Clinicopathological and prognostic significance of epithelial mesenchymal transition-related protein expression in intrahepatic cholangiocarcinoma

Cholangiokines: undervalued modulators in the hepatic microenvironment

The biliary epithelial cells, also known as cholangiocytes, line the intra- and extrahepatic bile ducts, forming a barrier between intra- and extra-ductal environments. Cholangiocytes are mostly known to modulate bile composition and transportation. In hepatobiliary diseases, bile duct injury leads to drastic alterations in cholangiocyte phenotypes and their release of soluble mediators, which can vary depending on the original insult and cellular states (quiescence, senescence, or proliferation). The cholangiocyte-secreted cytokines (also termed cholangiokines) drive ductular cell proliferation, portal inflammation and fibrosis, and carcinogenesis. Hence, despite the previous consensus that cholangiocytes are bystanders in liver diseases, their diverse secretome plays critical roles in modulating the intrahepatic microenvironment. This review summarizes recent insights into the cholangiokines under both physiological and pathological conditions, especially as they occur during liver injury-regeneration, inflammation, fibrosis and malignant transformation processes.

Postoperative Prognostic Predictors of Bile Duct Cancers: Clinical Analysis and Immunoassays of Tissue Microarrays

Background/Aims

Cholangiocarcinoma frequently recurs even after curative resection. Expression levels of proteins such as epidermal growth factor receptor (EGFR), Snail, epithelial cadherin (E-cadherin), and interleukin-6 (IL-6) examined by immunohistochemistry have been studied as potential prognostic factors for cholangiocarcinoma. The aim of this study was to investigate significant factors affecting the prognosis of resectable cholangiocarcinoma.

Methods

Ninety-one patients who underwent surgical resection at Samsung Medical Center for cholangiocarcinoma from 1995 to 2013 were included in this study. Expression levels of E-cadherin, Snail, IL-6, membranous EGFR, and cytoplasmic EGFR were analyzed by immunohistochemistry using tissue microarray blocks made from surgical specimens.

Results

Patients with high levels of membranous EGFR in tissue microarrays had significantly shorter overall survival (OS) and disease-free survival (DFS): high membranous EGFR (score 0-2) 38.0 months versus low membranous EGFR (score 3) 14.4 months (p=0.008) and high membranous EGFR (score 0-2) 23.2 months versus low membranous EGFR (score 3) 6.1 months (p=0.004), respectively. On the other hand, E-cadherin, Snail, cytoplasmic EGFR, and IL-6 did not show significant association with OS or DFS. Patients with distant metastasis had significantly higher IL-6 levels than those with locoregional recurrence (p=0.01).

Conclusions

This study showed that overexpression of membranous EGFR was significantly associated with shorter OS and DFS in surgically resected bile duct cancer patients. In addition, higher IL-6 expression was a predictive marker for recurrence in cholangiocarcinoma patients with distant organ metastasis after surgical resection.

Characteristics and clinical significance of polyploid giant cancer cells in laryngeal carcinoma

OBJECTIVES

We aimed to construct an induction system for polyploid giant cancer cells (PGCCs), as well as to investigate PGCC features and clinical significance.

METHODS

A laryngeal neoplasm-PGCC induction system was constructed using paclitaxel liposomes (PTX). We used western blots to compare expression of epithelial-mesenchymal transition-related proteins, stem cell interrelated proteins, and cyclin-associated proteins. We then measured PGCC count in tissue samples of patients with laryngeal neoplasms and analyzed its relationship with prognosis. Statistical significance was determined using t-tests.

RESULTS

PTX successfully induced PGCCs. Western blotting showed that CyclinB1, CDC25C, CDK1, E-cadherin, and EIF-4A expression decreased in PGCCs compared with normal cancer cells, whereas vimentin and CD133 expression increased. Number of PGCCs in laryngeal cancer tissues and overall survival time were inversely correlated (P < .05).

CONCLUSIONS

PTX successfully induces PGCC formation in laryngeal carcinoma, which may be the cause of poor prognosis in patients with laryngeal cancer.Level of Evidence: 4.

Circular RNA circ_0001588 sponges miR-211-5p to facilitate the progression of glioblastoma via up-regulating YY1 expression

BACKGROUND

As the most common and detrimental brain tumor with high invasiveness and poor prognosis, glioblastoma (GBM) has severely threatened people's health globally. Therefore, it is of great importance and necessary to identify the molecular mechanisms involved in tumorigenesis and development, thus contributing to potential therapeutic targets and strategies.

METHODS

The level of circ_0001588 was detected in 68 pairs of GBM tissues and adjacent normal tissues and human glioma cell lines via a real-time quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). Then, the effect of circ_0001588 on the proliferation, migration and invasion of glioma cells was evaluated. In addition, potential downstream targets of circ_0001588 were forecasted by circBANK and Starbase. Their interaction was confirmed by introducing luciferase reporter assays. Moreover, sh-circ_0001588 transfected U251 cells were used to form tumors in vivo. Finally, the functional mechanism of circ_0001588 was identified by qRT-PCR, western blotting, xenograft and immunohistochemistry (IHC) assays.

RESULTS

The expression of circ_0001588 is markedly up-regulated in GBM tissues and human gliomas cells. Additionally, increased expression of circ_0001588 is positively relevant with poor survival in GBM patients. The down-regulation of circ_0001588 distinctly inhibits the proliferation, migration and invasion of GBM in vitro, as well as tumor growth in vivo. Moreover, knockdown of circ_0001588 reduces the tumor volume and weight, enhances the relative IHC staining index of E-cadherin and decreases the relative IHC staining index of Ki-67, Yin Yang 1 (YY1) and vinmentin in vivo. Mechanistically, circ_0001588 locates in the cytoplasm, which is directly bound with miR-211-5p. Furthermore, circ_0001588 can positively regulate YY1 via sponging miR-211-5p. Moreover, circ_0001588 accelerates the proliferation, migration and invasion of GBM by modulating miR-211-5p/YY1 signaling.

