Pathogenesis, diagnosis, and management of cholangiocarcinoma

[Diagnostics and treatment of cholangiocellular carcinoma]

Cholangiocellular carcinoma (CCA) is the second most frequent primary liver carcinoma and is an aggressive tumor, which is mostly diagnosed in advanced stages. The overall survival is poor. Histpathological analysis of tumor biopsies or cytological analysis of biliary brushings can be used to confirm the diagnosis. A differentiation is made between distal, perihilar and intrahepatic CCA. The anatomical position determines the diagnostic and therapeutic strategy. Before diagnostic or therapeutic measures are undertaken it is essential to resolve biliary obstruction via endoscopic stenting or percutaneous biliary drainage. Depending on the tumor stage curative treatment options comprise radical surgical resection with hepaticojejunostomy or in selected cases liver transplantation. For intrahepatic or distal CCA liver transplantation is not indicated. In the palliative setting systemic chemotherapy with gemcitabine and cisplatin leads to a significant improvement in survival time.

Deregulated MicroRNAs in Biliary Tract Cancer: Functional Targets and Potential Biomarkers

Biliary tract cancer (BTC) is still a fatal disease with very poor prognosis. The lack of reliable biomarkers for early diagnosis and of effective therapeutic targets is a major demanding problem in diagnosis and management of BTC. Due to the clinically silent and asymptomatic characteristics of the tumor, most patients are diagnosed at an already advanced stage allowing only for a palliative therapeutic approach. MicroRNAs are small noncoding RNAs well known to regulate various cellular functions and pathologic events including the formation and progression of cancer. Over the last years, several studies have shed light on the role of microRNAs in BTC, making them potentially attractive therapeutic targets and candidates as biomarkers. In this review, we will focus on the role of oncogenic and tumor suppressor microRNAs and their direct targets in BTC. Furthermore, we summarize and discuss data that evaluate the diagnostic power of deregulated microRNAs as possible future biomarkers for BTC.

Aberrant activation of Notch signaling in extrahepatic cholangiocarcinoma: clinicopathological features and therapeutic potential for cancer stem cell-like properties

BACKGROUND

Little is known about the roles of Notch signaling in cholangiocarcinoma (CC). The expression of hairy and enhancer of split 1 (Hes-1) has not been investigated yet in resected specimens of CC. Notch signaling has been reported to be related to cancer stem cell (CSC) like properties in some malignancies. Our aim is to investigate the participation of Notch signaling in resected specimens of extrahepatic CC (EHCC) and to evaluate the efficacy of CC cells with CSC-like properties by Notch signaling blockade.

METHODS

First, the expression of Notch1, 2, 3, 4 and Hes-1 was examined by immunohistochemistry in 132 resected EHCC specimens. The clinicopathological characteristics in the expression of Notch receptors and Hes-1 were investigated. Second, GSI IX, which is a γ-secretase-inhibitor, was used for Notch signaling blockade in the following experiment. Alterations of the subpopulation of CD24⁺CD44⁺ cells, which are surface markers of CSCs in EHCC, after exposure with GSI IX, gemcitabine (GEM), and the combination of GSI IX plus GEM were assessed by flow cytometry using the human CC cell lines, RBE, HuCCT1 and TFK-1. Also, anchorage-independent growth and mice tumorigenicity in the cells recovered by regular culture media after GSI IX exposure were assessed.

RESULTS

Notch1, 2, 3, 4 and Hes-1 in the resected EHCC specimens were expressed in 50.0, 56.1, 42.4, 6.1, and 81.8 % of the total cohort, respectively. Notch1 and 3 expressions were associated with poorer histological differentiation (P = 0.008 and 0.053). The patients with the expression of at least any one of Notch1-3 receptors, who were in 80.3 % of the total, exhibited poorer survival (P = 0.050). Similarly, the expression of Hes-1 tended to show poor survival (P = 0.093). In all of the examined CC cell lines, GSI IX treatment significantly diminished the subpopulation of CD24⁺CD44⁺ cells. Although GEM monotherapy relatively increased the subpopulation of CD24⁺CD44⁺ cells in all lines, GSI IX plus GEM attenuated it. Anchorage-independent growth and mice tumorigenicity were inhibited in GSI IX-pretreated cells in RBE and TFK-1 (P < 0.05).

CONCLUSION

Aberrant Notch signaling is involved with EHCC. Inhibition of Notch signaling is a novel therapeutic strategy for targeting cells with CSC-like properties.

LncRNAs H19 and HULC, activated by oxidative stress, promote cell migration and invasion in cholangiocarcinoma through a ceRNA manner

Background

Long non-coding RNAs (lncRNAs) are known to play important roles in different cell contexts, including cancers. However, little is known about lncRNAs in cholangiocarcinoma (CCA), a cholangiocyte malignancy with poor prognosis, associated with chronic inflammation and damage to the biliary epithelium. The aim of the study is to identify if any lncRNA might associate with inflammation or oxidative stress in CCA and regulate the disease progression.

Methods

In this study, RNA-seqs datasets were used to identify aberrantly expressed lncRNAs. Small interfering RNA and overexpressed plasmids were used to modulate the expression of lncRNAs, and luciferase target assay RNA immunoprecipitation (RIP) was performed to explore the mechanism of miRNA-lncRNA sponging.

Results

We firstly analyzed five available RNA-seqs datasets to investigate aberrantly expressed lncRNAs which might associate with inflammation or oxidative stress. We identified that two lncRNAs, H19 and HULC, were differentially expressed among all the samples under the treatment of hypoxic or inflammatory factors, and they were shown to be stimulated by short-term oxidative stress responses to H₂O₂ and glucose oxidase in CCA cell lines. Further studies revealed that these two lncRNAs promoted cholangiocyte migration and invasion via the inflammation pathway. H19 and HULC functioned as competing endogenous RNAs (ceRNAs) by sponging let-7a/let-7b and miR-372/miR-373, respectively, which activate pivotal inflammation cytokine IL-6 and chemokine receptor CXCR4.

Conclusions

Our study revealed that H19 and HULC, up-regulated by oxidative stress, regulate CCA cell migration and invasion by targeting IL-6 and CXCR4 via ceRNA patterns of sponging let-7a/let-7b and miR-372/miR-373, respectively. The results suggest that these lncRNAs might be the chief culprits of CCA pathogenesis and progression. The study provides new insight into the mechanism linking lncRNA function with CCA and may serve as novel targets for the development of new countermeasures of CCA.

Electronic supplementary material

The online version of this article (doi:10.1186/s13045-016-0348-0) contains supplementary material, which is available to authorized users.

The case for immune-based approaches in biliary tract carcinoma

Biliary tract cancers (BTC) comprise a group of uncommon malignancies in which the standard therapies are minimally effective and evolve slowly. Like the majority of gastrointestinal cancers, with some notable exceptions, the impact of immune-based approaches has yet to be seen. However, the etiological background of BTC-overlapping in almost every known causative or associated factor with inflammation-provides a strong clue that these approaches may have an impact in this group of diseases. This review covers what we currently know about the role of the immune system in the etiology of BTC, highlighting differences by subtype, and pointing to the therapeutic opportunities currently entering the clinic or about to do so. (Hepatology 2016;64:1785-1791).

Current Status on Cholangiocarcinoma and Gallbladder Cancer

BACKGROUND

Cholangiocarcinomas (CC) as well as gallbladder cancers are relatively rare and intractable diseases. Clinical, pathological, and epidemiological studies on these tumors have been under investigation. The current status and/or topics on biliary tract cancers have been reported in the East West Association of Liver Tumor (EWALT), held in Milano, Italy in 2015.

SUMMARY

All the authors, herein, specifcally reported the current status and leading-edge findings on biliary tract cancers as the following sequence: epidemiology of CC, surgical therapy for intrahepatic CC, surgical therapy for perihilar CC, surgical therapy for gallblad der cancer, chemotherapy for biliary tract cancers, and new histological features in CC.

