Effect of transforming growth factor-β1 on human intrahepatic cholangiocarcinoma cell growth

Targeting tumor microenvironment for cholangiocarcinoma: Opportunities for precision medicine

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CCA has a dismal prognosis, and it is usually diagnosed in advanced stage for which available treatments have limited efficacy.

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CCA TME presents an abundant desmoplastic stroma and exhibits a high heterogeneity.

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TME plays a central role in cancer development and in the resistance to treatments.

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Treatments targeting the TME in association with cytotoxic agents could represent a promising therapeutic strategy.

Systemic treatments (e.g., chemotherapy and targeted therapies) have limited efficacy for patients with locally advanced – unresectable – and metastatic cholangiocarcinoma (CCA), with an overall survival of less than a year. Tumor microenvironment (TME) represents the ecosystem surrounding the tumor which comprises immune cells, fibroblasts, endothelial cells, and a wide range of soluble factors. CCA TME is characterized by an abundant desmoplastic stroma, exhibits a high heterogeneity and it plays a central role in cancer onset and progression. There is growing evidence suggesting that it is possible to target TME in association with other treatment modalities, such as cytotoxic chemotherapy or targeted therapies, paving the way to possible combination strategies with a synergistic effect. Herein, we describe the components of CCA TME – such as cancer-associated fibroblasts and other cells of pivotal importance - with their most relevant interactions, focusing on the preclinical rationale for the development of effective anticancer treatments.

Comparison of growth features and cancer stem cell prevalence in intrahepatic and extrahepatic cholangiocarcinoma cell lines

Aim of the study

Intra- and extrahepatic cholangiocarcinoma (I-CCA and E-CCA respectively) exhibit different growth features that contribute to different clinical outcomes. Cancer stem cells (CSCs) influence tumor growth and thereby may be responsible for these differences. The aim of this study was to document and compare the growth features of human I-CCA and E-CCA cell lines and determine whether any differences observed could be explained by differences in the prevalence and/or stem cell surface marker (SCSM) expression profiles of CSCs within the tumor cell lines.

Material and methods

Six CCA cells lines, three I-CCA and three E-CCA, were studied. Tumor cell growth features including cell proliferation, colony/spheroid formation, migration and invasion were documented. CSC prevalence and SCSM expression profiles were examined by flow cytometry.

Results

I-CCA cells had significantly increased proliferative activity, shorter doubling times and were more invasive than E-CCA cells, while colony/spheroid formation and migration were similar in the two cell populations. There were no significant differences in CSC prevalence rates or SCSM expression profiles.

Conclusions

These findings suggest that I-CCA cells proliferate at a more rapid rate and are more invasive than E-CCA cells but the differences cannot be explained by differences in the prevalence or SCSM expression profiles of CSCs within the tumor cell population.

Tenascin-W Is a Novel Stromal Marker in Biliary Tract Cancers

Extrahepatic cancers of the biliary system are typically asymptomatic until after metastasis, which contributes to their poor prognosis. Here we examined intrahepatic cholangiocarcinomas (n = 8), carcinomas of perihilar bile ducts (n = 7), carcinomas of the gallbladder (n = 11) and hepatic metastasis from carcinomas of the gallbladder (n = 4) for the expression of the extracellular matrix glycoproteins tenascin-C and tenascin-W. Anti-tenascin-C and anti-tenascin-W immunoreactivity was found in all biliary tract tumors examined. Unlike tenascin-C, tenascin-W was not detected in normal hepatobiliary tissue. Tenascin-W was also expressed by the cholangiocarcinoma-derived cell line Huh-28. However, co-culture of Huh-28 cells with immortalized bone marrow-derived stromal cells was necessary for the formation and organization of tenascin-W fibrils in vitro. Our results indicate that tenascin-W may be a novel marker of hepatobiliary tumor stroma, and its absence from many normal tissues suggests that it may be a potential target for biotherapies.

