients were divided into weakly (0-3 pts; n = 17 patients; 24.66 %), moderate (4-5 pts; n = 22; 31.88 %), and strongly (6-7 pts; n = 30; 43.46 %) stained groups. Patients whose specimens demonstrated borderline statistical significant (p = 0.052) low staining for HER2 had higher survival rates when compared with other cases. Increased HER2 expression has no prognostic, and predictive value in cancers of pancreas, biliary tract, and ampulla vateri. If HER2 will be evaluated in these types of cancer, membranous, as well as cytoplasmic staining properties should be taken into account.

Molecular pathogenesis of intrahepatic cholangiocarcinoma

Cholangiocarcinoma (CCA) is an orphan cancer of the hepatobiliary tract, the incidence of which has increased in the past decade. The molecular pathogenesis of this treatment-refractory disease is poorly understood. Desmoplasia is a key causal feature of CCA; however, a majority of tumors develop with no apparent etiological background. The impact of the stromal compartment on tumor progression as well as resistance to therapy is in vogue, and the epithelial-stromal crosstalk may present a target for novel treatment strategies. As such, the complexity of tumor cellularity and the molecular mechanisms underlying the diversity of growth patterns of this malignancy remain a clinical concern. It is crucial to advance our present understanding of the molecular pathogenesis of CCA to improve current clinical strategies and patient outcome. This will facilitate the delineation of patient subsets and individualization for precision therapies. Many questions persevere as to the evolutionary process and cellular origin of the initial transforming event, the context of intratumoral plasticity and the causal driver action. Next-generation sequencing has begun to underline the persistent alterations, which may be the trigger of acquired drug resistance, and the cause of metastasis and disease recurrence. A complex issue that remains is to account for the heterogeneous pool of "backseat" aberrations, which in chromosomal proximity to the causative variant are likely to influence, for example, drug response. This review explores the recent advances in defining the molecular pathways implicated in the development of this devastating disease and, which present putative clinical strategies.

Interleukin-6 and cyclooxygenase-2 in hilar cholangiocarcinoma

The pathogenesis of hilar cholangiocarcinoma is a complex process involving progressive abnormalities of cell proliferation, apoptosis and differentiation. The progress of molecular biology techniques and the advances in research of malignant tumor cell receptors and proliferation regulation at the molecular level have led to the development of molecular targeted therapy. In recent years, many studies suggest that interleukin-6 (IL-6) and cyclooxygenase-2 (COX-2) levels are correlated with the development and prognosis of cholangiocarcinoma. A more detailed understanding of the roles of cytokines may provide new therapeutic targets for hilar cholangiocarcinoma. In this paper, we review the progress in research of IL-6 and COX in hilar cholangiocarcinoma.

miR-21 targets 15-PGDH and promotes cholangiocarcinoma growth

miRNAs are a group of small, noncoding RNAs that modulate the translation of genes by binding to specific target sites in the target mRNA. This study investigated the biologic function and molecular mechanism of miR-21 in human cholangiocarcinoma. In situ hybridization analysis of human cholangiocarcinoma specimens showed increased miR-21 in cholangiocarcinoma tissue compared with the noncancerous biliary epithelium. Lentiviral transduction of miR-21 enhanced human cholangiocarcinoma cell growth and clonogenic efficiency in vitro, whereas inhibition of miR-21 decreased these parameters. Overexpression of miR-21 also promoted cholangiocarcinoma growth using an in vivo xenograft model system. The NAD(+)-linked 15-hydroxyprostaglandin dehydrogenase (15-PGDH/HPGD), a key enzyme that converts the protumorigenic prostaglandin E2 (PGE2) to its biologically inactive metabolite, was identified as a direct target of miR-21 in cholangiocarcinoma cells. In parallel, cyclooxygenase-2 (COX2) overexpression and PGE2 treatment increased miR-21 levels and enhanced miR-21 promoter activity in human cholangiocarcinoma cells.