KEY MESSAGE

The present review article will update the knowledge on biliary tract cancers, en hancing the quality of daily clinical practice. However, many features about these cancers remain unknown; further studies are required to establish disease-specific optimal treatment strategies.

TAZ regulates cell proliferation and sensitivity to vitamin D3 in intrahepatic cholangiocarcinoma

The transcriptional coactivator with PDZ binding motif (TAZ) is reported as one of the nuclear effectors of Hippo-related pathways. TAZ is found overexpressed in many primary tumors and could regulate many biological processes. However, little is known about the role of TAZ in Intrahepatic Cholangiocarcinoma (ICC). In this study, we found that TAZ is expressed more in ICC tissues than in peritumoral tissue, and a robust expression of TAZ is correlated with a lower overall survival rate of ICC patients after hepatectomy. TAZ knockdown results in an increase in cell apoptosis, a promotion of cell-cycle arrest and a decrease in tumor size and weight in vivo through an increased expression of p53. Vitamin D3 can also inhibit cell proliferation by promoting p53 expression in ICC cells. A reduction in TAZ can also enhance the sensitivity of tumor cells to vitamin D by regulating the p53/CYP24A1 pathway. In conclusion, TAZ is associated with the proliferation and drug-resistance of ICC cells, and could be a novel therapeutic target for the treatment of ICC.

Bile duct carcinoma recurrence in the papillary region in a long-term survivor of hilar cholangiocarcinoma: a case report

Background

Because of its high rate of early recurrence and its poor prognosis, long-term survival after cholangiocarcinoma is rare; therefore, only limited information on patients surviving more than 5 years after surgical therapy is available.

Case presentation

We report the case of a 57-year-old white man who developed a distal bile duct carcinoma 9 years after curative surgical therapy of intrahepatic cholangiocarcinoma. He had undergone a right lobe hemihepatectomy 11 years ago. Nine years later, he was diagnosed with a distal bile duct carcinoma and a duodenopancreatectomy was performed. On histologic examination both carcinomas revealed a tubular and papillary growth pattern with cancer-free resection margins and for both carcinomas there were no signs of lymphatic infiltration or metastatic spreading. Targeted next-generation sequencing showed an identical activating mutation pattern in both carcinomas.

Conclusions

Late recurrence of cholangiocarcinoma, even anatomically distant to the primary, in long-time survivors is possible and could be caused by a distinct tumor biology. A better understanding of the individual tumor biology could help hepatologists as well as hepatobiliary and pancreatic surgeons in their daily treatment of these patients.

Metformin potentiates the anticancer activities of gemcitabine and cisplatin against cholangiocarcinoma cells in vitro and in vivo

Metformin, an oral biguanide drug used to treat type 2 diabetes, has displayed anticancer activities in several types of cancer cells. The combination of gemcitabine and cisplatin is the standard chemotherapy regimen for cholangiocarcinoma, but its benefit is limited. The present study aimed to investigate whether metformin could enhance the activities of gemcitabine and cisplatin against cholangiocarcinoma, and the underlying mechanisms. Metformin inhibited the proliferation of human cholangiocarcinoma RBE and HCCC-9810 cells and induced cell cycle arrest at the G0/G1 phase by increasing the activation of AMP-activated protein kinase (AMPK) pathways. Metformin upregulated the expression of p21Waf1 and p27kip1, and downregulated the expression of cyclin D1, a key protein required for cell cycle progression. The combination of gemcitabine and cisplatin inhibited the proliferation and induced the apoptosis of human cholangiocarcinoma cells by inducing the phosphorylation of AMPK, downregulating cyclin D1, and activating caspase-3. Administration of metformin enhanced the efficacy of gemcitabine and cisplatin to suppress the growth of cholangiocarcinoma tumors established in experimental models by inhibiting cell proliferation and inducing cell apoptosis through their effects on AMPK, cyclin D1 and caspase-3. Given that metformin has been used to treat type 2 diabetes patients for over half a century due to its superior safety profile, the results presented here indicate that metformin may be a potent agent for enhancing the efficacy of gemcitabine and cisplatin in the treatment of cholangiocarcinoma.

Improving the diagnostic yield of single-operator cholangioscopy-guided biopsy of indeterminate biliary strictures: ROSE to the rescue? (with video)

BACKGROUND AND AIMS

Tissue diagnosis, regardless of technique or endoscope used, can be challenging in patients with indeterminate biliary strictures (IDBSs). This exploratory study evaluated the utility and role of rapid onsite evaluation of touch imprint cytology (ROSE-TIC) when single-operator cholangioscopy (SOC)-guided biopsies of IDBSs are performed.

METHODS

Patients with IDBSs were evaluated by intraprocedural ROSE-TIC during SOC-guided biopsy procedures. Final diagnosis was established by long-term patient follow-up in conjunction with off-site findings or surgical histology. The main outcome measure was to evaluate the utility of ROSE-TIC by determination of its operating characteristics and comparison with off-site histologic assessment.

RESULTS

Of 31 patients with IDBSs, tissue diagnosis was indeterminate at prior ERCP-guided brush and/or biopsy in 14, prior EUS-guided FNA (EUS-FNA) in 6, and a mass could not be identified at EUS in 11. The mean number of biopsies performed was 3.3 (range 1-8), and diagnostic interpretation by ROSE-TIC was diagnostic and/or suspicious for carcinoma in 15, benign in 13, atypical-reactive in 2, and bile duct intraductal papillary mucinous neoplasm in 1. Final diagnosis by surgical histology (n = 4), death by disease (n = 10), and patient follow-up (n = 17) showed that the overall sensitivity of ROSE-TIC for diagnosing malignancy was 100%, specificity 88.9%, positive predictive value 86.7%, negative predictive value 100%, and diagnostic accuracy 93.5%.

CONCLUSIONS

Preliminary data suggest that the diagnostic outcomes of SOC-guided biopsies in IDBSs can be significantly improved by using ROSE-TIC. This technique also may benefit centers that rely mainly on fluoroscopy-guided intraductal biopsies.

Dilation of Strictures in Patients with Inflammatory Bowel Disease: Who, When and How

Stricture formation occurs in up to 40% of patients with inflammatory bowel disease (IBD). Patients are often symptomatic, resulting in significant morbidity, hospitalizations, and loss of productivity. Strictures can be managed endoscopically in addition to traditional surgical management (sphincteroplasty or resection of the affected bowel segments). About 3% to 5% patients with IBD develop primary sclerosing cholangitis (PSC), which results in stricture formation in the biliary tree, managed for the most part by endoscopic therapies. In this article, we discuss endoscopic management of strictures both in the alimentary tract and biliary tree in patients with IBD and/or PSC.

The rise of the FGFR inhibitor in advanced biliary cancer: the next cover of time magazine?

Cholangiocarcinomas (CCAs) are heterogeneous tumors arising from the biliary tract with features of cholangiocyte differentiation. CCAs are aggressive tumors with limited treatment options and poor overall survival. Only a subset of CCA patients with early stage disease can avail potentially curative treatment options. For advanced biliary tract tumors, currently there are limited effective treatment modalities. Recent advances have provided greater insight into the genomic landscape of CCAs. The fibroblast growth factor receptor (FGFR) pathway is involved in key cellular processes essential to survival and differentiation. Accordingly, aberrant FGFR signaling has significant oncogenic potential. Recent discovery of FGFR2 gene fusions in CCA has heightened interest in FGFR inhibition in advanced biliary tract cancer. These findings have served as a catalyst for ongoing clinical investigation of FGFR inhibition in CCA patients with various FGFR signaling abnormalities. Herein, we review FGFR aberrations in CCA and their prognostic implications, FGFR targeting as a viable therapeutic option in advanced biliary tract malignancies, and future directions for development of combination approaches utilizing FGFR inhibition.

