Distribution and density of tertiary lymphoid structures predict clinical outcome in intrahepatic cholangiocarcinoma.

BACKGROUND & AIMS: The prognostic value and clinical relevance of tertiary lymphoid structures (TLSs) in intrahepatic cholangiocarcinoma (iCCA) remain unclear. Thus, we aimed to investigate the prognostic value and functional involvement of TLSs in iCCA. METHODS: We retrospectively included 962 patients from 3 cancer centers across China. The TLSs at different anatomic subregions were quantified and correlated with overall survival (OS) by Cox regression and Kaplan-Meier analyses. Multiplex immunohistochemistry (mIHC) was applied to characterize the composition of TLSs in 39 iCCA samples. RESULTS: A quaternary TLS scoring system was established for the intra-tumor region (T score) and peri-tumor region (P score) respectively. T scores positively correlated with favorable prognosis (p <0.001), whereas a high P score signified worse survival (p <0.001). mIHC demonstrated that both T follicular helper and regulatory T cells were significantly increased in intra-tumoral TLSs compared to peri-tumoral counterparts (p <0.05), and regulatory T cell frequencies within intra-tumoral TLSs were positively associated with P score (p <0.05) rather than T score. Collectively, the combination of T and P scores stratified iCCAs into 4 immune classes with distinct prognoses (p <0.001) that differed in the abundance and distribution pattern of TLSs. Patients displaying an immune-active pattern had the lowest risk, with 5-year OS rates of 68.8%, whereas only 3.4% of patients with an immune-excluded pattern survived at 5 years (p <0.001). The C-index of the immune class was statistically higher than the TNM staging system (0.73 vs. 0.63, p <0.001). These results were validated in an internal and 2 external cohorts. CONCLUSIONS: The spatial distribution and abundance of TLSs significantly correlated with prognosis and provided a useful immune classification for iCCA. T follicular helper and regulatory T cells may play a critical role in determining the functional orientation of spatially different TLSs. LAY SUMMARY: Tertiary lymphoid structures (TLSs) are associated with favorable prognosis in a number of cancers. However, their role in intrahepatic cholangiocarcinoma (iCCA) remains unclear. Herein, we comprehensively evaluated the spatial distribution, abundance, and cellular composition of TLSs in iCCA, and revealed the opposite prognostic impacts of TLSs located within or outside the tumor. This difference could be mediated by the different immune cell subsets present within the spatially distinct TLSs. Based on our analysis, we were able to stratify iCCAs into 4 immune subclasses associated with varying prognoses.

Extracellular RNA transfer from non-malignant human cholangiocytes can promote cholangiocarcinoma growth.

Extracellular vesicles (EV) within the cellular secretome are emerging as modulators of pathological processes involved in tumor growth through their ability to transfer donor-derived RNA into recipient cells. While the effects of tumor and stromal cell EVs within the tumor microenvironment have been studied, less is known about the contributions of normal, nontransformed cells. We examined the impact of EVs within the cellular secretome from nonmalignant cells on transformed cell growth and behavior in cholangiocarcinoma cells. These effects were enhanced in the presence of the pro-fibrogenic mediator TGF-ß. We identified miR-195 as a TGF-ß responsive miRNA in normal cells that can be transferred via EV to tumor cells and regulate cell growth, invasion, and migration. The effects of miR-195 involve modulation of the epithelial-mesenchymal transition through direct effects on the transcription factor Snail. These studies provide in vitro and in vivo evidence for the impact of normal cellular secretome on transformed cell growth, show the importance of EV RNA transfer, and identify mechanisms of EV-mediated transfer of miRNA as a contributor to tumor development, which may provide new therapeutic opportunities for targeting human cholangiocarcinoma.

Persistent status of metabolic syndrome and risk of cholangiocarcinoma: A Korean nationwide population-based cohort study.

