Yuko Kakuda

Epithelial-Mesenchymal Transition Induced by Transforming Growth Factor-β1/Snail Activation Aggravates Invasive Growth of Cholangiocarcinoma

Epithelial-mesenchymal transition is an important mechanism behind initiation of cancer invasion and metastasis. This study was performed to clarify the involvement of epithelial-mesenchymal transition in the progression of cholangiocarcinoma. Cholangiocarcinoma cell lines, CCKS-1 and TFK-1, were treated with transforming growth factor-beta1 (TGF-beta1), and the phenotypic changes and invasive activity were examined. Immunohistochemical analysis was performed using tissue sections of cholangiocarcinoma. In vitro, TGF-beta1 induced mesenchymal features in CCKS-1 and TFK-1 characterized by the reduction of E-cadherin and cytokeratin 19 expression and the induction of mesenchymal markers, such as vimentin and S100A4. TGF-beta1 also induced the nuclear expression of Snail, and the invasive activity was significantly increased in both cell lines. Studies using a mouse xenograft model showed that TGF-beta1 worsened the peritoneal dissemination of CCKS-1. All these changes by TGF-beta1 were inhibited by the simultaneous administration of soluble TGF-beta type II receptor. In vivo, six (16%) of 37 cholangiocarcinoma cases showed marked immunoreactivity of Snail in their nuclei. In these six cases, the immuno-expression of cytokeratin 19 was significantly reduced, and the expression of vimentin was significantly increased. The Snail expression significantly correlated with the lymph node metastasis and a poor survival rate of the patients. These results suggest that epithelial-mesenchymal transition induced by TGF-beta1/Snail activation is closely associated with the aggressive growth of cholangiocarcinoma, resulting in a poor prognosis.

Incidence of and risk factors for hepatocellular carcinoma in primary biliary cirrhosis: National data from Japan

Primary biliary cirrhosis (PBC) primarily affects females and is rarely complicated by hepatocellular carcinoma (HCC). Although the HCC incidence in PBC patients is low, several characteristics and risk factors associated with its development have been reported. In this study, national data concerning the current status of carcinogenesis in PBC patients in Japan are reviewed. Using data from two national questionnaire surveys, we investigated the clinicopathological findings associated with HCC in PBC patients. According to the data of all reviewed PBC patients, the HCC incidence was 2.4% (71/2946). The HCC incidence by gender was 5.1% (19/370) in males and 2.0% (52/2576) in females, and the proportion of males was 26.7%. Prognosis was significantly poorer in the PBC patients with HCC than in those without. Multivariate analysis of risk factors associated with HCC by gender revealed histological stage at the time of PBC diagnosis as an independent risk factor associated with the development of HCC in females, but not in males. Furthermore, data from another national survey of 178 PBC patients with HCC (male/female = 49/129; proportion of males 27.5%) revealed that the duration between the diagnosis of PBC and that of HCC was significantly shorter in males than in females. In addition, histological stage at the time of HCC diagnosis was an independent risk factor for HCC in females, whereas no risk factors were identified in males. Conclusion: these data indicate that males are at risk of developing HCC at any histological stage of PBC. Therefore, male PBC patients in particular should be carefully screened for HCC from the early stages of PBC. (HEPATOLOGY 2013)

Evaluation of a new histologic staging and grading system for primary biliary cirrhosis in comparison with classical systems

Recently, our research team proposed a new histologic staging and grading system for primary biliary cirrhosis (PBC) that takes into account necroinflammatory activity and histologic heterogeneity. The present study aimed to confirm the usefulness of the new evaluation system. A total of 152 liver biopsy specimens and clinical data (including outcomes in patients with PBC before treatment with ursodeoxycholic acid) were analyzed with respect to the new system. Staging was evaluated on the basis of 3 histologic components (fibrosis, bile duct loss, and deposition of orcein-positive granules), and grading was assessed on the basis of chronic cholangitis activity and hepatitis activity. Concurrently, the classical systems, that is, the Scheuer and Ludwig staging systems, were also assessed and compared with our new system. PBC cases showed different distributions in each stage of the 3 systems. The new staging and grading system reflected liver dysfunctions before specific treatment. This was on a par with the results obtained using the classical systems. Development of cirrhosis-related conditions correlated well with the new staging system compared with the 2 classical staging systems, and in particular, the amount of deposition of orcein-positive granules could reflect development of cirrhosis-related conditions (scores 0-1 versus scores 2-3 groups, P < .0001). In conclusion, the new PBC staging system was demonstrated to reflect clinicolaboratory features, and its progression was associated with the development of cirrhosis-related conditions.

Clinicopathological significance of 'subtypes with stem-cell feature' in combined hepatocellular-cholangiocarcinoma.

