Intrahepatic Bile Duct Epithelium Research Articles

Intrahepatic cholelithiasis with gallbladder-like metaplasia of intrahepatic bile ducts associated with gallbladder agenesis in a wild boar.

An unknown-aged adult female wild boar (Sus scrofa) was brought to Kyungpook National University for postmortem examination. Gross examination revealed gallbladder agenesis. Histologically, the liver was cirrhotic and had intrahepatic cholelithiasis, the choleliths were yellow, brown, gray, and black, and had coffin-lid and pyramidal appearances. Fourier-transform infrared spectroscopy analysis revealed that the components were 80% struvite and 20% calcium oxalate monohydrate. Chronic inflammatory cell infiltration was observed, with hyperplastic hepatocellular nodules characterized by large nuclei, prominent nucleoli, and scant cytoplasm with frequent binucleation, surrounded by thick fibrous septa. The epithelium of intrahepatic bile ducts that contained choleliths had undergone gallbladder-like metaplasia, which might have been induced by chronic irritation from the stones or by the accompanying chronic bacterial infection that was observed in Gram stains.

Dense GM-CSFRα-expressing immune infiltration is allied with longer survival of intrahepatic cholangiocarcinoma patients.

Intrahepatic cholangiocarcinoma (iCCA) is a cancer arising from intrahepatic bile duct epithelium. An iCCA incidence is increasing worldwide; however, the outcome of the disease is dismal. The linkage between chronic inflammation and iCCA progression is well established, but the roles of granulocyte-macrophage colony-stimulating factor (GM-CSF) remain unrevealed. Thus, a better understanding of GM-CSF functions in CCA may provide an alternative approach to CCA treatment. Differential GM-CSF and GM-CSFRα mRNA expressions in CCA tissues were investigated by Gene Expression Profiling Interactive Analysis (GEPIA) based on The Cancer Genome Atlas (TCGA) database. The protein expressions and localizations of GM-CSF and its cognate receptor (GM-CSFRα) in iCCA patients' tissues were demonstrated by the immunohistochemistry (IHC) techniques. The survival analyses were performed using Kaplan-Meier survival analysis with log-rank test and Cox proportional hazard regression model for multivariate analysis. The GM-CSF productions and GM-CSFRα expressions on CCA cells were assessed by ELISA and flow cytometry. The effects of GM-CSF on CCA cell proliferation and migration were evaluated after recombinant human GM-CSF treatment. The relationship between GM-CSF or GM-CSFRα level and related immune cell infiltration was analyzed using the Tumor Immune Estimation Resource (TIMER). GEPIA analysis indicated GM-CSF and GM-CSFRα expressions were higher in CCA tissues than in normal counterparts, and high GM-CSFRα was related to the longer disease-free survival of the patients (p < 0.001). IHC analysis revealed that CCA cells differentially expressed GM-CSF, while GM-CSFRα was expressed on cancer-infiltrating immune cells. The patient whose CCA tissue contained high GM-CSF expressed CCA, and moderate to dense GM-CSFRα-expressing immune cell infiltration (ICI) acquired longer overall survival (OS) (p = 0.047), whereas light GM-CSFRα-expressing ICI contributed to an increased hazard ratio (HR) to 1.882 (95% CI [1.077-3.287]; p = 0.026). In non-papillary subtype, an aggressive CCA subtype, patients with light GM-CSFRα-expressing ICI had shorter median OS (181 vs. 351 days; p = 0.002) and the HR was elevated to 2.788 (95% CI [1.299-5.985]; p = 0.009). Additionally, TIMER analysis demonstrated GM-CSFRα expression was positively correlated with neutrophil, dendritic cell, and CD8+ T cell infiltrations, though it was conversely related to M2-macrophage and myeloid-derived suppressor cell infiltration. However, the direct effects of GM-CSF on CCA cell proliferation and migration were not observed in the current study. Light GM-CSFRα-expressing ICI was an independent poor prognostic factor for iCCA patients. Anti-cancer functions of GM-CSFRα-expressing ICI were suggested. Altogether, the benefits of acquired GM-CSFRα-expressing ICI and GM-CSF for CCA treatment are proposed herein and require elucidation.