OBJECTIVE: It is unknown whether persistent metabolic syndrome (MetS) is associated with an increased risk of cholangiocarcinoma (CCA). Therefore, we investigated the risk of CCA according to changes in MetS status. RESEARCH DESIGN AND METHODS: This nationwide cohort study included 8,581,407 adults who underwent anthropometric measurements and laboratory tests in two consecutive national health screenings during 2009-2012 and observed the subjects until 2017. Individuals with cancer, or follow-up duration <1 year were excluded (n = 377,915). Subjects were classified into the MetS-free, MetS-developed, MetS-improved, and MetS-persistent groups. The outcome was the incidence of CCA, identified using the claims database. Multivariable Cox proportional hazards regression models were used. RESULTS: Among the 8,203,492 subjects (mean age 48.9 ± 12.8 years; 56.7% male), 7506 CCA patients were newly identified during a median follow-up of 5.1 years. The probability of CCA was consistently higher in the MetS-persistent group than in the MetS-free group (P < 0.001). MetS-persistent status was significantly associated with an increased risk of CCA compared with the MetS-free status (unadjusted hazard ratio [HR] 2.8, 95% confidence interval [CI] 2.66-2.95), even after adjusting for multiple covariates (adjusted HR 1.07, 95% CI 1.01-1.13). Improved or newly developed MetS was not associated with CCA risk in the fully adjusted model (aHR 1.02, 95% CI 0.94-1.10 and aHR 0.99, 95% CI 0.92-1.06, respectively). CONCLUSIONS: MetS was associated with an increased risk of CCA if it persisted for ≥2 years. Our finding suggests that MetS may be a potentially modifiable risk factor for CCA.

Is surgery justified for elderly patients with extrahepatic cholangiocarcinoma? Reappraisal from a viewpoint of comorbidity and organ function.

PURPOSE: The benefit of surgery for older patients with extrahepatic cholangiocarcinoma (EHCC) has not been established and the differences in the general condition of younger vs. older patients remain unclear. METHODS: Patients who underwent curative surgery for EHCC were divided into two groups according to age: those younger than 75 years old (younger group) and those aged 75 years or older (older group). We analyzed the clinical data of the two groups retrospectively. RESULTS: Among the 116 patients analyzed, 45 (38.8%) were in the older group. Regarding comorbidity, only cardiac disease was significantly more common in the older patients; however, the cardiac function of the two groups was identical. There were no significant differences in the prevalence of kidney and lung disease, but renal function was significantly deteriorated and the incidence of the mixed ventilatory defect was significantly greater in the older group. The overall 5-year survival rates for the younger and older groups were 52.4% vs. 50.4% of all cholangiocarcinoma patients (p = 0.458), 42.4% vs. 51.3% of those with hilar cholangiocarcinoma (p = 0.718), and 69.0% vs. 49.1% of those with distal cholangiocarcinoma (p = 0.534), respectively. CONCLUSIONS: Improved survival after surgery can be expected in well-selected older cholangiocarcinoma patients. Comorbidities were not necessarily reflected in organ function, with precise organ function assessment being more important when selecting surgical candidates.

Single-cell atlas of tumor cell evolution in response to therapy in hepatocellular carcinoma and intrahepatic cholangiocarcinoma.

BACKGROUND & AIMS: Intratumor molecular heterogeneity is a key feature of tumorigenesis and is linked to treatment failure and patient prognosis. Herein, we aimed to determine what drives tumor cell evolution by performing single-cell transcriptomic analysis. METHODS: We analyzed 46 hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (iCCA) biopsies from 37 patients enrolled in interventional studies at the NIH Clinical Center, with 16 biopsies collected before and after treatment from 7 patients. We developed a novel machine learning-based consensus clustering approach to track cellular states of 57,000 malignant and non-malignant cells including tumor cell transcriptome-based functional clonality analysis. We determined tumor cell relationships using RNA velocity and reverse graph embedding. We also studied longitudinal samples from 4 patients to determine tumor cellular state and its evolution. We validated our findings in bulk transcriptomic data from 488 patients with HCC and 277 patients with iCCA. RESULTS: Using transcriptomic clusters as a surrogate for functional clonality, we observed an increase in tumor cell state heterogeneity which was tightly linked to patient prognosis. Furthermore, increased functional clonality was accompanied by a polarized immune cell landscape which included an increase in pre-exhausted T cells. We found that SPP1 expression was tightly associated with tumor cell evolution and microenvironmental reprogramming. Finally, we developed a user-friendly online interface as a knowledge base for a single-cell atlas of liver cancer. CONCLUSIONS: Our study offers insight into the collective behavior of tumor cell communities in liver cancer as well as potential drivers of tumor evolution in response to therapy. LAY SUMMARY: Intratumor molecular heterogeneity is a key feature of tumorigenesis that is linked to treatment failure and patient prognosis. In this study, we present a single-cell atlas of liver tumors from patients treated with immunotherapy and describe intratumoral cell states and their hierarchical relationship. We suggest osteopontin, encoded by the gene SPP1, as a candidate regulator of tumor evolution in response to treatment.

