Cancer review: Cholangiocarcinoma

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

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

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

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

A Gene Expression Signature Associated with Overall Survival in Patients with Hepatocellular Carcinoma Suggests a New Treatment Strategy

Despite improvements in the management of liver cancer, the survival rate for patients with hepatocellular carcinoma (HCC) remains dismal. The survival benefit of systemic chemotherapy for the treatment of liver cancer is only marginal. Although the reasons for treatment failure are multifactorial, intrinsic resistance to chemotherapy plays a primary role. Here, we analyzed the expression of 377 multidrug resistance (MDR)-associated genes in two independent cohorts of patients with advanced HCC, with the aim of finding ways to improve survival in this poor-prognosis cancer. Taqman-based quantitative polymerase chain reaction revealed a 45-gene signature that predicts overall survival (OS) in patients with HCC. Using the Connectivity Map Tool, we were able to identify drugs that converted the gene expression profiles of HCC cell lines from ones matching patients with poor OS to profiles associated with good OS. We found three compounds that convert the gene expression profiles of three HCC cell lines to gene expression profiles associated with good OS. These compounds increase histone acetylation, which correlates with the synergistic sensitization of those MDR tumor cells to conventional chemotherapeutic agents, including cisplatin, sorafenib, and 5-fluorouracil. Our results indicate that it is possible to modulate gene expression profiles in HCC cell lines to those associated with better outcome. This approach also increases sensitization of HCC cells toward conventional chemotherapeutic agents. This work suggests new treatment strategies for a disease for which few therapeutic options exist.

Guggulsterone-induced apoptosis in cholangiocarcinoma cells through ROS/JNK signaling pathway

Cholangiocarcinoma (CCA), the most common biliary tract malignancy, is arising from the bile duct epithelium with the global significantly increased morbidity and mortality. Here, we showed the effect of guggulsterone, a steroid found in the resin of the guggul plant, on human HuCC-T1 and RBE CCA cells. Exposure to various concentrations of guggulsterone for multiple action time resulted in significant apoptosis in the CCA cells via activating both extrinsic and intrinsic pathways. Furthermore, we demonstrated that the apoptosis of CCA cells was induced by Reactive oxygen species (ROS) mediated JNK signaling pathway. Consistently, inhibition of JNK activity, overexpression of JBD, its binding protein or reduction of ROS by overexpression of catalase, all decreased apoptotic cells. Our results also revealed that guggulsterone-induced apoptosis was coupled with endoplasmic reticulum stress (ERS) in CHOP-dependent pathway. Downregulation of CHOP instead of other ERS markers could inhibit CCA cell apoptosis. Taken together, our results showed that guggulsterone could induce apoptosis of human CCA cells through ROS/JNK signaling pathway, indicating that guggulsterone could be important for the clinical therapy of CCA.

miR-367 promotes proliferation and invasion of hepatocellular carcinoma cells by negatively regulating PTEN

MicroRNAs play important roles in the carcinogenesis of many types of cancers by inhibiting gene expression at posttranscriptional level. However, the roles of microRNAs in hepatocellular carcinoma, are still unclear. Here, we identified that miR-367 promotes hepatocellular carcinoma (HCC) cell proliferation by negatively regulates its target gene PTEN. The expression of miR-367 and PTEN are significantly inverse correlated in 35 HCC patients. In HCC cell line, CCK-8 proliferation assay indicated that the cell proliferation was promoted by miR-367, while miR-367 inhibitor significantly inhibited the cell proliferation. Transwell assay showed that miR-367 mimics significantly promoted the migration and invasion of HCC cells, whereas miR-367 inhibitors significantly reduced cell migration and invasion. Luciferase assays confirmed that miR-367 directly bound to the 3'untranslated region of PTEN, and western blotting showed that miR-367 suppressed the expression of PTEN at the protein levels. This study indicated that miR-367 negatively regulates PTEN and promotes proliferation and invasion of HCC cells. Thus, miR-367 may represent a potential therapeutic target for HCC intervention.

Neoadjuvant treatment of biliary tract cancer: state-of-the-art and new perspectives

Gall bladder cancer (GBC), and intrahepatic and extrahepatic (perihilar or distal bile duct's) cholangiocarcinomas (CCA) are usually diagnosed in locally advanced or node-positive stage, with a short survival rate. Thus, it appears essential to explore novel strategies for improving disease downstage and radical surgery. Chemoradiotherapy followed by liver transplantation seems to be one of the most promising approaches for intrahepatic or perihilar disease while chemotherapy with novel radiotherapy techniques (such stereotactic body radiation) emerged as an attractive preoperative treatment in distal diseases. In this paper, we will review currently available knowledge about neoadjuvant treatment of biliary tract cancers (BTC) paying attention to challenges that make this type of management in clinical practice difficult.

Current diagnosis and treatment of primary intrahepatic cholangiocarcinoma

Primary intrahepatic cholangiocarcinoma (ICC) is a rare malignancy arising from intrahepatic biliary epithelial cells and is also defined as cholangiohepatoma. It is the second most common primary liver malignancy after hepatocellular carcinoma. Epidemiologic research shows that the incidence rate of ICC has increased in recent years. Till now, surgical resection remains the only effective treatment to cure the disease, but single-center large-sample clinical trials are still limited. Early diagnosis of ICC is difficult due to the lack of specific clinical manifestations. The rate of resection is low, while the mortality is high and the prognosis is poor. With the development of medical imaging and pathological diagnosis technology, the early diagnosis and overall survival rates are increasing. Comprehensive therapy including non-surgical treatment plays a more and more important role in improving the prognosis. The aim of this study is to review the advances in the diagnosis and treatment of ICC in recent years.