Case report: Secondary sclerosing cholangitis induced by lapatinib and vinorelbine in a metastasis breast cancer patient

Secondary sclerosing cholangitis (SSC) is a rare cholestatic liver disease that may have a severe clinical course. A 61‐year‐old woman with a history of metastasis breast cancer was admitted to our hospital for the second cycle of chemotherapy with lapatinib and vinorelbine. The patient had no reports of elevated liver function tests (LFTs) in the previous multiple chemotherapies or history of liver disease. However, the admission laboratory results showed severe cholestatic liver injury with the possibility of SSC by magnetic resonance cholangiopancreatography. Although chemotherapy was discontinued and patient was treated with hepatoprotective drugs, the LFTs did not improve and liver biopsy indicated mild injury of intrahepatic bile duct epithelium and hepatocyte. We added ursodeoxycholic acid and prednisolone to protect the liver, and laboratory data showed a response. To prevent the progression, lapatinib and vinorelbine were reintroduced and transient increases in alanine aminotransferase and γ‐glutamyl transpeptidase were observed. With no evidence of viral or autoimmune liver disease, SSC induced by lapatinib and vinorelbine was diagnosed. This is the first case report of tyrosine kinase inhibitors and vinorelbine induced SSC and clinicians should be aware of the possibility of it. More case reports about this adverse drug reaction are needed to delineate optimal management.

Prognostic impact of hepatitis B or C on intrahepatic cholangiocarcinoma.

Background/AimsIntrahepatic cholangiocarcinoma (ICC) is the second-most common primary liver malignancy, arising from the peripheral intrahepatic bile duct epithelium. Hepatitis B virus (HBV) or hepatitis C virus (HCV) may be involved in the development of ICC. We explored the prognostic value of hepatitis virus infection, as well as other prognostic factors affecting survival in patients with ICC.MethodsA retrospective chart review was performed for patients diagnosed with ICC between August 2005 and December 2018 at Konkuk University Medical Center. We identified a total of 131 patients with ICC. Overall survival rates of patients with and without hepatitis were determined. Univariate and multivariate analyses were used to estimate factors influencing survival outcomes.ResultsA total of 17.6% (23/131) of patients were positive for HBV or HCV. Hepatitis B positive ICC patients were significantly younger with higher albumin and higher α-fetoprotein than those without hepatitis viral infections. The median survival of hepatitis-positive and hepatitis-negative groups was 280 and 213 days, respectively. Survival rates were not significantly different between the two groups (p = 0.279). Multivariate analyses indicated that lower serum carbohydrate antigen 19-9 (CA 19-9) (p < 0.001), lower T stage (p = 0.042), the absence of lymph-node metastasis (p = 0.043), and receiving curative surgery (p = 0.033) were independent predictors of better outcomes.ConclusionsWhile hepatitis influenced a number of clinical features in ICC patients, it did not affect survival rate. Prognostic factors influencing survival outcomes with ICC were CA 19-9 level, T stage, the presence of lymph node metastasis, and curative surgery.

Patient-Derived Organoids from Human Bile: An In Vitro Method to Study Cholangiopathies.

Cholangiopathies, including primary sclerosing cholangitis, are a group of heterogeneous diseases characterized by inflammation and fibrosis of the intrahepatic and extrahepatic bile duct epithelium. Studies, especially of primary sclerosing cholangitis, have been hampered by the difficulty in accessing the cholangiocyte, instability of in vitro culture systems, and reliance on (limited) samples from end-stage disease. Here we describe a novel method of culturing biliary cells from bile of primary sclerosing cholangitis patients undergoing endoscopic retrograde cholangiopancreatography for clinical indications. These 3D organoid cultures demonstrate a biliary phenotype, can be maintained in vitro, and biobanked for future analyses. Given the need for diagnostic and therapeutic endoscopic retrograde cholangiopancreatography throughout the disease in many primary sclerosing cholangitis patients, this method can provide longitudinal studies in individual patients, allowing for a correlation of gene expression with disease status. These organoids can react to inflammatory stimuli, resulting in the secretion of chemo/cytokines indicative of the reactive immune phenotype characteristic of primary sclerosing cholangitis. Therefore, bile-derived organoids provide a model to study the pathogenesis and pharmacotherapeutic treatment of cholangiopathies.

