Aberrant expression of CDX2 is closely related to the intestinal metaplasia and MUC2 expression in intraductal papillary neoplasm of the liver in hepatolithiasis

GP2-enriched pancreatic progenitors give rise to functional beta cells in vivo and eliminate the risk of teratoma formation

Human pluripotent stem cell (hPSC)-derived pancreatic progenitors (PPs) can be differentiated into beta-like cells in vitro and in vivo and therefore have therapeutic potential for type 1 diabetes (T1D) treatment. However, the purity of PPs varies across different hPSC lines, differentiation protocols, and laboratories. The uncommitted cells may give rise to non-pancreatic endodermal, mesodermal, or ectodermal derivatives in vivo, hampering the safety of hPSC-derived PPs for clinical applications and their differentiation efficiency in research settings. Recently, proteomics and transcriptomics analyses identified glycoprotein 2 (GP2) as a PP-specific cell surface marker. The GP2-enriched PPs generate higher percentages of beta-like cells in vitro, but their potential in vivo remains to be elucidated. Here, we demonstrate that the GP2-enriched-PPs give rise to all pancreatic cells in vivo, including functional beta-like cells. Remarkably, GP2 enrichment eliminates the risk of teratomas, which establishes GP2 sorting as an effective method for PP purification and safe pancreatic differentiation.

Intrahepatic cholangiocarcinoma: Morpho-molecular pathology, tumor reactive microenvironment, and malignant progression

Intrahepatic cholangiocarcinoma (iCCA) is a relatively rare, but highly lethal and biologically complex primary biliary epithelial cancer arising within liver. After hepatocellular carcinoma, iCCA is the second most common primary liver cancer, accounting for approximately 10-20% of all primary hepatic malignancies. Over the last 10-20 years, iCCA has become the focus of increasing concern largely due to its rising incidence and high mortality rates in various parts of the world, including the United States. The challenges posed by iCCA are daunting and despite recent progress in the standard of care and management options for iCCA, the prognosis for this cancer continues to be dismal. In an effort to provide a framework for advancing our understanding of iCCA malignant aggressiveness and therapy resistance, this review will highlight key etiological, biological, molecular, and microenvironmental factors hindering more effective management of this hepatobiliary cancer. Particular focus will be on critically reviewing the cell origins and morpho-molecular heterogeneity of iCCAs, providing mechanistic insights into high risk fibroinflammatory cholangiopathies associated with iCCA development, and notably discussing the deleterious role played by the tumor reactive desmoplastic stroma in regulating iCCA malignant progression, lymphangiogenesis, and tumor immunobiology.

Targeted next-generation sequencing identifies distinct clinicopathologic and molecular entities of intraductal papillary neoplasms of the bile duct

Intraductal papillary neoplasm of the bile duct (IPNB) is a mass-forming neoplasm in the bile duct considered to be the biliary counterpart of pancreatic intraductal papillary mucinous neoplasm (IPMN). By its cell lineage, IPNB can be classified into gastric, intestinal, pancreatobiliary, and oncocytic types. Recently, a group of Japanese and Korean pathologists proposed that IPNB be classified into two types, with type 1, being the histological counterpart of IPMN and type 2, having a more complex histological architecture. We used targeted next-generation sequencing to study the molecular change of 37 IPNBs and identified frequent mutations of KRAS (49%), GNAS (32%), RNF43 (24%), APC (24%), TP53 (24%), and CTNNB1 (11%) in IPNBs. Intestinal-type IPNB was associated with KRAS, GNAS, and RNF43 mutations. Japan-Korea consensus type 1 was associated with KRAS and GNAS mutations. All four IPNBs with CTNNB1 mutations were of pancreatobiliary type and located in the extrahepatic bile duct. A hierarchical analysis identified three distinct groups within IPNB: group 1 was Japan-Korea consensus type 1 tumors with macroscopic mucin, old age, and frequent KRAS, GNAS, and RNF43 mutations. Group 2 was Japan-Korea consensus type 2 with intestinal differentiation and frequent KRAS mutation but rare GNAS mutation, MUC2 expression, and macroscopic mucin. Group 3 was characterized by CTNNB1 mutation, extrahepatic location, lack of expression of intestinal markers, Japan-Korea consensus type 2, and lack of mutations in KRAS, APC, RNF43, and GNAS. Our results indicated that IPNB is a heterogeneous disease and that the activation of Ras-mitogen-activated protein kinase (MAPK), Wnt/β-catenin, and G-protein-coupled receptor (GPCR)-cAMP signaling is the main oncogenic mechanism of IPNB.

CK20 and lymph node involvement predict adverse outcome of malignant intraductal papillary neoplasm of the bile duct

OBJECTIVES

To identify prognostic factors of malignant intraductal papillary neoplasm of the bile duct (m-IPNB).

MATERIALS AND METHODS

We included 38 consecutive cases which underwent surgical resection and diagnosed as IPNB with malignant component from January 2003 to January 2017. Clinicopathological variables were collected to conduct survival analysis and identify prognostic factors.

RESULTS

The median overall survival (OS) of m-IPNB was 76.0 months, with 1-, 3-, and 5-year survival rates of 97.2%, 73.5%, and 59.8%, respectively. The median RFS was 48.0 months with 1-, 3-, and 5-year recurrence-free survival (RFS) rate was 83.2%, 59.8%, and 44.6%, respectively. Univariate analysis showed that elevation of carcinoembryonic antigen CEA, lymph node involvement, resection margin status, degree of periductal invasion, and positive expression of CK20 were associated with both OS and RFS of m-IPNB. After multivariate Cox models analysis, lymph node involvement and positive expression of CK20 were identified as independent prognostic factors for OS, while lymph node involvement and resection margin status were independent prognostic factors for RFS. The median OS of patients with m-IPNB involving lymphatic metastases and positive expression of CK20 was 27.0±8.8 months and 51.0±12.4 months, respectively. The median RFS of cases with lymph node involvement and R1 resection was 10.0±3.3 months and 25.0±6.9 months, respectively. However, there was no significant difference in OS or RFS between cases of pancreaticobiliary and intestinal subtype.

CONCLUSIONS

Lymph node involvement and positive expression of CK20 are independent prognostic factors for shorter OS of m-IPNB, while patients with lymph node involvement and positive resection margin are at higher risk of tumor recurrence.

Mucins: the Old, the New and the Promising Factors in Hepatobiliary Carcinogenesis

Mucins are large O-glycoproteins with high carbohydrate content and marked diversity in both the apoprotein and the oligosaccharide moieties. All three mucin types, trans-membrane (e.g., MUC1, MUC4, MUC16), secreted (gel-forming) (e.g., MUC2, MUC5AC, MUC6) and soluble (non-gel-forming) (e.g., MUC7, MUC8, MUC9, MUC20), are critical in maintaining cellular functions, particularly those of epithelial surfaces. Their aberrant expression and/or altered subcellular localization is a factor of tumour growth and apoptosis induced by oxidative stress and several anti-cancer agents. Abnormal expression of mucins was observed in human carcinomas that arise in various gastrointestinal organs. It was widely believed that hepatocellular carcinoma (HCC) does not produce mucins, whereas cholangiocarcinoma (CC) or combined HCC-CC may produce these glycoproteins. However, a growing number of reports shows that mucins can be produced by HCC cells that do not exhibit or are yet to undergo, morphological differentiation to biliary phenotypes. Evaluation of mucin expression levels in precursors and early lesions of CC, as well as other types of primary liver cancer (PLC), conducted in in vitro and in vivo models, allowed to discover the mechanisms of their action, as well as their participation in the most important signalling pathways of liver cystogenesis and carcinogenesis. Analysis of mucin expression in PLC has both basic research and clinical value. Mucins may act as oncogenes and tumour-promoting (e.g., MUC1, MUC13), and/or tumour-suppressing factors (e.g., MUC15). Given their role in promoting PLC progression, both classic (MUC1, MUC2, MUC4, MUC5AC, MUC6) and currently tested mucins (e.g., MUC13, MUC15, MUC16) have been proposed to be important diagnostic and prognostic markers. The purpose of this review was to summarize and update the role of classic and currently tested mucins in pathogenesis of PLC, with explaining the mechanisms of their action in HCC carcinogenesis. It also focuses on determination of the diagnostic and prognostic role of these glycoproteins in PLC, especially focusing on HCC, CC and other hepatic tumours with- and without biliary differentiation.

