The novel epithelial-mesenchymal transition-related proteins and their therapeutic targets in cholangiocarcinoma: a narrative review.

Background and Objective: Cholangiocarcinoma (CCA), a liver cancer of bile duct epithelial cells, is a severe health issue in northeastern Thailand. The epithelial-mesenchymal transition (EMT) is a crucial process in the development of CCA. To comprehend oncogenic EMT in CCA, several newly found EMT factors are being explored in these underlying pathways. This narrative review explained the latest in vitro and in vivo findings on the molecular mechanisms of 21 new EMT-related proteins that affect CCA progression. Methods: We evaluated the PubMed database for relevant articles that fulfilled our criteria for investigating the molecular pathways of the novel EMT markers involved in oncogenic EMT and how they contribute to CCA development, including cell proliferation, apoptosis, invasion, migration, and chemoresistance. Key Content and Findings: We discuss the potential of these new EMT markers as diagnostic, prognostic, and therapeutic indicators for CCA and describe their underlying mechanisms in the development of the disease. The discovery of several oncogenic EMT proteins and their key signaling pathways and downstream targets will also broaden novel paths of investigation into the diagnosis and targeted treatment of CCA. Conclusions: The EMT-related proteins that were found are good sources of knowledge and interesting information for future research. The possible ways to treat CCA that could be tested in clinical trials were also discussed.

Alteration of STK11 Expression Associated With Cholangiocarcinoma Progression.

BACKGROUND/AIM: Serine/threonine kinase 11 (STK11), a tumor suppressor, controls 5' AMP-activated protein kinase (AMPK) signaling in a variety of cellular functions. Mutated STK11 has been identified as a novel driver gene that promotes cancer progression. The purpose of this study was to investigate the alteration of STK11 and its correlation with clinicopathological data in cholangiocarcinoma (CCA). MATERIALS AND METHODS: Gene mutation and expression analyses were performed using cBioportal and Gene Expression Profiling Interactive Analysis version 2 (GEPIA2). qRT-PCR was performed to measure STK11 mRNA levels and immunohistochemistry was performed to investigate STK11 protein expression in CCA tissues. RESULTS: The results from publicly available cancer datasets showed that 2.7% of CCA cases had STK11 mutations. Most of STK11 gene mutations are of the truncating type and result in low STK11 mRNA and protein expression. We detected a correlation between STK11 mutation status and the tendency for shorter patient survival. The results of qRT-PCR revealed that STK11 mRNA levels were statistically significantly lower in CCA patients with mutated STK11 compared to those with wild-type STK11 (p-value=0.013). Immunohistochemical staining showed high STK11 expression in 43.8% and low expression in 56.2% of CCA tissues examined. Low STK11 protein expression resulted in poor prognosis compared with high STK11 expression, especially in CCA papillary carcinoma. Univariate and multivariate analysis revealed that high STK11 expression was associated with a decreased hazard ratio of patient survival rates (HR=0.696, p-value=0.06 and HR=0.666, p-value=0.04, respectively). CONCLUSION: Alteration of STK11 mutational or mRNA/protein status might be used as a potential predictive biomarker for the prognosis of the clinical outcomes in CCA patients.

Serum α2,6-sialylated glycoform of serotransferrin as a glycobiomarker for diagnosis and prediction of clinical severity in cholangiocarcinoma.

BACKGROUND: Glycoprotein sialylation changes are associated with severe development of various cancers. We previously discovered the sialylation of serotransferrin (TF) in cholangiocarcinoma (CCA) using glycoproteomics approach. However, a simple and reliable method for validating sialylation of a specific glycobiomarker is urgently needed. METHODS: We identified the altered glycosylation in CCA tissues by glycoproteomics approach using mass spectrometry. An enzyme-linked lectin assay (ELLA) was developed for determining the serum levels of sialylated TF in CCA, hepatocellular carcinoma (HCC) and healthy controls in training and validation cohorts. RESULTS: The nine highly sialylated glycoforms of TF were markedly abundant in CCA tumor tissues than in control. Serum SNA-TF and MAL1-TF were significantly higher in CCA patients. Under receiver operating characteristic curve, serum SNA-TF concentrations significantly differentiated CCA from healthy control. Higher SNA-TF were significantly correlated with severe tumor stages and lymph node metastasis. The combined SNA-TF, MAL1-TF, and CA19-9 as a novel glycobiomarkers panel demonstrated the highest specificity (96.2%) for distinguishing CCA from HCC patients. In CCA patients with low CA19-9 levels, SNA-TF in combination with CA19-9 achieved in 97% diagnostic accuracy. CONCLUSIONS: Sialylated serotransferrin glycoforms could be used as a novel glycobiomarker for diagnosis and prediction of clinical severity in CCA patients.

