The landscape of targeted therapies for cholangiocarcinoma: current status and emerging targets. Oncotarget. 2016;7:46750-46767. [PMID: 27102149 PMCID: PMC5216834 DOI: 10.18632/oncotarget.8775]

PTEN deficiency induces an extrahepatic cholangitis-cholangiocarcinoma continuum via aurora kinase A in mice

BACKGROUND & AIMS

The PTEN-AKT pathway is frequently altered in extrahepatic cholangiocarcinoma (eCCA). We aimed to evaluate the role of PTEN in the pathogenesis of eCCA and identify novel therapeutic targets for this disease.

METHODS

The Pten gene was genetically deleted using the Cre-loxp system in biliary epithelial cells. The pathologies were evaluated both macroscopically and histologically. The characteristics were further analyzed by immunohistochemistry, reverse-transcription PCR, cell culture, and RNA sequencing. Some features were compared to those in human eCCA samples. Further mechanistic studies utilized the conditional knockout of Trp53 and Aurora kinase A (Aurka) genes. We also tested the effectiveness of an Aurka inhibitor.

RESULTS

We observed that genetic deletion of the Pten gene in the extrahepatic biliary epithelium and peri-ductal glands initiated sclerosing cholangitis-like lesions in mice, resulting in enlarged and distorted extrahepatic bile ducts in mice as early as 1 month after birth. Histologically, these lesions exhibited increased epithelial proliferation, inflammatory cell infiltration, and fibrosis. With aging, the lesions progressed from low-grade dysplasia to invasive carcinoma. Trp53 inactivation further accelerated disease progression, potentially by downregulating senescence. Further mechanistic studies showed that both human and mouse eCCA showed high expression of AURKA. Notably, the genetic deletion of Aurka completely eliminated Pten deficiency-induced extrahepatic bile duct lesions. Furthermore, pharmacological inhibition of Aurka alleviated disease progression.

CONCLUSIONS

Pten deficiency in extrahepatic cholangiocytes and peribiliary glands led to a cholangitis-to-cholangiocarcinoma continuum that was dependent on Aurka. These findings offer new insights into preventive and therapeutic interventions for extrahepatic CCA.

IMPACT AND IMPLICATIONS

The aberrant PTEN-PI3K-AKT signaling pathway is commonly observed in human extrahepatic cholangiocarcinoma (eCCA), a disease with a poor prognosis. In our study, we developed a mouse model mimicking cholangitis to eCCA progression by conditionally deleting the Pten gene via Pdx1-Cre in epithelial cells and peribiliary glands of the extrahepatic biliary duct. The conditional Pten deletion in these cells led to cholangitis, which gradually advanced to dysplasia, ultimately resulting in eCCA. The loss of Pten heightened Akt signaling, cell proliferation, inflammation, fibrosis, DNA damage, epigenetic signaling, epithelial-mesenchymal transition, cell dysplasia, and cellular senescence. Genetic deletion or pharmacological inhibition of Aurka successfully halted disease progression. This model will be valuable for testing novel therapies and unraveling the mechanisms of eCCA tumorigenesis.

Current and Future Therapeutic Targets for Directed Molecular Therapies in Cholangiocarcinoma

We conducted a comprehensive review of the current literature of published data, clinical trials (MEDLINE; ncbi.pubmed.com), congress contributions (asco.org; esmo.org), and active recruiting clinical trains (clinicaltrial.gov) on targeted therapies in cholangiocarcinoma. Palliative treatment regimens were analyzed as well as preoperative and perioperative treatment options. We summarized the current knowledge for each mutation and molecular pathway that is or has been under clinical evaluation and discussed the results on the background of current treatment guidelines. We established and recommended targeted treatment options that already exist for second-line settings, including IDH-, BRAF-, and NTRK-mutated tumors, as well as for FGFR2 fusion, HER2/neu-overexpression, and microsatellite instable tumors. Other options for targeted treatment include EGFR- or VEGF-dependent pathways, which are known to be overexpressed or dysregulated in this cancer type and are currently under clinical investigation. Targeted therapy in CCA is a hallmark of individualized medicine as these therapies aim to specifically block pathways that promote cancer cell growth and survival, leading to tumor shrinkage and improved patient outcomes based on the molecular profile of the tumor.

Emerging Therapies in Management of Cholangiocarcinoma

Cholangiocarcinoma is a heterogeneous group of biliary tract cancers that has a poor prognosis and globally increasing incidence and mortality. While surgical resection remains the only curative option for the treatment of cholangiocarcinoma, the majority of cancers are unresectable at the time of diagnosis. Additionally, the prognosis of cholangiocarcinoma remains poor even with the current first-line systemic therapy regimens, highlighting the difficulty of treating locally advanced, metastatic, or unresectable cholangiocarcinoma. Through recent developments, targetable oncogenic driver mutations have been identified in the pathogenesis of cholangiocarcinoma, leading to the utilization of molecular targeted therapeutics. In this review, we comprehensively discuss the latest molecular therapeutics for the treatment of cholangiocarcinoma, including emerging immunotherapies, highlighting promising developments and strategies.

Unveiling the immunogenomic landscape of cholangiocarcinoma: Identifying new prognostic markers and therapeutic targets based on CCL5 expression

BACKGROUND

Cholangiocarcinoma (CCA) stands as an aggressive malignancy of the biliary tract. The interplay between the tumor and immune system plays a pivotal role in disease progression and treatment outcomes. Hence, the present study aimed to extensively explore the immunogenomic landscape of CCA, with the objective of unveiling unique molecular and immunological signatures that could guide personalized therapeutic approaches.

METHODS

The study collected data from The Cancer Genome Atlas databases, performed gene set variation analysis for the chemokine ligand 5 (CCL5) high/low expression group, conducted principal component analysis, gene set enrichment analysis enrichment and mutation pattern analysis, generated a heatmap, and performed cox regression analysis.

RESULTS

The two discrete subpopulations were found to exhibit contrasting mutational and immunogenomic characteristics, emphasizing the heterogeneity of CCA. These subsets also showed pronounced discrepancies in the infiltration of immune cells, indicating diverse interactions with the tumor immune microenvironment. Furthermore, the dissimilarities in mutational patterns were observed within the two CCA subgroups, with PBRM1 and BAP1 emerging as the most frequently mutated genes. In addition, a prognostic framework was formulated and validated utilizing the expression profiles of COX16 and RSAD2 genes, effectively segregating patients into high-risk and low-risk cohorts. Furthermore, the connections between immune-related parameters and these risk groups were identified, underscoring the potential significance of the immune microenvironment in patient prognosis. In vitro experiments have shown that COX16 promotes the proliferation and metastasis of CCA cells, whereas RSAD2 inhibits it.

CONCLUSIONS

The present study provides an intricate depiction of the immunogenomic landscape of CCA based on CCL5 expression, thereby paving the way for novel immunotherapy strategies and prognostic assessment.

Tumoral Intraductal Neoplasms of the Bile Ducts Comprise Morphologically and Genetically Distinct Entities

CONTEXT.—

Tumoral (grossly visible) intraductal neoplasms of the bile ducts are still being characterized.

OBJECTIVE.—

To investigate their morphologic, immunohistochemical, and molecular features.

DESIGN.—

Forty-one cases were classified as gastric-, intestinal-, pancreatobiliary-type intraductal papillary neoplasm (IPN), intraductal oncocytic papillary neoplasm (IOPN), or intraductal tubulopapillary neoplasm (ITPN) on the basis of histology. All neoplasms were subjected to targeted next-generation sequencing.

RESULTS.—

The mean age at diagnosis was 69 years (42-81 years); male to female ratio was 1.3. Most neoplasms (n = 23, 56%) were extrahepatic/large (mean size, 4.6 cm). The majority (n = 32, 78%) contained high-grade dysplasia, and 68% (n = 28) revealed invasion. All gastric-type IPNs (n = 9) and most ITPNs/IOPNs showed consistent colabeling for CK7/MUC6, which was less common among others (P = .004). Intestinal-type IPNs (n = 5) showed higher rates of CK20 expression than others (P < .001). Overall, the most commonly mutated genes included TP53 and APC, while copy number variants affected ELF3 and CDKN2A/B. All gastric-type IPNs contained an alteration affecting the Wnt signaling pathway; 7 of 9 (78%) showed aberrations in the MAPK pathway. Mutations in APC and KRAS were common in gastric-type IPNs as compared with others (P = .01 for both). SMAD4 was more frequently mutated in intestinal-type IPNs (P = .02). Pancreatobiliary-type IPNs (n = 14) exhibited frequent alterations in tumor suppressor genes including TP53, CDKN2A/B, and ARID2 (P = .04, P = .01 and P = .002, respectively). Of 6 IOPNs analyzed, 3 (50%) revealed ATP1B1-PRKACB fusion. ITPNs (n = 6) showed relatively few recurrent genetic aberrations. Follow-up information was available for 38 patients (median, 58.5 months). The ratio of disease-related deaths was higher for the cases with invasion (56% versus 10%).