The expression and clinicopathological role of CDX2 in intrahepatic cholangiocarcinoma

The aim of this study was to examine the expression and clinicopathological role of caudal homeobox 2 (CDX2) in intrahepatic cholangiocarcinoma (ICC). CDX2 expression was determined immunohistochemically in 93 patients with ICC. The association between CDX2 expression and clinicopathological features of ICC was also examined in patients with ICC. Immunohistochemical staining for CDX2 was noted in 27 patients (29.03%); patients with CDX2-positive tumors had significant survival advantages over those with CDX2- negative tumors (median survival was 40 months for patients with CDX2-positive tumors and 13 months for patients with CDX2-negative tumors; the hazard ratio was 0.36, the 95% confidence interval was 0.22-0.59, and p < 0.001). The rate of CDX2 expression was 13.46% in patients with lymphatic invasion and 48.78% in patients without lymphatic invasion (χ² = 13.88, p < 0.01); positivity for CDX2 expression was significantly higher in patients with well-differentiated or moderately differentiated tumors than that in patients with poorly differentiated tumors (41.7% in patients with well-differentiated tumors, 47.6% in patients with moderately differentiated tumors, and 20.0% in patients with poorly differentiated tumors; Mann-Whitney U test, p = 0.01). In addition, CDX2 expression differed significantly in patients with ICC due to hepatolithiasis and patients with ICC not due to hepatolithiasis (36.51% and 13.33%, respectively, χ² = 5.30, p = 0.02). Positivity for CDX2 expression resulted in significant survival advantages for patients with ICC. CDX2 might be used as a prognostic marker in patients with ICC.

Gallbladder papillary neoplasms share pathological features with intraductal papillary neoplasm of the bile duct

Intraductal papillary neoplasm of the bile duct (IPNB) has been widely recognized. However, the knowledge of intracystic papillary neoplasm of the gallbladder (IPNG) including papillary adenoma and adenocarcinoma is not well defined. In this study, we compared the clinicopathological and immunohistochemical features between 32 IPNG cases and 32 IPNB cases. IPNG-1 (low-high grade dysplasia) exhibited an earlier onset age, smaller tumor size and lower level of CK20 expression compared to IPNG-2 (invasive carcinoma). Histologically, pancreaticobiliary and intestinal subtype accounted for nearly half of IPNG or IPNB (44.4% and 48.1% vs. 44.0% and 44.0%), respectively. Immunohistochemically, 88.9% of IPNG and 92.0% of IPNB cases were positive for MUC1, and 96.3% and 92.0% for CK7, respectively. CDX2 and MUC2 were more highly expressed in the intestinal subtype than in other subtypes. CK20 expression increased in parallel with tumor progression. In addition, 53.1% of IPNG cases and 68.6% of IPNB cases exhibited invasive carcinoma, and showed significant survival advantages to conventional gallbladder adenocarcinoma and cholangiocarcinoma, respectively. In conclusion, papillary adenoma and adenocarcinoma of the gallbladder can be recognized as different pathological stages of IPNG, and they share pathological features with IPNB.

Pathogenesis and classification of intrahepatic cholangiocarcinoma: different characters of perihilar large duct type versus peripheral small duct type

Intrahepatic cholangiocarcinomas (ICCs) are made up of heterogenous carcinomas arising from different anatomical sites of the liver. Two types of candidate stem/progenitor cells of the biliary tree are postulated to exist at the peribiliary glands for large bile ducts and at the canals of Hering for small ducts and hepatocytes. According to the recent observations, ICCs can be subclassified into two types: tumors involving the large bile ducts comparable in size to the intrahepatic second branches and composed of a tubular or papillary component with tall columnar epithelium, and tumors involving the smaller duct than segmental branches and composed of small tubules with cuboidal epithelium. Perihilar large duct type ICCs can be interpreted as arising from large bile duct type ICCs, and peripheral small duct type ICCs may arise from small bile duct type or ductular type ICCs. Chronic biliary inflammation induces neoplastic change of the large bile ducts and thereby progression to the perihilar large duct type ICC, which can be grossly classified into periductal filtrating type ICC and intraductal growth type ICC, while chronic hepatitis or cirrhosis induces mass-forming peripheral small duct type ICC. The different morphological and molecular features, including stromal components and tumor vasculature, support the hypothesis that perihilar large duct type ICCs and peripheral small duct type ICCs arise from different backgrounds, have different carcinogenetic pathways, and exhibit different biologic behaviors.

GNAS and KRAS mutations are common in intraductal papillary neoplasms of the bile duct

Intraductal papillary neoplasms of the bile duct (IPNB) shows favorable prognosis and is regarded as a biliary counterpart of intraductal papillary mucinous neoplasm (IPMN) of the pancreas. Although activating point mutations of GNAS at codon 201 have been detected in approximately two thirds of IPMNs of the pancreas, there have been few studies on GNAS mutations in IPNBs. This study investigates the status of GNAS and KRAS mutations and their association with clinicopathological factors in IPNBs. We examined the status of GNAS mutation at codon 201 and KRAS mutation at codon 12&13, degree of mucin production and immunohistochemical expressions of MUC mucin core proteins in 29 patients (M/F = 15/14) with IPNB in intrahepatic and perihilar bile ducts (perihilar IPNB) and 6 patients (M/F = 5/1) with IPNB in distal bile ducts (distal IPNB). GNAS mutations and KRAS mutations were detected in 50% and 46.2% of IPNBs, respectively. There was no significant correlation between the status of GNAS mutation and clinicopathological factors in IPNBs, whereas, the status of KRAS mutation was significantly inversely correlated with the degree of MUC2 expression in IPNBs (p<0.05). All IPNBs with GNAS mutation only showed high-mucin production. Degree of mucin production was significantly higher in perihilar IPNBs than distal IPNBs (p<0.05). MUC2 and MUC5AC expression was significantly higher in IPNBs with high-mucin production than those with low-mucin production (p<0.01 and p<0.05, respectively). In conclusions, this study firstly disclosed frequent GNAS mutations in IPNBs, similarly to IPMNs. This may suggest a common histopathogenesis of IPNBs and IPMNs. The status of KRAS mutations was inversely correlated to MUC2 expression and this may suggest heterogeneous properties of IPNBs. IPNBs with high-mucin production are characterized by perihilar location and high expression of MUC2 and MUC5AC, irrespective of the status of GNAS and KRAS mutations.

LPS increases MUC5AC by TACE/TGF-α/EGFR pathway in human intrahepatic biliary epithelial cell

BACKGROUND

Mucin 5AC (MUC5AC) overproduction plays important roles in stone formation and recurrence of hepatolithiasis. We aim to investigate the involved mechanism and the potential target to block this process.

METHODS

42 bile duct samples from hepatolithiasis and 15 normal bile duct samples from hemangioma patients were collected for detecting MUC5AC expression by immunohistochemistry. MUC5AC and phosphoepidermal growth factor receptor (pEGFR) expressions in human intrahepatic biliary epithelial cells (HIBECs) cultured with or without lipopolysaccharide (LPS) were detected by real-time PCR and western blot analysis. Transforming growth factor-α (TGF-α) secretion in HIBECs was detected by ELISA.

RESULTS

MUC5AC was overexpressed in bile ducts of hepatolithiasis samples compared with bile ducts from hemangioma samples. LPS upregulated MUC5AC expression in HIBECs. LPS promoted EGFR activation, and inhibiting EGFR activation by AG1478 significantly decreased LPS-induced MUC5AC overexpression in HIBECs. Moreover, LPS increased TGF-α secretion, and inhibiting tumor necrosis factor-α converting enzyme (TACE), which has been implicated in ectodomain cleavage of TGF-α, significantly inhibited LPS-induced EGFR activation and subsequent MUC5AC overexpression in HIBECs.