The management of autoimmunity in patients with cholestatic liver diseases

Cholestatic liver diseases are rare diseases that often lead to cirrhosis and its consequent complications. In addition to liver-related morbidity, patients with cholestatic liver diseases often suffer from autoimmune diseases that affect several organs and tissues. The robust and efficient data collection and collaboration between hepatologists and rheumatologists have led to significant advancements in understanding the relationship between the cholestatic liver diseases and associated autoimmune diseases. In this paper, we discuss the cholestatic liver diseases (primary biliary cirrhosis, primary sclerosing cholangitis and immunoglobulin G4 associated cholangitis) and associated autoimmune diseases.

Fascin Induces Epithelial-Mesenchymal Transition of Cholangiocarcinoma Cells by Regulating Wnt/β-Catenin Signaling

Background

Our preliminary study suggested that the expression of Fascin was increased in cholangiocarcinoma, which indicating poor prognosis The present study aimed to explore the roles and mechanisms of Fascin during the progression of cholangiocarcinoma.

Material/Methods

We evaluated the knockdown effect of endogenous Fascin expression by Short hairpin RNA (shRNA) in QBC939 cells. Cell proliferation was confirmed by MTS assay. Migration and invasion assay was used to examine the cell invasive ability. Tumorigenesis abilities in vivo were analyzed with a xenograft tumor model. Western blot analysis was used to test epithelial-mesenchymal transition (EMT) biomarkers and critical proteins in the Wnt/β-catenin signaling pathway.

Results

shRNA-mediated gene knockdown of Fascin significantly inhibited cell proliferation, invasion, and EMT, and shRNA-Fascin markedly inhibited the xenograft tumor volume. Silencing of Fascin up-regulated phosphorylation of β-catenin and decreased its nuclear localization. Additionally, knockdown of Fascin led to the upregulation of β-catenin and E-cadherin expression in plasma membrane fraction of QBC939 cells.

Conclusions

Our data indicate a key role of Fascin in cell proliferation, migration, and invasion in cholangiocarcinoma. Fascin promotes EMT of cholangiocarcinoma cells, in part through regulating Wnt/β-catenin signaling.

Antitumor effect of FGFR inhibitors on a novel cholangiocarcinoma patient derived xenograft mouse model endogenously expressing an FGFR2-CCDC6 fusion protein

Cholangiocarcinoma is a highly lethal cancer with limited therapeutic options. Recent genomic analysis of cholangiocarcinoma has revealed the presence of fibroblast growth factor receptor 2 (FGFR2) fusion proteins in up to 13% of intrahepatic cholangiocarcinoma (iCCA). FGFR fusions have been identified as a novel oncogenic and druggable target in a number of cancers. In this study, we established a novel cholangiocarcinoma patient derived xenograft (PDX) mouse model bearing an FGFR2-CCDC6 fusion protein from a metastatic lung nodule of an iCCA patient. Using this PDX model, we confirmed the ability of the FGFR inhibitors, ponatinib, dovitinib and BGJ398, to modulate FGFR signaling, inhibit cell proliferation and induce cell apoptosis in cholangiocarcinoma tumors harboring FGFR2 fusions. In addition, BGJ398 appeared to be superior in potency to ponatinib and dovitinib in this model. Our findings provide a strong rationale for the investigation of FGFR inhibitors, particularly BGJ398, as a therapeutic option for cholangiocarcinoma patients harboring FGFR2 fusions.

Profiling of downregulated blood-circulating miR-150-5p as a novel tumor marker for cholangiocarcinoma

Altered microRNA (miRNA) expression plays a role in cholangiocarcinoma (CCA) development; thus, detection of blood-circulating miRNAs could be useful as CCA markers. This study profiled serum miRNA levels in patients with primary sclerosing cholangitis (PSC) and CCA and then assessed the role of miR-150-5p in CCA progression in vitro. Three samples were randomly selected from each of 50 sera of healthy controls, 30 PSC sera, and 28 CCA sera with matched bile samples for miRNA microarray profiling. The dysregulated miRNAs were confirmed using qRT-PCR, and miR-150-5p was selected for further in vitro and ex vivo studies. The miRNA microarray identified three dysregulated miRNAs in both CCA and PSC samples, while miR-150-5p level was consistently lower in CCA sera, bile, and tissues than in normal control and PSC sera (P < 0.05). Furthermore, levels of miR-150-5p were associated with serum carbohydrate antigen 19-9 (CA19-9) levels and CCA pathological grade. Bioinformatic Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analyses showed that miR-150-5p could regulate hand-full gene pathways, including cancer pathway (P < 0.01). However, overexpression of miR-150-5p inhibited proliferation, migration, and invasion capability of CCA cells (P < 0.05). Luciferase reporter assay showed that miR-150-5p bound to an oncogene Ets including gene-1 (ELK1), and Western blot data confirmed that miR-150-5p suppressed ELK1 expression in CCA cell lines. These results suggest that reduced miR-150-5p expression could contribute to CCA development and progression due to uncontrolled ELK1 expression. Thus, further study could evaluate miR-150-5p as a novel target and predictor for CCA prevention and treatment.

Cholangiocarcinoma, gone without the Wnt?

Cholangiocarcinoma (CCA) is a relatively rare malignancy of the intra- or extra-hepatic bile ducts that is classified according to its anatomical localization as intrahepatic, perihilar or distal. Overall, CCA has a dismal prognosis due to typical presentation at an advanced irresectable stage, lack of effective non-surgical treatments, and a high rate of disease recurrence. CCA frequently arises on a background of chronic liver inflammation and cholestasis. Chronic inflammation is accompanied by enhanced cell turnover with generation of additional inflammatory stimuli, and a microenvironment rich in pro-inflammatory mediators and proliferative factors that enable accumulation of mutations, transformation and expansion of mutated cells. A recent study by Boulter et al implicates the Wnt signaling cascade in cholangiocarcinogenesis. Wnt ligands Wnt7B and Wnt10A were found to be highly overexpressed in human CCA tissue. Wnt7B protein was present throughout the tumor stroma, and often co-localized with a subset of CD68⁺ macrophages. To address in a direct manner whether Wnt signaling is engaged in development of CCA, Boulter et al explored the Wnt signaling pathway in an experimental model that recapitulates the multi-stage progression of human CCA. Wnt ligands found to be elevated in human CCA were also upregulated during the course of CCA development following thioacetamide treatment. Wnt10a increased during the (pre-cancerous) regenerative phase, while Wnt7b induction paralleled tumor growth. Along with upregulation of target genes, the findings demonstrate that the canonical Wnt pathway is progressively activated during cholangio-carcinogenesis. Macrophage depletion, eliminating a major source of Wnt7b, prevented activation of the canonical Wnt cascade, and resulted in reduced number and volume of tumors in this model. Moreover, specific inhibitors of the canonical Wnt pathway (ICG-001 and C-59) caused reduction of tumor area and number, in xenograft and thioacetamide models of CCA. The aggregated findings show that experimental, and presumably human CCA, is a Wnt-driven tumor. Modulation of Wnt signaling, alone or in combination with surgical or chemotherapy approaches, holds promise in the management of this fatal malignancy.

Biliary cancer: Utility of next-generation sequencing for clinical management

BACKGROUND

Biliary tract cancers (BTCs) typically present at an advanced stage, and systemic chemotherapy is often of limited benefit.

METHODS

Hybrid capture-based comprehensive genomic profiling (CGP) was performed for 412 intrahepatic cholangiocarcinomas (IHCCAs), 57 extrahepatic cholangiocarcinomas (EHCCAs), and 85 gallbladder carcinomas (GBCAs). The mutational profile was correlated with the clinical outcome of standard and experimental therapies for 321 patients. Clinical variables, detected mutations, and administered therapies were correlated with overall survival (OS) in a Cox regression model.