CONCLUSIONS.—

Tumoral intraductal neoplasms of the bile ducts, similar to their counterparts in the pancreas, are morphologically and genetically heterogeneous.

EASL-ILCA Clinical Practice Guidelines on the management of intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinoma (iCCA) develops inside the liver, between bile ductules and the second-order bile ducts. It is the second most frequent primary liver cancer after hepatocellular carcinoma, and its global incidence is increasing. It is associated with an alarming mortality rate owing to its silent presentation (often leading to late diagnosis), highly aggressive nature and resistance to treatment. Early diagnosis, molecular characterisation, accurate staging and personalised multidisciplinary treatments represent current challenges for researchers and physicians. Unfortunately, these challenges are beset by the high heterogeneity of iCCA at the clinical, genomic, epigenetic and molecular levels, very often precluding successful management. Nonetheless, in the last few years, progress has been made in molecular characterisation, surgical management, and targeted therapy. Recent advances together with the awareness that iCCA represents a distinct entity amongst the CCA family, led the ILCA and EASL governing boards to commission international experts to draft dedicated evidence-based guidelines for physicians involved in the diagnostic, prognostic, and therapeutic management of iCCA.

Identification of immune related gene signature for predicting prognosis of cholangiocarcinoma patients

Objective

To identify the gene subtypes related to immune cells of cholangiocarcinoma and construct an immune score model to predict the immunotherapy efficacy and prognosis for cholangiocarcinoma.

Methods

Based on principal component analysis (PCA) algorithm, The Cancer Genome Atlas (TCGA)-cholangiocarcinoma, GSE107943 and E-MTAB-6389 datasets were combined as Joint data. Immune genes were downloaded from ImmPort. Univariate Cox survival analysis filtered prognostically associated immune genes, which would identify immune-related subtypes of cholangiocarcinoma. Least absolute shrinkage and selection operator (LASSO) further screened immune genes with prognosis values, and tumor immune score was calculated for patients with cholangiocarcinoma after the combination of the three datasets. Kaplan-Meier curve analysis determined the optimal cut-off value, which was applied for dividing cholangiocarcinoma patients into low and high immune score group. To explore the differences in tumor microenvironment and immunotherapy between immune cell-related subtypes and immune score groups of cholangiocarcinoma.

Results

34 prognostic immune genes and three immunocell-related subtypes with statistically significant prognosis (IC1, IC2 and IC3) were identified. Among them, IC1 and IC3 showed higher immune cell infiltration, and IC3 may be more suitable for immunotherapy and chemotherapy. 10 immune genes with prognostic significance were screened by LASSO regression analysis, and a tumor immune score model was constructed. Kaplan-Meier (KM) and receiver operating characteristic (ROC) analysis showed that RiskScore had excellent prognostic prediction ability. Immunohistochemical analysis showed that 6 gene (NLRX1, AKT1, CSRP1, LEP, MUC4 and SEMA4B) of 10 genes were abnormal expressions between cancer and paracancer tissue. Immune cells infiltration in high immune score group was generally increased, and it was more suitable for chemotherapy. In GSE112366-Crohn's disease dataset, 6 of 10 immune genes had expression differences between Crohn's disease and healthy control. The area under ROC obtained 0.671 based on 10-immune gene signature. Moreover, the model had a sound performance in Crohn's disease.

Conclusion

The prediction of tumor immune score model in predicting immune microenvironment, immunotherapy and chemotherapy in patients with cholangiocarcinoma has shown its potential for indicating the effect of immunotherapy on patients with cholangiocarcinoma.

FGFR Inhibitors in Cholangiocarcinoma-A Novel Yet Primary Approach: Where Do We Stand Now and Where to Head Next in Targeting This Axis?

Cholangiocarcinomas (CCAs) are rare but aggressive tumours with poor diagnosis and limited treatment options. Molecular targeted therapies became a promising proposal for patients after progression under first-line chemical treatment. In light of an escalating prevalence of CCA, it is crucial to fully comprehend its pathophysiology, aetiology, and possible targets in therapy. Such knowledge would play a pivotal role in searching for new therapeutic approaches concerning diseases' symptoms and their underlying causes. Growing evidence showed that fibroblast growth factor/fibroblast growth factor receptor (FGF/FGFR) pathway dysregulation is involved in a variety of processes during embryonic development and homeostasis as well as tumorigenesis. CCA is known for its close correlation with the FGF/FGFR pathway and targeting this axis has been proposed in treatment guidelines. Bearing in mind the significance of molecular targeted therapies in different neoplasms, it seems most reasonable to move towards intensive research and testing on these in the case of CCA. However, there is still a need for more data covering this topic. Although positive results of many pre-clinical and clinical studies are discussed in this review, many difficulties lie ahead. Furthermore, this review presents up-to-date literature regarding the outcomes of the latest clinical data and discussion over future directions of FGFR-directed therapies in patients with CCA.

The role of tumor microenvironment reprogramming in primary liver cancer chemotherapy resistance

Primary liver cancer (PLC), including hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC), and other rare tumours, is the second leading cause of cancer-related mortality. It has been a major contributor to the cancer burden worldwide. Of all primary liver cancer, HCC is the most common type. Over the past few decades, chemotherapy, immunotherapy and other therapies have been identified as applicable to the treatment of HCC. However, evidence suggests that chemotherapy resistance is associated with higher mortality rates in liver cancer. The tumour microenvironment (TME), which includes molecular, cellular, extracellular matrix(ECM), and vascular signalling pathways, is a complex ecosystem. It is now increasingly recognized that the tumour microenvironment plays a pivotal role in PLC prognosis, progression and treatment response. Cancer cells reprogram the tumour microenvironment to develop resistance to chemotherapy drugs distinct from normal differentiated tissues. Chemotherapy resistance mechanisms are reshaped during TME reprogramming. For this reason, TME reprogramming can provide a powerful tool to understand better both cancer-fate processes and regenerative, with the potential to develop a new treatment. This review discusses the recent progress of tumour drug resistance, particularly tumour microenvironment reprogramming in tumour chemotherapy resistance, and focuses on its potential application prospects.

Heterogeneous molecular behavior in liver tumors (HCC and CCA) of two patients with acute intermittent porphyria

INTRODUCTION

Acute intermittent porphyria (AIP) is a very rare (orphan) metabolic disorder of porphyrin biosynthesis which is characterized by elevated plasma and urine levels of 5-aminolevulinic acid (5-ALA) and porphobilinogen (PBG). Patients with this disorder which is caused by a germline mutation of the hydroxymethylbilan-synthase (HMBS)-gene have a high risk of primary liver cancer which may be determined by disease activity. The exact mechanism of carcinogenesis of this rare tumor is unknown, however.

MATERIALS AND METHODS

We analyzed paraffin-embedded formalin-fixed liver tumor and normal liver specimens of two female AIP patients treated at the Munich EPNET center. One patient had developed hepatocellular carcinoma (HCC), the other intrahepatic cholangiocarcinoma (CCA). Since biallelic inactivation of HMBS had been observed in one study, we used Sanger and next-generation sequencing with a 8 gene porphyria panel plus 6 potential modifier loci to search for mutations in DNA extractions.

RESULTS

In the patient with the HCC, we found a second inactivating mutation in the HMBS gene in the tumor but not in the adjacent normal liver tissue. No mutation could be found in the liver tissues of the patient with CCA, however.

CONCLUSIONS

Biallelic inactivation of HMBS or protoporphyrinogen-oxidase (PPOX), another enzyme of porphyrin biosynthesis, has been observed in patients with acute porphyrias and liver tumors. We could confirm this in our patient with HCC with a mutation in HMBS but not in the one with CCA. Since 5-ALA can be converted into carcinogenic substances such as 4,5-dioxovaleric acid (DOVA) or 3,6-dihydropyrazine-2,5-dipropanoic acid (= cyclic dimerization product of 5-ALA), local production of these metabolites in hepatic areas with complete loss of HMBS activity may contribute to liver carcinogenesis.