CONCLUSION

Our results suggested that LPS increases MUC5AC expression through the TACE/TGF-α/EGFR pathway in HIBECs. This new finding might give light to the prevention of stone formation and recurrence of hepatolithiasis.

Transgenic overexpression of cdx1b induces metaplastic changes of gene expression in zebrafish esophageal squamous epithelium

Cdx2 has been suggested to play an important role in Barrett's esophagus or intestinal metaplasia (IM) in the esophagus. To investigate whether transgenic overexpression of cdx1b, the functional equivalent of mammalian Cdx2 in zebrafish, may lead to IM of zebrafish esophageal squamous epithelium, a transgenic zebrafish system was developed by expressing cdx1b gene under the control of zebrafish keratin 5 promoter (krt5p). Gene expression in the esophageal squamous epithelium of wild-type and transgenic zebrafish was analyzed by Affymetrix microarray and confirmed by in situ hybridization. Morphology, mucin expression, cell proliferation, and apoptosis were analyzed by hematoxylin & eosin (HE) staining, Periodic acid Schiff (PAS) Alcian blue staining, proliferating cell nuclear antigen (PCNA) immunohistochemical staining, and TUNEL assay as well. cdx1b was found to be overexpressed in the nuclei of esophageal squamous epithelial cells of the transgenic zebrafish. Ectopic expression of cdx1b disturbed the development of this epithelium in larval zebrafish and induced metaplastic changes in gene expression in the esophageal squamous epithelial cells of adult zebrafish, that is, up-regulation of intestinal differentiation markers and down-regulation of squamous differentiation markers. However, cdx1b failed to induce histological IM, or to modulate cell proliferation and apoptosis in the squamous epithelium of adult transgenic zebrafish.

The silence of MUC2 mRNA induced by promoter hypermethylation associated with HBV in Hepatocellular Carcinoma

Background

To evaluate the promoter methylation status of MUC2 gene and mRNA expression in patients with hepatocellular carcinoma.

Methods

We analyzed MUC2 methylation by MSP, and MUC2 mRNA by real-time PCR in 74 HCC.

Results

MUC2 mRNA were lower in HCC tissues (Mean _-ΔCt = −4.70) than that in Non-HCC tissues (Mean _-ΔCt = −2.98). Expression of MUC2 was elevated in only 23 (31.08%) of the 74 HCC patients. MUC2 promoter was hypermethylated in 62.2% (46/74) of HCCs, and in only 18.9% (14/74) of non-tumor samples. MUC2 mRNA were lower in HCC patients with hypermethylation (Mean _-ΔΔCt = −2.25) than those with demethylation (Mean _-ΔΔCt = −0.22), and there is a decreased tendency for MUC2 mRNA in HCC patients with promoter hypermethylation (p = 0.011). There was a significantly correlation found between MUC2 mRNA and HBV and AFP in HCC. The loss of MUC2 mRNA and hypermethylation could be poor prognostic factors. After treated by 5-Aza-CdR and TSA, we found that MUC2 mRNA induced significantly in 7721, Huh7 and HepG2 cells.

Conclusion

The results suggested that MUC2 mRNA silenced by promoter hypermethylation is associated with high levels HBV in HCC.

Overexpression of enhancer of zeste homolog 2 and MUC1 may be related to malignant behaviour in intraductal papillary neoplasm of the bile duct

AIMS

  Intraductal papillary neoplasm of the bile duct (IPNB) usually has a favourable prognosis, but occasionally is associated with invasive carcinoma. Overexpression of the polycomb group protein enhancer of zeste homolog 2 (EZH2) is involved in the progression of malignant tumours. In this study, we examined the significance of EZH2 expression in IPNB and its association with clinicopathological features and the expression of p16(INK4a) , p53 and mucin core proteins.

METHODS AND RESULTS

  We examined immunohistochemically the expression of EZH2, p16(INK4a) , MUC mucin core proteins and p53 in 15 patients with IPNB without invasion, including the cystic variant [male/female ratio (M/F) = 9/6], and in 19 with IPNB associated with invasive carcinoma (M/F = 13/6). The expression levels of EZH2, p53 and MUC1 were significantly lower (P < 0.01), and of MUC6 were significantly higher (P < 0.05), in IPNB without invasion than in IPNB with invasion. Expression of EZH2 was significantly correlated with expression of MUC1 (P < 0.01) and inversely correlated with expression of MUC6 (P < 0.05). In cholangiocarcinoma cells (HuCTT-1 and TFK-1), knockdown of EZH2 and MUC1 by small interfering RNA decreased invasion and proliferation, whereas knockdown of MUC6 increased invasion.

CONCLUSIONS

  Overexpression of EZH2 may be associated with malignant behaviour in IPNB in parallel with up-regulated MUC1 expression and down-regulated MUC6 expression.

Gastric intestinal metaplasia revisited: function and regulation of CDX2

Intestinal metaplasia of the stomach is a preneoplastic lesion that appears following Helicobacter pylori infection and confers increased risk for gastric cancer development. However, the molecular networks connecting infection to lesion formation and the cellular origin of this lesion remain largely unknown. A more comprehensive understanding of how intestinal metaplasia arises and is maintained will be a major breakthrough towards developing novel therapeutic interventions. Furthermore, after ascertaining the pivotal role of CDX2 in establishing and maintaining intestinal metaplasia, it becomes important to decipher the upstream molecular pathways leading to its ectopic expression. Here, we review the pathophysiology of intestinal metaplasia in the context of the molecular network involved in its establishment and maintenance, with emphasis on CDX2 function and regulation.

Caco-2 and LS174T cell lines provide different models for studying mucin expression in colon cancer

To compare the differences in MUC2 and MUC5AC mRNA among four colon cancer cell lines and to identify the best in vitro models for studying mucin expression, quantitative real-time polymerase chain reaction was used to measure the expression of MUC2 and MUC5AC mRNA in Caco-2, HT29, LoVo, and LS174T cell lines. The levels of MUC2 mRNA expression in the four colon cancer cell lines ranked in order of mRNA abundance were: LS174T>LoVo>HT-29>Caco-2. In contrast to MUC2, the abundances of MUC5AC mRNA were in the order: Caco-2>HT-29>LS174T>LoVo. Caco-2 (highest level of MUC5AC mRNA) and LS174T (highest level of MUC2 mRNA) were used to investigate the phenotypes. Morphologically, Caco-2 cells were larger with low electron density mucus-storing vacuoles, many cell surface microvilli, and no obvious intercellular spaces between cells, compared to LS174T cells. The proliferative and invasive capacities of LS174T cells were significantly higher than those of Caco-2 cells. Caco-2 and LS174T cells provide excellent in vitro models for studying mucin expression in colon cancer.

A comparative study of intraductal papillary neoplasia of the biliary tract and pancreas

Intraductal papillary mucinous neoplasm of the pancreas is a rare but well-established entity in contrast to intraductal papillary mucinous neoplasm of the biliary tract. The aim of this study was to compare the clinicopathologic features of intraductal papillary mucinous neoplasms of the biliary tract and of the pancreas. Twenty patients who underwent resection for intraductal papillary mucinous neoplasm of the biliary tract were compared with 29 cases resected for intraductal papillary mucinous neoplasm of the pancreas. Clinicopathologic characteristics and resection specimens of all patients were reassessed and immunohistochemically screened for expression of a distinct set of tumor markers. Median ages of patients with intraductal papillary mucinous neoplasms of the biliary tract and of the pancreas were 66 and 62 years, respectively (P < .05). Twelve patients with intraductal papillary mucinous neoplasm of the biliary tract (60%) had neoplasms with infiltrating carcinoma, compared with 6 patients with intraductal papillary mucinous neoplasm of the pancreas (21%, P < .05). Cytokeratin 7 and 20 expressions were equal in biliary and pancreatic intraductal papillary mucinous neoplasms. Cytokeratin 20 expression was mainly found in intestinal-type tumors. Gastric, pancreaticobiliary, and oncocytic subtypes were all observed in the intraductal papillary mucinous neoplasm of the biliary tract group. The distribution was significantly different from the intraductal papillary mucinous neoplasm of the pancreas group. The 3-year overall survival rate of malignant biliary and pancreatic intraductal papillary mucinous neoplasm was 63% and 65%, respectively (P = .798). Positive lymph nodes and a high expression of membranous mucin were associated with a significantly shorter overall survival in patients with malignant intraductal papillary mucinous neoplasm. Finally, p53 and Ki67 proliferation index were both associated with the carcinogenesis of intraductal papillary mucinous neoplasm, whereas DPC4 and CDX2 were not. Clinicopathologic features of intraductal papillary mucinous neoplasm of the biliary tract largely resemble those of intraductal papillary mucinous neoplasm of the pancreas, although intraductal papillary mucinous neoplasm of the biliary tract was associated with a higher malignancy rate at the time of surgical treatment. The level of membranous mucin expression and positive lymph nodes are significant prognosticators in patients with malignant intraductal papillary mucinous neoplasm.