RESULTS

The most frequent genetic aberrations (GAs) observed were tumor protein 53 (TP53; 27%), cyclin-dependent kinase inhibitor 2A/B (CDKN2A/B; 27%), KRAS (22%), AT-rich interactive domain-containing protein 1A (ARID1A; 18%), and isocitrate dehydrogenase 1 (IDH1; 16%) in IHCCA; KRAS (42%), TP53 (40%), CDKN2A/B (17%), and SMAD4 (21%) in EHCCA; and TP53 (59%), CDKN2A/B (19%), ARID1A (13%), and ERBB2 (16%) in GBCA. Fibroblast growth factor receptor (FGFR; 11%) and IDH mutations (20%) were mostly limited to IHCCA but appeared to be mutually exclusive. In the IHCCA group, TP53 and KRAS mutations were associated significantly with poor OS, whereas FGFR2 mutations were associated with improved OS (P = .001), a younger age at onset, and female sex. IDH1/2 mutations were not prognostic. In a multivariate model, the effects of TP53 and FGFR GAs remained significant (P < .05). Patients with FGFR GAs had superior OS with FGFR-targeted therapy versus standard regimens (P = .006). Targeted therapy in IHCCA was associated with a numerical OS improvement (P = .07).

CONCLUSIONS

This is the largest clinically annotated data set of BTC cases with CGP and indicates the potential of CGP for improving outcomes. CGP should be strongly considered in the management of BTC patients. Cancer 2016;122:3838-3847. © 2016 American Cancer Society.

Immunohistochemistry using monoclonal antibody MsMab-2 is useful to detect IDH1 R132L in intrahepatic cholangiocarcinoma

Immunohistochemical analysis using specific antibodies is a useful and convenient method to detect proteins altered by somatic mutations. We previously generated the rat monoclonal antibody MsMab-2, which recognizes isocitrate dehydrogenase (IDH)1 R132L and IDH2 R172M. In the present study, we used an immunohistochemical method to examine MsMab-2 immunoreactivity in 95 cases of intrahepatic cholangiocarcinoma, including five IDH1 R132L and one IDH2 R172M mutant cases confirmed by direct sequencing. Tissue microarray section slides of all IDH1/2-mutant and wild-type cases, as well as whole section slides of IDH1 R132L and IDH2 R172M cases were immunostained using an autostainer. All IDH1 R132L cases showed positive staining for MsMab-2, while other IDH1/2 mutant and IDH1/2 wild-type cases were negative. Tumor cells of the immunopositive cases invariably showed strong reactivity using whole-section slides. We consider immunohistochemical analysis using MsMab-2 to be a useful means of detecting IDH1 R132L. Further analysis of its effectiveness against IDH2 R172M is necessary because of the small sample size in this study.

Cadherin-6 is a putative tumor suppressor and target of epigenetically dysregulated miR-429 in cholangiocarcinoma

Cholangiocarcinoma (CC) is a rare malignancy of the extrahepatic or intrahepatic biliary tract with an outstanding poor prognosis. Non-surgical therapeutic regimens result in minimally improved survival of CC patients. Global genomic analyses identified a few recurrently mutated genes, some of them in genes involved in epigenetic patterning. In a previous study, we demonstrated global DNA methylation changes in CC, indicating major contribution of epigenetic alterations to cholangiocarcinogenesis. Here, we aimed at the identification and characterization of CC-related, differentially methylated regions (DMRs) in potential microRNA promoters and of genes targeted by identified microRNAs. Twenty-seven hypermethylated and 13 hypomethylated potential promoter regions of microRNAs, known to be associated with cancer-related pathways like Wnt, ErbB, and PI3K-Akt signaling, were identified. Selected DMRs were confirmed in 2 independent patient cohorts. Inverse correlation between promoter methylation and expression suggested miR-129-2 and members of the miR-200 family (miR-200a, miR-200b, and miR-429) as novel tumor suppressors and oncomiRs, respectively, in CC. Tumor suppressor genes deleted in liver cancer 1 (DLC1), F-box/WD-repeat-containing protein 7 (FBXW7), and cadherin-6 (CDH6) were identified as presumed targets in CC. Tissue microarrays of a representative and well-characterized cohort of biliary tract cancers (n=212) displayed stepwise downregulation of CDH6 and association with poor patient outcome. Ectopic expression of CDH6 on the other hand, delayed growth in the CC cell lines EGI-1 and TFK-1, together suggesting a tumor suppressive function of CDH6. Our work represents a valuable repository for the study of epigenetically altered miRNAs in cholangiocarcinogenesis and novel putative, CC-related tumor suppressive miRNAs and oncomiRs.

14-3-3ζ and aPKC-ι synergistically facilitate epithelial-mesenchymal transition of cholangiocarcinoma via GSK-3β/Snail signaling pathway

Cholangiocarcinoma (CCA) invasion and metastasis are the primary causes of poor survival rates in patients. The epithelial-mesenchymal transition (EMT) is a crucial step in cancer invasion and metastasis. However, it is still unclear of the molecular mechanism. In this study, the expression of 14-3-3ζ and atypical protein kinase C-ι (aPKC-ι) was further detected in CCA tissues and cell lines. Meanwhile, we established the EMT model of CCA cells and investigated 14-3-3ζ and aPKC-ι co-regulatory effect on the EMT in vitro and in vivo. Further, we identified the downstream molecular glycogen synthase kinase 3 beta (GSK-3β)/Snail signalling pathway that contribute to regulating the EMT. Our data showed that the expression of 14-3-3ζ and aPKC-ι was synergistically increased in CCA tissues compared with adjacent noncancerous tissues and was intimately associated with differentiation and the tumour-node-metastasis (TNM) stage. Multivariate Cox regression analysis indicated that high 14-3-3ζ and aPKC-ι expression separately predicted a poor prognosis and were independent prognostic indicators in patients with CCA. The CO-IP experiment confirmed that the mutual binding relationship between 14-3-3ζ and aPKC-ι. Small interfering RNAs and siRNA rescue experiment demonstrated that 14-3-3ζ and aPKC-ι regulated each other. In addition, 14-3-3ζ and aPKC-ι pretreatment by si-RNA inhibit the phosphorylated GSK-3β and Snail expression during EMT. Meanwhile, silence of 14-3-3ζ or aPKC-ι suppressed CCA cells migration, metastasis and proliferation in vitro and in vivo. Our study demonstrates that 14-3-3ζ and aPKC-ι synergistically facilitate EMT of CCA via GSK-3β/Snail signalling pathway, and may be potential therapeutic target for CCA.

Leukemia inhibitory factor protects cholangiocarcinoma cells from drug-induced apoptosis via a PI3K/AKT-dependent Mcl-1 activation

Cholangiocarcinoma is an aggressive, strongly chemoresistant liver malignancy. Leukemia inhibitory factor (LIF), an IL-6 family cytokine, promotes progression of various carcinomas. To investigate the role of LIF in cholangiocarcinoma, we evaluated the expression of LIF and its receptor (LIFR) in human samples. LIF secretion and LIFR expression were assessed in established and primary human cholangiocarcinoma cell lines. In cholangiocarcinoma cells, we tested LIF effects on proliferation, invasion, stem cell-like phenotype, chemotherapy-induced apoptosis (gemcitabine+cisplatin), expression levels of pro-apoptotic (Bax) and anti-apoptotic (Mcl-1) proteins, with/without PI3K inhibition, and of pSTAT3, pERK1/2, pAKT. LIF effect on chemotherapy-induced apoptosis was evaluated after LIFR silencing and Mcl-1 inactivation.

Results show that LIF and LIFR expression were higher in neoplastic than in control cholangiocytes; LIF was also expressed by tumor stromal cells. LIF had no effects on cholangiocarcinoma cell proliferation, invasion, and stemness signatures, whilst it counteracted drug-induced apoptosis. Upon LIF stimulation, decreased apoptosis was associated with Mcl-1 and pAKT up-regulation and abolished by PI3K inhibition. LIFR silencing and Mcl-1 blockade restored drug-induced apoptosis.

In conclusion, autocrine and paracrine LIF signaling promote chemoresistance in cholangiocarcinoma by up-regulating Mcl-1 via a novel STAT3- and MAPK-independent, PI3K/AKT-dependent pathway. Targeting LIF signaling may increase CCA responsiveness to chemotherapy.