Taurocholate Induces Cyclooxygenase-2 Expression via the Sphingosine 1-phosphate Receptor 2 in a Human Cholangiocarcinoma Cell Line

Cholangiocarcinoma (CCA) is a rare, but highly malignant primary hepatobiliary cancer with a very poor prognosis and limited treatment options. Our recent studies reported that conjugated bile acids (CBAs) promote the invasive growth of CCA via activation of sphingosine 1-phosphate receptor 2 (S1PR2). Cyclooxygenase-2 (COX-2)-derived prostaglandin E2 (PGE2) is the most abundant prostaglandin in various human malignancies including CCA. Previous studies have indicated that COX-2 was highly expressed in CCA tissues, and the survival rate of CCA patients was negatively associated with high COX-2 expression levels. It has also been reported that CBAs induce COX-2 expression, whereas free bile acids inhibit COX-2 expression in CCA mouse models. However, the underlying cellular mechanisms and connection between S1PR2 and COX-2 expression in CCA cells have still not been fully elucidated. In the current study, we examined the role of S1PR2 in conjugated bile acid (taurocholate, (TCA))-induced COX-2 expression in a human HuCCT1 CCA cell line and further identified the potential underlying cellular mechanisms. The results indicated that TCA-induced invasive growth of human CCA cells was correlated with S1PR2-medated up-regulation of COX-2 expression and PGE2 production. Inhibition of S1PR2 activation with chemical antagonist (JTE-013) or down-regulation of S1PR2 expression with gene-specific shRNA not only reduced COX-2 expression, but also inhibited TCA-induced activation of EGFR and the ERK1/2/Akt-NF-κB signaling cascade. In conclusion, S1PR2 plays a critical role in TCA-induced COX-2 expression and CCA growth and may represent a novel therapeutic target for CCA.

Autophagy in cholangiocarcinoma

Autophagy is a process through which cells utilize lysosomal hydrolases to degrade abnormal proteins and damaged organelles. This process allows cells to reuse degradation products and degrade harmful substances to maintain intracellular stability. Autophagy is normally maintained at a low level. Cells under unfavorable conditions activate autophagy to cope with unfavorable adverse factors. Autophagy participates in many physiological and pathological processes, such as cell aging, bacterial invasion, neurodegenerative diseases, apoptosis and tumor development. Autophagy also plays important roles in tumorigenesis, tumor progression, metastasis, relapse, and drug resistance of a variety of tumors including cholangiocarcinoma. However, the detailed mechanisms remain unclear. Analysis of the mechanism and regulation of autophagy in the genesis and development of cholangiocarcinoma has important significance and application value. This review summarizes the advances in research of autophagy in cholangiocarcinoma.

Cell-SELEX based selection and optimization of DNA aptamers for specific recognition of human cholangiocarcinoma QBC-939 cells

Cholangiocarcinoma (CCA) is a very aggressive biliary tract malignancy with no efficient early diagnosis and therapeutics available, so there is a call for effective molecular probes. Herein, we performed cell-based systematic evolution of ligands by exponential enrichment (cell-SELEX) to obtain aptamers for the specific recognition of human cholangiocarcinoma QBC-939 cells. By coordinating sequence homology analysis and secondary structure analysis, we successfully obtained two aptamers with dissociation constants (Kd) in the low nanomolar range. A 23 nt truncated sequence was identified after further analysis on the secondary structure. More importantly, because hepatocellular carcinoma SMMC-7721 cells were employed as the control in the counter selection, the obtained aptamers demonstrated excellent specificity to the target cells, and no binding to several other hepatocellular carcinoma cell lines was observed. Moreover, the aptamers were initially found to recognize membrane proteins, giving them great potential in the field of biomarker discovery. These newly generated aptamers may play a key role in the early diagnosis and clinical treatment of CCA.

Cohort profile: cholangiocarcinoma screening and care program (CASCAP)

BACKGROUND

Cholangiocarcinoma (CCA) is an extremely aggressive cancer that is usually fatal. Although globally morbidity and mortality are increasing, knowledge of the disease remains limited. The Mekong region of Southeast Asia, and particularly the northeast of Thailand, has by far the highest incidence of CCA worldwide with 135.4 per 100,000 among males and 43.0 per 100,000 among females being reported in Khon Kaen Province. Most patients are first seen during late stage disease with 5-year survival being less than 10%. Starting in 1984, control and prevention strategies have been focused on health education. Although early detection can substantially increase 5-year survival, there are currently no strategies to increase early diagnosis.

METHODS/DESIGN

The Cholangiocarcinoma Screening and Care Program (CASCAP) is a prospective cohort study comprising two cohorts- the screening and the patient cohorts. For the screening cohort, ultrasound examination will be carried out regularly at least annually to determine whether there is current bile duct and/or liver pathology so that the optimal screening program for early diagnosis can be established. This cohort is expected to include at least 150,000 individuals coming from high-risk areas for CCA. For the patient cohort, it is estimated that about 25,000 CCA patients will be included during the 5-year recruitment period. All CCA patients will be treated according to routine clinical care and followed so that effective surgical treatment can be formulated. This cohort is indeed a conventional cancer registry. Thus, CASCAP is an ongoing project in which the number of participants changes dynamically.

DISCUSSIONS

This is the first project on CCA that involves screening the at risk population at the community level. At the time of preparing this report, a total of 85,927 individuals have been enrolled in the screening cohort, 55.0% of whom have already undergone ultrasound screening, and 2661 CCA cases have been enrolled in the patient cohort. Among the participants of the screening, whose mean age was 53.8±9.8 years, 55.6% were female, 77.5% attained primary school as the highest level of education, 79.9% were farmers, 29.9%, reported having relatives with CCA, 89.1% had eaten uncooked fish, and 42.2% of those who had been tested for liver fluke were found to be infected.