Screening potential biomarkers of cholangiocarcinoma based on gene chip meta-analysis and small-sample experimental research

Cholangiocarcinoma (CCA) is a rare malignant tumor associated with poor prognosis. This study aimed to identify CCA biomarkers by investigating differentially expressed genes (DEGs) between CCA patients and healthy subjects obtained from the Gene Expression Omnibus database. Bioinformatics tools, including the Illumina BaseSpace Correlation Engine (BSCE) and Gene Expression Profiling Interactive Analysis (GEPIA), were used. The initial DEGs from GSE26566, GSE31370, and GSE77984 were analyzed using GEO2R and Venn, and protein–protein interaction networks were constructed using STRING. The BSCE was applied to assess curated CCA studies to select additional DEGs and them DEGs across the 10 biosets, which was supported by findings in the literature. The final 18 DEGs with clinical significance for CCA were further verified using GEPIA. These included CEACAM6, EPCAM, LAMC2, MMP11, KRT7, KRT17, KRT19, SFN, and SOX9, which were upregulated, and ADH1A, ALDOB, AOX1, CTH, FGA, FGB, FGG, GSTA1, and OTC, which were downregulated in CCA patients. Among these 18 genes, 56 groups of genes (two in each group) were significantly related, and none were independently and differentially expressed. The hub genes FGA, OTC, CTH, and MMP11, which were most correlated with the 18 DEGs, were screened using STRING. The significantly low expression of FGA, OTC, and CTH and significantly high expression of MMP11 were verified by immunohistochemical analysis. Overall, four CCA biomarkers were identified that might regulate the occurrence and development of this disease and affect the patient survival rate, and they have the potential to become diagnostic and therapeutic targets for patients with CCA.

Cancerization of ducts in hilar cholangiocarcinoma

Invasive cancers that arise from ductal structures can infiltrate and colonize pre-existing ducts in a process referred to as cancerization of ducts (COD). COD in cholangiocarcinoma is an under-studied process whose clinical significance remains poorly understood. Even though both cancerized ducts and biliary intraepithelial neoplasias (BilINs) show dysplastic changes, hallmarks of COD are (i) an abrupt transition from the normal/reactive epithelium to severe dysplasia and (ii) close proximity to invasive carcinoma with similar cytologic features. We investigated 113 cases of surgically resected hilar cholangiocarcinoma and identified COD in 37 cases (33%). Using immunohistochemistry, we found that COD and adjacent invasive carcinoma had a concordant pattern of p53 and SMAD4 staining in 95% (21/22) and 100% (21/21) of cases, respectively. In contrast, BilINs and cancerized ducts showed significantly lower levels of concordance in p53 and SMAD4 staining at 44% (8/18) and 47% (8/17) of cases, respectively (P = 0.0007 and 0.0001, respectively). By univariate analysis, positive lymph node metastasis (P = 0.027), positive final bile duct margin (P = 0.021), and the presence of COD (P = 0.020) were associated with decreased overall survival. We further performed multivariate analysis to demonstrate that positive lymph node metastasis (P = 0.031), positive final bile duct margin (P = 0.035), and COD (P = 0.0051) were correlated with decreased overall survival. Together, our study highlights that COD is a clinically significant process in hilar cholangiocarcinoma that can be identified using morphological criteria in conjunction with p53 and SMAD4 immunolabeling.

Computational study on novel natural compound inhibitor targeting IDH1_R132H

Isocitrate dehydrogenases (IDH) catalyze the oxidative decarboxylation of isocitrate to 2-oxoglutarate. IDH1 mutation has been reported in various tumors especially Cholangiocarcinoma, while the IDH1_R132H is reported to be the most common mutation of IDH1. IDH1_R132H inhibitors are effective anti-cancer drugs and have shown significant therapeutic effects in clinical. In this study, two novel natural compounds were identified to combine respectively with IDH1_R132H with a stronger binding force with conductive to interaction energy. They also showed low toxicity potential. Molecular dynamics simulation analysis demonstrated that the candidate ligands-IDH1_R132H complexes is stable in natural circumstances with favorable potential energy. Thus, Styraxlignolide F and Tremulacin were screened as promising IDH1_R132H inhibitors. We provide a solid foundation for the design and development of IDH1_R132H targeted drugs.

Novel Nitric Oxide Donor Dinitroazetidine-Coumarin Hybrids as Potent Anti-Intrahepatic Cholangiocarcinoma Agents

Intrahepatic cholangiocarcinoma (iCC) is a serious liver cancer threatening human health. However, there are a few chemotherapeutic drugs for the treatment of iCC in the clinic. It is extremely urgent to develop new drugs for iCC. In this study, twenty dinitroazetidine and coumarin hybrids were synthesized and evaluated anti-iCC bioactivity as a new type of nitric oxide (NO) donors. Among them, compounds 2–5 and 21 showed a higher antiproliferative activity against RBE cell lines (human intrahepatic cholangiocarcinoma cell lines) and low cytotoxicity in nontumor cells (HOSEpiC and T29). The preliminary study of pharmacology mechanism indicated that compounds 2–5 and 21 could release effective concentration of NO in RBE cell lines, which leaded to inhibit the proliferation of RBE cell lines. The research results revealed that compound 3 inhibited the proliferation of RBE cell lines by inducing apoptosis and arresting cell cycle at G₂/M phase. Additionally, compound 3 had acceptable metabolic stability. Therefore, compound 3 was merited to further explore for developing a desirable NO donor lead with anti-iCC activity.

Combination gemcitabine and PD-L1xCD3 bispecific T cell engager (BiTE) enhances T lymphocyte cytotoxicity against cholangiocarcinoma cells

Cholangiocarcinoma (CCA) is a lethal cancer with rapid progression and poor survival. Novel and more effective therapies than those currently available are, therefore, urgently needed. Our research group previously reported the combination of gemcitabine and cytotoxic T lymphocytes to be more effective than single-agent treatment for the elimination of CCA cells. However, gemcitabine treatment of CCA cells upregulates the expression of an immune checkpoint protein (programmed death-ligand 1 [PD-L1]) that consequently inhibits the cytotoxicity of T lymphocytes. To overcome this challenge and take advantage of PD-L1 upregulation upon gemcitabine treatment, we generated recombinant PD-L1xCD3 bispecific T cell engagers (BiTEs) to simultaneously block PD-1/PD-L1 signaling and recruit T lymphocytes to eliminate CCA cells. Two recombinant PD-L1xCD3 BiTEs (mBiTE and sBiTE contain anti-PD-L1 scFv region from atezolizumab and from a published sequence, respectively) were able to specifically bind to both CD3 on T lymphocytes, and to PD-L1 overexpressed after gemcitabine treatment on CCA (KKU213A, KKU055, and KKU100) cells. mBiTE and sBiTE significantly enhanced T lymphocyte cytotoxicity against CCA cells, especially after gemcitabine treatment, and their magnitudes of cytotoxicity were positively associated with the levels of PD-L1 expression. Our findings suggest combination gemcitabine and PD-L1xCD3 BiTE as a potential alternative therapy for CCA.

Corticosteroid-Refractory Myositis After Dual BRAF and MEK Inhibition in a Patient with BRAF V600E-Mutant Metastatic Intrahepatic Cholangiocarcinoma

Intrahepatic cholangiocarcinoma is a rare malignancy, which is rich in actionable alterations. Genomic aberrations in the mitogen-activated protein kinase (MAPK) pathway are common, and BRAF exon 15 p.V600E mutations are present in 5–7% of biliary tract cancers (BTC). Dual inhibition of BRAF and MEK has been established for BRAF-mutated melanoma and lung cancer, and recent basket trials have shown efficacy of this combination in BRAF V600E-mutant BTCs. Here, we report on a patient with BRAF exon 15 p.V600E mutant metastatic intrahepatic cholangiocarcinoma who was started on BRAF and MEK inhibition with vemurafenib and combimetinib. Shortly thereafter, he developed debilitating myositis, which was refractory to corticosteroids, requiring therapeutic plasma exchange and intravenous immunoglobulin. We also review BRAF as a target in BTCs, relevant clinical trials, and adverse events associated with BRAF and MEK inhibition.