IMPLICATIONS

Cholangiocarcinogenesis and tumor progression are regulated by a novel interplay between COX-2/PGE2 and miR-21 signaling, which converges at 15-PGDH.

miR-101 inhibits cholangiocarcinoma angiogenesis through targeting vascular endothelial growth factor (VEGF)

Recent evidence has suggested an important role of miRNAs in liver biology and diseases, although the implication of miRNAs in cholangiocarcinoma remains to be defined further. This study was designed to examine the biological function and molecular mechanism of miR-101 in cholangiocarcinogenesis and tumor progression. In situ hybridization and quantitative RT-PCR were performed to determine the expression of miR-101 in human cholangiocarcinoma tissues and cell lines. Compared with noncancerous biliary epithelial cells, the expression of miR-101 is decreased in 43.5% of human cholangiocarcinoma specimens and in all three cholangiocarcinoma cell lines used in this study. Forced overexpression of miR-101 significantly inhibited cholangiocarcinoma growth in severe combined immunodeficiency mice. miR-101-overexpressed xenograft tumor tissues showed decreased capillary densities and decreased levels of vascular endothelial growth factor (VEGF) and cyclooxygenase-2 (COX-2). The VEGF and COX-2 mRNAs were identified as the bona fide targets of miR-101 in cholangiocarcinoma cells by both computational analysis and experimental assays. miR-101 inhibits cholangiocarcinoma angiogenesis by direct targeting of VEGF mRNA 3'untranslated region and by repression of VEGF gene transcription through inhibition of COX-2. This study established a novel tumor-suppressor role of miR-101 in cholangiocarcinoma and it suggests the possibility of targeting miR-101 and related signaling pathways for future therapy.

Cholangiocarcinoma: Biology, Clinical Management, and Pharmacological Perspectives

Cholangiocarcinoma (CCA), or tumor of the biliary tree, is a rare and heterogeneous group of malignancies associated with a very poor prognosis. Depending on their localization along the biliary tree, CCAs are classified as intrahepatic, perihilar, and distal, and these subtypes are now considered different entities that differ in tumor biology, the staging system, management, and prognosis. When diagnosed, an evaluation by a multidisciplinary team is essential; the team must decide on the best therapeutic option. Surgical resection of tumors with negative margins is the best option for all subtypes of CCA, although this is only achieved in less than 50% of cases. Five-year survival rates have increased in the recent past owing to improvements in imaging techniques, which permits resectability to be predicted more accurately, and in surgery. Chemotherapy and radiotherapy are relatively ineffective in treating nonoperable tumors and the resistance of CCA to these therapies is a major problem. Although the combination of gemcitabine plus platinum derivatives is the pharmacological treatment most widely used, to date there is no standard chemotherapy, and new combinations with targeted drugs are currently being tested in ongoing clinical trials. This review summarizes the biology, clinical management, and pharmacological perspectives of these complex tumors.

Mortality among persons in care with hepatitis C virus infection: the Chronic Hepatitis Cohort Study (CHeCS), 2006-2010

BACKGROUND

The number of deaths in hepatitis C virus (HCV)-infected persons recorded on US death certificates has been increasing, but actual rates and causes of death in these individuals have not been well elucidated.

METHODS

Disease-specific, liver-related, and non-liver-related mortality data for HCV-infected patients in an observational cohort study, the Chronic Hepatitis Cohort Study (CHeCS) at 4 US healthcare systems, were compared with multiple cause of death (MCOD) data in 12 million death certificates in 2006-2010. Premortem diagnoses, liver biopsies, and FIB-4 scores (a noninvasive measure of liver damage) were examined.

RESULTS

Of 2 143 369 adult patients seen at CHeCS sites in 2006-2010, 11 703 (0.5%) had diagnosed chronic HCV infection, and 1590 (14%) died. The majority of CHeCS decedents were born from 1945 to 1965 (75%), white (50%), and male (68%); mean age of death was 59 years, 15 years younger than MCOD deaths. The age-adjusted mortality rate for liver disease in CHeCS was 12 times higher than the MCOD rate. Before death, 63% of decedents had medical record evidence of chronic liver disease, 76% had elevated FIB-4 scores, and, among those biopsied, 70% had moderate or worse liver fibrosis. However, only 19% of all CHeCS decedents and only 30% of those with recorded liver disease had HCV listed on their death certificates.

CONCLUSIONS

HCV infection is greatly underdocumented on death certificates. The 16 622 persons with HCV listed in 2010 may represent only one-fifth of about 80 000 HCV-infected persons dying that year, at least two-thirds of whom (53 000 patients) would have had premortem indications of chronic liver disease.

Histological features of precancerous and early cancerous lesions of biliary tract carcinoma

Biliary tract carcinoma develops within the intrahepatic or extrahepatic biliary tree and gallbladder. Primary sclerosing cholangitis, hepatolithiasis, congenital choledochal cyst, liver fluke infection, pancreatobiliary maljunction, toxic exposures and hepatitis virus infection are risk factors for the development of human biliary carcinoma. The precise molecular abnormalities of biliary carcinogenesis are still unknown, but chronic inflammatory conditions induce the production of reactive oxygen or nitrogen species leading to DNA damage. Recent studies indicate that cholangiocarcinoma of the large bile duct may arise in premalignant lesions such as biliary intraepithelial neoplasm (BilIN) and intraductal papillary neoplasm of the bile duct (IPNB). BilIN and IPNB are generally confined to the large and septal-sized bile duct. BilINs are occasionally observed in non-biliary liver cirrhosis as well as chronic biliary disease. In contrast, the precursor lesion of intrahepatic cholangiocarcinoma of the small bile duct type remains unclear. We herein demonstrated the histological characteristics of different tumor development pathways from premalignant lesion to carcinoma in different sites of the biliary tree.