Thrombospondin 1 and 2 along with PEDF inhibit angiogenesis and promote lymphangiogenesis in intrahepatic cholangiocarcinoma.

BACKGROUND & AIMS: The microenvironment of intrahepatic cholangiocarcinoma (iCCA) is hypovascularized, with an extensive lymphatic network. This leads to rapid cancer spread into regional lymph nodes and the liver parenchyma, precluding curative treatments. Herein, we investigated which factors released in the iCCA stroma drive the inhibition of angiogenesis and promote lymphangiogenesis. METHODS: Quantitative proteomics was performed on extracellular fluid (ECF) proteins extracted both from cancerous and non-cancerous tissues (NCT) of patients with iCCA. Computational biology was applied on a proteomic dataset to identify proteins involved in the regulation of vessel formation. Endothelial cells incubated with ECF from either iCCA or NCT specimens were used to assess the role of candidate proteins in 3D vascular assembly, cell migration, proliferation and viability. Angiogenesis and lymphangiogenesis were further investigated in vivo by a heterotopic transplantation of bone marrow stromal cells, along with endothelial cells in SCID/beige mice. RESULTS: Functional analysis of upregulated proteins in iCCA unveils a soluble angio-inhibitory milieu made up of thrombospondin (THBS)1, THBS2 and pigment epithelium-derived factor (PEDF). iCCA ECF was able to inhibit in vitro vessel morphogenesis and viability. Antibodies blocking THBS1, THBS2 and PEDF restored tube formation and endothelial cell viability to levels observed in NCT ECF. Moreover, in transplanted mice, the inhibition of blood vessel formation, the de novo generation of the lymphatic network and the dissemination of iCCA cells in lymph nodes were shown to depend on THBS1, THBS2 and PEDF expression. CONCLUSIONS: THBS1, THBS2 and PEDF reduce blood vessel formation and promote tumor-associated lymphangiogenesis in iCCA. Our results identify new potential targets for interventions to counteract the dissemination process in iCCA. LAY SUMMARY: Intrahepatic cholangiocarcinoma is a highly aggressive cancer arising from epithelial cells lining the biliary tree, characterized by dissemination into the liver parenchyma via lymphatic vessels. Herein, we show that the proteins THBS1, THBS2 and PEDF, once released in the tumor microenvironment, inhibit vascular growth, while promoting cancer-associated lymphangiogenesis. Therefore, targeting THBS1, THBS2 and PEDF may be a promising strategy to reduce cancer-associated lymphangiogenesis and counteract the invasiveness of intrahepatic cholangiocarcinoma.

Expression patterns and prognostic significances of RRM1 and ERCC1 in pancreatic carcinoma and cholangiocarcinoma.