The new insight of treatment in Cholangiocarcinoma

Cholangiocarcinoma (CCA) is a relatively rare malignant tumor originating from the bile duct epithelial cells, and it is one of the malignant tumors with fast growth in incidence and death rate in recent years. CCA carries a very poor prognosis due to a typically late clinical presentation and a poor response to current therapeutics. Currently, surgery is the only possible curative treatment, radiotherapy and chemotherapy also play an important role in slowing down disease progression, while targeted therapy and immunotherapy are changing with each passing day and their combined effect may have great potential for the treatment of CCA; Clinical trials of various treatment options for CCA are also being conducted. This article reviews the different treatment options for CCA and explores the adjuvant treatment for it from a new perspective. In the future, the goal of treatment should be multiple and combined for different CCA patients to achieve individualized programs and improve overall survival.

Genetic Screens Identify a Context-Specific PI3K/p27Kip1 Node Driving Extrahepatic Biliary Cancer

Biliary tract cancer ranks among the most lethal human malignancies, representing an unmet clinical need. Its abysmal prognosis is tied to an increasing incidence and a fundamental lack of mechanistic knowledge regarding the molecular basis of the disease. Here, we show that the Pdx1-positive extrahepatic biliary epithelium is highly susceptible toward transformation by activated PIK3CAH1047R but refractory to oncogenic KrasG12D. Using genome-wide transposon screens and genetic loss-of-function experiments, we discover context-dependent genetic interactions that drive extrahepatic cholangiocarcinoma (ECC) and show that PI3K signaling output strength and repression of the tumor suppressor p27Kip1 are critical context-specific determinants of tumor formation. This contrasts with the pancreas, where oncogenic Kras in concert with p53 loss is a key cancer driver. Notably, inactivation of p27Kip1 permits KrasG12D-driven ECC development. These studies provide a mechanistic link between PI3K signaling, tissue-specific tumor suppressor barriers, and ECC pathogenesis, and present a novel genetic model of autochthonous ECC and genes driving this highly lethal tumor subtype.

SIGNIFICANCE

We used the first genetically engineered mouse model for extrahepatic bile duct carcinoma to identify cancer genes by genome-wide transposon-based mutagenesis screening. Thereby, we show that PI3K signaling output strength and p27Kip1 function are critical determinants for context-specific ECC formation. This article is highlighted in the In This Issue feature, p. 2945.

RNF43 overexpression attenuates the Wnt/β-catenin signalling pathway to suppress tumour progression in cholangiocarcinoma

RING finger protein 43 (RNF43) is a ubiquitin E3 ligase that negatively regulates Wnt/β-catenin signalling. Mutation, inactivation and downregulation of RNF43 in cholangiocarcinoma (CCA) are associated with a less favourable prognosis. Since the functional role of RNF43 in CCA has not yet been demonstrated, the present study aimed to assess the effect of its overexpression in mediating CCA suppression via Wnt/β-catenin signalling pathway inhibition. Accordingly, RNF43 was overexpressed, and various malignant phenotypic changes studied, including cell proliferation, cell migration, chemotherapeutic sensitivity and the expression of several Wnt/β-catenin target genes. Overexpression of RNF43 in the CCA cell-line KKU-213B hindered activation of Wnt/β-catenin signalling, evidenced by: i) Accumulation of β-catenin in the cytoplasmic fraction and downregulation of several known Wnt target genes at the mRNA level [AXIN2, survivin (BIRC5), CCND1, MMP-7, c-MYC and ABCB1 (MDR1)]; ii) a reduction of cell proliferation; iii) a significant decrease in KKU-213B cell migration with RNF43 overexpression via upregulation of E-cadherin (CDH1); and iv) a reduction in N-cadherin (CDH2), MMP-2, MMP-7 and MMP-9. In addition, overexpression of RNF43 increased 5-fluorouracil sensitivity and downregulation of ABC transporter genes [including ABCB1 and ABCC1 (MRP1)]. The current results demonstrate a functional role for RNF43 in CCA by: i) Blocking β-catenin nuclear translocation; and ii) the subsequent downregulation of Wnt/β-catenin target genes (the latter being involved in the progression of CCA and chemotherapeutic drug susceptibility). Therefore, the present findings suggest that RNF43 could serve a tumour suppressive role in CCA.

Knockdown of PSMC2 contributes to suppression of cholangiocarcinoma development by regulating CDK1

Cholangiocarcinoma (CCA) has been well known as the second most common primary tumor of hepatobiliary system. PSMC2 (proteasome 26S subunit ATPase 2) is a key member of the 19S regulatory subunit of 26S proteasome, responsible for catalyzing the unfolding and translocation of substrates into the 20S proteasome, whose role in CCA is totally unknown. In this study, the results of immunohistochemistry analysis showed the upregulation of PSMC2 in CCA tissues compared with normal tissues, which was statistically analyzed to be associated with CCA tumor grade. Subsequently, the loss-of-function study suggested that knockdown of PSMC2 significantly suppressed cell proliferation, cell migration, promoted cell apoptosis and arrested cell cycle distribution in vitro. The decreased tumorigenicity of CCA cells with PSMC2 knockdown was confirmed in vivo by using mice xenograft model. In PSMC2 knockdown cells, pro-apoptotic protein Caspase3 was upregulated; anti-apoptotic proteins such as Bcl-2 and IGF-II were downregulated; among EMT markers, E-cadherin was upregulated while N-cadherin and Vimentin were downregulated, by which may PSMC2 regulates cell apoptosis and migration. Furthermore, through RNA-seq and verification by qPCR, western blotting and co-IP assays, CDK1 was identified as the potential downstream of PSMC2 mediated regulation of CCA. PSMC2 and CDK1 showed mutual regulation effects on expression level of each other. Knockdown of PSMC2 could aggregate the influence of CDK1 knockdown on cellular functions of CCA cells. In summary, our findings suggested that PSMC2 possesses oncogene-like functions in the development and progression of CCA through regulating CDK1, which may be used as an effective therapeutic target in CCA treatment.

Actionability evaluation of biliary tract cancer by genome transcriptome analysis and Asian cancer knowledgebase

INTRODUCTION

Treatment options for biliary tract cancer (BTC) are very limited. It is necessary to investigate actionable genes and candidate drugs using a sophisticated knowledgebase (KB) and characterize BTCs immunologically for evaluating the actionability of molecular and immune therapies.

MATERIALS AND METHODS

The genomic and transcriptome data of 219 patients with BTC who underwent surgery were analyzed. Actionable mutations and candidate drugs were annotated using the largest available KB of the Asian population (CancerSCAN^®). Predictive biomarkers of immune checkpoint inhibitors were analyzed using DNA and RNA sequencing data.

RESULTS

Twenty-two actionable genes and 43 candidate drugs were annotated in 74 patients (33.8%). The most frequent actionable genes were PTEN (7.3%), CDKN2A (6.8%), KRAS (6.4%). BRCA2, CDKN2A, and FGFR2 mutations were most frequently identified in case of intrahepatic cholangiocarcinoma. PTEN and CDKN2A mutations were associated with significantly shorter overall survival. PD-L1 and PD-1 expression was significantly higher in case of extrahepatic cholangiocarcinoma and T-cell-high expression. In total, 49.7% of cases were evaluated as having actionability for molecular therapy or immune checkpoint inhibitors.

CONCLUSIONS

Identifying actionable genes and candidate drugs using the KB contribute to the development of therapeutic drugs and personalized treatment for BTC.

Molecular Oncology of Gall Bladder Cancer

Gall bladder carcinoma (GBC) is a worldwide problem, with a higher incidence in areas of the world where cholelithiasis is common. As GBC is usually diagnosed in an advanced stage, the mortality is high. An understanding of the molecular pathways of carcinogenesis and the mutations involved in the development and progression of GBC could be useful in early diagnosis. Understanding molecular markers of prognosis as well as predictors of outcome could also potentially benefit patients undergoing treatment. New therapies targeting major molecular pathways and immunotherapy are exciting novel therapeutic options. This review focuses on the current understanding of the molecular oncology of GBC.