CONCLUSIONS

These results illustrate a new circ_0001588/miR-211-5p/YY1 regulatory signaling axis in GBM.

LGR5 induces β-catenin activation and augments tumour progression by activating STAT3 in human intrahepatic cholangiocarcinoma

BACKGROUND & AIMS

LGR5 enhances Wnt-β-catenin signalling; however, involvement of LGR5 or Wnt-β-catenin signalling in ICC progression has not been reported.

METHODS

Functions and regulations of LGR5-mediated β-catenin activation in ICC progression were evaluated using surgical specimens collected from 61 ICC patients or 2 ICC cell lines.

RESULTS

LGR5 expression was increased in some cases of ICC. It was positively correlated with β-catenin activation, OLFM4 expression and STAT3 activation, and negatively correlated with GRIM19 expression in ICC, thereby enhancing cancer stem cell (CSC)-like property and EMT. High LGR5 expression was an independent factor for poor prognosis in ICC after operation. In vitro, Wnt inhibition by IWP-2 suppressed β-catenin activation, OLFM4 expression and STAT3 activation. IWP-2 treatment decreased expression of EpCAM, CD133, vimentin and increased E-cadherin expression. The rate of mesenchymal cells was decreased and cell invasiveness was suppressed after IWP-2 treatment, suggesting that Wnt-β-catenin signalling enhanced CSC-like property and EMT by activating STAT3. In addition, LGR5 knockdown inhibited β-catenin activation, resulting in suppression of β-catenin-induced STAT3 activation through inhibition of OLFM4-GRIM19 cascade. As these results, LGR5 knockdown suppressed CSC-like property and EMT. Therefore, LGR5 was a key regulator for β-catenin activation, and β-catenin was unable to be activated without LGR5.

CONCLUSIONS

LGR5 is essential for β-catenin activation induced by Wnt signalling. Activated β-catenin further activates STAT3 and enhances CSC-like property and EMT, leading to aggressive tumour progression and poor prognosis in patients with ICC. Therefore, LGR5 is an excellent prognostic predictor and a promising therapeutic target for ICC.

Lcn2-derived Circular RNA (hsa_circ_0088732) Inhibits Cell Apoptosis and Promotes EMT in Glioma via the miR-661/RAB3D Axis

Background: Glioma is the most common malignant tumor of the central nervous system, and often displays invasive growth. Recently, circular RNA (circRNA), which is a novel non-coding type of RNA, has been shown to play a vital role in glioma tumorigenesis. However, the functions and mechanism of lipocalin-2 (Lcn2)-derived circular RNA (hsa_circ_0088732) in glioma progression remain unclear.

Methods: We evaluated hsa_circ_0088732 expression by fluorescence in situ hybridization (FISH), Sanger sequencing, and PCR assays. Cell apoptosis was evaluated by flow cytometry and Hoechst 33258 staining. Transwell migration and invasion assays were performed to measure cell metastasis and viability. In addition, the target miRNA of hsa_circ_0088732 and the target gene of miR-661 were predicted by a bioinformatics analysis, and the interactions were verified by dual-luciferase reporter assays. RAB3D expression was analyzed by an immunochemistry assay, and E-cadherin, N-cadherin, and vimentin protein expression were examined by western blot assays. A mouse xenograft model was developed and used to analyze the effects of hsa_circ_0088732 on glioma growth in vivo.

Results: We verified that hsa_circ_0088732 is circular and highly expressed in glioma tissues. Knockdown of hsa_circ_0088732 induced glioma cell apoptosis and inhibited glioma cell migration, invasion, and epithelial-mesenchymal transition (EMT). We found that hsa_circ_0088732 negatively regulated miR-661 by targeting miR-661, and RAB3D was a target gene of miR-661. In addition, inhibition of miR-661 promoted glioma cell metastasis and suppressed cell apoptosis. Knockdown of RAB3D induced cell apoptosis and suppressed cell metastasis. Moreover, hsa_circ_0088732 accelerated glioma progression through its effects on the miR-661/RAB3D axis. Finally, results from a mouse xenograft model confirmed that knockdown of hsa_circ_0088732 induced miR-661 expression, resulting in suppression of RAB3D expression and inhibition of tumor growth in vivo.

Conclusion: We demonstrated that hsa_circ_0088732 facilitated glioma progression by sponging miR-661 to increase RAB3D expression. This study provides a theoretical basis for understanding the development and occurrence of glioma, as well as for the development of targeted drugs.

Prognostic value of multiple epithelial mesenchymal transition-associated proteins in intrahepatic cholangiocarcinoma

The aim of the present study was to investigate the expression of epithelial mesenchymal transition (EMT)-associated proteins and their prognostic value in intrahepatic cholangiocarcinoma (ICC). The expression of six EMT-associated proteins, including E-cadherin, N-cadherin, Vimentin, Snail family transcriptional repressor 1 (Snail), Snail family transcriptional repressor 2 (Slug) and S100 calcium binding protein A4 (S100A4) was determined by immunohistochemistry in 109 patients with ICC who had received surgery. Survival analysis showed that patients with low E-cadherin expression (P<0.001) or high S100A4 (P<0.001) or Snail (P<0.001) expression had a reduced survival time. Based on the numbers of alterations in the expression of EMT-associated proteins as determined by immunohistochemical analysis, the patients were categorized as low (score, 0-3; n=75) or high (score, ≥4; n=34) EMT expression groups. The high EMT expression group was significantly associated with positive lymph node metastasis (P=0.023) and late Tumor-Node-Metastasis (TNM) stage (P<0.001). Furthermore, patients in the high EMT expression group had a significantly poorer overall survival time than those in the low EMT expression group (P<0.001). Multivariate analysis indicated that EMT status was a significant independent predictor for overall survival time (P=0.004), and was linked to surgical margin (P=0.013) and TNM stage (P<0.001). In conclusion, the reduced expression of E-cadherin and high expression of Snail and S100A4 were significantly associated with the poor survival of patients with ICC after surgery. The EMT protein expression status was associated with ICC progression, and may be considered as an independent prognostic indicator for patients with ICC.