Expression of CDX2 and hepatocyte antigen in benign and malignant lesions of gallbladder and its correlation with histopathologic type and clinical outcome

Recent studies have shown that both CDX2 and Hepatocyte antigen (Hep) are detected in different types of cancer and associated with clinical prognosis. However, fever studies have examined gallbladder cancer specimens, and little is known about the clinicopathological significance of both CDX2 and Hep expression in gallbladder adenocarcinomas. In present study, we examined the expression frequencies of CDX2 and Hepatocyte antigen (Hep), and explored their clinicopathologic significances in gallbladder adenocarcinoma. Immunohistochemistry was used to detect and compare the frequencies of CDX2 and Hep expression in 108 samples of gallbladder adenocarcinoma, 46 peri-tumor tissues and 35 chronic cholecystitis. The expression frequencies for CDX2 and Hep were 49/108 (45.4%) and 45/108 (41.7%) in gallbladder carcinoma; 13/46 (28.3%) and 11/46 (23.9) in peri-tumor tissues; 5/35 (14.3%) and 2/35 (5.7%) in chronic cholecystitis. The positive staining of CDX2 or Hep in gallbladder adenocarcinoma was significantly higher than that in peritumoral tissues (both, P < 0.05), and chronic cholecystits (both, P < 0.01). The expression of CDX2 or Hep was negatively correlated to grade of differentiation, tumor size and lymph node metastasis (P < 0.01 or P < 0.05). Elevated expression frequency of CDX2 or Hep was associated with increased overall survival (P = 0.003 or P = 0.002). Multivariate Cox regression analysis showed that CDX2 (P = 0.014) or Hep (P = 0.026) expression was an independent prognostic predictor in gallbladder adenocarcinoma. CDX2 and Hep might function as important biological markers in the development and prognosis of gallbladder adenocarcinoma.

Biliary epithelial apoptosis, autophagy, and senescence in primary biliary cirrhosis

Primary biliary cirrhosis (PBC) is a chronic cholestatic liver disease characterized serologically by the high prevalence of anti-mitochondrial autoantibodies (AMAs) and histologically by the cholangitis of small bile ducts, eventually followed by extensive loss of the small bile duct. An autoimmune pathogenesis is suggested by clinical and experimental studies, but there remain issues regarding the etiology, the significance of AMAs in the pathogenesis of bile duct lesions, and so on. The unique properties of apoptosis in biliary epithelial cells (BECs), in which there is exposure of autoantigen to the effectors of the immune system, are proposed to be a cause of bile duct lesions in PBC. Recent progress disclosed that cellular senescence and autophagy are involved in bile duct lesions in PBC. Senescent BECs may modulate the periductal microenvironment by expressing senescence-associated secretory phenotypes, including various chemokines, and contribute to the pathogenesis of bile duct lesions in PBC.

Pathophysiology of intestinal metaplasia of the stomach: emphasis on CDX2 regulation

IM (intestinal metaplasia) of the stomach is a pre-neoplastic lesion that usually follows Helicobacter pylori infection and that confers increased risk for gastric cancer development. After setting the role played by CDX2 (Caudal-type homeobox 2) in the establishment of gastric IM, it became of foremost importance to unravel the regulatory mechanisms behind its de novo expression in the stomach. In the present paper, we review the basic pathology of gastric IM as well as the current knowledge on molecular pathways involved in CDX2 regulation in the gastric context.

Bile ductular cells undergoing cellular senescence increase in chronic liver diseases along with fibrous progression

We investigated the pathologic significance of ductular reactions in chronic liver diseases with respect to cellular senescence. The expression of senescence-associated markers (p16(INK4a) and p21(WAF1/Cip1)), cell proliferation, cell cycle markers (cyclin D and cyclin A), and neural cell adhesion molecule (NCAM) was examined immunohistochemically in primary biliary cirrhosis (PBC, n = 37), chronic viral hepatitis (n = 39), nonalcoholic steatohepatitis (n = 25), and control normal livers (n = 12). The expression of p16(INK4a) and p21(WAF1/Cip1) was frequently found in ductular cells in the advanced stage of chronic liver diseases, especially in PBC (P < .05). Double immunostaining disclosed that most senescent cells expressed cyclin D (G(1)-phase marker). NCAM was frequently coexpressed in ductular cells showing senescence-associated markers. Some ductular cells in ductular reactions in chronic liver diseases were at G(1) arrest and undergoing cellular senescence. Such senescent cells may be involved in the progression of fibrosis of these diseases, particularly in PBC.

Cdx genes, inflammation, and the pathogenesis of intestinal metaplasia

Intestinal metaplasia (IM) is a biologically interesting and clinically relevant condition in which one differentiated type of epithelium is replaced by another that is morphologically similar to normal intestinal epithelium. Two classic examples of this are gastric IM and Barrett's esophagus (BE). In both, a chronic inflammatory microenvironment, provoked either by Helicobacter pylori infection of the stomach or acid and bile reflux into the esophagus, precedes the metaplasia. The Caudal-related homeodomain transcription factors Cdx1 and Cdx2 are critical regulators of the normal intestinal epithelial cell phenotype. Ectopic expression of Cdx1 and Cdx2 occurs in both gastric IM as well as in BE. This expression precedes the onset of the metaplasia and implies a causal role for these factors in this process. We review the observations regarding the role of chronic inflammation and the Cdx transcription factors in the pathogenesis of gastric IM and BE.

Intrahepatic cholangiocarcinoma progression: prognostic factors and basic mechanisms

In this review, we will examine various molecular biomarkers for their potential to serve as independent prognostic factors for predicting survival outcome in postoperative patients with progressive intrahepatic cholangiocarcinoma. Specific rodent models of intrahepatic cholangiocarcinoma that mimic relevant cellular, molecular, and clinical features of the human disease are also described, not only in terms of their usefulness in identifying molecular pathways and mechanisms linked to cholangiocarcinoma development and progression, but also for their potential value as preclinical platforms for suggesting and testing novel molecular strategies for cholangiocarcinoma therapy. Last, recent studies aimed at addressing the role of desmoplastic stroma in promoting intrahepatic cholangiocarcinoma progression are highlighted in an effort to underline the potential value of targeting tumor stromal components together with that of cholangiocarcinoma cells as a novel therapeutic option for this devastating cancer.