Transforming Growth Factor-Beta (TGFβ) Signaling Pathway in Cholangiocarcinoma

Cholangiocarcinoma is a deadly cancer worldwide, associated with a poor prognosis and limited therapeutic options. Although cholangiocarcinoma accounts for less than 15% of liver primary cancer, its silent nature restricts early diagnosis and prevents efficient treatment. Therefore, it is of clinical relevance to better understand the molecular basis of cholangiocarcinoma, including the signaling pathways that contribute to tumor onset and progression. In this review, we discuss the genetic, molecular, and environmental factors that promote cholangiocarcinoma, emphasizing the role of the transforming growth factor β (TGFβ) signaling pathway in the progression of this cancer. We provide an overview of the physiological functions of TGFβ signaling in preserving liver homeostasis and describe how advanced cholangiocarcinoma benefits from the tumor-promoting effects of TGFβ. Moreover, we report the importance of noncoding RNAs as effector molecules downstream of TGFβ during cholangiocarcinoma progression, and conclude by highlighting the need for identifying novel and clinically relevant biomarkers for a better management of patients with cholangiocarcinoma.

Inhibition of IL-10 and TGF-β receptors on dendritic cells enhances activation of effector T-cells to kill cholangiocarcinoma cells

Tumor escapes host immune responses by producing immunosuppressive cytokines, such as IL-10 and TGF-β, secreted into the tumor microenvironment. These cytokines play important roles in the suppression of dendritic cell (DC) function, leading to decreased immune responses of the effector CD4⁺ and CD8⁺ T cells. To improve DC functions and enhance cytolytic activity of activated effector T-cells, we suppressed the effect of these cytokines on DCs by using specific neutralizing antibodies that inhibit IL-10 and TGF-β receptors. Monocyte-derived DCs generated in vitro showed up-regulation of MHC (HLA-DR) and co-stimulatory molecules (CD40 and CD86). The IL-10 and TGF-β receptors were expressed and localized on cell membrane of DCs, as shown by Western blot analysis and immunofluorescence staining, whereas the IL-10 and TGF-β ligands were detected in the culture supernatants of DCs and cholangiocarcinoma (CCA) cell line, respectively. Inhibition of the IL-10 and TGF-β receptors on DCs by specific neutralizing antibodies significantly increased level of IFN-γ and enhanced cytolytic activity of the DC-activated effector T-cells against CCA cell line. These results indicate that the IL-10 and TGF-β receptors are the targets for inhibition to increase DC functions and enhance cytolytic activity of the DC-activated effector T-cells against CCA cells. Thus, inhibition of the IL-10 and TGF-β receptors on DCs is crucial in the preparation of DC-activated effector T cells for adoptive T-cell therapy.

Inhibition of ERK1/2 Signaling Impairs the Promoting Effects of TGF-β1 on Hepatocellular Carcinoma Cell Invasion and Epithelial-Mesenchymal Transition

Transforming growth factor-β (TGF-β) and ERK signaling have been implicated in various human cancers including hepatocellular carcinoma, but the underlying mechanism remains largely unclear. In this study, we aimed to explore the role of ERK1/2 in the regulation of TGF-β’s promoting and suppressive activities in HCC cells. Our data showed that treatment with TGF-β1 enhanced invasion and epithelial–mesenchymal transition (EMT) in HCC HepG2 cells, accompanied with increased MMP9 production and activation of Smad2/3 and ERK1/2, but inhibited tumor cell proliferation. These effects were eliminated by treatment with SB431542, a TGF-β inhibitor. Afterward, treatment with the MEK1/2 inhibitor U0126 reduced the TGF-β1-induced invasion and vimentin and MMP9 secretion in HepG2 cells, without affecting the inhibitory effects of TGF-β1 on HepG2 cell proliferation. Moreover, inhibition of Smad2/3 expression attenuated TGF-β1-induced cell invasion, ERK1/2 phosphorylation, and MMP9 production in HepG2 cells. However, knockdown of Slug only reduced cell invasion but did not affect ERK1/2 activation and MMP9 secretion in HepG2 cells. These data indicate that TGF-β1 activates ERK1/2 in HepG2 cells through the Smad2/3 pathway but not the Slug pathway. In summary, our study demonstrates that inhibition of ERK1/2 signaling attenuates the promoting effects of TGF-β1 on the metastatic phenotypes of HCC cells without affecting its suppressive effects on HCC cell proliferation. Therefore, we suggest that ERK1/2 may be used as a molecular target for the treatment of TGF-β-responsive HCC.