The spectrum of tumors harboring BAP1 gene alterations

Germline mutations in the BRCA1-associated protein (BAP1) gene (MIM # 603089) are associated with a substantially increased risk for developing melanoma, mesothelioma, and renal cell carcinoma. Somatic inactivation of the BAP1 gene was noted in these and other tumors types, including esophageal cancer and cholangiocarcinoma. The favorable response of BRCA1/2-associated tumors to poly (ADP-ribose) polymerase (PARP) inhibitor therapy, raises the possibility that tumors harboring BAP1 mutations may exhibit similar sensitivity to PARP inhibitor therapy. Given the possibility that BAP1 alterations may have therapeutic implications, this study was aimed to describe the spectrum of tumors that harbor BAP1 alterations. The Foundation Medicine database was queried for known or likely pathogenic BAP1 genomic variants through July 2019. Overall, 4982/374,694 (1.81%) tumors harbored pathogenic BAP1 genomic alterations. Highest rates were noted in mesothelioma (45.24%), cholangiocarcinoma (13.37%), renal cell carcinoma (10.52%), thymic cancer (8.16%), salivary gland cancer (6.18%), and melanoma (5.1%). There were 59 unique BAP1 short variants detected in at least 10 samples. More same tissue tumors of squamous cell histology harbored BAP1 alterations than adenocarcinomas. The current study highlights tumor types that display higher than previously appreciated rates of somatic BAP1 genomic alterations.

Promising Molecular Targets for the Targeted Therapy of Biliary Tract Cancers: An Overview

Biliary tract cancer (BTC) is a leading cause of cancer-related death, due to the limited benefits of current systematic therapies and the heterogeneity of the tumor itself. High heterogeneity means that the clinical and molecular features vary between different subtypes of BTC, while the underlying molecular mechanisms remain unclear. Targeted therapy, where inhibitors are developed to selectively combine with targeted molecules in order to block abnormal signaling pathways in BTC, has shown promise as an emerging form of treatment for various types of cancer. In this article, a comprehensive review is conducted to examine potential molecular targets for BTC targeted therapy and their mechanisms. Furthermore, preliminary data published from clinical trials is utilized to analyze the main drugs used to combat BTC. The collective information presented in this article has provided useful insights into the current understanding of BTC.

Will advanced cholangiocarcinoma become a targetable malignancy?

Cholangiocarcinoma and biliary tract cancers are rare but aggressive tumors that are characterized by an heterogenous molecular and genetic footprint. Genetic aberrations such as FGFR2 fusion and ErBb2 amplification are common in those cancers. Recent studies aimed at exploring the efficacy and benefit of targeted therapy in the treatment of advanced cholangiocarcinoma. Many promising drugs exist and warrant additional investigations. This review will summarize available results and highlight therapeutic strategies incorporated in clinical trials.

Near-infrared photoimmunotherapy (NIR-PIT) on cholangiocarcinoma using a novel catheter device with light emitting diodes

Near-infrared photoimmunotherapy (NIR-PIT) is a novel therapy for cancers that uses NIR light and antibody-photosensitizer (IR700) conjugates. However, it is difficult to deliver NIR light into the bile duct for cholangiocarcinoma (CCA) from the conventional extracorporeal apparatus. Thus, in this study, we developed a dedicated catheter with light emitting diodes (LEDs) that supersedes conventional external irradiation devices; we investigated the therapeutic effect of NIR-PIT for CCA using the novel catheter. The new catheter was designed to be placed in the bile duct and a temperature sensor was attached to the tip of the catheter to avoid thermal burn. An anti-epidermal growth factor receptor (EGFR) antibody, Panitumumab-IR700 conjugate or anti-human epidermal growth factor receptor type 2 (HER2) antibody, Trastuzumab-IR700 conjugate, was used with EGFR- or HER2-expressing cell lines, respectively. The in vitro efficacy of NIR-PIT was confirmed in cultured cells; the capability of the new catheter for NIR-PIT was then tested in a mouse tumor model. NIR-PIT via the developed catheter treated CCA xenografts in mice. NIR-PIT had an effect in Panitumumab-IR700 conjugate- and Trastuzumab-IR700 conjugate-treated CCA cells that depended on the receptor expression level. Tumor growth was significantly suppressed in mice treated with NIR-PIT using the novel catheter compared with controls (P < .01). NIR-PIT was an effective treatment for EGFR- and HER2-expressing CCA cells, and the novel catheter with mounted LEDs was useful for NIR-PIT of CCA.

Novel AMBRA1-ALK fusion identified by next-generation sequencing in advanced gallbladder cancer responds to crizotinib: a case report

Gallbladder cancer (GBC) is the most aggressive malignancy of the biliary tract with poor prognosis. Several targetable genetic alterations have been identified in GBC; however, responses to targeted therapy are disappointing. We report a case of a 58-year-old Chinese woman with GBC who was detected with a novel ALK genomic rearrangement and received crizotinib after progression from first-line chemotherapy. The patient was diagnosed with stage IV adenocarcinoma of the neck of the gallbladder and received oxaliplatin combined with capecitabine as first-line therapy. After four cycles of this chemotherapy regimen, the patient started to show obstructive jaundice, and progressive disease was evaluated. Biliary drainage surgery was performed to alleviate the symptoms of obstructive jaundice. Upon referral to our department, her archived tissue samples were submitted for next-generation sequencing (Burning Rock Biotech) and immunohistochemistry, which identified the presence of a novel AMBRA1-ALK rearrangement and ALK overexpression, respectively. Oral crizotinib was administered achieving partial response within two cycles of treatment, which lasted for 7 months. AMBRA1-ALK has not been previously reported in any solid tumors and its sensitivity to crizotinib is not well characterized. Moreover, ALK alterations have been rarely reported for GBC. This case suggests that a subset of GBC might be driven by aberrant ALK signaling, which could potentially be explored as a biomarker of therapeutic response to ALK inhibitors in GBC. Moreover, our case report contributes an incremental step in understanding the genetic heterogeneity in GBC and provides clinical evidence of the utility of next-generation sequencing in exploring actionable mutations to expand treatment choices in rare solid tumors including GBC.

Continuum of care for advanced biliary tract cancers

Biliary tract cancers (BTC) are a heterogeneous group of epithelial neoplasms, with a poor prognosis. Advanced BTC remains a challenging, non-curable disease. In this review, we provide an overview of the medical treatment options in advanced BTC and new strategies under development. Gemcitabine plus platinum chemotherapy is the standard first-line therapy in this setting. Recently, 5-fluorouracil, folinic acid plus oxaliplatin (FOLFOX) regimen became the only second-line therapy to be prospectively validated beyond failure of gemcitabine plus cisplatin combination in a phase III study, even though chemotherapy yielded modest survival improvement over best supportive care. Anti-epidermal growth factor receptor and antiangiogenic antibodies have not demonstrated any survival benefit in unselected patient populations. In recent years, knowledge about the molecular heterogeneity of BTC has considerably increased with the advent of large-scale genomic and transcriptomic analyses, opening up new perspectives for so-called personalised targeted therapies. Patients with BTC may be particularly good candidates for biomarker-driven strategies in clinical practice. Among current developments, the targeting of fibroblast growth factor receptor and isocitrate dehydrogenase gene alterations are the most promising avenues, and combination immunotherapies are under investigation.

Italian Clinical Practice Guidelines on Cholangiocarcinoma - Part I: Classification, diagnosis and staging

Cholangiocarcinoma (CCA) is the second most common primary liver cancer, characterized by a poor prognosis and resistance to chemotherapeutics. The progressive increase in CCA incidence and mortality registered worldwide in the last two decades and the need to clarify various aspects of clinical management have prompted the Italian Association for the Study of the Liver (AISF) to commission the drafting of dedicated guidelines in collaboration with a group of Italian scientific societies. These guidelines have been formulated in accordance with the Italian National Institute of Health indications and developed by following the GRADE method and related advancements.

Omics-Based Platforms: Current Status and Potential Use for Cholangiocarcinoma

Cholangiocarcinoma (CCA) has been identified as a highly malignant cancer that can be transformed from epithelial cells of the bile duct, including intrahepatic, perihilar and extrahepatic. High-resolution imaging tools (abdominal ultrasound, computed tomography and percutaneous transhepatic cholangial drainage) are recruited for diagnosis. However, the lack of early diagnostic biomarkers and treatment evaluation can lead to serious outcomes and poor prognosis (i.e., CA19-9, MUC5AC). In recent years, scientists have established a large number of omics profiles to reveal underlying mechanisms and networks (i.e., IL-6/STAT3, NOTCH). With these results, we achieved several genomic alteration events (i.e., TP53_mut, KRAS_mut) and epigenetic modifications (i.e., DNA methylation, histone modification) in CCA cells and clinical patients. Moreover, we reviewed candidate gene (such as NF-kB, YAP1) that drive gene transcription factors and canonical pathways through transcriptomics profiles (including microarrays and next-generation sequencing). In addition, the proteomics database also indicates which molecules and their directly binding status could trigger dysfunction signatures in tumorigenesis (carbohydrate antigen 19-9, mucins). Most importantly, we collected metabolomics datasets and pivotal metabolites. These results reflect the pharmacotherapeutic options and evaluate pharmacokinetic/pharmacodynamics in vitro and in vivo. We reversed the panels and selected many potentially small compounds from the connectivity map and L1000CDS² system. In this paper, we summarize the prognostic value of each candidate gene and correlate this information with clinical events in CCA. This review can serve as a reference for further research to clearly investigate the complex characteristics of CCA, which may lead to better prognosis, drug repurposing and treatment strategies.