Molecular aspects of cholangiocarcinoma

Novel targets for therapeutic or chemopreventive approaches against cholangiocarcinoma (CCA) are urgently needed. In this review article, we discuss the molecular aspects of CCA including the role of erbB receptor tyrosine kinases (RTKs), downstream signaling pathways of these erbB RTKs, inflammatory mediators during gallbladder carcinogenesis and bile acids based on our study using a mouse model for human CCA (BK5.erbB2 mice) as well as additional information in the literature.

Cocarcinogenic effects of intrahepatic bile acid accumulation in cholangiocarcinoma development

Bile acid accumulation in liver with cholangiolar neoplastic lesions may occur before cholestasis is clinically detected. Whether this favors intrahepatic cholangiocarcinoma development has been investigated in this study. The E. coli RecA gene promoter was cloned upstream from Luc2 to detect in vitro direct genotoxic ability by activation of SOS genes. This assay demonstrated that bile acids were not able to induce DNA damage. The genotoxic effect of the DNA-damaging agent cisplatin was neither enhanced nor hindered by the hepatotoxic and hepatoprotective glycochenodeoxycholic and glycoursodeoxycholic acids, respectively. In contrast, thioacetamide metabolites, but not thioacetamide itself, induced DNA damage. Thus, thioacetamide was used to induce liver cancer in rats, which resulted in visible tumors after 30 weeks. The effect of bile acid accumulation on initial carcinogenesis phase (8 weeks) was investigated in bile duct ligated (BDL) animals. Serum bile acid measurement and determination of liver-specific healthy and tumor markers revealed that early thioacetamide treatment induced hypercholanemia together with upregulation of the tumor marker Neu in bile ducts, which were enhanced by BDL. Bile acid accumulation was associated with increased expression of interleukin (IL)-6 and downregulation of farnesoid X receptor (FXR). Bile duct proliferation and apoptosis activation, with inverse pattern (BDL > thioacetamide + BDL >> thioacetamide vs. thioacetamide > thioacetamide + BDL > BDL), were observed. In conclusion, intrahepatic accumulation of bile acids does not induce carcinogenesis directly but facilitates a cocarcinogenic effect due to stimulation of bile duct proliferation, enhanced inflammation, and reduction in FXR-dependent chemoprotection.

IMPLICATIONS

This study reveals that bile acids foster cocarcinogenic events that impact cholangiocarcinoma.

Intrahepatic cholangiocarcinoma: pathogenesis and rationale for molecular therapies

Intrahepatic cholangiocarcinoma (ICC) is an aggressive malignancy with very poor prognosis. Genome-wide, high-throughput technologies have made major advances in understanding the molecular basis of this disease, although important mechanisms are still unclear. Recent data have revealed specific genetic mutations (for example, KRAS, IDH1 and IDH2), epigenetic silencing, aberrant signaling pathway activation (for example, interleukin (IL)-6/signal transducer and activator of transcription 3 (STAT3), tyrosine kinase receptor-related pathways) and molecular subclasses with unique alterations (for example, proliferation and inflammation subclasses). In addition, some ICCs share common genomic traits with hepatocellular carcinoma. All this information provides the basis to explore novel targeted therapies. Currently, surgery at early stage is the only effective therapy. At more advanced stages, chemotherapy regimens are emerging (that is, cisplatin plus gemcitabine), along with molecular targeted agents tested in several ongoing clinical trials. Nonetheless, a first-line conclusive treatment remains an unmet need. Similarly, there are no studies assessing tumor response related with genetic alterations. This review explores the recent advancements in the knowledge of the molecular alterations underlying ICC and the future prospects in terms of therapeutic strategies leading towards a more personalized treatment of this neoplasm.