A chronic toxicity study of diphenylarsinic acid in the drinking water of C57BL/6J mice for 52 weeks.

Diphenylarsinic acid (DPAA), a neurotoxic organic arsenical, is present in the groundwater and soil in some regions of Japan due to illegal dumping. The purpose of the present study was to evaluate the potential toxicity of DPAA when administered to mice in their drinking water for 52 weeks. DPAA was administered to mice at concentrations of 0, 6.25, 12.5, and 25 ppm in their drinking water for 52 weeks. There were no significant differences in final body weights between the control groups and the DPAA treatment groups in male or female mice. Relative liver weights were significantly increased in males treated with 25 ppm DPAA, and absolute liver weights were significantly decreased in female mice treated with 25 ppm DPAA. In female mice, cholangitis and simple bile duct hyperplasia were observed in the 12.5 and 25 ppm DPAA groups, and focal necrosis of hepatocytes was observed in the 25 ppm DPAA group. Proteomic analysis and Ingenuity Pathway Analysis identified 18 proteins related to hepatotoxicity that were overexpressed in the female 25 ppm group. The phase I metabolic enzyme CYP2E1 was one of these overexpressed proteins. Immunostaining confirmed high expression of CYP2E1 in the livers of females in the 25 ppm group. These results suggest that DPAA is toxic to the intrahepatic bile duct epithelium and hepatocytes in female mice and that CYP2E1 might be involved in DPAA-associated toxicity. The no-observed-adverse-effect levels of DPAA were 12.5 ppm (1.6 mg/kg bw/day) for males and 6.25 ppm (1.1 mg/kg bw/day) for females under the conditions of this study.

Emerging therapies for the treatment of cholangiocarcinoma

Cholangiocarcinoma (CCA) is a cancer arising from the epithelium of intrahepatic or extrahepatic bile ducts. Cholangiocarcinoma often has a poor prognosis due to late diagnosis and the incidence and mortality rate of intrahepatic CCA appear to be increasing. Current therapies include surgical resection, orthotopic liver transplantation, chemotherapy/chemoradiation and palliative care. Depending on the location, the 5-year survival for CCA ranges from 27–60%. Emerging new therapies are currently being developed for treating CCA include immunotherapy, altering the tumor microenvironment, targeting growth factor gene mutations and signal pathways and that control tumor growth, and targeting gene therapy. The objective of this paper is to summarize the research that is currently ongoing for treating this challenging disease.

Mucins and NCAM (CD56) in intrahepatic cholangiocarcinogenesis

Introduction: Cholangiocarcinoma is the second most common malignant neoplasm of the hepatobiliary system. During cholangiocarcinogenesis phenotypic changes occur in the ductal epithelium, including the expression of mucins (MUC). However, the evaluating studies of the expression of mucins in the different stages of cholangiocarcinogenesis are scarce. CD56 has also contributed in differentiating benign ductal proliferation and cholangiocarcinoma; however, its expression has not been evaluated in dysplastic epithelium of the bile duct yet. Objective: To assess immunohistochemical profile of (MUC) 1, 2, 5, 6, and CD56 in cholangiocarcinoma, pre-neoplastic and reactive lesions in the epithelium of intrahepatic bile ducts. Material and methods: Immunohistochemical expression of MUC 1, 2, 5, 6, and CD56 were studied for 11 cases of cholangiocarcinoma and 83 intrahepatic bile ducts (67 reactive and 16 dysplastic). Variables were considered significant when p < 0.05. Results: The expression of MUC1 occurred in about 90% of the cholangiocarcinomas, contrasting with the low frequency of positive cases in reactive and dysplastic bile ducts (p < 0.001). However, there was no statistically significant difference in the expression of MUC5, MUC6 and CD56 between the reactive or dysplastic lesions and cholangiocarcinoma. The anti-MUC2 antibody was negative in all cases. Conclusions: MUC1 contributed for the differential diagnosis between cholangiocarcinoma and pre-neoplastic and reactive/regenerative lesions of intrahepatic bile ducts, and it should compose the antibodies panel aiming at improvement of these differential diagnoses. In contrast, MUC2, MUC5, MUC6 and CD56 were not promising in differentiating all the phases of cholangiocarcinogenesis.

Hepatitis B virus infection and intrahepatic cholangiocarcinoma.