Arctigenin inhibits cholangiocarcinoma progression by regulating cell migration and cell viability via the N-cadherin and apoptosis pathway.

Northeast Thailand has the highest incidence of cholangiocarcinoma (CCA) in the world. The lack of promising diagnostic markers and appropriate therapeutic drugs is the main problem for metastatic stage CCA patients who have a poor prognosis. N-cadherin, a cell adhesion molecule, is usually upregulated in cancers and has been proposed as an important mediator in epithelial-mesenchymal transition (EMT), one of the metastasis processes. Additionally, it has been shown that arctigenin, a seed isolated compound from Arctium lappa, can inhibit cancer cell progression via suppression of N-cadherin pathway. In this study, we investigated the protein expression of N-cadherin and its correlation with clinicopathological data of CCA patients, as well as the impact of arctigenin on KKU-213A and KKU-100 CCA cell lines and its underlying mechanisms. Immunohistochemistry results demonstrated that high expression of N-cadherin was significantly associated with severe CCA stage (p = 0.027), and shorter survival time (p = 0.002) of CCA patients. The mean overall survival times between low and high expression of N-cadherin were 31.6 and 14.8 months, respectively. Wound healing assays showed that arctigenin significantly inhibited CCA cell migration by downregulating N-cadherin whereas upregulating E-cadherin expression. Immunocytochemical staining revealed that arctigenin suppressed the expression of N-cadherin in both CCA cell lines. Furthermore, flow cytometry and western blot analysis revealed that arctigenin significantly reduced CCA cell viability and induced apoptosis via the Bax/Bcl-2/caspase-3 pathway. This research supports the use of N-cadherin as a prognostic marker for CCA and arctigenin as a potential alternative therapy for improving CCA treatment outcomes.

Establishment of a Potential Serum Biomarker Panel for the Diagnosis and Prognosis of Cholangiocarcinoma Using Decision Tree Algorithms.

Potential biomarkers which include S100 calcium binding protein A9 (S100A9), mucin 5AC (MUC5AC), transforming growth factor ß1 (TGF-ß1), and angiopoietin-2 have previously been shown to be effective for cholangiocarcinoma (CCA) diagnosis. This study attempted to measure the sera levels of these biomarkers compared with carbohydrate antigen 19-9 (CA19-9). A total of 40 serum cases of CCA, gastrointestinal cancers (non-CCA), and healthy subjects were examined by using an enzyme-linked immunosorbent assay. The panel of biomarkers was evaluated for their accuracy in diagnosing CCA and subsequently used as inputs to construct the decision tree (DT) model as a basis for binary classification. The findings showed that serum levels of S100A9, MUC5AC, and TGF-ß1 were dramatically enhanced in CCA patients. In addition, 95% sensitivity and 90% specificity for CCA differentiation from healthy cases, and 70% sensitivity and 83% specificity for CCA versus non-CCA cases was obtained by a panel incorporating all five candidate biomarkers. In CCA patients with low CA19-9 levels, S100A9 might well be a complementary marker for improved diagnostic accuracy. The high levels of TGF-ß1 and angiopoietin-2 were both associated with severe tumor stages and metastasis, indicating that they could be used as a reliable prognostic biomarkers panel for CCA patients. Furthermore, the outcome of the CCA burden from the Classification and Regression Tree (CART) algorithm using serial CA19-9 and S100A9 showed high diagnostic efficiency. In conclusion, results have shown the efficacy of CCA diagnosis and prognosis of the novel CCA-biomarkers panel examined herein, which may prove be useful in clinical settings.

Circulating TGF-ß1 as the potential epithelial mesenchymal transition-biomarker for diagnosis of cholangiocarcinoma.