N-cadherin in cancer metastasis, its emerging role in haematological malignancies and potential as a therapeutic target in cancer

In many types of solid tumours, the aberrant expression of the cell adhesion molecule N-cadherin is a hallmark of epithelial-to-mesenchymal transition, resulting in the acquisition of an aggressive tumour phenotype. This transition endows tumour cells with the capacity to escape from the confines of the primary tumour and metastasise to secondary sites. In this review, we will discuss how N-cadherin actively promotes the metastatic behaviour of tumour cells, including its involvement in critical signalling pathways which mediate these events. In addition, we will explore the emerging role of N-cadherin in haematological malignancies, including bone marrow homing and microenvironmental protection to anti-cancer agents. Finally, we will discuss the evidence that N-cadherin may be a viable therapeutic target to inhibit cancer metastasis and increase tumour cell sensitivity to existing anti-cancer therapies.

MiR-590-3p suppresses epithelial-mesenchymal transition in intrahepatic cholangiocarcinoma by inhibiting SIP1 expression

The functional roles and clinical significances of miR-590-3p in ICC remain unclear. In the current study, we investigated the expression of miR-590-3p in tissues and sera of ICC by real-time quantitative polymerase chain reaction. We found miR-590-3p was significantly down-regulated in the sera and tissues of ICC patients, especially in those patients with lymph node metastasis or distant metastasis. AUC curves and Cox proportional hazards mode revealed serum miR-590-3p could be novel diagnostic and prognostic biomarker for ICC patients. MiR-590-3p dramatically suppressed epithelial-mesenchymal transition, cell migration, and invasion of ICC cells. SIP1 was identified as direct and functional target of miR-590-3p in ICC cells by luciferase assays. Finally, we found SIP1 expression was inversely correlated with miR-590-3p and closely related to diminished survival in ICC patients. These findings reveal functional and mechanistic roles of miR-590-3p and EMT activator SIP1 in the pathogenesis of ICC.

STAT3 overexpression promotes metastasis in intrahepatic cholangiocarcinoma and correlates negatively with surgical outcome

Signal transducer and activator of transcription 3 (STAT3) promotes tumor progression in many types of cancer. In this study, we analyzed the prognostic value of this marker in human intrahepatic cholangiocarcinoma (ICC). Using real-time PCR, western blot and immunohistochemistry assays, we found that STAT3 is overexpressed in ICC patients. STAT3 expression correlated with several clinicopathological features, including tumor size, pathological satellite, vascular invasion, undifferentiated-type histology, lymph node metastasis and TNM stage in two independent cohorts of ICC patients. Patients with high STAT3 levels had a poor prognosis in terms of overall survival (OS) and disease-free survival (DFS). Multivariate survival analysis indicated that STAT3 is an independent prognostic factor for OS and DFS. Furthermore, we observed that STAT3 overexpression promotes the invasion, metastasis and proliferation of ICC cells in vitro and in vivo, and also promotes STAT3 phosphorylation. These findings suggest that STAT3 expression correlated negatively with surgical outcome and inhibition of STAT3 expression may constitute a novel target for the treatment of ICC patients.

Silencing of Kangai 1 C-terminal interacting tetraspanin suppresses progression of cholangiocarcinoma

Cholangiocarcinoma (CC) is the second most common primary hepatic malignancy. CC treatment options are very limited especially for patients with distant metastasis. Kangai 1 C-terminal interacting tetraspanin (KITENIN) is highly expressed in numerous cancers, but the role of KITENIN in CC remains unknown. Here, we have investigated for the first time the function of KITENIN in human CC cell lines (TFK-1, SZ-1), tissues and a CC mouse model (Alb-Cre/LSL-KRAS^G12D/p53^L/L). KITENIN was expressed in 92.2% of human CC tissues, in murine CC samples and also in human CC cell lines. Knockdown of KITENIN by small interfering RNA (siRNA) effectively reduced proliferation, migration, invasion and colony formation in both intra- and extra-hepatic CC cells. The expression of epithelial-mesenchymal transition (EMT) markers like N-cadherin, Vimentin, Snail and Slug were suppressed in KITENIN knockdown CC cells. Our results indicate that KITENIN is crucial for cholangiocarcinogenesis and it might become a potential therapeutic target for human CC treatment.

Periostin promotes malignant potential by induction of epithelial-mesenchymal transition in intrahepatic cholangiocarcinoma

Periostin, a secreted matricellular protein, has been reported to induce epithelial‐mesenchymal transition (EMT), which increases motility and invasiveness in various epithelial cancer cells. Periostin is also overexpressed in intrahepatic cholangiocarcinoma (ICC) and suggested to be a biomarker for tumor progression and poor prognosis; however, its functional role in ICC is not fully understood. Here, we investigated whether periostin influences malignant potential through the induction of EMT in ICC. Analyses of surgical resected ICC specimens revealed that the gene expression of periostin was significantly higher in ICC tumors than in adjacent nontumor liver tissues and was closely correlated with the expression of mesenchymal markers, including N‐cadherin, vimentin, and fibronectin. However, the expression level of periostin varied in each case. Consistently, the expression of periostin in HuH28 (an undifferentiated ICC cell) was markedly higher than in HuCCT‐1 (a moderately differentiated ICC cell). In addition, high‐level secretion of periostin into culture media was observed in HuH28 but not in HuCCT‐1. To identify the biological significance of periostin in EMT, gene silencing of periostin by small interfering RNA was performed in HuH28 cells. Periostin knockdown in HuH28 cells significantly down‐regulated mesenchymal markers and up‐regulated epithelial markers, suggesting the reversal of EMT, namely mesenchymal‐epithelial transition. Along with these changes, cell proliferation was significantly suppressed by 52%. In addition, cell migration and invasion were significantly suppressed by 62% and 61%, respectively, with reduced gene expression of matrix metalloproteinase 2. Interestingly, chemosensitivity to gemcitabine was also significantly improved by periostin depletion. Conclusion: Periostin plays an important role in the regulation of malignant potential through EMT and is suggested to be a novel target for the treatment of ICC. (Hepatology Communications 2017;1:1099–1109)

Blocking ERK1/2 signaling impairs TGF-β1 tumor promoting function but enhances its tumor suppressing role in intrahepatic cholangiocarcinoma cells

Background

Transforming growth factor-β (TGF-β) plays a paradoxical role in cancer: it suppresses proliferation at early stages but promotes metastasis at late stages. This cytokine is upregulated in cholangiocarcinoma and is implicated in cholangiocarcinoma invasion and metastasis. Here we investigated the roles of non-Smad pathway (ERK1/2) and Smad in TGF-β tumor promoting and suppressing activities in intrahepatic cholangiocarcinoma (ICC) cells.