Identifying survival-associated ceRNA clusters in cholangiocarcinoma

Competing endogenous RNAs (ceRNAs) represent a novel layer regulations of long non-coding RNAs (lncRNAs) and genes that play important roles in cancer pathogenesis by binding microRNAs (miRNAs). However, the competition mechanism of ceRNAs in cholangiocarcinoma (CHOL) is not fully understood. In this study, we constructed a dysregulated ceRNA competitive network (CCEN) to globally characterize the competing difference between CHOL and normal tissues. Then, we integrated affinity propagation and Kaplan‑Meier (K-M) methods to identify functional clusters associated with survival. A total of 7 key ceRNA clusters were identified. Further functional annotation analyses found that Cluster23 and Cluster32 involved cell based functions, and the loss of ceRNA competitive relations in clusters may contribute to CHOL, by disturbing important biological processes, such as 'Pathway in cancer', MAPK and Neurotrophin signaling pathway. This study provides further insights into understanding the competitive mechanism of ceRNAs in CHOL.

ZEB1 expression is associated with prognosis of intrahepatic cholangiocarcinoma

BACKGROUND/AIM

Intrahepatic cholangiocarcinoma (ICC) is one of the most aggressive malignant tumours, so the identification of molecular targets for ICC is an important issue. Zinc finger E-box binding homeobox 1 (ZEB1) is a key inducer of epithelial-mesenchymal transition (EMT). The aim of the present study was to clarify the clinical significance of ZEB1 in ICC and the associations between ZEB1 expression and EMT-related proteins.

METHODS

We immunohistochemically examined the expression of EMT-related proteins, namely ZEB1, vimentin and E-cadherin, in ICC specimens from 102 patients. The clinicopathological and prognostic values of these markers were evaluated.

RESULTS

ZEB1 and vimentin were expressed in 46.1% and 43.1% of tumours, respectively, and E-cadherin expression was lost in 44.1% of tumours. ZEB1 expression showed a significant inverse correlation with E-cadherin expression (p=0.004) and a positive correlation with vimentin expression (p=0.022). Altered expression of ZEB1 was associated with aggressive tumour characteristics, including advanced tumour stage (p=0.037), undifferentiated-type histology (p=0.017), lymph node metastasis (p=0.024) and portal vein invasion (p=0.037). Moreover, overall survival rates were significantly lower for patients with high ZEB1 expression than for patients with low ZEB1 expression (p=0.027). Kaplan-Meier analysis also identified E-cadherin expression (p=0.041) and vimentin expression (p=0.049) as prognostic indicators for overall survival.

CONCLUSIONS

ZEB1 expression is associated with tumour progression and poor prognosis in patients with ICC through positive correlations with vimentin and negative correlations with E-cadherin. ZEB1 expression is associated with a poor prognosis and might be an attractive target for the treatment of ICC.

Clinical prognostic significance of regional and extended lymphadenectomy for biliary cancer with para-aortic lymph node metastasis: A systematic review and meta-analysis

BACKGROUND

The aim of our study was to evaluate clinical prognostic significance of regional and extended lymphadenectomy for biliary cancer with para-aortic lymph node metastasis.

METHODS

A thorough literature search was performed in PubMed/Medline, Cochrane Central Register, Embase, ISI Web of Science and Google Scholar between January 1965 and May 2014 with restricted articles for the English language. Data were processed for a meta-analysis by RevMan 5 software.

RESULTS

Altogether 10 retrospective studies were finally enrolled in our study. For positive para-aortic lymph node group irrespective of regional lymph node metastasis, the overall 1-, 3-, 5-yr pooled RR estimates of survival rates were 2.30, 1.70, and 1.42. There were significant differences between positive para-aortic lymph node group and negative group. For positive para-aortic lymph node group in the setting of regional lymph node metastasis, the overall 1-, 3-, 5-yr pooled RR estimates of survival rates were 1.57, 1.29, and 1.11, respectively. The long-term outcomes referred to 5-yr survival rate were similar between para-aortic lymph node metastasis and regional lymph node metastasis only.

DISCUSSION

Radical resection with extended lymphadenectomy should be caution in terms of the results of an intraoperative sampling biopsy of para-aortic lymph node, which requires a well-designed, prospective controlled study in the future.

The hepatic, biliary, and pancreatic network of stem/progenitor cell niches in humans: A new reference frame for disease and regeneration

Stem/progenitors for liver, biliary tree, and pancreas exist at early stages of development in the definitive ventral endoderm forming the foregut. In humans, they persist postnatally as part of a network, with evidence supporting their contributions to hepatic and pancreatic organogenesis throughout life. Multiple stem cell niches persist in specific anatomical locations within the human biliary tree and pancreatic ducts. In liver and pancreas, replication of mature parenchymal cells ensures the physiological turnover and the restoration of parenchyma after minor injuries. Although actively debated, multiple observations indicate that stem/progenitor cells contribute to repair pervasive, chronic injuries. The most primitive of the stem/progenitor cells, biliary tree stem cells, are found in peribiliary glands within extrahepatic and large intrahepatic bile ducts. Biliary tree stem cells are comprised of multiple subpopulations with traits suggestive of maturational lineage stages and yet capable of self-replication and multipotent differentiation, being able to differentiate to mature liver cells (hepatocytes, cholangiocytes) and mature pancreatic cells (including functional islet endocrine cells). Hepatic stem cells are located within canals of Hering and bile ductules and are capable of differentiating to hepatocyte and cholangiocyte lineages. The existence, phenotype, and anatomical location of stem/progenitors in the adult pancreas are actively debated. Ongoing studies suggest that pancreatic stem cells reside within the biliary tree, primarily the hepatopancreatic common duct, and are rare in the pancreas proper. Pancreatic ducts and pancreatic duct glands harbor committed pancreatic progenitors.

CONCLUSION

The hepatic, biliary, and pancreatic network of stem/progenitor cell niches should be considered as a framework for understanding liver and pancreatic regeneration after extensive or chronic injuries and for the study of human chronic diseases affecting these organs. (Hepatology 2016;64:277-286).

An Overview of the Evolution of Direct Cholangioscopy Techniques for Diagnosis and Therapy

Direct examination of the biliary tree with endoscopes has been a challenge since endoscopists began performing endoscopic retrograde cholangiopancreatography (ERCP) in the late 1960s. Previously, surgeons had used rigid instruments intraoperatively, which made examination difficult. The first direct cholangioscopy performed by an endoscopist was likely unintentionally done in a patient with postsurgical anatomy. Indirect imaging, ERCP, and percutaneous transhepatic cholangiography are helpful modalities for examining the biliary tree, but they are limited procedures, particularly with regard to the evaluation and treatment of strictures and bile duct stones. This article reviews the history and evolution of direct cholangioscopy since the advent of flexible endoscopes. Additionally, the article describes a new single-operator cholan-gioscopy technique for direct visualization of the biliary tree for diagnosis and intervention. There remains opportunity for innovation as endoscopists strive for safe and less-invasive methods for the identification and treatment of biliary pathology.

The diagnostic performance of serum MUC5AC for cholangiocarcinoma: A systematic review and meta-analysis

Specific diagnostic biomarker for cholangiocarcinoma (CCA) has been lacking. This systematic review and meta-analysis was performed aiming to investigate serum MUC5AC's diagnostic performance on CCA.Studies investigating serum MUC5AC's diagnostic value on CCA were retrieved from Pubmed, Embase, and Cochrane Library. The methodology quality of included studies was assessed according to QUADAS-2. Diagnostic 2 × 2 table was extracted from each eligible study, Meta-disc 1.4 was used for statistical analysis, data synthesis was done using a random-effects model. Subgroup analyses were conducted according to region and array method.Six eligible studies were identified, a total of 1213 patients were involved in the meta-analysis. The AUC on SROC was 0.9138, and the Q* was 8463. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio (DOR) were 0.69 (95% CI: 0.65-0.73), 0.93 (95% CI: 0.91-0.95), 8.99 (95% CI: 5.65-14.30), 0.33 (95% CI: 0.24-0.46), and 33.98 (95% CI: 20.12-57.40), respectively. Targeting MUC5AC's epitope has a higher pooled sensitivity than targeting MUC5AC protein (0.77 vs 0.63). There was substantial cross-study heterogeneity.Serum MUC5AC might be potentially used as a surrogate marker in the diagnosis of CCA. However, the appropriate array method and the optimum cut-off value are yet to be decided.