BACKGROUND: Cholangiocarcinoma (CCA) is a malignant tumor arising from bile duct epithelium. The oncogenic risk factor is infection by the liver fluke, Opisthorchis viverrini (Ov). One of key mechanism in the development of CCA is epithelial mesenchymal transition (EMT). We aimed to investigate the expression of EMT-related proteins namely, E-cadherin, TGF-ß1 and BMP-7 in CCA tissues, to determine the level of candidate EMT-related protein, and to examine whether there were significant correlations with clinicopathological data in sera of CCA patients compared with normal groups. METHODS: The expression of E-cadherin, TGF-ß1 and BMP-7 was analyzed in human CCA tissues by immunohistochemistry and altered expressions compared to clinicopathological data were analyzed to identify the potential candidate EMT-biomarker. Subsequently, the level of candidate marker was determined in sera of CCA patients compared with normal and inflammatory-related diseases groups by enzyme-linked immunosorbent assay (ELISA). RESULTS: Immunohistochemical analysis showed that E-cadherin was expressed at a low level whereas TGF-ß1 and BMP-7 showed high expression in CCA tissues when compared with liver from cadaveric donor. Interestingly, only high TGF-ß1 expression in CCA tissues was significantly correlated with lymph node metastasis, severe cancer stage, intrahepatic CCA type and shorter survival time of CCA patients (P<0.05). Consequently, TGF-ß1 was selected to determine the level in serum of CCA patients using ELISA. The results showed that serum TGF-ß1 level was elevated in CCA patients compared to the normal group. Patients with high TGF-ß1 levels were significantly correlated with metastasis status (P=0.03). Furthermore, receiver operating characteristic (ROC) analysis showed that serum TGF-ß1 level is effective in distinguishing CCA patients from normal at the cut-off of 38.54 ng/mL with high sensitivity (71.1%) and specificity (68.9%) and from inflammatory-related diseases group at the cut-off of 38.67 ng/mL with effective sensitivity (68.0%) and specificity (71.1%). Furthermore, TGF-ß1 could serve as a novel metastatic biomarker in CCA to diagnose the disease with 48.95 ng/mL as the cut-off along with the desired sensitivity and specificity (48.2% and 88.9% respectively). CONCLUSIONS: The results of this study show that TGF-ß1 could be a potential EMT-biomarker for diagnosis and prognosis of CCA.

Antifibrotic effect of xanthohumol in combination with praziquantel is associated with altered redox status and reduced iron accumulation during liver fluke-associated cholangiocarcinogenesis.

Cholangiocarcinoma (CCA) caused by infection of the liver fluke Opisthorchis viverrini, (Ov) is the major public health problem in northeast Thailand. Following Ov infection the subsequent molecular changes can be associated by reactive oxygen species (ROS) induced chronic inflammation, advanced periductal fibrosis, and cholangiocarcinogenesis. Notably, resistance to an activation of cell death in prolonged oxidative stress conditions can occur but some damaged/mutated cells could survive and enable clonal expansion. Our study used a natural product, xanthohumol (XN), which is an anti-oxidant and anti-inflammatory compound, to examine whether it could prevent Ov-associated CCA carcinogenesis. We measured the effect of XN with or without praziquantel (PZ), an anti-helminthic treatment, on DNA damage, redox status change including iron accumulation and periductal fibrosis during CCA genesis induced by administration of Ov and N-dinitrosomethylamine (NDMA) in hamsters. Animals were randomly divided into four groups: group I, Ov infection and NDMA administration (ON); group II, Ov infection and NDMA administration and PZ treatment (ONP); the latter 2 groups were similar to group I and II, but group III received additional XN (XON) and group IV received XN plus PZ (XONP). The results showed that high 8-oxodG (a marker of DNA damage) was observed throughout cholangiocarcinogenesis. Moreover, increased expression of CD44v8-10 (a cell surface in regulation of the ROS defense system), whereas decreased expression of phospho-p38MAPK (a major ROS target), was found during the progression of the bile duct cell transformation. In addition, high accumulation of iron and expression of transferrin receptor-1 (TfR-1) in both malignant bile ducts and inflammatory cells were detected. Furthermore, fibrosis also increased with the highest level being on day 180. On the other hand, the groups of XN with or without PZ supplementations showed an effective reduction in all the markers examined, including fibrosis when compared with the ON group. In particular, the XONP group, in which a significant reduction DNA damage occurred, was also found to have iron accumulation and fibrosis compared to the other groups. Our results show that XN administered in combination with PZ could efficiently prevent CCA development and hence provide potential chemopreventive benefits in Ov-induced cholangiocarcinogenesis.