Methods

TGF-β1 effects on proliferation, invasion and migration of ICC cells, KKU-M213 and/or HuCCA-1, were investigated using MTT, colony formation, in vitro Transwell and wound healing assays. Levels of mRNAs and proteins/phospho-proteins were measured by quantitative (q)RT-PCR and Western blotting respectively. E-cadherin localization was examined by immunofluorescence and secreted MMP-9 activity was assayed by gelatin zymography. The role of ERK1/2 signaling was evaluated by treating cells with TGF-β1 in combination with MEK1/2 inhibitor U0126, and that of Smad2/3 and Slug using siSmad2/3- and siSlug-transfected cells.

Results

h-TGF-β1 enhanced KKU-M213 cell invasion and migration and induced epithelial-mesenchymal transition as shown by an increase in vimentin, Slug and secreted MMP-9 levels and by a change in E-cadherin localization from membrane to cytosol, while retaining the cytokine’s ability to attenuate cell proliferation. h-TGF-β1 stimulated Smad2/3 and ERK1/2 phosphorylation, and the MEK1/2 inhibitor U0126 attenuated TGF-β1-induced KKU-M213 cell invasion and MMP-9 production but moderately enhanced the cytokine growth inhibitory activity. The latter effect was more noticeable in HuCCA-1 cells, which resisted TGF-β-anti-proliferative activity. Smad2/3 knock-down suppressed TGF-β1 ability to induce ERK1/2 phosphorylation, Slug expression and cell invasion, whereas Slug knock-down suppressed cell invasion and vimentin expression but marginally affected ERK1/2 activation and MMP-9 secretion. These results indicate that TGF-β1 activated ERK1/2 through Smad2/3 but not Slug pathway, and that ERK1/2 enhanced TGF-β1 tumor promoting but repressed its tumor suppressing functions.

Conclusions

Inhibiting ERK1/2 activation attenuates TGF-β1 tumor promoting effect (invasion) but retains its tumor suppressing role, thereby highlighting the importance of ERK1/2 in resolving the TGF-β paradox switch.

Electronic supplementary material

The online version of this article (doi:10.1186/s12935-017-0454-2) contains supplementary material, which is available to authorized users.

Epithelial-mesenchymal transition in cholangiocarcinoma: From clinical evidence to regulatory networks

Cholangiocarcinoma (CCA) is an aggressive tumor with a poor prognosis due to its late clinical presentation and the lack of effective non-surgical therapies. Unfortunately, most of the patients are not eligible for curative surgery owing to the presence of metastases at the time of diagnosis. Therefore, it is important to understand the steps leading to cell dissemination in patients with CCA. To metastasize from the primary site, cancer cells must acquire migratory and invasive properties by a cell plasticity-promoting phenomenon known as epithelial-mesenchymal transition (EMT). EMT is a reversible dynamic process by which epithelial cells gradually adopt structural and functional characteristics of mesenchymal cells, and has lately become a centre of attention in the field of metastatic dissemination. In the present review, we aim to provide an extensive overview of the current clinical data and the prognostic value of different EMT markers that have been analysed in CCA. We summarize all the regulatory networks implicated in EMT from the membrane receptors to the main EMT-inducing transcription factors (SNAIL, TWIST and ZEB). Furthermore, since a tumor is a complex structure not exclusively formed by tumor cells, we also address the prominent role of the main cell types of the desmoplastic stroma that characterizes CCA in the regulation of EMT. Finally, we discuss the therapeutic considerations and difficulties faced to develop an effective anti-EMT treatment due to the redundancies and bypasses among the pathways regulating EMT.

Knockdown of Sall4 inhibits intrahepatic cholangiocarcinoma cell migration and invasion in ICC-9810 cells

In spite of improvements in surgical technology, the resectability and curability of intrahepatic cholangiocarcinoma (ICC) are still low. Our previous study showed that the strong Sal-like protein 4 (Sall4)-positive cases had shorter overall survival compared to Sall4-negative cases, indicating an oncogenic role of Sall4 in ICC. In this study, we aimed to explore the precise mechanism of Sall4 on ICC cell invasion and metastasis. We evaluated the expression of Sall4, PTEN, and Bmi-1 in 28 cases of adjacent tissues and 175 cases of ICC tissues by using immunohistochemical staining. We found that the expression of Sall4 and Bmi-1 was significantly increased in ICC tissues compared with the adjacent tissues, while PTEN expression was reduced in ICC tissues compared with the adjacent tissues, and there was a reverse relationship between Sall4 and PTEN in ICC, whereas there was a positive correlation in Sall4 and Bmi-1 expression in ICC. In addition, overall survival analysis showed that ICC patients with low PTEN exhibited a worse prognosis than ICC patients with high PTEN, and lower Bmi-1 expression showed a better prognosis than ICC patients with high Bmi-1. By a battery of experiments in vitro, we demonstrated that Sall4 promotes ICC cell proliferation, and progression of ICC might be through PTEN/PI3K/Akt and Bmi-1/Wnt/β-catenin signaling and enhancing epithelial-mesenchymal transition process. Thus, Sall4 may be a potential target for the treatment of ICC metastasis.