The diagnosis and treatment of cholangiocarcinoma

BACKGROUND

Cholangiocarcinoma (CCA) is the second most common primary hepatic tumor in Germany, with about 3500 new cases per year. In recent years, its prognosis has improved because of wider resections and the establishment of local treatment and chemotherapy in the palliative situation.

METHODS

This review is based on pertinent articles that were retrieved by a selective literature search in the PubMed database with the keywords "cholangiocarcinoma AND diagnostic OR therapy." Articles in English or German published up to January 2014 were considered.

RESULTS

The sole curative treatment for CCA is surgery, but 40-85% of all patients have recurrent disease even after radical excision. Because of this high recurrence rate, adjuvant treatments are now under intense discussion. For unresectable CCA without distant metastases, small case series have shown that liver transplantation can yield promising survival rates of over 50% at 5 years. For many patients with CCA, however, only palliative treatments can be offered, including endoscopic clearing of the biliary pathways. Because of the low prevalence of the disease, there have been only a few phase 3 studies of palliative chemotherapy for CCA. On the basis of one positive phase 3 study, chemotherapy with gemcitabine and cisplatin is considered the standard and now plays an established role in palliative care.

CONCLUSION

CCA presents a special challenge in gastroenterology, oncology, and visceral surgery because of the difficulty in establishing the diagnosis, local complications in the biliary pathways, and a high recurrence rate after resection. Future studies should address not only the role of adjuvant chemotherapy, but also the efficacy of combined local and systemic treatment.

miR-17-92 cluster promotes cholangiocarcinoma growth: evidence for PTEN as downstream target and IL-6/Stat3 as upstream activator

miR-17-92 is an oncogenic miRNA cluster implicated in the development of several cancers; however, it remains unknown whether the miR-17-92 cluster is able to regulate cholangiocarcinogenesis. This study was designed to investigate the biological functions and molecular mechanisms of the miR-17-92 cluster in cholangiocarcinoma. In situ hybridization and quantitative RT-PCR analysis showed that the miR-17-92 cluster is highly expressed in human cholangiocarcinoma cells compared with the nonneoplastic biliary epithelial cells. Forced overexpression of the miR-17-92 cluster or its members, miR-92a and miR-19a, in cultured human cholangiocarcinoma cells enhanced tumor cell proliferation, colony formation, and invasiveness, in vitro. Overexpression of the miR-17-92 cluster or miR-92a also enhanced cholangiocarcinoma growth in vivo in hairless outbred mice with severe combined immunodeficiency (SHO-Prkdc(scid)Hr(hr)). The tumor-suppressor, phosphatase and tensin homolog deleted on chromosome 10 (PTEN), was identified as a bona fide target of both miR-92a and miR-19a in cholangiocarcinoma cells via sequence prediction, 3' untranslated region luciferase activity assay, and Western blot analysis. Accordingly, overexpression of the PTEN open reading frame protein (devoid of 3' untranslated region) prevented miR-92a- or miR-19a-induced cholangiocarcinoma cell growth. Microarray analysis revealed additional targets of the miR-17-92 cluster in human cholangiocarcinoma cells, including APAF-1 and PRDM2. Moreover, we observed that the expression of the miR-17-92 cluster is regulated by IL-6/Stat3, a key oncogenic signaling pathway pivotal in cholangiocarcinogenesis. Taken together, our findings disclose a novel IL-6/Stat3-miR-17-92 cluster-PTEN signaling axis that is crucial for cholangiocarcinogenesis and tumor progression.

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.

IQGAP1 promotes CXCR4 chemokine receptor function and trafficking via EEA-1+ endosomes

IQGAP1 mediates CXCR4 cell surface expression and signaling by regulating EEA-1⁺ endosome interactions with microtubules during CXCR4 trafficking and recycling.

IQ motif–containing GTPase-activating protein 1 (IQGAP1) is a cytoskeleton-interacting scaffold protein. CXCR4 is a chemokine receptor that binds stromal cell–derived factor-1 (SDF-1; also known as CXCL12). Both IQGAP1 and CXCR4 are overexpressed in cancer cell types, yet it was unclear whether these molecules functionally interact. Here, we show that depleting IQGAP1 in Jurkat T leukemic cells reduced CXCR4 expression, disrupted trafficking of endocytosed CXCR4 via EEA-1⁺ endosomes, and decreased efficiency of CXCR4 recycling. SDF-1–induced cell migration and activation of extracellular signal-regulated kinases 1 and 2 (ERK) MAPK were strongly inhibited, even when forced overexpression restored CXCR4 levels. Similar results were seen in KMBC and HEK293 cells. Exploring the mechanism, we found that SDF-1 treatment induced IQGAP1 binding to α-tubulin and localization to CXCR4-containing endosomes and that CXCR4-containing EEA-1⁺ endosomes were abnormally located distal from the microtubule (MT)-organizing center (MTOC) in IQGAP1-deficient cells. Thus, IQGAP1 critically mediates CXCR4 cell surface expression and signaling, evidently by regulating EEA-1⁺ endosome interactions with MTs during CXCR4 trafficking and recycling. IQGAP1 may similarly promote CXCR4 functions in other cancer cell types.

Halogenated hydrocarbon solvent-related cholangiocarcinoma risk: biliary excretion of glutathione conjugates of 1,2-dichloropropane evidenced by untargeted metabolomics analysis

Recently, the International Agency for Research on Cancer issued a warning about the carcinogenicity of 1,2-dichloropropane (1,2-DCP) to humans based on an epidemiological study suggesting a relationship between the incidence of cholangiocarcinoma and occupational exposure to halogenated hydrocarbon solvent comprised mostly of 1,2-DCP. Although this dihaloalkane has been used in various industrial fields, there has been no biological evidence explaining the cholangiocarcinoma latency, as well as little understanding of general cholangiocarcinoma risk. In the present study, we explored the biliary excretion of 1,2-DCP metabolites by an untargeted metabolomics approach and the related molecular mechanism with in vitro and in vivo experiments. We hypothesized that the biliary excretion of carcinogens derived from 1,2-DCP contribute to the increased cholangiocarcinoma risk. We found that 1,2-DCP was conjugated with glutathione in the liver, and that the glutathione-conjugated forms of 1,2-DCP, including a potential carcinogen that contains a chloride atom, were excreted into bile by the bile canalicular membrane transporter, ABCC2. These results may reflect a risk in the backfiring of biliary excretion as a connatural detoxification systems for xenobiotics. Our findings would contribute to uncover the latent mechanism by which the chronic exposure to 1,2-DCP increases cholangiocarcinoma risk and future understanding of cholangiocarcinoma biology.