Transforming Growth Factors α and β Are Essential for Modeling Cholangiocarcinoma Desmoplasia and Progression in a Three-Dimensional Organotypic Culture Model

To gain insight into the cellular and molecular interactions mediating the desmoplastic reaction and aggressive malignancy of mass-forming intrahepatic cholangiocarcinoma (ICC), we modeled ICC desmoplasia and progression in vitro. A unique three-dimensional (3D) organotypic culture model was established; within a dilute collagen-type I hydrogel, a novel clonal strain of rat cancer-associated myofibroblasts (TDF_SM) was co-cultured with a pure rat cholangiocarcinoma cell strain (TDE_CC) derived from the same ICC type as TDF_SM. This 3D organotypic culture model reproduced key features of desmoplastic reaction that closely mimicked those of the in situ tumor, as well as promoted cholangiocarcinoma cell growth and progression. Our results supported a resident liver mesenchymal cell origin of the TDF_SM cells, which were not neoplastically transformed. Notably, 3D co-culturing of TDE_CC cells with TDF_SM cells provoked the formation of a dense fibrocollagenous stroma in vitro that was associated with significant increases in both proliferative TDF_SM myofibroblastic cells and TDE_CC cholangiocarcinoma cells accumulating within the gel matrix. This dramatic desmoplastic ICC-like phenotype, which was not observed in the TDE_CC or TDF_SM controls, was highly dependent on transforming growth factor (TGF)-β, but not promoted by TGF-α. However, TGF-α was determined to be a key factor for promoting cholangiocarcinoma cell anaplasia, hyperproliferation, and higher malignant grading in this 3D culture model of desmoplastic ICC.

Hepatitis C virus infection of cholangiocarcinoma cell lines

Hepatitis C virus (HCV) infects the liver and hepatocytes are the major cell type supporting viral replication. Hepatocytes and cholangiocytes derive from a common hepatic progenitor cell that proliferates during inflammatory conditions, raising the possibility that cholangiocytes may support HCV replication and contribute to the hepatic reservoir. We screened cholangiocytes along with a panel of cholangiocarcinoma-derived cell lines for their ability to support HCV entry and replication. While primary cholangiocytes were refractory to infection and lacked expression of several entry factors, two cholangiocarcinoma lines, CC-LP-1 and Sk-ChA-1, supported efficient HCV entry; furthermore, Sk-ChA-1 cells supported full virus replication. In vivo cholangiocarcinomas expressed all of the essential HCV entry factors; however, cholangiocytes adjacent to the tumour and in normal tissue showed a similar pattern of receptor expression to ex vivo isolated cholangiocytes, lacking SR-BI expression, explaining their inability to support infection. This study provides the first report that HCV can infect cholangiocarcinoma cells and suggests that these heterogeneous tumours may provide a reservoir for HCV replication in vivo.

Anti-cancer effect and gene modulation of ET-743 in human biliary tract carcinoma preclinical models

Background

Standard chemotherapy in unresectable biliary tract carcinoma (BTC) patients is based on gemcitabine combined with platinum derivatives. However, primary or acquired resistance is inevitable and no second-line chemotherapy is demonstrated to be effective. Thus, there is an urgent need to identify new alternative (chemo)therapy approaches.

Methods

We evaluated the mechanism of action of ET-743 in preclinical models of BTC. Six BTC cell lines (TFK-1, EGI-1, TGBC1, WITT, KMCH, HuH28), two primary cell cultures derived from BTC patients, the EGI-1 and a new established BTC patient-derived xenografts, were used as preclinical models to investigate the anti-tumor activity of ET-743 in vitro and in vivo. Gene expression profiling was also analyzed upon ET-743 treatment in in vivo models.

Results

We found that ET-743 inhibited cell growth of BTC cell lines and primary cultures (IC50 ranging from 0.37 to 3.08 nM) preferentially inducing apoptosis and activation of the complex DNA damage-repair proteins (p-ATM, p-p53 and p-Histone H2A.x) in vitro. In EGI-1 and patient-derived xenografts, ET-743 induced tumor growth delay and reduction of vasculogenesis. In vivo ET-743 induced a deregulation of genes involved in cell adhesion, stress-related response, and in pathways involved in cholangiocarcinogenesis, such as the IL-6, Sonic Hedgehog and Wnt signaling pathways.

Conclusions

These results suggest that ET-743 could represent an alternative chemotherapy for BTC treatment and encourage the development of clinical trials in BTC patients resistant to standard chemotherapy.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2407-14-918) contains supplementary material, which is available to authorized users.