Tumorigenesis and phenotypic characteristics of mucin-producing bile duct tumors: an immunohistochemical approach

Intraductal papillary neoplasm of the bile duct (IPNB) is characterized by exophytic proliferation of neoplastic epithelial cells with fibrovascular stalks in bile duct lumen, mucin hypersecretion, and considerable dilatation or multilocular changes of the affected bile ducts. A mucin-producing bile duct tumor is an IPNB with excessive mucin production and clinical symptoms. Herein, the phenotypes as well as the tumorigenesis and progression of IPNB are reviewed with immunohistochemical assistance. The tumors are subdivided into three phenotypes: pancreatobiliary, intestinal, and gastric. About half of IPNB cases are of the pancreatobiliary type, and the remaining half are of the intestinal type. Aberrant expression of CDX2 with MUC2 and CK20 is related to the development of intestinal metaplasia. Inactivation of P16INK4a and nuclear expression of beta-catenin are related to the development of IPNB. Decreased expression of membranous beta-catenin and E-cadherin and aberrant expression of MMP-7 and -9 and of MUC1 are related to invasion of IPNB with tubular adenocarcinoma, whereas MUC2 is involved in the invasion of IPNB with mucinous carcinoma. IPNB can be regarded as a counterpart of intraductal papillary mucinous neoplasm (IPMN) of the pancreas, particularly the main duct type. More comparative studies between IPNB and pancreatic IPMN are recommended for further analysis of these papillary neoplasms.

Mucin gene expression in bile of patients with and without gallstone disease, collected by endoscopic retrograde cholangiography

AIM: To investigate the pattern of mucin expression and concentration in bile obtained during endoscopic retrograde cholangiography (ERC) in relation to gallstone disease.

METHODS: Bile samples obtained at ERC from 29 consecutive patients, 17 with and 12 without gallstone disease were evaluated for mucin content by gel filtration on a Sepharose CL-4B column. Dot blot analysis for bile mucin apoproteins was performed with antibodies to Mucin 1 (MUC1), MUC2, MUC3, MUC5AC, MUC5B and MUC6. Staining intensity score (0-3) was used as a measure of antigen expression.

RESULTS: MUC1, MUC2, MUC3, MUC5AC, MUC5B and MUC6 were demonstrated in 34.4%, 34.4%, 51.7%, 51.7%, 55.1% and 27.5% of bile samples, respectively. The staining intensity scores were 0.62 ± 0.94, 0.58 ± 0.90, 0.79 ± 0.97, 1.06 ± 1.22, 1.20 ± 1.26 and 0.41 ± 0.73, respectively. Mean mucin concentration measured in bile by the Sepharose CL-4B method was 22.8 ± 24.0 mg/mL (range 3.4-89.0 mg/mL). Mean protein concentration was 8.1 ± 4.8 mg/mL (range 1.7-23.2 mg/mL).

CONCLUSION: High levels of MUC3, MUC5AC and MUC5B are expressed in bile aspirated during ERC examination. A specific pattern of mucin gene expression or change in mucin concentration was not found in gallstone disease.

Intraductal papillary neoplasm of the bile duct associated with Clonorchis sinensis infection

Intraductal papillary neoplasm of bile duct (IPNB) is one of the precursor lesions of cholangiocarcinoma. Although hepatolithiasis has been extensively studied in its association with IPNBs, there had been no comprehensive study of IPNBs with Clonorchis sinensis infection. Twelve IPNBs were selected from 20 surgically resected cholangiocarcinomas, positive for C. sinensis tests (60%) and compared with eight IPNBs, selected from 51 resected cholangiocarcinomas, negative for C. sinensis tests (16%), by histologic and immunohistochemical studies of mucin core proteins and cytokeratin panels. The predominant immuno-phenotype of IPNB cases with Clonorchiasis was pancreatobiliary type (MUC1+/MUC2-/CDX2-; 9/12 cases), while that of IPNB cases with negative for C. sinensis was intestinal type (MUC1-/MUC2+/CDX2+; 6/8; p = 0.04). The prevalence of IPNBs was higher when patients with cholangiocarcinoma had Clonorchiasis. IPNBs with Clonorchiasis tended to have a more pancreatobiliary phenotype, which suggests IPNBs with Clonorchiasis may have a different tumorigenesis pathway from IPNBs with other etiologies.

Tumor necrosis factor-alpha induces the aberrant expression of mucus core protein-2 in non-neoplastic biliary epithelial cells via the upregulation of CDX2 in chronic cholangitis

AIM

Chronic cholangitis, such as hepatolithiasis, is frequently associated with goblet cell metaplasia and the aberrant expression of mucus core protein-2 (MUC2). In this study, we clarified the role of inflammatory cytokines in the expression of MUC2 in lining biliary epithelial cells (BEC) in chronic cholangitis with an emphasis on CDX2, an intestine-specific transcription factor.

METHODS

We used human hepatolithiatic livers and polycystic kidney (PCK) rats, an animal model of Caroli's disease, and cultured BEC from PCK rats. As a control, extrahepatic biliary obstruction and histologically normal livers and Crj:CD rats were used.

RESULTS

Immunohistochemically, tumor necrosis factor-alpha (TNF-alpha) was expressed in periductal inflammatory cells and BEC of the affected intrahepatic bile ducts with an aberrant expression of MUC2 and CDX2 in hepatolithiasis and the PCK rats. In cultured BEC, TNF-alpha, interleukin (IL)-1beta, IL-6, and interferon-gamma induced the expression of CDX2 mRNA, though only TNF-alpha additionally induced the expression of MUC2 mRNA. The expression of CDX2 mRNA and the MUC2 protein induced in BEC by TNF-alpha were abolished by pretreatment of nuclear factor-kappaB inhibitors.

CONCLUSION

The aberrant expression of CDX2 and MUC2 in the affected bile ducts showing goblet cell metaplasia was closely associated with TNF-alpha expressed in periductal infiltrating inflammatory cells and BEC. TNF-alpha induced the expression of CDX2 and MUC2 in cultured BEC. Taken together, it seems likely that TNF-alpha plays a role in MUC2 expression via CDX2 upregulation in the bile ducts with chronic cholangitis and goblet cell metaplasia.

Pathology of peripheral intrahepatic cholangiocarcinoma with reference to tumorigenesis

Cholangiocarcinomas (CCs) are neoplasms with cholangiocyte differentiation, and may arise from cholangiocytes of the biliary tree and possibly cholangiocyte progenitor cells. Intrahepatic CCs can be divided into the perihilar and peripheral types. Peripheral CCs present grossly as a mass forming tumor, and histologically as an adenocarcinoma of varying shapes and phenotypes. Some peripheral CCs (ductular type) are characterized by: (i) a histological resemblance to reactive bile ductules; (ii) the expression of neural cell adhesion molecule (NCAM) and vimentin. This type shows: (i) grossly, a blurred border; and (ii) histologically, carcinoma cells replacing the adjoining hepatocytes at the border of the tumor. It is frequently associated with neutrophilic infiltration and also with granulocyte and granulocyte macrophage colony-stimulating factors. We propose to call this type "ductular CC." The other peripheral CC (duct type) includes ordinary adenocarcinoma with well to moderately differentiated tubular and micropapillary patterns and is negative for NCAM but positive for mucin. This type can be called "duct CC," and shows a rather compressive growth. Interestingly, CC components of combined hepatocellular CC share the features of ductular CC, suggesting that hepatic progenitor cells may be involved in the tumorigenesis of ductular CC. The biological behavior of ductular CC and duct CC remains obscure, and follow-up and molecular studies on these tumors are required in order for these two CCs to be recognized as disease entities, and so as to evaluate their carcinogenesis.

A case of asymptomatic intraductal papillary neoplasm of the bile duct without hepatolithiasis

A 65-year-old woman was found to have dilatation of the intrahepatic bile duct in the right anterior segment during a general health. Laboratory data were within normal ranges and no solid mass was detected in her abdominal computer tomography (CT) or nuclear magnetic resonance imaging (MRI). However, endoscopic retrograde cholangiopancreatography (ERCP) demonstrated an obstruction of the right bile duct. Intraoperative cholangiography showed stenosis of the intrahepatic bile duct in the anterior inferior segment (B5) and narrowness of the intrahepatic bile duct in the anterior superior segment (B8), so that we strongly suspected intrahepatic cholangiocarcinoma (ICC). Histologically, surgically resected liver specimens, without tumor mass by macroscopic observation, showed intraductal papillary proliferation with fibrovascular cores and intraductal spreading of carcinoma in situ throughout a considerable area, especially in bile ductules around the peripheral small portal area. Furthermore, the immunohistochemical profile of the tumor (MUC5AC+/CK7+) was compatible with an intraductal papillary neoplasm of the bile duct (IPN-B). Consequently, this case was diagnosed as IPN-B with spreading CIS, stageI(pT1, pN0, P0, H1, M0). We report a case of IPN-B with interesting histopathological findings and emphasize that cholangiography is especially helpful for the diagnosis of bile duct dilatation due to infiltration of carcinoma cells.