BACKGROUND: Aggressive pancreatobiliary tumors often require oxaliplatin-based therapies, instead of standard gemcitabine-based therapy and biomarker studies at diagnosis to decide the appropriate therapeutic regimen. The ribonucleotide Reductase catalytic subunit M1 (RRM1) and excision repair cross-complementing gene-1 (ERCC1) are related to DNA synthesis and repair and essential in this regard. However, apart from the therapeutic benefit, their prognostic implication is controversial. METHODS: In this retrospective study, paraffin-embedded tissue from 51 cases of pancreatic cancer and 29 cases of cholangiocarcinoma were evaluated for RRM1 and ERCC1 expression by immunohistochemical technique along with 18 control pancreatic and biliary tissues. The semiquantitatively H score was calculated based on stain distribution and stain intensities. RESULTS: Both RRM1 and ERCC1 expression were high in tumor epithelium than in controls (RRM1: the difference was statistically significant in cholangiocarcinoma (P = 0.008); ERCC1: the difference was statistically significant both in pancreatic and cholangiocarcinoma (P < 0.05)]. However, no correlation was noted between RRM1 and ERCC1-low and high tumors with histological markers of prognosis and overall survival in these patients. CONCLUSIONS: The present study adds further evidence against the controversy that if RRM1 and ERCC1 expression in pancreatic and biliary carcinomas have any prognostic significance apart from their proven therapeutic benefits in these tumors.

USP9X promotes apoptosis in cholangiocarcinoma by modulation expression of KIF1Bß via deubiquitinating EGLN3.

BACKGROUND: Cholangiocarcinoma represents the second most common primary liver malignancy. The incidence rate has constantly increased over the last decades. Cholangiocarcinoma silent nature limits early diagnosis and prevents efficient treatment. METHODS: Immunoblotting and immunohistochemistry were used to assess the expression profiling of USP9X and EGLN3 in cholangiocarcinoma patients. ShRNA was used to silence gene expression. Cell apoptosis, cell cycle, CCK8, clone formation, shRNA interference and xenograft mouse model were used to explore biological function of USP9X and EGLN3. The underlying molecular mechanism of USP9X in cholangiocarcinoma was determined by immunoblotting, co-immunoprecipitation and quantitative real time PCR (qPCR). RESULTS: Here we demonstrated that USP9X is downregulated in cholangiocarcinoma which contributes to tumorigenesis. The expression of USP9X in cholangiocarcinoma inhibited cell proliferation and colony formation in vitro as well as xenograft tumorigenicity in vivo. Clinical data demonstrated that expression levels of USP9X were positively correlated with favorable clinical outcomes. Mechanistic investigations further indicated that USP9X was involved in the deubiquitination of EGLN3, a member of 2-oxoglutarate and iron-dependent dioxygenases. USP9X elicited tumor suppressor role by preventing degradation of EGLN3. Importantly, knockdown of EGLN3 impaired USP9X-mediated suppression of proliferation. USP9X positively regulated the expression level of apoptosis pathway genes de through EGLN3 thus involved in apoptosis of cholangiocarcinoma. CONCLUSION: These findings help to understand that USP9X alleviates the malignant potential of cholangiocarcinoma through upregulation of EGLN3. Consequently, we provide novel insight into that USP9X is a potential biomarker or serves as a therapeutic or diagnostic target for cholangiocarcinoma.

Long-term live imaging and multiscale analysis identify heterogeneity and core principles of epithelial organoid morphogenesis.

BACKGROUND: Organoids are morphologically heterogeneous three-dimensional cell culture systems and serve as an ideal model for understanding the principles of collective cell behaviour in mammalian organs during development, homeostasis, regeneration, and pathogenesis. To investigate the underlying cell organisation principles of organoids, we imaged hundreds of pancreas and cholangiocarcinoma organoids in parallel using light sheet and bright-field microscopy for up to 7 days. RESULTS: We quantified organoid behaviour at single-cell (microscale), individual-organoid (mesoscale), and entire-culture (macroscale) levels. At single-cell resolution, we monitored formation, monolayer polarisation, and degeneration and identified diverse behaviours, including lumen expansion and decline (size oscillation), migration, rotation, and multi-organoid fusion. Detailed individual organoid quantifications lead to a mechanical 3D agent-based model. A derived scaling law and simulations support the hypotheses that size oscillations depend on organoid properties and cell division dynamics, which is confirmed by bright-field microscopy analysis of entire cultures. CONCLUSION: Our multiscale analysis provides a systematic picture of the diversity of cell organisation in organoids by identifying and quantifying the core regulatory principles of organoid morphogenesis.

Quantitative magnetic resonance imaging predicts individual future liver performance after liver resection for cancer.