Intrahepatic cholangiocarcinoma (ICC) is a devastating malignant tumor arising from the peripheral intrahepatic bile duct epithelium. The incidence and mortality of ICC is markedly increasing over the past two decades worldwide, though the cause for this rise in incidence is unclear, thus intensifying the search for alternative etiological agents and pathogenetic mechanisms. Hepatolithiasis, primary sclerosing cholangitis, parasitic infection (Opisthorchis viverrini or Clonorchis sinensis), fibropolycystic liver disease, and chemical carcinogen exposure are thought to be the risk factors for ICC. Nevertheless, the majority of ICC patients do not have any of these risk factors, and none of the established risk factors can explain the recent increasing trend of ICC. Therefore, identifying other risk factors may lead to the prevention and early detection of ICC. Chronic hepatitis B virus (HBV) infection is the predominant cause of hepatocellular carcinoma in HBV-endemic areas. This review discusses the evidence implicating chronic HBV infection as a likely etiology of ICC and the pathogenetic mechanisms that might be involved.

Combined targeting of AKT and mTOR using MK‐2206 and RAD001 is synergistic in the treatment of cholangiocarcinoma

Cholangiocarcinoma (CCA) is a rare, but devastating disease arising from the epithelium of intrahepatic and extrahepatic bile ducts. There are neither effective systemic therapies nor satisfying treatment options for inoperable CCA. Histopathological and biochemical studies of CCA show frequent dysregulation of the phosphatidylinositol 3-kinase/AKT/mammalian target of rapamycin (mTOR) pathway. Therefore, we investigated the efficacy of the mTOR inhibitor RAD001 and the impact of AKT signaling following mTOR inhibition in the treatment of CCA. RAD001 significantly inhibits proliferation of CCA cell lines, however, a concentration-dependent and isoform specific feedback activation of the three AKT isoforms (AKT1, AKT2 and AKT3) was observed after mTOR inhibition. As activation of AKT might limit the RAD001-mediated anti-tumor effect, the efficacy of combined mTOR and AKT inhibition was investigated using the allosteric AKT inhibitor MK-2206. Our results show that inhibition of AKT potentiates the efficacy of mTOR inhibition both in vitro and in a xenograft mouse model in vivo. Mechanistically, the antiproliferative effect of the pan-AKT inhibitor MK2206 in the CCA cell line TFK-1 was due to inhibition of AKT1 and AKT2, because knockdown of either AKT1 or AKT2, but not AKT3, showed a synergistic reduction of cell proliferation in combination with mTOR treatment. Finally, using an AKT isoform specific in vitro kinase assay, enzymatic activity of each of the three AKT isoforms was detected in all tissue samples from CCA patients, analyzed. In summary, our preclinical data suggest that combined targeting of mTOR and AKT using RAD001 and MK-2206 might be a new, effective strategy for the treatment of CCA.

A chimeric antibody to L1 cell adhesion molecule shows therapeutic effect in an intrahepatic cholangiocarcinoma model

Intrahepatic cholangiocarcinoma (ICC), a malignant tumor derived from the intrahepatic bile duct epithelium, has a poor prognosis and is refractory to conventional chemotherapy and radiation therapy. Thus, there is an urgent need to develop new effective therapeutic strategies for this disease. We previously found that L1 cell adhesion molecule (L1CAM) plays an important role in tumor progression of ICC, and we generated a murine mAb, A10-A3 (IgG1), that binds to the Ig1 domain of L1CAM. In the present study, we further characterized A10-A3, constructed a chimeric A10-A3 antibody (cA10-A3) containing the constant regions of human IgG1, and evaluated the therapeutic potential in a human ICC xenograft nude mice model. The affinities (KD) of A10-A3 and cA10-A3 for soluble L1CAM were 1.8 nM and 1.9 nM, respectively, as determined by competition ELISA. A10-A3 inhibited L1CAM homophilic binding and was slowly internalized into the tumor cells, but it did not significantly inhibit proliferation of ICC cells in vitro. cA10-A3 mediated antibody-dependent cell-mediated cytotoxicity in vitro and displayed anti-tumor activity in the ICC animal model. These results suggest that the humanized A10-A3 antibody may have potential as an anticancer agent for the treatment of ICC.