Determining the effect of transforming growth factor-β1 on cdk4 and p27 in gastric cancer and cholangiocarcinoma

Gastric cancer and cholangiocarcinoma are problematic throughout the world due to their destructive malignancy. In attempts to treat cholangiocarcinoma and gastric cancer, researchers often explore the effects of transforming growth factor-β1 (TGF-β1). TGF-β1 plays a crucial role in causing cell cycle arrest and fibrosis in cancer cells. The present study aimed to identify whether TGF-β1 is capable of functioning as an antitumor agent in two cancer cell lines; cholangiocarcinoma and gastric cancer. The downregulation of cyclin dependent kinase (cdk) 4 and the upregulation of p27 were investigated, in order to identify possible antitumor functions of TGF-β1. A number of different methods were implemented, including cell proliferation assay, bicinchoninic acid (BCA) assay and western blot analysis with TGF-β1, AGS (human gastric cancer cell line) and SUN-1196 (human cholangiocarcinoma cell line). In the AGS study, cdk4 values decreased from 1.000 to 0.670 and then to 0.664, with increasing TGF-β1 concentrations of 0, 0.5 and 5 ng/ml, respectively. By contrast, p27 values increased from 1.000 to 1.391 and then to 1.505, with increasing TGF-β1 concentrations of 0, 0.5 and 5 ng/ml, respectively. In the SUN-1196 study, p27 values increased from 0.548 to 0.807 and then to 0.844 with increasing TGF-β1 concentrations of 5, 25 and 50 ng/ml, respectively. Certain concentrations of TGF-β1 play antitumor roles in gastric cancer through the down-regulation of cdk4 and upregulation of p27. Certain TGF-β1 concentrations also have antitumor roles in cholangiocarcinoma through the upregulation of p27. With these results, we came a step closer to finding a cure for cholangiocarcinoma and gastric cancer.

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

Background

The aim of this study was to examine the patterns of expression of epithelial-mesenchymal transition (EMT)-related proteins in intrahepatic cholangiocarcinoma. The clinicopathological and prognostic value of these markers was also evaluated.

Methods

We detected the expression status of three EMT-related proteins, ie, E-cadherin, vimentin, and N-cadherin, by immunohistochemistry in consecutive intrahepatic cholangiocarcinoma specimens from 96 patients.

Results

The frequency of loss of the epithelial marker E-cadherin, and acquisition of mesenchymal markers, vimentin and N-cadherin, in intrahepatic cholangiocarcinoma was 43.8%, 37.5% and 57.3%, respectively. Altered expression of EMT markers was associated with aggressive tumor behavior, including lymph node metastasis, undifferentiated-type histology, advanced tumor stage, venous invasion, and shorter overall survival. Moreover, loss of E-cadherin was retained as an independent prognostic factor for patients with intrahepatic cholangiocarcinoma in multivariate analysis.

Conclusion

Our results suggest that the EMT process is associated with tumor progression and a poor outcome in patients with intrahepatic cholangiocarcinoma, and inhibition of EMT might offer novel promising molecular targets for the treatment of affected patients.

Molecular Markers in the Pathogenesis of Cholangiocarcinoma: Potential for Early Detection and Selection of Appropriate Treatment

Cholangiocarcinoma (CC) is a primary malignancy that arises from cholangiocytes, the epithelial cells lining the bile duct livers. The worldwide incidence of CC is increasing and despite of combined therapeutic strategies, its prognosis remains poor. Till now surgery remains the only curative treatment modality. Over the past years, several important studies have yielded new insights into the molecular mechanisms of cholangiocarcinoma. This review focused on critical molecular player during the development from inflammation and cellular and molecular pathogenesis of this disease. The novel prophylactic and therapeutic approach deals especially the molecules involved in inflammation of cholangiocite or those related to promotion and progression of CC. The elucidation of their specific effects and interaction of this complex mechanism will accelerate the development of new biomarker for early detection and predictor factors outcome in CC.

JAK-STAT pathway in carcinogenesis: Is it relevant to cholangiocarcinoma progression

The features of JAK-STAT signaling in liver cells are discussed in the current review. The role of this signaling cascade in carcinogenesis is accentuated. The possible involvement of this pathway and alteration of its elements are compared for normal cholangiocytes, cholangiocarcinoma predisposition and development. Prolactin and interleukin-6 are described in detail as the best studied examples. In addition, the non-classical nuclear translocation of cytokine receptors is discussed in terms of its possible implication to cholangiocarcinoma development.