PARP Inhibitors in Biliary Tract Cancer: A New Kid on the Block?

Poly adenosine diphosphate-ribose polymerase inhibitors (PARPi) represent an effective therapeutic strategy for cancer patients harboring germline and somatic aberrations in DNA damage repair (DDR) genes. BRCA1/2 mutations occur at 1–7% across biliary tract cancers (BTCs), but a broader spectrum of DDR gene alterations is reported in 28.9–63.5% of newly diagnosed BTC patients. The open question is whether alterations in genes that are well established to have a role in DDR could be considered as emerging predictive biomarkers of response to platinum compounds and PARPi. Currently, data regarding PARPi in BTC patients harboring BRCA and DDR mutations are sparse and anecdotal; nevertheless, a variety of clinical trials are testing PARPi as monotherapy or in combination with other anticancer agents. In this review, we provide a comprehensive overview regarding the genetic landscape of DDR pathway deficiency, state of the art and future therapeutic implications of PARPi in BTC, looking at combination strategies with immune-checkpoint inhibitors and other anticancer agents in order to improve survival and quality of life in BTC patients.

Targeting CLK3 inhibits the progression of cholangiocarcinoma by reprogramming nucleotide metabolism

CDC-like kinase 3 (CLK3) is a dual specificity kinase that functions on substrates containing serine/threonine and tyrosine. But its role in human cancer remains unknown. Herein, we demonstrated that CLK3 was significantly up-regulated in cholangiocarcinoma (CCA) and identified a recurrent Q607R somatic substitution that represented a gain-of-function mutation in the CLK3 kinase domain. Gene ontology term enrichment suggested that high CLK3 expression in CCA patients mainly was associated with nucleotide metabolism reprogramming, which was further confirmed by comparing metabolic profiling of CCA cells. CLK3 directly phosphorylated USP13 at Y708, which promoted its binding to c-Myc, thereby preventing Fbxl14-mediated c-Myc ubiquitination and activating the transcription of purine metabolic genes. Notably, the CCA-associated CLK3-Q607R mutant induced USP13-Y708 phosphorylation and enhanced the activity of c-Myc. In turn, c-Myc transcriptionally up-regulated CLK3. Finally, we identified tacrine hydrochloride as a potential drug to inhibit aberrant CLK3-induced CCA. These findings demonstrate that CLK3 plays a crucial role in CCA purine metabolism, suggesting a potential therapeutic utility.

A review of systemic therapy in biliary tract carcinoma

Biliary tract carcinoma (BTC) has a poor prognosis and is increasing in incidence. Although surgery, chemotherapy and other treatment modalities have improved, surgery remains the only potential curative treatment and is appropriate for only those few patients who present with localized, resectable disease. However, for the majority of patients, unresectable disease is evident at diagnosis and about 95% of patients die within 10 years, despite the majority receiving chemotherapy. Long-term survival is significantly greater for patients with resected BTC compared to those with unresectable disease. In unresected disease, life expectancy is limited, with first-line gemcitabine/cisplatin (GEM/CIS) accepted as standard of care. Currently no standard second-line regimen which provides significant improvement of clinical outcomes exists for those who present with refractory disease or who relapse after first-line treatment. Of particular importance is establishing the impact of best supportive care (BSC) as a benchmark for survival outcomes to which the impact of treatment modalities can be compared. Survival outcome often differs significantly for patients with different prognostic factor profiles even when receiving the same therapy so that it can be difficult to predict which patient subgroup might benefit most from which therapy. Therefore, the influence of prognostic factors on survival under different therapies as well as under BSC needs to be further assessed in order to arrive at truly evidence-based, best therapeutic decisions for individual patients. Encouraging new research into the genomic landscape of BTC may help to further subdivide the BTC population into molecular-genetic clusters likely to be sensitive to different targeted therapy approaches leading to further improvements in survival. Consequently, an unmet need exists not only to develop new and more effective therapies for this devastating disease, but also to integrate original research findings into a more complex, dynamic, individualized therapeutic decision model to aid clinicians in making evidence-based, best therapeutic decisions for individual patients.

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.

Overexpression of 14-3-3δ Predicts Poor Prognosis in Extrahepatic Cholangiocarcinoma Patients

The protein 14-3-3δ interacts with Trp53 to maintain G2 arrest and thus regulates the cell cycle. Though dysfunction of 14-3-3δ caused by hyper-methylation of CpG islands was reported in several carcinomas, the exact role of this protein in the development of extrahepatic cholangiocarcinoma has not been fully elucidated. Here, we aim at investigating the clinical relevance between 14-3-3δ and human extrahepatic cholangiocarcinoma. We collected extrahepatic cholangiocarcinoma specimens of 65 patients in Beijing Chao Yang Hospital and evaluated their 14-3-3δ expression using immunohistochemistry. We categorized the patients into different subgroups according to clinic pathological factors, such as sex, age, tumor size, pathological classification, lymph node metastasis status, tumor stage, and serum markers including CEA, CA-242, or CA19-9, and further evaluated the correlation between 14-3-3δ expression and these potential prognostic factors. As a result, we detected 14-3-3δ expression in 53 out of 65 specimens (81.5%), and the expression was positively correlated with TNM stage, lymph node metastasis, and overall survival. Our results suggest that 14-3-3δ serves as an oncogenic driver in extrahepatic cholangiocarcinoma tumorigenesis rather than a cell cycle regulator; the overexpression of 14-3-3δ might be frequently acquired by tumor cells to escape appropriate cell cycle regulation. Thus, 14-3-3δ could be a potential target for extrahepatic cholangiocarcinoma diagnosis and therapy.

Loss of c-Jun N-terminal Kinase 1 and 2 Function in Liver Epithelial Cells Triggers Biliary Hyperproliferation Resembling Cholangiocarcinoma

Targeted inhibition of the c‐Jun N‐terminal kinases (JNKs) has shown therapeutic potential in intrahepatic cholangiocarcinoma (CCA)‐related tumorigenesis. However, the cell‐type‐specific role and mechanisms triggered by JNK in liver parenchymal cells during CCA remain largely unknown. Here, we aimed to investigate the relevance of JNK1 and JNK2 function in hepatocytes in two different models of experimental carcinogenesis, the dethylnitrosamine (DEN) model and in nuclear factor kappa B essential modulator (NEMO)^{hepatocyte‐specific knockout (Δhepa)} mice, focusing on liver damage, cell death, compensatory proliferation, fibrogenesis, and tumor development. Moreover, regulation of essential genes was assessed by reverse transcription polymerase chain reaction, immunoblottings, and immunostainings. Additionally, specific Jnk2 inhibition in hepatocytes of NEMO^Δhepa/JNK1^Δhepa mice was performed using small interfering (si) RNA (siJnk2) nanodelivery. Finally, active signaling pathways were blocked using specific inhibitors. Compound deletion of Jnk1 and Jnk2 in hepatocytes diminished hepatocellular carcinoma (HCC) in both the DEN model and in NEMO^Δhepa mice but in contrast caused massive proliferation of the biliary ducts. Indeed, Jnk1/2 deficiency in hepatocytes of NEMO^Δhepa (NEMO^Δhepa/JNK^Δhepa) animals caused elevated fibrosis, increased apoptosis, increased compensatory proliferation, and elevated inflammatory cytokines expression but reduced HCC. Furthermore, siJnk2 treatment in NEMO^Δhepa/JNK1^Δhepa mice recapitulated the phenotype of NEMO^Δhepa/JNK^Δhepa mice. Next, we sought to investigate the impact of molecular pathways in response to compound JNK deficiency in NEMO^Δhepa mice. We found that NEMO^Δhepa/JNK^Δhepa livers exhibited overexpression of the interleukin‐6/signal transducer and activator of transcription 3 pathway in addition to epidermal growth factor receptor (EGFR)‐rapidly accelerated fibrosarcoma (Raf)‐mitogen‐activated protein kinase kinase (MEK)‐extracellular signal‐regulated kinase (ERK) cascade. The functional relevance was tested by administering lapatinib, which is a dual tyrosine kinase inhibitor of erythroblastic oncogene B‐2 (ErbB2) and EGFR signaling, to NEMO^Δhepa/JNK^Δhepa mice. Lapatinib effectively inhibited cystogenesis, improved transaminases, and effectively blocked EGFR‐Raf‐MEK‐ERK signaling. Conclusion: We define a novel function of JNK1/2 in cholangiocyte hyperproliferation. This opens new therapeutic avenues devised to inhibit pathways of cholangiocarcinogenesis.