Combined Hepatocellular Carcinoma and Intrahepatic Cholangiocarcinoma: Outcome After Liver Transplantation

Combined hepatocellular carcinoma and intrahepatic cholangiocarcinoma is a rare hepatobiliary malignancy incorporating components derived from both hepatocyte and intrahepatic bile duct epithelium. The natural history, treatment, and prognosis of this distinct cancer differ from hepatocellular carcinoma (HCC) or cholangiocarcinoma (CC) and are not completely understood. There is considerable controversy about the classification, treatment, and survival, which in turn is related to the rarity of the condition. Treatment options include surgical resection and the prognosis is believed to be better than CC but worse than HCC alone. We report a single-center liver transplantation experience with the management of three patients with combined HCC-ICC with LT. Two patients were transplanted with presumed HCC within Milan criteria and the other patient was noted to have an incidental nodule in the explanted liver. Histomorphology and immunohistochemical studies revealed the presence of combined HCC-ICC in all three explants. One patient died 144 days after LT due to metastatic tumor. The second patient is alive and is tumor free at 8.5 years post-LT, and the third patient died of metastatic tumor at 155 days after LT. Good long-term survival can be achieved in at least some patients with this combined tumor type.

L1 Cell Adhesion Molecule Is a Novel Therapeutic Target in Intrahepatic Cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICC), a highly malignant hepatobiliary cancer, has a poor prognosis and is refractory to conventional therapies. The aim of this study is to discover a novel molecular target for the treatment of ICC. To discover novel cancer-associated membrane antigens expressed in ICC cells, we generated monoclonal antibodies (mAb) by immunizing mice with intact ICC cell lines and screened for those that bind to the plasma membrane of ICC cells but not to normal cells. The mAb A10-A3 was selected and its target antigen was identified as the L1 cell adhesion molecule. Expression of L1 in ICC was evaluated by immunohistochemical analysis of tumor samples from 42 ICC patients. The functional significance of L1 expression in the tumor progression of ICC was investigated by L1 suppression, L1 overexpression, and antibody treatment. L1 was not expressed in normal hepatocytes and intrahepatic bile duct epithelium but highly expressed in 40.5% of ICC patients, remarkably at the invasive front of the tumors. Suppression of L1 with short hairpin RNA significantly decreased proliferation, migration, and invasion of ICC cells in vitro. Consistently, L1 overexpression in ICC cells enhanced proliferation, migration, invasion, and apoptosis resistance. In addition, L1 short hairpin RNA or anti-L1 mAb significantly reduced the tumor growth in nude mice bearing ICC xenograft. We identified that L1 is expressed in ICC. L1 plays an important role in the tumor progression of ICC by enhancing cell proliferation, migration, invasion, and survival. L1 may represent a novel therapeutic target for ICC.

Primary liver cancer: intrahepatic cholangiocarcinoma emerges from the shadows

Intrahepatic cholangiocarcinoma (ICC) is an uncommon malignant neoplasm that arises from intrahepatic bile duct epithelium. ICC accounts for approximately 10% of all primary liver cancers worldwide and is the second most common primary hepatic malignancy after hepatocellular carcinoma (HCC) [1]. In part, due to the relative rarity of the disease, no distinction was made in the sixth edition of the American Joint Committee on Cancer (AJCC)/International Union Against Cancer (UICC) staging manual between ICC and HCC [2]. The appropriateness of this single staging system was controversial, due to the inherent differences in the etiology and biology of the two diseases. Several previous staging systems have been proposed based on data from Japan, where the experience with ICC has been more pronounced. The applicability of these systems to ICC in Western countries, however, was unclear. Recently, the staging of ICC has been revised and improved in the seventh edition of the AJCC/UICC Cancer Staging Manual [3]. The changes address the need for an empiric data-derived staging system for ICC distinct from HCC. The new ICC staging system places an emphasis on multiplicity of tumors, presence of vascular invasion, and lymph node metastasis. Impetus to revise the staging system