WAVE3 Induces EMT and Promotes Migration and Invasion in Intrahepatic Cholangiocarcinoma

BACKGROUND

Wiskott-Aldrich syndrome protein family verprolin-homologous protein 3 (WAVE3) plays a critical role in cancer progression and metastasis. However, the specific role of WAVE3 in intrahepatic cholangiocarcinoma (ICC) has not been studied.

AIMS

This study aimed to explore the role and mechanism of WAVE3 in the progression and metastasis of ICC.

METHODS

The expression of WAVE3 in ICC tissues and adjacent non-cancerous tissues was detected by immunohistochemistry. Western blot analysis was utilized to detect the expression of WAVE3 in ICC cells. A transwell assay was used to assess the potential for migration and invasion. The expression of WAVE3 in CC-LP-1 cells was knocked down by small interfering RNA (siRNA) interference.

RESULTS

The expression of WAVE3 in ICC tissues was significantly higher than that in adjacent non-cancerous tissues. The overall survival was lower in the subgroup of ICC patients with higher WAVE3 expression compared to the subgroup with a lower level of WAVE3 expression. WAVE3 expression was an adverse prognostic factor for ICC patients. CC-LP-1 cells expressed higher levels of WAVE3 protein compared to RBE cells and human intrahepatic biliary epithelial cells, which correlated with greater migration and invasion capabilities compared with the RBE cells. After the transfection of CC-LP-1 cells with WAVE3 siRNA, the level of WAVE3 protein was significantly decreased, accompanied by a marked reduction in migration, invasion and proliferation. Moreover, after the knockdown of WAVE3 expression in CC-LP-1 cells, the protein levels of Slug and Vimentin were significantly decreased, while that of E-cadherin was significantly increased.

CONCLUSIONS

WAVE3 may represent a new adverse prognostic factor for patients with ICC. This protein enhances migration and invasion capabilities in ICC, most likely through the induction of an epithelial-mesenchymal transition.

Cholangiocarcinoma: Present Status and Molecular Aspects of Diagnosis

Cholangiocarcinomas are neoplasms that involve the epithelial cells of the bile duct, also known as cholangiocytes. This disease is difficult to diagnose early, as most symptoms present late in the disease. In addition, the specific anatomic position can cause periductal extension and result in a very low radical excision rate and a very poor prognosis. Improved understanding of the features underlying the onset of cholangiocarcinoma and its carcinogenic mechanism may lead to early diagnosis and better prognosis. With the development of molecular biology, much has been learned about oncogenes, tumor-suppressor genes, DNA methylation, microRNAs, and the molecular mechanisms of tumor invasion and metastasis. Based on our research and others, this review article will discuss the current status and prospects of early diagnosis of cholangiocarcinoma.

The number of polyploid giant cancer cells and epithelial-mesenchymal transition-related proteins are associated with invasion and metastasis in human breast cancer

Background

Previously, we reported that polyploid giant cancer cells (PGCCs) induced by cobalt chloride (CoCl₂) could have generated daughter cells with strong invasiveness and migration capabilities via asymmetric divisions. This study compared the expression of epithelial-mesenchymal transition (EMT)-related proteins, including E-cadherin, N-cadherin, and vimentin, between PGCCs and their daughter cells, and control breast cancer cell lines MCF-7 and MDA-MB-231. The clinicopathological significance of EMT-related protein expression in human breast cancer was analyzed.

Methods

Western blot was used to compare the expression levels of E-cadherin, N-cadherin, and vimentin in breast cancer lines MCF-7 and MDA-MB-231, between PGCCs with budding daughter cells and control breast cancer cells. Furthermore, 167 paraffin-embedded breast tumor tissue samples were analyzed, including samples obtained from 52 patients with primary breast cancer with lymph node metastasis (group I) and their corresponding lymph node metastatic tumors (group II), 52 patients with primary breast cancer without metastasis (group III), and 11 patients with benign breast lesions (group IV). The number of PGCCs was compared among these four groups.

Results

The number of PGCCs increased with the malignant grade of breast tumor. Group IIhad the highest number of PGCCs and the differences among group I, II, III and IV had statistically significance (P =0.000). In addition, the expression of E-cadherin (P = 0.000), N-cadherin (P = 0.000), and vimentin (P = 0.000) was significantly different among the four groups. Group II exhibited the highest expression levels of N-cadherin and vimentin and the lowest expression levels of E-cadherin.

Conclusions

These data suggest that the number of PGCCs and the EMT-related proteins E-cadherin, N-cadherin, and vimentin may be valuable biomarkers to assess metastasis in patients with breast cancer.

Electronic supplementary material

The online version of this article (doi:10.1186/s13046-015-0277-8) contains supplementary material, which is available to authorized users.

Epithelial-to-Mesenchymal Transition and Cancer Invasiveness: What Can We Learn from Cholangiocarcinoma?

In addition to its well-established role in embryo development, epithelial-to-mesenchymal transition (EMT) has been proposed as a general mechanism favoring tumor metastatization in several epithelial malignancies. Herein, we review the topic of EMT in cholangiocarcinoma (CCA), a primary liver cancer arising from the epithelial cells lining the bile ducts (cholangiocytes) and characterized by an abundant stromal reaction. CCA carries a dismal prognosis, owing to a pronounced invasiveness and scarce therapeutic opportunities. In CCA, several reports indicate that cancer cells acquire a number of EMT biomarkers and functions. These phenotypic changes are likely induced by both autocrine and paracrine signals released in the tumor microenvironment (cytokines, growth factors, morphogens) and intracellular stimuli (microRNAs, oncogenes, tumor suppressor genes) variably associated with specific disease mechanisms, including chronic inflammation and hypoxia. Nevertheless, evidence supporting a complete EMT of neoplastic cholangiocytes into stromal cells is lacking, and the gain of EMT-like changes by CCA cells rather reflects a shift towards an enhanced pro-invasive phenotype, likely induced by the tumor stroma. This concept may help to identify new biomarkers of early metastatic behavior along with potential therapeutic targets.