Antitumor effect of the novel sphingosine kinase 2 inhibitor ABC294640 is enhanced by inhibition of autophagy and by sorafenib in human cholangiocarcinoma cells

Sphingosine kinase 2 (Sphk2) has an oncogenic role in cancer. A recently developed first-in-class Sphk2 specific inhibitor ABC294640 displays antitumor activity in many cancer models. However, the role of Sphk2 and the antitumor activity of its inhibitor ABC294640 are not known in cholangiocarcinoma. We investigated the potential of targeting Sphk2 for the treatment of cholangiocarcinoma. We found that Sphk2 is overexpressed in five established human cholangiocarcinoma cell lines (WITT, HuCCT1, EGI-1, OZ and HuH28) and a new patient-derived cholangiocarcinoma cell line (LIV27) compared to H69 normal cholangiocytes. Inhibition of Sphk2 by ABC294640 inhibited proliferation and induced caspase-dependent apoptosis. Furthermore, we found that ABC294640 inhibited STAT3 phosphorylation, one of the key signaling pathways regulating cholangiocarcinoma cell proliferation and survival. ABC294640 also induced autophagy. Inhibition of autophagy by bafilomycin A1 or chloroquine potentiated ABC294640-induced cytotoxicity and apoptosis. In addition, ABC294640 in combination with sorafenib synergistically inhibited cell proliferation of cholangiocarcinoma cells. Strong decreases in STAT3 phosphorylation were observed in WITT and HuCCT1 cells exposed to the ABC294640 and sorafenib combination. These findings provide novel evidence that Sphk2 may be a rational therapeutic target in cholangiocarcinoma. Combinations of ABC294640 with sorafenib and/or autophagy inhibitors may provide novel strategies for the treatment of cholangiocarcinoma.

A Hippo and Fibroblast Growth Factor Receptor Autocrine Pathway in Cholangiocarcinoma

Herein, we have identified cross-talk between the Hippo and fibroblast growth factor receptor (FGFR) oncogenic signaling pathways in cholangiocarcinoma (CCA). Yes-associated protein (YAP) nuclear localization and up-regulation of canonical target genes was observed in CCA cell lines and a patient-derived xenograft (PDX). Expression of FGFR1, -2, and -4 was identified in human CCA cell lines, driven, in part, by YAP coactivation of TBX5. In turn, FGFR signaling in a cell line with minimal basal YAP expression induced its cellular protein expression and nuclear localization. Treatment of YAP-positive CCA cell lines with BGJ398, a pan-FGFR inhibitor, resulted in a decrease in YAP activation. FGFR activation of YAP appears to be driven largely by FGF5 activation of FGFR2, as siRNA silencing of this ligand or receptor, respectively, inhibited YAP nuclear localization. BGJ398 treatment of YAP-expressing cells induced cell death due to Mcl-1 depletion. In a YAP-associated mouse model of CCA, expression of FGFR 1, 2, and 4 was also significantly increased. Accordingly, BGJ398 treatment was tumor-suppressive in this model and in a YAP-positive PDX model. These preclinical data suggest not only that the YAP and Hippo signaling pathways culminate in an Mcl-1-regulated tumor survival pathway but also that nuclear YAP expression may be a biomarker to employ in FGFR-directed therapy.

A novel mouse model of intrahepatic cholangiocarcinoma induced by liver-specific Kras activation and Pten deletion

Intrahepatic cholangiocarcinoma (ICC) is an aggressive malignancy with poor prognosis and its incidence is increasing worldwide. Recently, several types of cells have been considered as the origin of ICC, namely cholangiocytes, liver progenitor cells, and hepatocytes. Here, we have established a novel mouse model of ICC by liver-specific Kras activation and Pten deletion. An activating mutation of Kras in combination with deletion of Pten was introduced in embryonic hepatic bipotential progenitor cells (so-called hepatoblasts) and mature hepatocytes using the Cre-loxP system. As a result, liver-specific Kras activation and homozygous Pten deletion cooperated to induce ICCs exclusively. In contrast, Kras activation in combination with heterozygous Pten deletion induced both ICCs and HCCs, whereas Kras activation alone resulted in HCCs but not ICCs. Furthermore, a cell-lineage visualization system using tamoxifen-inducible Cre-loxP demonstrated that the ICCs did not originate from hepatocytes but from cholangiocytes. Our data suggest that mice carrying liver-specific Kras activation in combination with homozygous Pten deletion should be useful for the investigation of therapeutic strategies for human ICC.

Multiple cellular origins and molecular evolution of intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICC) is an aggressive malignancy associated with unfavorable prognosis and for which no effective treatments are available. Its molecular pathogenesis is poorly understood. Genome-wide sequencing and high-throughput technologies have provided critical insights into the molecular basis of ICC while sparking a heated debate on the cellular origin. Cancer exhibits variabilities in origin, progression and cell biology. Recent evidence suggests that ICC has multiple cellular origins, including differentiated hepatocytes; intrahepatic biliary epithelial cells (IBECs)/cholangiocytes; pluripotent stem cells, such as hepatic stem/progenitor cells (HPCs) and biliary tree stem/progenitor cells (BTSCs); and peribiliary gland (PBG). However, both somatic mutagenesis and epigenomic features are highly cell type-specific. Multiple cellular origins may have profoundly different genomic landscapes and key signaling pathways, driving phenotypic variation and thereby posing significant challenges to personalized medicine in terms of achieving the optimal drug response and patient outcome. Considering this information, we have summarized the latest experimental evidence and relevant literature to provide an up-to-date view of the cellular origin of ICC, which will contribute to establishment of a hierarchical model of carcinogenesis and allow for improvement of the anatomical-based classification of ICC. These new insights have important implications for both the diagnosis and treatment of ICC patients.

Kaempferol inhibits the growth and metastasis of cholangiocarcinoma in vitro and in vivo

Kaempferol is a flavonoid that has been reported to exhibit antitumor activity in various malignant tumors. However, the role of kaempferol on cholangiocarcinoma (CCA) is largely unknown. In this article, we found that kaempferol inhibited proliferation, reduced colony formation ability, and induced apoptosis in HCCC9810 and QBC939 cells in vitro. Results from transwell assay and wound-healing assay demonstrated that kaempferol significantly suppressed the migration and invasion abilities of HCCC9810 and QBC939 cells in vitro. Kaempferol was found to decrease the expression of Bcl-2 and increase the expressions of Bax, Fas, cleaved-caspase 3, cleaved-caspase 8, cleaved-caspase 9, and cleaved-PARP. In addition, kaempferol also downregulated the levels of phosphorylated AKT, TIMP2, and MMP2. In vivo, it was found that the volume of subcutaneous xenograft (0.15 cm(3)) in the kaempferol-treated group was smaller than that (0.6 cm(3)) in the control group. Kaempferol also suppressed the number and volume of metastasis foci in the lung metastasis model, with no marked effects on body weight of mice. Immunohistochemistry assay showed that the number of Ki-67-positive cells was lower in the kaempferol-treated group than that in the control group. We further confirmed that the changes of apoptosis- and invasion-related proteins after kaempferol treatment in vivo were similar to the results in vitro. These data suggest that kaempferol may be a promising candidate agent for the treatment of CCA.

Imaging spectrum of cholangiocarcinoma: role in diagnosis, staging, and posttreatment evaluation

Cholangiocarcinoma, a tumor of biliary epithelium, is increasing in incidence. The imaging appearance, behavior, and treatment of cholangiocarcinoma differ according to its location and morphology. Cholangiocarcinoma is usually classified as intrahepatic, perihilar, or distal. The three morphologies are mass-forming, periductal sclerosing, and intraductal growing. As surgical resection is the only cure, prompt diagnosis and accurate staging is crucial. In staging, vascular involvement, longitudinal spread, and lymphadenopathy are important to assess. The role of liver transplantation for unresectable peripheral cholangiocarcinoma will be discussed. Locoregional therapy can extend survival for those with unresectable intrahepatic tumors. The main risk factors predisposing to cholangiocarcinoma are parasitic infections, primary sclerosing cholangitis, choledochal cysts, and viral hepatitis. Several inflammatory conditions can mimic cholangiocarcinoma, including IgG4 disease, sclerosing cholangitis, Mirizzi's syndrome, and recurrent pyogenic cholangitis. The role of PET in diagnosis and staging will also be discussed. Radiologists play a crucial role in diagnosis, staging, and treatment of this disease.

Loss of ezrin in human intrahepatic cholangiocarcinoma is associated with ectopic expression of E-cadherin

AIMS

Ezrin connects proteins from the plasma membrane to the subcortical cytoskeleton, and contributes to epithelial integrity by interacting with the cell-cell adhesion molecule E-cadherin. In the liver, ezrin is restricted to cholangiocytes, where it regulates biliary secretory functions. During carcinogenesis, ezrin expression is impaired and associated with enhancement of cell migratory activity in cancer cells; therefore, we aimed to analyse ezrin in cholangiocarcinogenesis.