An immunohistochemical study of osteopontin in hepatolithiasis

Mucin glycoprotein from the intrahepatic bile ducts, and from the intramural and extramural glandular epithelia, is thought to contribute to the formation of the matrix, or nucleus, in hepatolithiasis and to contribute to biomineralization systems. Osteopontin (OPN), a noncollagenous acidic bone matrix glycoprotein that possesses calcium-binding properties. To investigate the role of OPN in the genesis of hepatolithiasis, OPN was immunohistochemically studied in the intrahepatic bile ducts, intramural and extramural glands, and in stones. An immunohistochemical study was performed in 21 human liver specimens with hepatolithiasis, by the EnVision (Dako Japan, Kyoto, Japan) method. Staining for OPN was strongly positive in the epithelium of stone-laden intrahepatic bile ducts, intramural and extramural glands, and in stones. The stone-laden intrahepatic bile ducts were infiltrated by macrophages showing intense staining for OPN. Sections of the hepatolithiasis, viewed under low magnification, showed a lamellar pattern of OPN immunolabeling, and they showed a reticular pattern under high magnification. In the center of the stones, large nestlike membranous structures were frequently present. Our result indicates that OPN, an acidic glycoprotein from intrahepatic bile ducts and from intramural and extramural glandular epithelia, seems to be involved in lithiasis, both as a core protein in the early phase, and in the late phase.

Genetic Alteration of Keap1 Confers Constitutive Nrf2 Activation and Resistance to Chemotherapy in Gallbladder Cancer

Biliary tract cancer (BTC) is a highly malignant tumor, and identification of effective therapeutic targets to improve prognosis is urgently required. Oncogenic activation of survival genes is important for cancer cells to overcome oxidative stresses induced by their microenvironments that include chronic inflammation or exposure to anticancer drugs. We attempted to examine whether deregulation of Nrf2, a master transcriptional factor of various cytoprotective genes against oxidative stress, plays a role in the carcinogenesis of BTC. We screened genetic alteration of Keap1, a negative regulator of Nrf2, in BTC including tumors originated from gallbladder and extra- and intrahepatic bile ducts. Functional analysis of cancer-related mutant Keap1 in Nrf2 repression and the association between Nrf2 activation and resistance to 5-fluorouracil (5-FU) were investigated. Recurrent (in 1/11 cell lines and 6/53 primary tumors) Keap1 gene alterations were observed in BTC and were especially frequent (4/13, 30.7%) in gallbladder cancer (GBC). These alterations led to a considerable loss of Nrf2 repression activity, caused constitutive activation of Nrf2, and promoted cell proliferation. Down-regulation of Nrf2 activity by either Keap1 complementation or Nrf2 short interference RNA increased sensitivity to 5-FU in Keap1-altered BTC cells. Keap1 mutation occurs frequently in GBC. Aberrant Nrf2 activation provoked by Keap1 alteration is one of the molecular mechanisms for chemotherapeutic resistance in GBC and will be a novel therapeutic target as an enhancer of sensitivity to 5-FU-based regimens.

Hepatozelluläres Karzinom und Cholangiokarzinom - Unterschiedliche Prognose, Pathogenese und Therapie

Primary liver cancer is one of the most common cancer worldwide. Beside hepatocellular carcinoma (HCC), accounting for more than 80%, cholangiocarcinoma (CC) is the second most frequent primary malignant epithelial liver tumor. Combined hepatocellular-cholangiocarcinoma (HCC/CC) is a rare form of liver cancer with a frequency of 1%. Both, hepatocellular carcinoma and cholangiocarcinoma, show a wide geographical variation with low-incidence areas in North America and Europe and high incidence areas in Africa and Asia. Whereas hepatocellular carcinomas develop by malignant transformation of hepatocytes, cholangiocarcinomas arise from the small intrahepatic bile duct epithelium. The UICC-TNM classification of malignant liver tumors is applied for both tumor entities. 70-80% of hepatocellular carcinoma occur in cirrhotic liver. In high incidence areas, such as Asia and Africa, HCC is strongly associated with chronic viral hepatitis B and C and liver cirrhosis. Nutritional factors, toxins and metabolic diseases contribute also to hepatocarcinogenesis. The etiology of cholangiocarcinoma remains unclear, most occur in absence of known etiological factors. But several risk factors including hepatolithiasis, liver fluke infection, and anatomical abnormalities associated with inflammation of the biliary tract have been described.