The risk of poor post-operative outcome and the benefits of surgical resection as a curative therapy require careful assessment by the clinical care team for patients with primary and secondary liver cancer. Advances in surgical techniques have improved patient outcomes but identifying which individual patients are at greatest risk of poor post-operative liver performance remains a challenge. Here we report results from a multicentre observational clinical trial (ClinicalTrials.gov NCT03213314) which aimed to inform personalised pre-operative risk assessment in liver cancer surgery by evaluating liver health using quantitative multiparametric magnetic resonance imaging (MRI). We combined estimation of future liver remnant (FLR) volume with corrected T1 (cT1) of the liver parenchyma as a representation of liver health in 143 patients prior to treatment. Patients with an elevated preoperative liver cT1, indicative of fibroinflammation, had a longer post-operative hospital stay compared to those with a cT1 within the normal range (6.5 vs 5 days; p = 0.0053). A composite score combining FLR and cT1 predicted poor liver performance in the 5 days immediately following surgery (AUROC = 0.78). Furthermore, this composite score correlated with the regenerative performance of the liver in the 3 months following resection. This study highlights the utility of quantitative MRI for identifying patients at increased risk of poor post-operative liver performance and a longer stay in hospital. This approach has the potential to inform the assessment of individualised patient risk as part of the clinical decision-making process for liver cancer surgery.

JNK-mediated disruption of bile acid homeostasis promotes intrahepatic cholangiocarcinoma.

Metabolic stress causes activation of the cJun NH2-terminal kinase (JNK) signal transduction pathway. It is established that one consequence of JNK activation is the development of insulin resistance and hepatic steatosis through inhibition of the transcription factor PPARα. Indeed, JNK1/2 deficiency in hepatocytes protects against the development of steatosis, suggesting that JNK inhibition represents a possible treatment for this disease. However, the long-term consequences of JNK inhibition have not been evaluated. Here we demonstrate that hepatic JNK controls bile acid production. We found that hepatic JNK deficiency alters cholesterol metabolism and bile acid synthesis, conjugation, and transport, resulting in cholestasis, increased cholangiocyte proliferation, and intrahepatic cholangiocarcinoma. Gene ablation studies confirmed that PPARα mediated these effects of JNK in hepatocytes. This analysis highlights potential consequences of long-term use of JNK inhibitors for the treatment of metabolic syndrome.

In Vivo Models for Cholangiocarcinoma-What Can We Learn for Human Disease?

Cholangiocarcinoma (CCA) comprises a heterogeneous group of primary liver tumors. They emerge from different hepatic (progenitor) cell populations, typically via sporadic mutations. Chronic biliary inflammation, as seen in primary sclerosing cholangitis (PSC), may trigger CCA development. Although several efforts were made in the last decade to better understand the complex processes of biliary carcinogenesis, it was only recently that new therapeutic advances have been achieved. Animal models are a crucial bridge between in vitro findings on molecular or genetic alterations, pathophysiological understanding, and new therapeutic strategies for the clinic. Nevertheless, it is inherently difficult to recapitulate simultaneously the stromal microenvironment (e.g., immune-competent cells, cholestasis, inflammation, PSC-like changes, fibrosis) and the tumor biology (e.g., mutational burden, local growth, and metastatic spread) in an animal model, so that it would reflect the full clinical reality of CCA. In this review, we highlight available data on animal models for CCA. We discuss if and how these models reflect human disease and whether they can serve as a tool for understanding the pathogenesis, or for predicting a treatment response in patients. In addition, open issues for future developments will be discussed.

Synchronous Double Bile Duct Cancers with Distinct Genetic Features.

A 69-year-old man was referred to our hospital because of appetite loss. Imaging showed a nodular tumor in the perihilar bile duct and a second flat lesion in the distal bile duct. Right hepatopancreaticoduodenectomy was performed, and the histopathological findings demonstrated that the perihilar and distal lesions were moderately and poorly differentiated adenocarcinoma, respectively, and anatomically separated. Furthermore, the resected specimens showed no pancreaticobiliary maljunction. Histological and TP53 gene analyses in a rare case of synchronous double bile duct cancers suggest that there are various genetic pathways through which bile duct cancer develops, highlighting the complexity of its pathogenesis.