Serum mucin 3A as a potential biomarker for extrahepatic cholangiocarcinoma

BACKGROUND/AIMS

The aim of this study is to evaluate serum mucin 3A (MUC3A) as a candidate biomarker for extrahepatic cholangiocarcinoma (EHCC).

PATIENTS AND METHODS

35 Patients with EHCC, 30 patients with pancreatic cancer, 35 patients with gallbladder carcinoma and 78 patients with benign biliary disease were enrolled during January 2015 to January 2016. Serum MUC3A, carbohydrate antigen 19-9 (CA19-9) and carcinoembryonic antigen (CEA) were measured in these patients. Pathology reports of patients with EHCC were collected.

RESULTS

(1) The serum levels of MUC3A (87.3 ± 10.8 ng/ml) in patients with EHCC were higher than in patients with pancreatic cancer (63.2 ± 7.7 ng/ml, P < 0.001), patients with gallbladder carcinoma (59.0 ± 10.3 ng/ml, P < 0.001) and patients with benign biliary disease (56.6 ± 13.1 ng/ml, P < 0.001). (2) ROC analysis showed that using MUC3A could clearly distinguish patients with EHCC from those without EHCC with a threshold of 73.2 ng/ml. (3) According to ROC analysis, the sensitivity, specificity, and accuracy of serum MUC3A for diagnosis of EHCC were 94.3%, 89.5% and 90.4%, respectively, which were all significantly higher than CA19-9 and CEA. (4) The serum levels of MUC3A at 1 month post-operatively in 35 patients with EHCC were decreased compared to pre-operative levels (51.8 ± 5.6 vs. 87.3 ± 10.8 ng/ml, P < 0.01). (5) Compared with 20 patients with low MUC3A levels (≤88.8 ng/ml), 15 patients with high MUC3A levels (>88.8 ng/ml) had higher percentage of lymph node metastasis (66.7% vs. 25%, P = 0.014), surrounding tissue infiltration (80% vs. 30%, P = 0.003), and UICC staging IIa-III (86.7% vs. 35%, P = 0.002).

CONCLUSION

The diagnostic efficiency for EHCC of MUC3A is obviously superior to CA19-9 and CEA, and a high level of serum MUC3A indicates a poor prognosis, therefore, MUC3A can be used as a potential diagnostic and prognostic biomarker for EHCC.

PKM2 upregulation promotes malignancy and indicates poor prognosis for intrahepatic cholangiocarcinoma

BACKGROUND

Although pyruvate kinase M2 (PKM2) has been shown to be among the crucial enzymes that regulate aerobic glycolysis in multiple tumour cells, its role in the treatment and prognosis of intrahepatic cholangiocarcinoma (ICC) remains unclear. This study primarily aimed to determine whether the expression status of PKM2 is potentially associated with the clinical outcomes of ICC.

METHODS

PKM2 expression was evaluated in ICC cell lines and tissues via real-time quantitative reverse-transcription polymerase chain reaction, immunofluorescence assays, and Western blot, and its prognostic value was determined according to its impact on the overall survival of patients.

RESULTS

We found that PKM2 is highly expressed in ICC, and this was correlated with patient survival. Moreover, we found that PKM2 knockdown could considerably inhibit ICC cell proliferation, invasion, and migration in vitro.

CONCLUSIONS

PKM2 was overexpressed in ICC, and it may regulate proliferation, invasion, and migration and lead to poor prognosis. Thus, PKM2 might be a potential independent prognostic factor for ICC.

Targeted deep sequencing contributes to guiding personalized targeted therapy for advanced biliary tract cancer patients with non‑radical resection: A real‑world study

Targeted therapy based on specific genetic alterations has been proven to be an effective treatment for various types of cancer. In the present study, we aimed to explore the efficacy of personalized targeted therapy guided by targeted deep sequencing for patients with advanced biliary tract cancer (BTC) after non-radical resection. Targeted deep sequencing was performed on 49 patients with BTC, to whom biologic agents were recommended. Among 32 patients with stage IV and R2 resection (a non-radical resection), 21 patients underwent conventional chemotherapy (mGEMOX), while the remaining 11 patients received a personalized targeted agent. The genomic landscape of the 49 patients with BTC was determined and the results showed that genetic alterations were enriched in the ERBB family and cell cycle pathway. After a median follow-up of 12 months, the 11 BTC patients with personalized targeted therapy showed a median progression-free survival (PFS) of 4.5 months (2.5–20.5 months), a median overall survival (OS) of 12.9 months (4.7–24.8 months) and a disease control rate (DCR) of 63.6%. In the other 21 BTC patients, who were undergoing conventional chemotherapy, the BTC patients had a median PFS of 1.5 months (0.5–11.6 months), a median OS of 4.1 months (1.3–18.4 months), and a DCR of 33.3%. In addition, 36.4% of the patients in the personalized targeted therapy group experienced grade >2 treatment-related toxicity vs. 19.0% of patients in the conventional chemotherapy group. This real-world study suggests that targeted deep sequencing contributes to the guidance of personalized targeted therapy based on individual actionable mutations, which may benefit advanced BTC patients undergoing non-radical resection.

Targets for therapy in biliary tract cancers: the new horizon of personalized medicine

Biliary tract cancers (BTCs) are a set of molecularly distinct and heterogeneous diseases. While cytotoxic chemotherapy remains the current standard of care for treatment-naïve and treatment-refractory unresectable disease, recently identified mutations driving oncologic development offer opportunities for targeted therapy. Currently, alterations in the fibroblast growth factor receptor (FGFR), isocitrate dehydrogenase (IDH), v-Raf murine sarcoma viral oncogene homolog B (BRAF), DNA damage repair, and HER2 pathways have demonstrated promising new therapeutic avenues, among others, and various studies have demonstrated clinical activity with targeted tyrosine kinase inhibitors and/or antibodies. In this review, we will discuss the currently identified targets for therapy in BTCs and review currently available data regarding clinical development of treatment options in these molecularly distinct subsets.

Long term recurrence free survival in a stage IV gallbladder cancer treated with chemotherapy plus trastuzumab and salvage liver resection

Surgery is the only treatment for biliary tract cancer with long term survival. Unfortunately, most patients are diagnosed at stage IV with distant metastases. In these circumstances, life expectancy is less than one year due to aggressive tumour biology and a lack of effective systemic therapies. HER2 overexpression or amplification is predominantly seen in extrahepatic cholangiocarcinoma and gallbladder cancer (10–18%) and rarely in intrahepatic cholangiocarcinoma (1%). Trastuzumab is a monoclonal antibody that targets HER-2. We present a clinical case with a stage IV gallbladder cancer (liver and interaortocaval lymph node metastases), which presented progression during first-line chemotherapy treatment, which prompted a change in therapy to study the Her 2/Neu mutation which showed an intense positive overexpression. A combination of HER2/Neu-directed therapy (Trastuzumab) with second-line chemotherapy, was able to achieve a long term complete radiological, metabolic, and biochemical response. A curative intention surgery was performed and the patient is alive and recurrence-free at five years. To the best of our knowledge, we present a case which is the first report of a patient with a Stage IV gallbladder cancer who achieved a five-year survival without recurrence after a conversion therapy combining chemotherapy plus Trastuzumab and radical salvage surgery.