Reappraisal of the therapeutic role of celecoxib in cholangiocarcinoma

Cholangiocarcinoma (CCA), a lethal disease, affects many thousands worldwide yearly. Surgical resection provides the best chance for a cure; however, only one-third of CCA patients present with a resectable tumour at the time of diagnosis. Currently, no effective chemotherapy is available for advanced CCA. Cyclooxygenase-2 (COX-2) is a potential oncogene expressing in human CCA tissues and represents a candidate target for treatment; however, COX-2 inhibitors increase the risk of negative cardiovascular events as application for chemoprevention aim. Here, we re-evaluated the effectiveness and safety of celecoxib, one widely used COX-2 inhibitor, in treating CCA. We demonstrated that celecoxib exhibited an anti-proliferative effect on CGCCA cells via cell cycle arrest at G2 phase and apoptosis induction. Treatment for 5 weeks high dose celecoxib (160 mg/kg) significantly repressed thioacetamide-induced CCA tumour growth in rats as monitored by animal positron emission tomography through apoptosis induction. No obviously observable side effects were noted during the therapeutic period. As retrospectively reviewing 78 intrahepatic mass-forming CCA patients, their survival was strongly and negatively associated with a positive resection margin and high COX-2 expression. Based on our result, we concluded that short-term high dose celecoxib may be a promising therapeutic regimen for CCA. Yet its clinical application still needs more studies to prove its safety.

Elevated expression of cyclooxygenase-2 and microsomal prostaglandin E synthase-1 in primary sclerosing cholangitis: ιmplications for cholangiocarcinogenesis

Cholangiocarcinoma (CCA) occurs frequently in primary sclerosing cholangitis (PSC). Cyclooxygenase-2 (COX-2) and microsomal prostaglandin E synthase-1 (mPGES-1) induced by inflammation are believed to mediate prostaglandin E2 (PGE2) production thereby promoting carcinogenesis. Their expression in PSC-associated CCA tissues and non-neoplastic bile duct epithelial cells (BDECs) in PSC was investigated. COX-2 and mPGES-1 levels in 15 PSC patients (7 with CCA) were scored using immunohistochemical staining. The results were compared with those obtained in CCA tissues and non-neoplastic BDECs (controls) of 15 sporadic CCA patients. Non-neoplastic BDECs from large and small bile ducts were investigated separately. The mRNA expression levels of COX-2 and mPGES-1 in CCA tissues were analyzed by quantitative polymerase chain reaction. Ki-67 immunostaining was performed to evaluate cell proliferation. COX-2 was strongly expressed in PSC-associated CCA tissues and non-neoplastic BDECs in PSC. This expression was significantly upregulated in both compared with sporadic CCA tissues and non-neoplastic BDECs in sporadic CCA (both P<0.01). mPGES-1 was expressed at moderate to strong levels in PSC. Compared with controls, the expression was significantly higher in non-neoplastic small BDECs (P<0.01). COX-2 mRNA levels were significantly higher in PSC-associated tissues than in sporadic CCA tissues (P<0.01). Conversely, no differences were observed in mPGES-1 mRNA levels. Ki-67 labeling indices were higher in PSC-associated CCA tissues and non-neoplastic BDECs in PSC than in controls. In conclusion, COX-2 and mPGES-1 were highly expressed in PSC-associated CCA tissues and non-neoplastic BDECs in PSC, suggesting the involvement of COX-2 and mPGES-1 in cholangiocarcinogenesis.

cDNA microarray profiling of rat cholangiocarcinoma induced by thioacetamide

Cholangiocarcinoma (CCA) is a malignant neoplasm affecting thousands of individuals worldwide. CCA develops through a multistep process. In the current study, an oral thioacetamide (TAA)‑induced model of rat CCA was established which generates the histological progression of human CCA, particularly the mass‑forming type. Seven male Sprague‑Dawley rats were treated with TAA for 24 weeks to induce CCA. Following the generation of the rat CCA model, whole rat genomic oligo microarray was performed to examine gene expression profiles in CCA and non‑cancerous liver samples. In brief, 10,427 genes were found to be differentially expressed (8,318 upregulated and 3,489 downregulated) in CCA compared with non‑tumor liver tissue. The top 50 genes (upregulated or downregulated) were selected and their functional involvement in various pathways associated with cancer progression was analyzed, including cell proliferation, apoptosis, metabolism and the cell cycle. In addition, increased expression of CLCA3, COL1A2, DCN, GLIPr2 and NID1, and decreased expression of CYP2C7 and SLC10A1 were validated by quantitative real‑time PCR. Immunohistochemical analysis was performed to determine the protein expression levels of GLIPr2 and SLC10A1. The gene expression profiling performed in this study provides a unique opportunity for understanding the carcinogenesis of TAA‑induced CAA. In addition, expression profiling of a number of specific genes is likely to provide important novel biomarkers for the diagnosis of CCA and the development of novel therapeutic strategies for CCA.