ZEB1 expression is associated with prognosis of intrahepatic cholangiocarcinoma

Background/Aim

Intrahepatic cholangiocarcinoma (ICC) is one of the most aggressive malignant tumours, so the identification of molecular targets for ICC is an important issue. Zinc finger E-box binding homeobox 1 (ZEB1) is a key inducer of epithelial–mesenchymal transition (EMT). The aim of the present study was to clarify the clinical significance of ZEB1 in ICC and the associations between ZEB1 expression and EMT-related proteins.

Methods

We immunohistochemically examined the expression of EMT-related proteins, namely ZEB1, vimentin and E-cadherin, in ICC specimens from 102 patients. The clinicopathological and prognostic values of these markers were evaluated.

Results

ZEB1 and vimentin were expressed in 46.1% and 43.1% of tumours, respectively, and E-cadherin expression was lost in 44.1% of tumours. ZEB1 expression showed a significant inverse correlation with E-cadherin expression (p=0.004) and a positive correlation with vimentin expression (p=0.022). Altered expression of ZEB1 was associated with aggressive tumour characteristics, including advanced tumour stage (p=0.037), undifferentiated-type histology (p=0.017), lymph node metastasis (p=0.024) and portal vein invasion (p=0.037). Moreover, overall survival rates were significantly lower for patients with high ZEB1 expression than for patients with low ZEB1 expression (p=0.027). Kaplan–Meier analysis also identified E-cadherin expression (p=0.041) and vimentin expression (p=0.049) as prognostic indicators for overall survival.

Conclusions

ZEB1 expression is associated with tumour progression and poor prognosis in patients with ICC through positive correlations with vimentin and negative correlations with E-cadherin. ZEB1 expression is associated with a poor prognosis and might be an attractive target for the treatment of ICC.

Distal bile duct carcinomas and pancreatic ductal adenocarcinomas: postulating a common tumor entity

The set definition of distal cholangiocarcinomas and adenocarcinomas of the pancreatic head is challenged by their close anatomical relation, similar growth pattern, and corresponding therapeutic outcome. They show a mutual development during embryologic organ formation and share phenotypic characteristics. This review will highlight the similarities with regard to the common origin of their primary organs, histopathological similarities, and modern clinical management. Thus, we propose to subsume those entities under a common superfamily.

Expression of E-cadherin and vimentin in oral squamous cell carcinoma

The aim of the study is to determine the levels of E-cadherin, vimentin expression in tumor tissues from patients with oral squamous cell carcinoma (OSCC), and the relationship between the expression of E-cadherin, vimentin and epithelial-mesenchymal transition, in order to explore its values for predicting the invasion and metastasis of oral squamous cell carcinoma, short survival of patients in many types of cancer. E-cadherin and vimentin expression of 10 benign and 42 OSCC tumor tissues was examined by immunohistochemical staining. E-cadherin is positively expressed in normal oral mucosa epithelium, but vimentin expression is not found in normal oral mucosa epithelia; the E-cadherin and vimentin were expressed in 26 of 42 (61.9%) and 16 of 42 (38.1%), respectively. No statistically difference was found for E-cadherin and vimentin expression in patients with different age, gender and tumor location, E-cadherin and vimentin expression was significantly associated with lymph node metastasis and tissue location (P<0.05); E-cadherin expression was also significantly associated with tumor stage (P<0.05); there are significantly difference between infiltrative margin and central area in patients with oral squamous cell carcinoma for E-cadherin and vimentin positive expression (P<0.05). E-cadherin and vimentin positive expression was associated with tumor metastasis of oral squamous cell carcinoma. Our study preliminarily confirmed that EMT phenomenon is existed during the development of oral squamous cell carcinoma. Co-evaluation of E-cadherin and vimentin might be a valuable tool for predicting OSCC patient outcome.

Effect of Twist and Bmi1 on intraductal papillary mucinous neoplasm of the pancreas

BACKGROUND

Intraductal papillary mucinous neoplasm (IPMN) is a well-established entity among pancreatic neoplasms that ranges from low-grade dysplasia to invasive carcinoma. Epithelial-mesenchymal transition (EMT) contributes to tumor progression in various cancers. Moreover, Notch signaling is one of the important upstream effectors of EMT promotion. Currently, it is unclear whether EMT causes pathological progression of IPMN.

AIM

We evaluated the expression of EMT-promoting transcription factors Twist and B cell-specific Moloney murine leukemia virus insertion site 1 (Bmi1) in IPMN.

METHODS

Patients who underwent resections at our institute and its affiliated hospital were enrolled in this study (n = 35). Protein expression of EMT markers Twist, Bmi1, Jagged1, and E-cadherin in resected specimens was investigated by immunohistochemistry. Expression of these proteins was compared with the clinicopathological factors and patient survival.

RESULTS

Positive expression of Twist and Bmi1 was observed in 40.0% and 42.9% of IPMNs, respectively. Twist and Bmi1 expression was significantly higher in IPMNs with high-grade dysplasia (P < 0.05) and invasive carcinoma (P < 0.05) than that in IPMNs with low-grade dysplasia. High expression of Twist was correlated with Jagged1 expression and inversely correlated with expression of E-cadherin (P = 0.06 and P < 0.05, respectively). In survival analyses, the recurrence rate was significantly higher in the group that showed simultaneous high expression of Twist and Bmi1 (P < 0.05).

CONCLUSIONS

Expression of Twist and Bmi1 is associated with aggressiveness and poor prognoses of IPMN through EMT promotion that might be induced by Notch signaling.

Dyskerin expression in human fetal, adult and neoplastic intrahepatic bile ducts: correlations with cholangiocarcinoma aggressiveness

AIMS

To investigate the immunohistochemical expression of dyskerin, a biomarker involved in ribosome production and telomere maintenance, in human fetal, adult and neoplastic bile ducts, and possible correlations with cholangiocarcinoma aggressiveness.