Neuroendocrine carcinoma of the liver associated with dermatomyositis: Autopsy case and review of the literature

Reported herein is an autopsy case of primary hepatic neuroendocrine carcinoma associated with dermatomyositis. A 71-year-old Japanese man, who was diagnosed with dermatomyositis 5 months before death, had multiple tumors within a non-cirrhotic liver. Histopathologically, the tumors were composed of small- and medium-sized round cells with clear cytoplasm arranged in nests, sheets or rosettes. Immunohistochemically, the tumor cells were positive for chromogranin A, neuron-specific enolase and CD56 and were negative for synaptophysin. This tumor was diagnosed as a primary hepatic neuroendocrine carcinoma with metastasis to the lung, gallbladder and lymph nodes around the pancreas and aorta; no primary lesions were detected in any other organ. The tumor cells were also positive for cytokeratin 7, cytokeratin 19 and epithelial membrane antigen but were negative for anti-hepatocyte antibody and AFP. These findings suggest that the tumor originated in intrahepatic bile duct epithelium. Various cancers have been reported in patients with dermatomyositis, but only seven cases of dermatomyositis associated with primary liver cancer have been reported. To the best of the authors' knowledge, this is the first report of dermatomyositis associated with primary hepatic neuroendocrine carcinoma.

Cloning and characterization of porcine aquaporin 1 water channel expressed extensively in gastrointestinal system

To clone and characterize the porcine aquaporins (AQPs) in the gastrointestinal system. A PCR-based cloning strategy and RACE were used to clone full-length AQP coding sequence from reversely transcribed pig liver cDNA. Stopped-flow light scattering and a YFP-based fluorescence method were used to measure the osmotic water permeability of erythrocytes and the stably transfected CHO cells. RT-PCR, Northern blot, and immunohistochemistry were used to determine the gastrointestinal expression and localization of cloned AQPs. Protein expression in transfected cells and red blood cells was analyzed by Western blot. An 813 bp cDNA encoding a 271 amino acid porcine aquaporin (designated pAQP1) was cloned from liver mRNA (pAQP1 has a 93% identity with human AQP1 and contains two NPA motifs conserved in AQP family, one consensus sequence for N-linked glycosylation, and one mercury-sensitive site at cysteine 191). RT-PCR analysis revealed extensive expression of pAQP1 mRNA in porcine digestive glands and gut. Northern blot showed a single 3.0 kb transcript in selected digestive organs. pAQP1 protein was localized at central lacteals of the small intestine, microvessles of salivary glands, as well as epithelium of intrahepatic bile ducts by immunoperoxydase. High osmotic water permeability that is inhibitable by HgCl2 was detected in porcine erythrocytes and CHO cells stably transfected with pAQP1 cDNA. Immunoblot analysis of porcine erythrocytes and pAQP-transfected CHO cells revealed an unglycosylated 28 ku band and larger glycosylated proteins. pAQP1 is the first porcine aquaporin that can be molecularly identified so far. The broad distribution of pAQP1 in epithelium and endothelium of porcine digestive organs may suggest an important role of channel-mediated water transport in fluid secretion/absorption as well as in digestive function and pathophysiology of the gastrointestinal system.

Gallbladder and bile duct carcinoma. Biology and pathology

Biliary tract cancers are a consequence of a stepwise malignant transformation of the biliary epithelium. Intrahepatic cholangiocarcinomas arises from any portions of the intrahepatic bile duct epithelium: the segmental or area ducts and their finer branches or intrahepatic small bile ducts. Cholangiocarcinoma arising from the hepatic ducts or near their junction are called hilar cholangiocarcinoma or Klatskin tumour, and are considered as extrahepatic lesion. Cancer of extrahepatic bile ducts may also arise in the Ductus cysticus or choledochus as well as in the gall bladder. For intrahepatic cholangiocarcinoma, the UICC-TNM classification system of malignant liver tumors is applied, differing from the UICC-TNM staging system of extrahepatic bile ducts and gall bladder carcinomas. The cause of carcinomas of the bile ducts remains speculative in most cases. However, chronic inflammation due to sclerosing cholangitis, hepatolithiasis or parasites is associated with carcinogenesis. Histopathologically, the vast majority are adenocarcinomas; mesenchymal tumors and primary melanomas are extremely rare. Different genetic alterations are discussed to be of importance.