Risk factors for intrahepatic cholangiocarcinoma: A case-control study in China

AIM: To carry out a hospital-based case-control study to investigate risk factors for intrahepatic cholangiocarcinoma (ICC) in China.

METHODS: A total of 312 ICC cases and 438 matched controls were included in the study. The presence of diabetes mellitus, hypertension, hepatolithiasis, primary sclerosing cholangitis, liver fluke infection (Clonorchis sinensis), was investigated through clinical records. Blood from all participants was tested for hepatitis B surface antigen (HBsAg) and anti-HCV antibodies. Odds ratios (OR) and 95% confidence intervals (95% CI) were estimated using conditional logistic regression.

RESULTS: Compared with controls, ICC patients had a higher prevalence of HBsAg seropositivity (48.4% vs 9.6%, P < 0.000), and hepatolithiasis (5.4% vs 1.1%, P = 0.001). By multivariate analysis, the significant risk factors for development of ICC were HBsAg seropositivity (adjusted OR, 8.876, 95% CI, 5.973-13.192), and hepatolithiasis (adjusted OR, 5.765, 95% CI, 1.972-16.851). The prevalence of anti-HCV seropositivity, diabetes mellitus, hypertension, cigarette smoking, and alcohol consumption were not significantly different between cases and controls.

CONCLUSION: These findings suggest that HBV infection and hepatolithiasis are strong risk factors for development of ICC in China.

Multilayered epithelium in a rat model and human Barrett's esophagus: similar expression patterns of transcription factors and differentiation markers

Background

In rats, esophagogastroduodenal anastomosis (EGDA) without concomitant chemical carcinogen treatment leads to gastroesophageal reflux disease, multilayered epithelium (MLE, a presumed precursor in intestinal metaplasia), columnar-lined esophagus, dysplasia, and esophageal adenocarcinoma. Previously we have shown that columnar-lined esophagus in EGDA rats resembled human Barrett's esophagus (BE) in its morphology, mucin features and expression of differentiation markers (Lab. Invest. 2004;84:753–765). The purpose of this study was to compare the phenotype of rat MLE with human MLE, in order to gain insight into the nature of MLE and its potential role in the development of BE.

Methods

Serial sectioning was performed on tissue samples from 32 EGDA rats and 13 patients with established BE. Tissue sections were immunohistochemically stained for a variety of transcription factors and differentiation markers of esophageal squamous epithelium and intestinal columnar epithelium.

Results

We detected MLE in 56.3% (18/32) of EGDA rats, and in all human samples. As expected, both rat and human squamous epithelium, but not intestinal metaplasia, expressed squamous transcription factors and differentiation markers (p63, Sox2, CK14 and CK4) in all cases. Both rat and human intestinal metaplasia, but not squamous epithelium, expressed intestinal transcription factors and differentiation markers (Cdx2, GATA4, HNF1α, villin and Muc2) in all cases. Rat MLE shared expression patterns of Sox2, CK4, Cdx2, GATA4, villin and Muc2 with human MLE. However, p63 and CK14 were expressed in a higher proportion of rat MLE compared to humans.

Conclusion

These data indicate that rat MLE shares similar properties to human MLE in its expression pattern of these markers, not withstanding small differences, and support the concept that MLE may be a transitional stage in the metaplastic conversion of squamous to columnar epithelium in BE.

[Hepaticolithiasis. Rare benign disease of the intrahepatic bile ducts]

Hepaticolithiasis is a rare disease of the intrahepatic bile ducts endemic to east Asia which also is known as oriental cholangiohepatitis. Beside strictures and metabolic disturbance, the main cause of intrahepatic stones is acquired or congenital malformation of the intrahepatic biliary ducts. In the following we show a case of hepaticolithiasis and concurrent pancreatic metaplasia.

Immunohistochemical analysis of the progression of flat and papillary preneoplastic lesions in intrahepatic cholangiocarcinogenesis in hepatolithiasis

BACKGROUND

Two types of precursor lesions, flat-type 'biliary intraepithelial neoplasia (BilIN)' and papillary-type 'intraductal papillary neoplasm of the bile duct (IPNB)', are proposed in the tumorigenesis of intrahepatic cholangiocarcinoma (ICC) in hepatolithiasis.

METHODS

In this study, the participation of cancer-related molecules in the progression of these two precursor lesions was examined, using 64 hepatolithiatic livers with BilIN lesions (45 livers) and IPNB lesions (19 livers) and 10 hepatolithiatic livers without neoplastic lesions as a control. The expression of E-cadherin, beta-catenin, matrix metalloproteinase-7 (MMP-7), membrane type 1-MMP (MT1-MMP), cyclin D1 and c-myc was immunohistochemically examined.

RESULTS

The membranous expression of beta-catenin decreased along with the progression in both BilIN and IPNB lineages. Membranous expression of E-cadherin was significantly decreased in invasive ICC with BilIN and IPNB in comparison with non-invasive counterparts. MMP-7 and MT1-MMP were commonly expressed in invasive ICC with BilIN (100%), while non-invasive lesions (BilIN-1, -2, -3) and the IPNB lineage were only occasionally and weakly positive for these molecules. Cyclin D1 and c-myc, target molecules of Wnt signalling, were frequently positive in the IPNB lineage (65 and 54% respectively), and interestingly nuclear beta-catenin staining, reflecting activation of Wnt signalling, was observed only in the IPNB lineage (22%) (P<0.05).

CONCLUSIONS

Decreased membranous expression of beta-catenin and E-cadherin is an early event in the tumorigenesis of both BilIN and IPNB lineages. The expression of MMP-7 and MT1-MMP was closely associated with invasive growth of the BilIN lineage. The Wnt signalling pathway may play an important role in the tumorigenesis of the IPNB lineage.

Overexpression of CDX2 perturbs HOX gene expression in murine progenitors depending on its N-terminal domain and is closely correlated with deregulated HOX gene expression in human acute myeloid leukemia

The mechanisms underlying deregulation of HOX gene expression in AML are poorly understood. The ParaHox gene CDX2 was shown to act as positive upstream regulator of several HOX genes. In this study, constitutive expression of Cdx2 caused perturbation of leukemogenic Hox genes such as Hoxa10 and Hoxb8 in murine hematopoietic progenitors. Deletion of the N-terminal domain of Cdx2 abrogated its ability to perturb Hox gene expression and to cause acute myeloid leukemia (AML) in mice. In contrast inactivation of the putative Pbx interacting site of Cdx2 did not change the leukemogenic potential of the gene. In an analysis of 115 patients with AML, expression levels of CDX2 were closely correlated with deregulated HOX gene expression. Patients with normal karyotype showed a 14-fold higher expression of CDX2 and deregulated HOX gene expression compared with patients with chromosomal translocations such as t(8:21) or t(15;17). All patients with AML with normal karyotype tested were negative for CDX1 and CDX4 expression. These data link the leukemogenic potential of Cdx2 to its ability to dysregulate Hox genes. They furthermore correlate the level of CDX2 expression with HOX gene expression in human AML and support a potential role of CDX2 in the development of human AML with aberrant Hox gene expression.