Wnt/ß-catenin signaling as an emerging potential key pharmacological target in cholangiocarcinoma.

Cholangiocarcinoma (CCA) is a fatal malignant tumor of biliary epithelial cells involving intra- or extra-hepatic bile ducts. The prognosis of CCA is generally poor due to its diagnosis at the late stages. The currently employed chemotherapeutic agents do not increase the survival rate in patients with unresectable CCA. Accordingly, there is a need to identify new therapeutic agents for the effective management of intra- and extra-hepatic CCA. Clinical as well as preclinical studies have suggested the key role of the activation of Wnt/ß-catenin signaling pathway in the induction and progression of CCA. There is an up-regulation of different Wnt ligands including Wnt2, Wnt3, Wnt5, Wnt7 and Wnt10 along with redistribution of ß-catenin (more expression in the nucleus and lesser on the cell surface due to nuclear translocation of ß-catenin) in different types of malignant biliary tumors. Apart from the role of this pathway in the induction and progression of CCA, this pathway is also involved in inducing multidrug resistance by inducing the expression of P-glycoprotein efflux pump on the cancer cells. These deleterious effects of Wnt/ß-catenin signaling are mediated in association with other signaling pathways involving microRNAs (miRNAs), PI3K/AKT/PTEN/GSK-3ß, retinoic acid receptors (RARs), dickkopf-1 (DKK1), protein kinase A regulatory subunit 1 α (PRKAR1A/PKAI), (SLAP), liver kinase B1 (LKB1) and CXCR4. The selective inhibitors of Wnt/ß-catenin signaling may be potentially employed to overcome multidrug-resistant, fatal CCA. The present review discusses the role of Wnt/ß-catenin along with its relation with other signaling pathways in the induction and progression of CCA.

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.

Neuroendocrine Changes in Cholangiocarcinoma Growth.

Cholangiocarcinoma (CCA) is a highly aggressive malignancy that emerges from the biliary tree. There are three major classes of CCA-intrahepatic, hilar (perihilar), or distal (extrahepatic)-according to the location of tumor development. Although CCA tumors are mainly derived from biliary epithelia (i.e., cholangiocytes), CCA can be originated from other cells, such as hepatic progenitor cells and hepatocytes. This heterogeneity of CCA may be responsible for poor survival rates of patients, limited effects of chemotherapy and radiotherapy, and the lack of treatment options and novel therapies. Previous studies have identified a number of neuroendocrine mediators, such as hormones, neuropeptides, and neurotransmitters, as well as corresponding receptors. The mediator/receptor signaling pathways play a vital role in cholangiocyte proliferation, as well as CCA progression and metastases. Agonists or antagonists for candidate pathways may lead to the development of novel therapies for CCA patients. However, effects of mediators may differ between healthy or cancerous cholangiocytes, or between different subtypes of receptors. This review summarizes current understandings of neuroendocrine mediators and their functional roles in CCA.

Iodine­131 metabolic radiotherapy leads to cell death and genomic alterations through NIS overexpression on cholangiocarcinoma.

Cholangiocarcinoma (CC) is an aggressive liver tumor with limited therapeutic options. Natrium­iodide symporter (NIS) mediates the uptake of iodine by the thyroid, representing a key component in metabolic radiotherapy using iodine­131 (131I) for the treatment of thyroid cancer. NIS expression is increased in CC, providing the opportunity for a novel therapeutic approach for this type of tumor. Thus, in this study, we aimed to evaluate therapeutic efficacy of 131I in two human CC cell lines. Uptake experiments analyzed the 131I uptake profiles of the tumor cell lines under study. The cells were irradiated with various doses of 131I to evaluate and characterize the effects of metabolic radiotherapy. NIS protein expression was assessed by immunofluorescence methods. Cell survival was evaluated by clonogenic assay and flow cytometry was used to assess cell viability, and the type of death and alterations in the cell cycle. The genomic and epigenetic characterization of both CC cells was performed before and after irradiation. NIS gene expression was evaluated in the CC cells by RT­qPCR. The results revealed that CC cells had a higher expression of NIS. 131I induced a decrease in cell survival in a dose­dependent manner. With the increasing irradiation dose, a decrease in cell viability was observed, with a consequent increase in cell death by initial apoptosis. Karyotype and array comparative genomic hybridization (aCGH) analyses revealed that both CC cell lines were near­triploid with several numerical and structural chromosomal rearrangements. NIS gene expression was increased in the TFK­1 and HuCCT1 cells in a time­dependent manner. On the whole, the findings of this study demonstrate that the presence of NIS in cholangiocarcinoma cell lines is crucial for the decreased cell viability and survival observed following the exposure of cholangiocarcinoma cells to 131I.