Combined hepatocellular‐cholangiocarcinoma (cHC‐CC), a malignant liver tumour with poor prognosis, is composed of hepatocellular carcinoma (HCC), cholangiocarcinoma (CC) and diverse components with intermediate features between HCC and CC, which correspond to hepatic progenitor cells. According to the WHO classification 2010, we surveyed the prevalence and clinicopathological significance of each subtype with stem‐cell features [SC subtype; typical subtype (TS), intermediate cell subtype (INT) and cholangiolocellular type (CLC)] in cHC‐CC and HCC.

Pathologic classification of cholangiocarcinoma: New concepts

Herein, we propose a new pathologic classification of cholangiocarcinoma (CCA) based on recent progress in studies of preinvasive CCA lesions and the relationship of CCA to hepatic progenitor cells, as well as a new concept with respect to the pathologic similarities between biliary and pancreatic neoplasms. Depending on anatomical location, CCA is classifiable as intrahepatic (iCCA), perihilar (pCCA), and distal CCA (dCCA). iCCA is classifiable as the conventional type and the bile ductular type, whereas pCCA and dCCA mainly present as conventional adenocarcinoma. In addition, these three CCAs may present as the intraductal neoplasm type or rare variants. Bile ductular CCA resembles proliferating bile ductules and expressing hepatic progenitor cell phenotypes. Four types of preinvasive lesions are proposed: flat, papillary, tubular lesion, and cystic lesion. These lesions are eventually followed by invasive CCA. Interestingly, these preinvasive lesions have pancreatic counterparts. This CCA classification may introduce a new field of CCA research.

Immunostaining for polycomb group protein EZH2 and senescent marker p16INK4a may be useful to differentiate cholangiolocellular carcinoma from ductular reaction and bile duct adenoma.

Intrahepatic cholangiocarcinoma arising in chronic advanced liver disease sometimes contains a component of cholangiolocellular carcinoma. Bile duct adenoma, a benign tumor/tumorous lesion and ductular reaction, is also composed of bile ductular cells, and the differential diagnosis is sometimes difficult. We have previously reported that cholangiolocellular carcinoma showed overexpression of a polycomb group protein EZH2, which participates in bypass/escape from cellular senescence during carcinogenesis. In contrast, the ductular reaction showed high expression of senescence-associated p16INK4a. In this study, we examined whether immunostaining for EZH2 and p16INK4a is useful for differential diagnosis among cholangiolocellular carcinoma, bile duct adenoma, and ductular reactions. Subjects included 33 patients with intrahepatic cholangiocarcinoma and combined hepatocellular-cholangiocarcinoma with components of cholangiolocellular carcinoma and 16 patients with bile duct adenoma. The expressions of EZH2 and p16INK4a were examined immunohistochemically. The expression of EZH2 was seen in all cases of cholangiolocellular carcinomas, but it was not observed in bile duct adenomas and ductular reactions, which were seen around carcinomas in 80% of cases. The extensive expression of p16INK4a was seen only in 4 cases of cholangiolocellular carcinomas (12%). In contrast, the expression of p16INK4a was seen in 13 cases (81%) of bile duct adenomas and in all cases of ductular reactions. The borderline between the component of cholangiolocellular carcinoma and the surrounding ductular reaction was clearly highlighted by the reverse expression pattern of EZH2 and p16INK4a in 69% of cases. In conclusion, immunostaining for EZH2 and p16INK4a may be useful for differential diagnosis among cholangiolocellular carcinomas, bile duct adenomas, and ductular reactions.

Clinicopathological study of primary biliary cirrhosis with interface hepatitis compared to autoimmune hepatitis

AIM To investigate histological and immunohistochemical differences in hepatitis between autoimmune hepatitis (AIH) and primary biliary cirrhosis (PBC) with AIH features. METHODS Liver needle biopsies of 41 PBC with AIH features and 43 AIH patients were examined. The activity of periportal and lobular inflammation was scored 0 (none or minimal activity) to 4 (severe), and the degree of hepatitic rosette formation and emperipolesis was semiquantatively scored 0-3. The infiltration of mononuclear cells positive for CD20, CD38, CD3, CD4, and CD8 and positive for immunoglobulins (IgG, IgM, and IgA) at the periportal areas (interface hepatitis) and in the hepatic lobules (lobular hepatitis) were semiquantitatively scored in immunostained liver sections (score 0-6). Serum aspartate aminotransferase (AST), immunoglobulins, and autoantibodies at the time of liver biopsy were correlated with the histological and immunohistochemical scores of individual lesions. RESULTS Lobular hepatitis, hepatitic rosette formation, and emperipolesis were more extensive and frequent in AIH than in PBC. CD3+, CD4+, and CD8+ cell infiltration scores were higher in the hepatic lobules and at the interface in AIH but were also found in PBC. The degree of mononuclear cell infiltration correlated well with the degree of interface and lobular hepatitis in PBC, but to a lesser degree in AIH. CD20+ cells were mainly found in the portal tracts and, occasionally, at the interface in both diseases. Elevated AST correlated well with the hepatocyte necroinflammation and mononuclear cell infiltration, specifically CD38+ cells in PBC. No correlation existed between autoantibodies and inflammatory cell infiltration in PBC or AIH. While most AIH cases were IgG-predominant at the interface, PBC cases were divided into IgM-predominant, IgM/IgG-equal, and IgG-predominant types, with the latter sharing several features with AIH. CONCLUSION These results suggest that the hepatocellular injuries associated with interface and lobular hepatitis in AIH and PBC with interface hepatitis may not be identical.