Interaction of Toll-like receptors with bacterial components induces expression of CDX2 and MUC2 in rat biliary epithelium in vivo and in culture

The mechanism of transformation of biliary epithelium leading to intestinal metaplasia, which is significantly involved in biliary diseases, remains unclear. CDX2, an intestine-specific transcription factor, is thought to regulate intestinal mucin MUC2 (mucus core protein) expression. We took advantage of polycystic kidney (PCK) rats as a model of chronic suppurative cholangitis with intestinal metaplasia and of cultured biliary epithelial cells (BECs) from PCK rats to clarify the causal relation between bacterial components such as pathogen-associated molecular patterns (PAMPs) and the development of intestinal metaplasia of bile ducts. Histological, immunohistochemical, and in situ hybridization studies were conducted in PCK rat livers. In cultured BECs, CDX2 and MUC2 were expressed following treatment with PAMPs and inhibitors (anti-Toll-like receptor (TLR)2/TLR4 antibody, nuclear factor-kappaB (NF-kappaB) inhibitor MG132). Chronic suppurative cholangitis with intestinal metaplasia developed as the PCK rats aged, and intestinal metaplasia and aberrant CDX2 and MUC2 expression developed in parallel. Intraluminal bacteria and the expression of TLR2 and TLR4 in BECs were demonstrated in the bile ducts, showing chronic suppurative cholangitis. In cultured BECs, treatment with PAMPs induced upregulation of CDX2 and MUC2 expression, and this effect was abolished by pretreatment with anti-TLR2 and anti-TLR4 antibody and MG132. A knockdown of CDX2 by CDX2 small interfering RNA inhibited MUC2 expression in cultured BECs induced by PAMPs, and transfection of CDX2 expression vector induced MUC2 expression. In conclusion, bacterial components may induce upregulation of the CDX2 expression followed by MUC2 expression via TLR and the NF-kappaB system in cultured BECs, and could be related to the development of intestinal metaplasia of the bile ducts.

Expression profiles of MUC mucins and trefoil factor family (TFF) peptides in the intrahepatic biliary system: physiological distribution and pathological significance

Mucin secreted by mucosal epithelial cells plays a role in the protection of the mucosal surface and also is involved in pathological processes. So far, MUC1-4, 5AC, 5B, 6-8, 11-13 and 15-17 genes coding the backbone mucin core protein have been identified in humans. Their diverse physiological distribution and pathological alterations have been reported. Trefoil factor family (TFF) peptides are mucin-associated molecules co-expressed with MUC mucins and involved in the maintenance of mucosal barrier and the biological behavior of epithelial and carcinoma cells. Intrahepatic biliary system is a route linking the bile canaliculi and the extrahepatic bile duct for the excretion of bile synthesized by hepatocytes. Biliary epithelial cells line in the intrahepatic biliary system, secreting mucin and other molecules involved in the maintenance and regulation of the system. In this review, the latest information regarding properties, expression profiles and regulation of MUC mucins and TFF peptides in the intrahepatic biliary system is summarized. In particular, we focus on the expression profiles and their significance of MUC mucins in developmental and normal livers, various hepatobiliary diseases and intrahepatic cholangiocarcinoma.

Increased TFF1 trefoil protein expression in Opisthorchis viverrini-associated cholangiocarcinoma is important for invasive promotion

AIMS

Cholangiocarcinoma (CCA) is a poor prognosis cancer that presents with metastatic disease. This cancer expresses MUC5AC, a mucin which normally co-expresses with trefoil factor family 1 (TFF1) protein. TFF1 is a signalling protein that can activate epithelial cell invasion and has been considered as a metastasis stimulating agent. The aim of this study was to determine the co-expression of TFF1 and MUC5AC in CCA tissues and examine the activity of TFF1 for stimulating the invasive property of CCA cell lines.

METHODS

In this study, TFF1 and MUC5AC were detected in CCA tissues by using immunohistochemistry. The correlations of both proteins expression with clinical data were analyzed. The activity of TFF1 was investigated using an in vitro invasion assay with established CCA cell lines KKU-100 and KKU-M213.

RESULTS

We demonstrated a high level of expression of TFF1 in 91.80% of CCA that is associated with a high level of co-expression with MUC5AC in 80.33% of cases. In vitro invasion assay showed that both cell lines have similar responses to TFF1 that could act as both a chemokinetic and chemotactic agent. The dose-response curves were bell-shaped.

CONCLUSION

TFF1 showed co-expression with MUC5AC in CCA tissues and invasive stimulating activity in vitro. These results may indicate a role for TFF1 in promoting tumor invasion in CCA.

Expression of the caudal-type homeodomain transcription factor CDX2 is related to clinical outcome in biliary tract carcinoma

BACKGROUND AND AIM

The caudal-type homeodomain transcriptional factor CDX2, a member of the caudal-related homeobox gene family, plays a crucial role in the regulation of cell proliferation and differentiation in the gut. Recent studies have reported that expression of CDX2 was an independent marker of outcome in patients with resected adenocarcinoma of ampulla of Vater, gastric cancer, and colon cancer. The clinicopathological significance of CDX2 expression has hitherto remained unclear in biliary tract carcinoma (BTC). The aim of this study was to determine whether CDX2 expression in BTC indicates clinical outcome.

METHODS

The expression of CDX2 was investigated immunohistochemically in surgically resected specimens from 164 patients with BTC, including 74 intrahepatic cholangiocarcinomas, 49 extrahepatic cholangiocarcinomas, and 41 gallbladder carcinomas. The correlation between expression of CDX2 and clinicopathological factors, including overall survival, tumor location, tumor stage, and degree of tumor differentiation, was examined in patients with BTC.

RESULTS

In total, 27 of the 164 (16.46%) patients with BTC expressed CDX2. The frequency of CDX2 expression was much higher in the extrahepatic cholangiocarcinomas (22.45%) and gallbladder carcinomas (29.27%) than in the intrahepatic cholangiocarcinomas (5.41%), the difference being statistically significant (P = 0.002). Factors influencing survival on univariate analysis were tumor stage (P < 0.00001), degree of tumor differentiation (P = 0.0002), and CDX2 expression (P = 0.01). On multivariate analysis using the Cox proportional hazard model, CDX2 expression and tumor stage were independent prognostic factors in patients with BTC.

CONCLUSION

Expression of CDX2 was an independent indicator of outcome in patients with BTC in addition to tumor stage and tumor differentiation. The mechanism by which CDX2 expression influences behavior of biliary tract carcinoma needs further investigation.

Decreased expression of Bmi1 is closely associated with cellular senescence in small bile ducts in primary biliary cirrhosis

Cellular senescence of biliary epithelial cells with p16INK4a and p21WAF1/Cip expression in damaged small bile ducts may be critical for progressive bile duct loss in primary biliary cirrhosis. We investigated the involvement of bmi1, a polycomb group gene repressing p16INK4a expression, in the pathogenesis of biliary cellular senescence. Bmi1 expression was examined immunohistochemically in livers taken from the patients with primary biliary cirrhosis (n=18) and other diseased (n=19) and normal livers (n=16). We examined the effect of oxidative stress and a short interference RNA (siRNA) targeting bmi1 on cellular senescence in cultured mouse biliary epithelial cells. Bmi1 was widely expressed in the nuclei of biliary epithelial cells in the control livers. In contrast, bmi1 expression was significantly decreased in damaged small bile ducts in 43% of livers with primary biliary cirrhosis of stage 1/2, coordinating with the increased p16INK4a expression. In cultured biliary epithelial cells, oxidative stress by H2O2 treatment significantly decreased bmi1 expression, followed by increased P16INK4a expression. A knockdown of bmi1 induced increased p16INK4a expression, decreased cell proliferation, and increased cellular senescence. In conclusion, the decreased bmi1 expression caused by oxidative stress may be involved in the pathogenesis of cellular senescence of biliary epithelial cells in primary biliary cirrhosis.