METHODS AND RESULTS

Sixty consecutive intrahepatic cholangiocarcinomas were collected and used for tissue microarray construction (total: 176 cores); clinical data and follow-up were also collected. Five fetal and 10 normal adult livers were included as controls. Automated immunohistochemistry for dyskerin, p53, and Ki67, and nucleolar silver staining, were performed. In normal livers, dyskerin expression was negative in smaller bile ducts (mean 44.8 μm) and positive in bile ducts of larger diameter (mean 116.1 μm; P < 0.001). Expression was positive in 56.7% of cholangiocarcinomas, and correlated with p53 mutation (P = 0.008) and a higher proliferative (Ki67) index (P = 0.003), which were included as markers of tumour aggressiveness. Finally, dyskerin-positive cholangiocarcinomas showed a negative trend in disease-free survival (P = 0.078) on univariate analysis.

CONCLUSIONS

The non-neoplastic biliary tree seems to progressively lose dyskerin expression from the major branches to the peripheral portal bile ducts. Similarly, intrahepatic cholangiocarcinomas showed two patterns of dyskerin expression, and the dyskerin-positive phenotype seemed to characterize more aggressive cholangiocarcinomas.

Molecular diagnosis of intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinomas (iCCA) are primary intrahepatic malignancies originating from biliary epithelia. While both hepatocellular cancer and iCCA can present as mass lesions within the liver, these cancers are distinct in their morphology, etiology, pathology, natural history and response to therapy. There is a need for accurate and sensitive molecular markers for the diagnosis of iCCA. Recent advances in elucidating molecular and genetic characteristics of iCCA offer the potential of molecular-based diagnosis of iCCA. Specific genetic mutations of IDH1/2, BAP1, p53, and KRAS, FGFR gene fusions and alterations in microRNA have all been described in iCCA. Although there are no accurate serum or biliary biomarkers currently available for diagnosis of iCCA, several potential candidates have been identified. Knowledge of specific genetic or molecular abnormalities offers potential for individualized approaches for the treatment of patients with iCCA in the future.

Review to better understand the macroscopic subtypes and histogenesis of intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinoma is macroscopically classified into three subtypes, mass-forming-type, periductal infiltrating-type, and intraductal growth-type. Each subtype should be preoperatively differentiated to perform the valid surgical resection. Recent researches have revealed the clinical, radiologic, pathobiological characteristics of each subtype. We reviewed recently published studies covering various aspects of intrahepatic cholangiocarcinoma (ICC), focusing especially on the macroscopic subtypes and stem cell features to better understand the pathophysiology of ICC and to establish the valid therapeutic strategy.

EGF/EGFR axis contributes to the progression of cholangiocarcinoma through the induction of an epithelial-mesenchymal transition

BACKGROUND & AIMS

Epithelial-mesenchymal transition (EMT) is a cellular process involved in cancer progression. The first step of EMT consists in the disruption of E-cadherin-mediated adherens junctions. Cholangiocarcinoma (CCA), a cancer with a poor prognosis due to local invasion and metastasis, displays EMT features. EGFR, a receptor tyrosine kinase, plays a major role in CCA progression. The aim of the study was to determine if EMT is induced by EGFR in CCA cells.

METHODS

In vivo, the expression of E-cadherin was analysed in CCA tumours of 100 patients and correlated with pathological features and EGFR expression, and in a xenograft model in mice treated with gefitinib, an inhibitor of EGFR. In vitro, the regulation of EMT by EGFR was investigated in CCA cell lines.

RESULTS

In human CCA, a cytoplasmic localization of E-cadherin occurred in 50% of the tumours was associated with the peripheral type of CCA, tumour size, the presence of satellite nodules and EGFR overexpression. In xenografted tumours, E-cadherin displayed a cytoplasmic pattern whereas the treatment of mice with gefitinib restored the membranous expression of E-cadherin. In vitro, EGF induced scattering of CCA cells that resulted from the disruption of adherens junctions. Internalization and decreased expression of E-cadherin, as well as nuclear translocation of β-catenin, were observed in EGF-treated CCA cells. In these cells, EMT-transcription factors (i.e., Slug and Zeb-1) and mesenchymal markers (i.e., N-cadherin and α-SMA) were induced, favoring cell invasiveness through cytoskeleton remodeling. All these effects were inhibited by gefitinib.

CONCLUSIONS

The EGF/EGFR axis triggers EMT in CCA cells highlighting the key role of this pathway in CCA progression.

Expression of vimentin and survivin in clear cell renal cell carcinoma and correlation with p53

PURPOSE

This study focuses on investigating the expression correlation of vimentin, survivin and p53 in clear cell renal cell carcinoma (ccRCC) and the clinical significance.

METHODS

The mRNA and protein expression levels of the vimentin, survivin and p53 were determined in ccRCC and adjacent normal renal tissues, using quantitative real-time-polymerase chain reaction (qRT-PCR) and Western blot. We detected the expression and localization of vimentin, survivin and p53 protein in ccRCC by immunohistochemistrical SP method and analyzed the relationships among clinical pathologic parameters and patient prognosis.

RESULTS

The expression of vimentin and survivin was significantly increased in ccRCC compared with adjacent normal renal tissues, which were positively correlated with the pathological grade and clinical stage (P < 0.05). p53 was highly expressed in ccRCC compared with normal tissues (P < 0.05), which was not positively correlated with the pathological grade and clinical stage (P > 0.05). Furthermore, univariate and multivariate analysis showed that high expression levels of vimentin and survivin were independent prognostic indicators for ccRCC. The levels of vimentin and survivin were positively correlated in ccRCC (r = 0.428, P < 0.01).

CONCLUSIONS

Reliable basis about biological behavior and prognosis judgments of ccRCC can be provided by combining detection of vimentin and survivin. Foundation and new ideas for gene therapy of ccRCC may be provided by further studying the relationship among vimentin, survivin and p53 in ccRCC.

Comprehensive multiple molecular profile of epithelial mesenchymal transition in intrahepatic cholangiocarcinoma patients

Background

The aim of this study is to investigate the expression profile of multiple epithelial mesenchymal transition (EMT)-related molecules in intrahepatic cholangiocarcinoma (ICC) and the related prognostic significance.