Dependency of Cholangiocarcinoma on Cyclin D-Dependent Kinase Activity

Cholangiocarcinoma (CCA) is a bile duct cancer with a very poor prognosis. Currently, there is no effective pharmacological treatment available for it. We showed that CCA ubiquitously relies on cyclin-dependent kinases 4 and 6 (CDK4/6) activity to proliferate. Primary CCA tissues express high levels of cyclin D1 and the specific marker of CDK4/6 activity, phospho-RB Ser780. Treatment of a 15-CCA cell line collection by pharmacological CDK4/6 inhibitors leads to reduced numbers of cells in the S-phase and senescence in most of the CCA cell lines. We found that expression of retinoblastoma protein (pRB) is required for activity of the CDK4/6 inhibitor, and that loss of pRB conferred CDK4/6 inhibitor-drug resistance. We also identified that sensitivity of CCA to CDK4/6 inhibition is associated with the activated KRAS signature. Effectiveness of CDK4/6 inhibition for CCA was confirmed in the three-dimensional spheroid-, xenograft-, and patient-derived xenograft models. Last, we identified a list of genes whose expressions can be used to predict response to the CDK4/6 inhibitor. Conclusion: We investigated a ubiquitous dependency of CCA on CDK4/6 activity and the universal response to CDK4/6 inhibition. We propose that the CDK4/6-pRB pathway is a suitable therapeutic target for CCA treatment.

Frequency and prognostic significance of isocitrate dehydrogenase 1 mutations in cholangiocarcinoma: a systematic literature review

BACKGROUND

The recognition of distinct molecular subgroups within cholangiocarcinoma (CC), along with the increasing availability of targeted therapies, suggests that further characterization of the prevalence and prognosis of frequently occurring subgroups may assist with the development of more effective treatment approaches for the management of CC. A systematic review was performed to investigate the prevalence of isocitrate dehydrogenase 1 (IDH1) mutations (mIDH1) in patients with CC, the possible clinical and prognostic significance of mIDH1, and the presence of co-mutations in tumors with mIDH1.

METHODS

This review was conducted using the Cochrane dual-reviewer methodology and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol (PRISMA-P) guidelines. Searches were performed in Embase, MEDLINE, the Cochrane Central Trials Register and Database of Systematic Reviews, and other Cochrane Library assets using terms for CC and mIDH1 with no language or date restrictions for articles published up to December 31, 2017. Searches were also performed of abstracts presented at the following conferences in 2016 and 2017: American Society of Clinical Oncology (ASCO), ASCO-Gastrointestinal Cancers Symposium (ASCO-GI), the European Society for Medical Oncology (ESMO), and ESMO-Asia. Screening was performed separately by two reviewers and cross-checked. Any discrepancies between reviewers were resolved by a senior researcher. Data from all selected references were recorded in a data extraction grid.

RESULTS

A total of 46 publications met the inclusion criteria and were included in the systematic review. Of these publications, 45 reported the frequency of mIDH1 among a total sample of 5,393 patients with CC. mIDH1 was enriched in intrahepatic CC (ICC), with 552 (13.1%; 95% CI, 12.1-14.2) of the 4,214 patients with ICC having the mutation compared with 9 (0.8%; 95% CI, 0.4-1.5%) of the 1,123 patients with extrahepatic CC (ECC). The percentage of females with mIDH1 CC (66.2%; 95% CI, 57.7-73.7%) was higher than in the overall CC population (44.4%). The frequency of mIDH1 in patients with ICC reported in individual studies ranged from 4.5-55.6%, and a significantly higher frequency was reported in non-Asian centers compared with Asian centers (weighted mean, 16.5% vs. 8.8%; P<0.001). The prevalence of mIDH1 in patients with ICC at USA centers was 18.0% (95% CI, 16.4-19.8%). Eleven publications reported the prevalence of co-mutations in patients with mIDH1 ICC, with the most frequent being AT-rich interactive domain-containing protein 1A (ARID1A) (22.0%), BRCA1-associated protein 1 (BAP1) (15.5%), and PBRM1 (13.3%). Eight publications investigated the possible prognostic significance of mIDH1. None of the studies reported a statistically significant association between mIDH1 and overall survival (OS), progression-free survival (PFS), or time to progression.

CONCLUSIONS

This systematic review substantiates the prevalence of mIDH1 in CC and further characterizes clinical, pathologic, and genetic covariates within this sub-population. Co-mutation data may inform future studies of mechanisms of response and resistance to mIDH1-targeted therapies.

Personalised approach in combined treatment of cholangiocarcinoma: a case report of healing from cholangiocellular carcinoma at stage IV

We describe a rare case of healing from low differentiated cholangiocarcinoma stage T4N1M0 with atypical genetic mutation in gene BRAF V600E for this tumor. A 38-year-old female patient was operated in National Surgery Institute due to cholangiocellular carcinoma (CCA) of left liver lobe with anterior abdominal wall invasion, invasion into diaphragm, pericardium. Left liver resection with lymphatic dissection, pericardial resection was performed. Adjuvant chemotherapy (GEMOX) didn't give any results. Treatment with pembrolizumab also didn't result in any improvement. Next generation sequencing molecular tumor profiling revealed mutation in BRAF V600E gene. Target therapy with dabrafenib and trametinib, a BRAF gene inhibitors was initiated and resulted in a full response. The patient is for 2 years tumor free with no signs of recurrence. To our knowledge our case report is longest in the world for stage IV CCA treated with dabrafenib + trametinib.

GATA1 gene silencing inhibits invasion, proliferation and migration of cholangiocarcinoma stem cells via disrupting the PI3K/AKT pathway

Background/aims: Intrahepatic cholangiocarcinoma (CCA) is the second most prevalent type primary liver malignancy, accompanied by an increasing global incidence and mortality rate. Research has documented the contribution of the GATA binding protein-1 (GATA1) in the progression of liver cancer. Here, we aim to investigate the role of GATA1 in CCA stem cells via the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) pathway.

Methods: Initially, microarray-based gene expression profiling was employed to identify the differentially expressed genes associated with CCA. Subsequently, an investigation was conducted to explore the potential biological significance behind the silencing of GATA1 and the regulatory mechanism between GATA1 and PI3K/AKT pathway. CCA cell lines QBC-939 and RBE were selected and treated with siRNA against GATA1 or/and a PI3K/AKT pathway inhibitor LY294002. In vivo experiment was also conducted to confirm in vitro findings.

Results: GATA1 exhibited higher expression in CCA samples and was predicted to affect the progression of CCA through blockade of the PI3K/AKT pathway. siRNA-mediated downregulation of GATA1 and LY294002 treatment resulted in reduced proliferation, migration and invasion abilities of CCA stem cells, together with impeded tumor growth, and led to increased cell apoptosis and primary cilium expression. Additionally, the siRNA-mediated GATA1 downregulation had an inhibitory effect on the PI3K/AKT pathway. LY294002 was manifested to enhance the inhibitory effects of GATA1 inhibition on CCA progression. These in vitro findings were reproduced in vivo on siRNA against GATA1 or LY294002 injected nude mice.

Conclusion: Altogether, the present study highlighted that downregulation of GATA1 via blockade of the PI3K/AKT pathway could inhibit the CCA stem cell proliferation, migration and invasion, and tumor growth, and promote cell apoptosis, primary cilium expression.

Cholangiocarcinoma: the quest for a second-line systemic treatment

Biliary tract cancers (BTC) are a heterogeneous group of epithelial neoplasms, with a poor prognosis. Advanced BTC remains a challenging, non-curable disease. Gemcitabine plus platinum chemotherapy is the standard of care as first-line (L1) therapy in this setting. Beyond failure of L1, available evidence to guide therapeutic decisions is scarce. Data from phase III studies are lacking and there is no validated strategy to date. In this review, we provide an overview of the systemic therapeutic options that can be proposed and unsolved questions in the management of patients with advanced BTC in the second-line (L2) setting. Criteria to select which patients should receive L2 therapy are ill defined and reliable prognostic tools and models to help estimate individual patient survival at the beginning of L2 are needed. Chemotherapy, mainly fluoropyrimidine-based yields modest survival results. There is insufficient evidence level to recommend a specific L2 chemotherapy regimen, and anti-epidermal growth factor receptor and antiangiogenic agents failed to demonstrate any survival improvement in a non-selected patient population. In recent years, knowledge about BTC molecular heterogeneity has considerably increased with the advent of high-throughput genomic and transcriptomic analyses, opening new avenues for targeted therapies. Patients with BTC may be particularly good candidates for biomarker-driven therapy in clinical practice. Among the ongoing developments, targeting of FGFR and IDH mutations and immune therapies hold many promises for the next future. In future L2 clinical trials, patients should be carefully characterized and stratified according to prognostic factors, disease subtype, and genetic drivers.