Cancer-associated fibroblasts in cholangiocarcinoma.

PURPOSE OF REVIEW: To give a state-of-art knowledge regarding cancer-associated fibroblasts (CAF) in cholangiocarcinoma (CCA) based both on direct evidence and studies on other desmoplastic cancers. High contingency of CAF characterizes CCA, a tumor with a biliary epithelial phenotype that can emerge anywhere in the biliary tree. Current treatments are very limited, the surgical resection being the only effective treatment but restricted to a minority of patients, whereas the remaining patients undergo palliative chemotherapy regimens. In cancer, CAF shape the tumor microenvironment, drive cancer growth and progression, and contribute to drug resistance. All these functions are accomplished through an interplay network between CAF and surrounding cells including tumor and other stromal cells, i.e. immune and endothelial cells. RECENT FINDINGS: Several studies have pointed out the existence of CAF sub-populations carrying out several and opposite functions, cancer-promoting or cancer-restraining as shown in pancreatic cancer, another prototypic desmoplastic tumor in which heterogeneity of CAF is well demonstrated. SUMMARY: New CAF functions are now emerging in pancreatic and breast cancers like the modulation of immune responses or tumor metabolism, opening new area for treatments.

The Hippo Pathway and YAP Signaling: Emerging Concepts in Regulation, Signaling, and Experimental Targeting Strategies With Implications for Hepatobiliary Malignancies.

The Hippo pathway and its effector protein YAP (a transcriptional coactivator) have been identified as important in the biology of both hepatocellular carcinoma and cholangiocarcinoma. First identified as a tumor suppressor pathway in Drosophila, the understanding of the mammalian YAP signaling and its regulation continues to expand. In its "on" function, the canonical regulatory Hippo pathway, a well-described serine/threonine kinase module, regulates YAP function by restricting its subcellular localization to the cytoplasm. In contrast, when the Hippo pathway is "off," YAP translocates to the nucleus and drives cotranscriptional activity. Given the role of Hippo/YAP signaling in hepatic malignancies, investigators have sought to target these molecules; however, standard approaches have not been successful based on the pathways' negative regulatory role. More recently, additional regulatory mechanisms, such as tyrosine phosphorylation, of YAP have been described. These represent positive regulatory events that may be targetable. Additionally, several groups have identified potentiating feed-forward signaling for YAP in multiple contexts, suggesting other experimental therapeutic approaches to interrupt these signaling loops. Herein we explore the current data supporting alternative YAP regulatory pathways, review the described feed-forward signaling cascades that are YAP dependent, and explore targeting strategies that have been employed in preclinical models of hepatic malignancies.

IgG4-related Sclerosing Cholangitis Mimicking Cholangiocarcinoma Diagnosed by Endoscopic Ultrasound-guided Fine-needle Aspiration.

A 58-year-old man was referred for obstructive jaundice. Imaging modalities revealed the presence of multiple pancreatic tumors and the stenosis of the middle common bile duct due to a hypoenhanced localized tumor. The multiple pancreatic tumors were histopathologically diagnosed as autoimmune pancreatitis by endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). To differentiate between IgG4-related sclerosing cholangitis (IgG4-SC) and cholangiocarcinoma, we diagnosed the biliary tumor as IgG4-SC by EUS-FNA because of insufficient pathological materials obtained in a transpapillary manner. We herein report a case of IgG4-SC diagnosed by EUS-FNA.