Methods

Immunohistochemistry was performed to determine the expression of E-cadherin, Vimentin, Snail, slug and β-catenin in a tissue microarray consisting of tumor tissues of 140 ICC patients undergoing curative resection. The correlation between the expression of these molecules and the clinicopathological characteristics of ICC patients was analyzed, and their prognostic implication was evaluated.

Results

Reduced E-cadherin and increased Vimentin expression, the characteristic changes of EMT, identified in 55.0% and 55.7% of primary ICCs, respectively, were correlated with lymphatic metastasis and poorer overall survival (OS) and disease-free survival (DFS) of ICCs. The overexpression of snail and nonmembranous β-catenin, which are the major regulators of the EMT, were identified in 49.2% and 45.7% of primary ICCs, while little slug expression was detected in ICCs. Cytoplasmic/nuclear β-catenin did not significantly predict worse DFS and was not related with E-cadherin loss. The overexpression of snail predicted worse OS and DFS. Snail overexpression correlated with the down-regulation of E-cadherin and the up-regulation of Vimentin. Inhibition of snail in an ICC cell line decreased the expression of E-cadherin, enhanced the expression of Vimentin and impaired the invasion and migration ability of ICC cells.

Conclusions

These data support the hypothesis that EMT plays vital roles in ICC progression and suggest that snail but not slug and β-catenin plays a crucial role in the EMT induction of ICC.

Down-regulating ribonuclease inhibitor enhances metastasis of bladder cancer cells through regulating epithelial-mesenchymal transition and ILK signaling pathway

Accumulating evidences implicate that ribonuclease inhibitor (RI) plays a suppressing role in cancer development. However, the mechanisms underlying antitumor of RI remain largely unknown. Epithelial-mesenchymal transition (EMT) is regarded as a key event in tumor progression. The reports have demonstrated that EMT was implicated in metastasis of bladder cancer. Therefore, we suppose that RI might involve regulating EMT of bladder cancer. Here bladder cancer T24 cells were transfected with pGensil-1-siRNA-RI vectors. HE staining, living cell observation, Phalloidine-FITC staining of microfilament, cell adhesion, scratch migration, and Matrigel invasion were examined respectively. RI expression and colocalization with ILK were detected using confocal microscope. Proteins associated with EMT were determined with Western blotting and immunohistochemistry in vivo and in vitro. Effects of RI expression on tumor growth, metastasis and EMT related proteins in BALB/C nude mouse and clinical human bladder cancer specimens were valued with histological, immunohistochemical and immunofluorescent examination respectively. We demonstrated that down-regulating RI increased cell proliferation, migration and invasion, changed cell morphology and adhesion, and rearranged cytoskeleton by inducing EMT and ILK signaling pathway in bladder cancer cells. In addition, we showed that down-regulating RI promoted tumorigenesis and metastasis of bladder cancer in vivo. Finally, we found that bladder cancer with invasive capability had higher Vimentin, Snail, Slug and Twist as well as lower E-cadherin and RI expression in clinical human specimens. Our results suggest that RI could play a novel role in inhibiting metastasis of bladder through regulating EMT and ILK signaling pathway.

The Enhanced metastatic potential of hepatocellular carcinoma (HCC) cells with sorafenib resistance

Acquired resistance towards sorafenib treatment was found in HCC patients, which results in poor prognosis. To investigate the enhanced metastatic potential of sorafenib resistance cells, sorafenib-resistant (SorR) cell lines were established by long-term exposure of the HCC cells to the maximum tolerated dose of sorafenib. Cell proliferation assay and qPCR of ABC transporter genes (ABCC1-3) were first performed to confirm the resistance of cells. Migration and invasion assays, and immunoblotting analysis on the expression of epithelial to mesenchymal transition (EMT) regulatory proteins were performed to study the metastatic potential of SorR cells. The expression of CD44 and CD133 were studied by flow cytometry and the gene expressions of pluripotency factors were studied by qPCR to demonstrate the enrichment of cancer stem cells (CSCs) in SorR cells. Control (CTL) and SorR cells were also injected orthotopically to the livers of NOD-SCID mice to investigate the development of lung metastasis. Increased expressions of ABCC1-3 were found in SorR cells. Enhanced migratory and invasive abilities of SorR cells were observed. The changes in expression of EMT regulatory proteins demonstrated an activation of the EMT process in SorR cells. Enriched proportion of CD44⁺ and CD44⁺CD133⁺ cells were also observed in SorR cells. All (8/8) mice injected with SorR cells demonstrated lung metastasis whereas only 1/8 mouse injected with CTL cells showed lung metastasis. HCC cells with sorafenib resistance demonstrated a higher metastatic potential, which may be due to the activated EMT process. Enriched CSCs were also demonstrated in the sorafenib resistant cells. This study suggests that advanced HCC patients with acquired sorafenib resistance may have enhanced tumor growth or distant metastasis, which raises the concern of long-term sorafenib treatment in advanced HCC patients who have developed resistance of sorafenib.

The challenge of cholangiocarcinoma: dissecting the molecular mechanisms of an insidious cancer

Cholangiocarcinoma is a fatal cancer of the biliary epithelium and has an incidence that is increasing worldwide. Survival beyond a year of diagnosis is less than 5%, and therapeutic options are few. Known risk factors include biliary diseases such as primary sclerosing cholangitis and parasitic infestation of the biliary tree, but most cases are not associated with any of these underlying diseases. Numerous in vitro and in vivo models, as well as novel analytical techniques for human samples, are helping to delineate the many pathways implicated in this disease, albeit at a frustratingly slow pace. As yet, however, none of these studies has been translated into improved patient outcome and, overall, the pathophysiology of cholangiocarcinoma is still poorly understood. There remains an urgent need for new approaches and models to improve management of this insidious and devastating disease. In this review, we take a bedside-to-bench approach to discussing cholangiocarcinoma and outline research opportunities for the future in this field.