METHODS AND RESULTS

Ezrin expression was evaluated by immunohistochemistry on tissue microarrays from 94 surgical specimens of intrahepatic cholangiocarcinoma (CCA), and correlated with clinicopathological factors and E-cadherin expression. Ezrin function was also analysed in human CCA cell lines. In CCA, ezrin was negative/weakly expressed in 49 cases (52%) and moderately/strongly expressed in 45 cases (48%), mostly in cell cytoplasm. The negative/weak expression of ezrin was more frequent in peripheral than in perihilar CCA (P = 0.002), and was associated with high tumour size (P = 0.001), low mucus secretion (P = 0.042), the presence of satellite nodules (P = 0.024), and ectopic cytoplasmic expression of E-cadherin (P = 0.005). In vitro, silencing of ezrin in CCA cells caused internalization of E-cadherin and favoured cell migration.

CONCLUSIONS

Ezrin is down-regulated during cholangiocarcinogenesis, and its loss results in a more aggressive phenotype.

Cholangiocarcinoma: Current opinion on clinical practice diagnostic and therapeutic algorithms: A review of the literature and a long-standing experience of a referral center

In the oncology landscape, cholangiocarcinoma is a challenging disease in terms of both diagnosis and treatment. Besides anamnesis and clinical examination, a definitive diagnosis of cholangiocarcinoma should be supported by imaging techniques (US, CT, MRI) and invasive investigations (ERC or EUS with brushing and FNA or US or CT-guided biopsy) followed by pathological confirmation. Surgery is the main curative option, so resectability of the tumour should be promptly assessed. Moreover, jaundice must be evaluated at the outset because biliary tract decompression with drainage and stent placement may be required. If the patient is resectable, pre-operative assessment of postoperative liver function is mandatory. After a curative resection, an adjuvant therapy may be administered. Otherwise, in cases with macroscopic residual disease after surgery or locally recurrent or unresectable cholangiocarcinoma at the diagnosis, first-line chemotherapy is the preferred strategy, possibly associated with radiotherapy and/or locoregional treatments. As the diagnostic and therapeutic pathway for cholangiocarcinoma can be declined in different modalities, patients should be promptly referred to a multidisciplinary team in a tertiary centre, familiar with this rare but lethal disease. Hence, the aim of the present paper is to focus on diagnostic and therapeutic algorithms based on the common guidelines and also on the clinical practice of multispecialist expert groups.

[Medical management of cholangiocarcinomas in 2015]

Cholangiocarcinoma is a rare malignancy carrying a poor prognosis. Most patients are diagnosed with advanced-stage disease and are then ineligible for surgical resection, which is the only potentially curative therapeutic modality. The aim of this article is to provide an up-to-date review of medical management of patients with cholangiocarcinoma. The benefit of adjuvant therapy in patients undergoing curative-intent surgery is under evaluation. Combination chemotherapy with gemcitabine and platinum is the standard first-line treatment for patients with advanced cholangiocarcinoma. Targeted agents are not currently recommended due to limited data on use in this setting. The role of second-line chemotherapy is not established in advanced cholangiocarcinoma. Identification of predictive and prognostic markers to select patients who could benefit from second-line therapy is a major issue. A better understanding of the biological and molecular mechanisms underlying the carcinogenesis and the phenotypic heterogeneity of cholangiocarcinoma may path the way of new therapeutic strategies.

Delivery of miR-200c Mimic with Poly(amido amine) CXCR4 Antagonists for Combined Inhibition of Cholangiocarcinoma Cell Invasiveness

Cholangiocarcinoma is the second most common primary liver malignancy with extremely poor prognosis due to early invasion and widespread metastasis. The invasion and metastasis are regulated by multiple factors including CXCR4 chemokine receptor and multiple microRNAs. The goal of this study was to test the hypothesis that inhibition of CXCR4 combined with the action of miR-200c mimic will cooperatively enhance the inhibition of the invasion of human cholangiocarcinoma cells. The results show that CXCR4-inhibition polycation PCX can effectively deliver miR-200c mimic and that the combination treatment consisting of PCX and miR-200c results in cooperative antimigration activity, most likely by coupling the CXCR4 axis blockade with epithelial-to-mesenchymal transition inhibition in the cholangiocarcinoma cells. The ability of the combined PCX/miR-200c treatment to obstruct two migratory pathways represents a promising antimetastatic strategy in cholangiocarcinoma.

Prognostic value of CA 19-9 kinetics during gemcitabine-based chemotherapy in patients with advanced cholangiocarcinoma

BACKGROUND

Little is known of the prognostic value of CEA/CA 19-9 kinetics during chemotherapy in patients with advanced cholangiocarcinoma (CCA).

METHODS

A total of 236 patients with pathologically confirmed advanced CCA received gemcitabine-based chemotherapy were reviewed, and 179 were eligible for analysis. Baseline, pre-, and post-treatment (after two cycles of chemotherapy) CEA and CA 19-9 values were checked, and survival was compared according to various cutting points of baseline measurement or extent of change of tumor marker level.

RESULTS

Patients with a ≥ 50% decline in CA 19-9 level had better survival than the others (16.0 vs 9.0 months). However, CEA decline did not predict survival gain. Significant favorable prognostic factors of survival in multivariable analysis included initial treatment response (HR 0.61), distal location of tumor (HR 0.46), baseline CA 19-9 level ≤ 1000 U/mL (HR 0.58), and ≥ 50% decline in CA 19-9 level (HR 0.50). Subgroup analysis was conducted in 114 patients with pre-treatment CA 19-9 > 37 U/mL and bilirubin ≤ 2 mg/dL. Decline ≥ 50% in CA 19-9 level still showed an independent prognostic significance (HR 0.45).

CONCLUSION

CA 19-9 but not CEA kinetics serves as a predictor of better survival in patients with advanced CCA on gemcitabine-based chemotherapy. A ≥ 50% decline in CA 19-9 level after two cycles of chemotherapy may have clinical utility as an early indicator of better response to gemcitabine-based chemotherapy.

Neutrophil-lymphocyte ratio predicts survival in patients with advanced cholangiocarcinoma on chemotherapy

The blood neutrophil-to-lymphocyte ratio (NLR) is reported to be a prognostic marker in several cancers. However, the prognostic role of NLR in patients with advanced cholangiocarcinoma on chemotherapy is unknown. A total of 221 patients with pathologically confirmed locally advanced or metastatic cholangiocarcinoma receiving first-line palliative chemotherapy were enrolled. Associations between baseline clinical and laboratory variables including NLR and survival were investigated. Patients were classified into two groups according to the NLR level (≤ 5 vs. >5). Median overall survival (OS) and time to progression (TTP) in patients with NLR ≤ 5 were 10.9 and 6.7 months, respectively, and 6.8 and 4.1 months in patients with NLR > 5 (P < 0.001, P = 0.002, respectively). In multivariate analysis, number of cycles of chemotherapy was a significant predictor of longer OS (HR 0.86, P < 0.001), whereas adverse prognostic factors for OS were CA 19-9 > 300 (HR 1.43, P = 0.025), CEA > 5 (HR 1.44, P = 0.029), higher stage (HR 1.69, P = 0.004), and NLR > 5 (HR 1.87, P < 0.001). NLR > 5 was also associated with reduced TTP (HR 1.66, P = 0.007). Among 50 patients with initial NLR > 5, 33 patients had NLR ≤ 5 after two cycles of chemotherapy and they had significantly better survival than the others (HR 0.48, P = 0.015). NLR independently predicts survival in patients with advanced cholangiocarcinoma undergoing chemotherapy. Considering cost-effectiveness and easy availability, NLR may be a useful biomarker for prognosis prediction.