Characterization of intraductal papillary neoplasm of bile duct with respect to histopathologic similarities to pancreatic intraductal papillary mucinous neoplasm

Intraductal papillary neoplasm of bile duct (IPNB) is a papillary tumor covered by well-differentiated neoplastic epithelium with fine fibrovascular cores in the dilated bile ducts. It reportedly shows similarities to intraductal papillary mucinous neoplasm of pancreas (IPMN), to various degrees. Herein, IPNB was pathologically analyzed by classifying 52 cases into 4 groups based on the histopathologic similarities to IPMN: group A (identical to IPMN, 19 cases), group B (similar to but slightly different from IPMN, 18 cases), group C (vaguely similar to IPMN, 5 cases), and group D (different from IPMN, 10 cases). In group A, intrahepatic and perihilar regions were mainly affected, most cases were of low/intermediate or high grade without invasion, and gastric type was the most common phenotype, followed by oncocytic and intestinal types. In groups C and D, perihilar and distal bile ducts were affected, almost all cases were of high grade with invasion, and most of them were of intestinal and pancreatobiliary phenotypes. Most group B cases were of intestinal phenotype, and all were of high grade with or without invasion. In conclusion, these 4 groups of IPNB showed unique pathologic features and behaviors. Group A cases were less aggressive and shared many features with IPMN, whereas group C and D cases were more aggressive and mainly found in perihilar and distal bile ducts. Group B resembling IPMN was intermediate between them. This classification may be useful in clinical practice and holds promise for a novel approach to analyze IPNB tumorigenesis.

Biliary adenofibroma with ominous features of imminent malignant changes

Biliary adenofibroma (BAF) is a rare, benign liver tumor. Herein, we report a case of BAF with histological features of imminent malignant changes. Ultrasound and CT revealed a solid 2.5-cm mass in the right liver lobe. The patient was asymptomatic and had no past medical history including liver disease. A general examination that included the abdomen and the laboratory data were normal. Because of the increase of its size, this tumor was surgically resected. Grossly, a 3.5-cm nodular mass abutted on the hepatic capsule was found, and its cut surface showed a well-circumscribed, whitish, and firm lesion that showed microcystic changes in the periphery and solid changes in the central parts. Histologically, the tumor showed a proliferation of tubulocystic structures embedded in a fibrous stroma. Microcysts were prevalent in the periphery, while tubular components with abundant fibrous stroma were in the central parts. The tubules were variably dilated and branched. This case closely resembled the previously reported cases of BAF, except that there were complicated papillary projections with fine fibrovascular cores in some of the microcysts and that the epithelial component in papillary projections showed dysplastic changes and increased cellular proliferative activities, implicating ominous features of imminent malignant changes. These dysplastic and papillary changes may be an intermediate lesion leading to malignancy, which have occasionally been reported in BAF.

Canals of Hering loss relates to the progression of the histological stages of primary biliary cirrhosis

Aims The canals of Hering (CoH), which are the most peripherally located bile drainage pathway, are considered a niche of hepatic progenitor cells. Recently, CoH loss has been described as an early feature of primary biliary cirrhosis (PBC). We investigated the correlation between CoH loss and the histopathological variables of PBC. Methods Liver biopsy specimens from 62 PBC patients (M:F=8:54, age=58±12 years) were evaluated prior to ursodeoxycholic acid treatment. Liver biopsies of patients with normal liver (n=11), chronic viral hepatitis (n=36) and non-alcoholic fatty liver disease (n=13) were used as controls. The number of CoH per definite area of hepatic parenchyma (c to p ratio) was calculated in individual cases. We compared the c to p ratios of PBC patients with that of controls and analysed the correlations with histological variables and clinical features. Results The c to p ratios in PBC patients with mild and extensive fibrosis were lower than those in controls with each degree of fibrosis. The c to p ratios were negatively correlated with stage, fibrosis, bile duct loss, orcein-positive granule deposition and hepatitis activities in PBC (p<0.01) and with alkaline phosphatase and total bilirubin levels at liver biopsies (p<0.05). Conclusions The number of CoH was low in early stages and further decreased with stage progression in PBC. CoH loss, reflecting a reduced supply of progenitor cells to the biliary tree, may be involved in the histological progression of PBC.