MUC2 expression is regulated by histone H3 modification and DNA methylation in pancreatic cancer

Mucins are highly glycosylated proteins that play important roles in carcinogenesis. In pancreatic neoplasia, MUC2 mucin has been demonstrated as a tumor suppressor and we have reported that MUC2 is a favorable prognostic factor. Regulation of MUC2 gene expression is known to be controlled by DNA methylation, but the role of histone modification for MUC2 gene expression has yet to be clarified. Herein, we provide the first report that the histone H3 modification of the MUC2 promoter region regulates MUC2 gene expression. To investigate the histone modification and DNA methylation of the promoter region of the MUC2 gene, we treated 2 human pancreatic cancer cell lines, PANC1 (MUC2-negative) and BxPC3 (MUC2-positive) with the DNA methyltransferase inhibitor 5-azacytidine (5-aza), the histone deacetylase inhibitor trichostatin A (TSA), and a combination of these agents. The DNA methylation level of PANC1 cells was decreased by all 3 treatments, whereas histone H3-K4/K9 methylation and H3-K9/K27 acetylation in PANC1 cells was changed to the level in BxPC3 cells by treatment with TSA alone and with the 5-aza/TSA combination. The expression level of MUC2 mRNA in PANC1 cells exhibited a definite increase when treated with TSA and 5-aza/TSA, whereas 5-aza alone induced only a slight increase. Our results suggest that histone H3 modification in the 5' flanking region play an important role in MUC2 gene expression, possibly affecting DNA methylation. An understanding of these intimately correlated epigenetic changes may be of importance for predicting the outcome of patients with pancreatic neoplasms.

Biliary cystic tumors with bile duct communication: a cystic variant of intraductal papillary neoplasm of the bile duct

Biliary cystic tumors, which are also called biliary cystadenoma and cystadenocarcinoma, are thought to be a heterogeneous disease entity, and some of them are known to show a luminal communication to the bile duct. In this study, we examined the clinicopathological features of nine cases of biliary cystic tumors with bile duct communication. They were composed of five males and four females with an average age of 67 years (52-84 years). They were multilocular (eight cases) or unilocular (one case), and all cases contained mucinous fluid. A direct luminal communication with the bile ducts was identified in five cases on preoperative or intraoperative cholangiographies. Biliary cystic tumors examined in this study were histologically adenoma (one case), adenocarcinoma in situ (six cases), and adenocarcinoma associated with microinvasive mucinous carcinoma (two cases). One case of adenocarcinoma in situ also had the adenoma component (adenocarcinoma in adenoma). Dysplastic mucinous epithelium proliferated in flat, micropapillary and papillary fashions within the intracystic spaces. Intraepithelial neoplasm was observed within non-dilated adjacent bile ducts, suggesting a direct luminal communication between the cystic tumors and the bile duct. Ovarian-like stroma was not observed in their walls in any cases. Immunohistochemically, seven cases expressed MUC1 or MUC2 in the neoplastic biliary epithelium. All cases except one were alive without any evidences of tumor recurrence after total excision (3-156 months after surgery). These clinicopathological features resembled those of intraductal papillary neoplasm of the bile duct, which had been reported as a biliary counterpart of pancreatic intraductal papillary mucinous neoplasm. In conclusion, biliary cystic tumors with bile duct communication could be regarded as intraductal papillary neoplasm with a prominent cystic dilatation of the bile duct and mucin retention, rather than true biliary cystic neoplasms.

Hepatolithiasis and intrahepatic cholangiocarcinoma: carcinogenesis based on molecular mechanisms

Hepatolithiasis is more frequently seen in East Asian countries than in Western countries, and it is well known to represent a high-risk state for intrahepatic cholangiocarcinoma. Intrahepatic cholangiocarcinoma is an aggressive tumor that shows a dismal outcome even after resection. Cancer results from multistep carcinogenesis; however, the precise molecular mechanisms involved in the genetic alterations in cancer remain unknown. The accumulation of alterations in cancer-related genes leads to disruptions in cell-cycle regulation and also to continuous cell proliferation. The present review provides an overview of cancer-related genes in intrahepatic cholangiocarcinogenesis arising in hepatolithiasis. Further study of molecular mechanisms in hepatolithiasis-related intrahepatic cholangiocarcinoma, and the delineation of the influence of the genes involved should lead to our understanding of cholangiocarcinogenesis.

Bedeutung der Immunhistochemie für die Diagnose des Cholangiokarzinoms

The correct diagnosis of intrahepatic cholangiocarcinoma (CC) is often confounded by the small size of the diagnostic specimen and the wide morphological range of carcinomas metastasising to the liver. Expression analysis of cytokeratins, glycoproteins, mucoproteins, adhesion molecules, receptors and transcription factors has been shown to be a valuable adjunct in the typing of carcinomas. For this study, the expression pattern of 30 well documented antibodies to CC and the most common metastatic adenocarcinomas of the liver were studied. CC show a rather distinct immunophenotype with co-expression of CK7, CK17, CD7 and a lack of CDX2. Although this pattern allows the separation of CC from most metastatic carcinomas, pancreatic carcinomas show a broad overlap with this expression pattern.

CDX2 does not suppress tumorigenicity in the human gastric cancer cell line MKN45

CDX2 is a Drosophila caudal-related homeobox transcription factor that is expressed specifically in the intestine. In mice, ectopic expression of CDX2 in the gastric mucosa gives rise to intestinal metaplasia and in one model, gastric carcinoma. In humans, increased CDX2 expression is associated with gastric intestinal metaplasia and tubular adenocarcinomas. These patterns of expression have shown that CDX2 is important for the initiation of intestinal metaplasia in the gastric mucosa, but the role of CDX2 in established gastric cancer remains unclear. We sought to determine whether CDX2 contributes to tumorigenic potential in established gastric cancer. The CDX2 gene in MKN45 gastric carcinoma cells was disrupted using targeted homologous recombination. The resulting CDX2-/- cells are essentially identical to their parental cells, with the exception of CDX2 ablation. We found no significant differences in the proliferation of CDX2-/- cells compared to CDX2+/+ cells, in vitro or in vivo. Molecular analyses show that loss of CDX2 predominantly altered the expression of genes involved in intestinal glandular differentiation and adhesion. However, there were no microscopic differences in tumor differentiation. We conclude that disruption of CDX2 in MKN45 cells does not significantly affect their tumorigenic potential.

Expression of phosphorylated ERK1/2 and homeodomain protein CDX2 in cholangiocarcinoma

PURPOSE

The extracellular signal-regulated kinase (ERK) 1/2 pathway plays important roles in the regulation of cell proliferation, differentiation and cell survival. The caudal-related homeobox protein CDX2 is essential for the development of the intestine, and is related to gastric and gallbladder cancers with the intestinal phenotype. However, the roles of ERK1/2 phosphorylation (pERK1/2) and CDX2 in cholangiocarcinogenesis remain unknown.

METHODS

We investigated the expression of pERK1/2, CDX2 and MUC2 in Thai cholangiocarcinoma (CCA) specimens by means of immunohistochemical staining, and compared the expression of these proteins with clinicopathological factors.

RESULTS

The pERK1/2 protein was expressed in 29 of 59 (49.2%) CCA cases. Interestingly, in tubular-type CCA, the frequency of pERK1/2 expression was associated with a higher grade of differentiation (P = 0.001). CDX2 expression was observed in 22 of the 59 (37.3%) CCA cases, showed a relationship with MUC2 expression (P = 0.001), and was much higher in papillary-type than tubular-type CCA (P = 0.002).

CONCLUSION

These results imply that pERK1/2 may be important for the differentiation of tubular-type CCA, while CDX2 is related to the intestinal phenotype of papillary-type CCA.

Aberrant maspin expression in gallbladder epithelium is associated with intestinal metaplasia in patients with cholelithiasis

OBJECTIVE

Aberrant expression of maspin protein related to DNA hypomethylation in the promoter region is frequently observed in gallbladder carcinomas, whereas the non-tumorous gallbladder epithelium is maspin negative. We investigated maspin expression in non-tumorous gallbladder epithelium in patients with cholelithiasis.

METHODS

An immunohistochemical study of maspin expression was performed in 69 patients with cholelithiasis and 30 patients with gastric cancer without cholelithiasis.

RESULTS

Immunoreactivity for maspin was observed in focal and patchy regions of the gallbladder epithelium. Positive immunoreactivity for maspin was significantly associated with the presence of intestinal metaplasia in patients with cholelithiasis (p<0.05).

CONCLUSION

The high incidence of aberrant maspin expression in both intestinal metaplasia and carcinoma of the gallbladder supports the assumption that intestinal metaplasia of the gallbladder may predispose to gallbladder carcinoma.