Iron-induced kidney cell damage: insights into molecular mechanisms and potential diagnostic significance of urinary FTL

Background: Iron overload can lead to organ and cell injuries. Although the mechanisms of iron-induced cell damage have been extensively studied using various cells, little is known about these processes in kidney cells. Methods: In this study, we first examined the correlation between serum iron levels and kidney function. Subsequently, we investigated the molecular impact of excess iron on kidney cell lines, HEK293T and HK-2. The presence of the upregulated protein was further validated in urine. Results: The results revealed that excess iron caused significant cell death accompanied by morphological changes. Transcriptomic analysis revealed an up-regulation of the ferroptosis pathway during iron treatment. This was confirmed by up-regulation of ferroptosis markers, ferritin light chain (FTL), and prostaglandin-endoperoxide synthase 2 (PTGS2), and down-regulation of acyl-CoA synthetase long-chain family member 4 (ACSL4) and glutathione peroxidase 4 (GPX4) using real-time PCR and Western blotting. In addition, excess iron treatment enhanced protein and lipid oxidation. Supportively, an inverse correlation between urinary FTL protein level and kidney function was observed. Conclusion: These findings suggest that excess iron disrupts cellular homeostasis and affects key proteins involved in kidney cell death. Our study demonstrated that high iron levels caused kidney cell damage. Additionally, urinary FTL might be a useful biomarker to detect kidney damage caused by iron toxicity. Our study also provided insights into the molecular mechanisms of iron-induced kidney injury, discussing several potential targets for future interventions.

Induction of apoptotic cell death of cholangiocarcinoma cells by tiliacorinine from Tiliacora triandra: A mechanistic insight

BACKGROUND

Cholangiocarcinoma (CCA) exhibits poor response to the present chemotherapeutic agents and frequently develops drug resistance. Finding novel anticancer drugs might enhance patient outcomes. Tiliacorinine, a bisbenzylisoquinoline alkaloid from the Thai medicinal plant Tiliacora triandra, effectively induced apoptosis of human CCA cell lines and inhibited tumor growth in mice. Here, we elucidate further the molecular mechanisms underlining the cytotoxicity of tiliacorinine and its implication in overcoming gemcitabine-resistance of CCA cells.

METHODS

Cytotoxicity of tiliacorinine against CCA cell lines was assessed using MTT assay. The molecular signaling was determined using Western blot analysis. Molecular docking simulations were applied to predict the binding affinity and orientation of tiliacorinine to the possible binding site(s) of the target proteins.

RESULTS

Tiliacorinine induced apoptotic cell death of CCA cells in a dose- and time-dependent manner. Tiliacorinine significantly suppressed the expression of anti-apoptotic proteins, Bcl-xL and XIAP; activated apoptotic machinery proteins, caspase-3, caspase-9, and PARP; and decreased the levels of pAkt and pSTAT3. EGF/EGFR activation model and molecular docking simulations revealed EGFR, Akt, and STAT3 as potent targets of tiliacorinine. Molecular docking simulations indicated a strong binding affinity of tiliacorinine to the ATP-binding pockets of EGFR, PI3K, Akt, JAK2, and SH2 domain of STAT3. Tiliacorinine could synergize with gemcitabine and restore the cytotoxicity of gemcitabine against gemcitabine-resistant CCA cells.

CONCLUSION

Tiliacorinine effectively induced apoptosis via binding and blocking the actions of EGFR, Akt, and STAT3.

GENERAL SIGNIFICANCE

Tiliacorinine is a novel multi-kinase inhibitor and possibly a potent anti-cancer agent, in cancers with high activation of EGFR.

BI6727 and GSK461364A, potent PLK1 inhibitors induce G2/M arrest and apoptosis against cholangiocarcinoma cell lines

Polo-like kinase 1 (PLK1) is an essential mitotic checkpoint protein that plays a key role in cell cycle division. Overexpression of PLK1 has been associated with poor prognosis in various cancers. Cholangiocarcinoma (CCA) is a lethal bile duct cancer and the current treatments in inoperable patients have not been satisfactory. In order to develop novel targeted therapies, we investigated the efficacy of BI6727 (volasertib) and GSK461364A, polo-like kinase 1 (PLK1) inhibitors in KKU-100 and KKU-213A CCA cell lines. PLK1 expression was significantly up-regulated in CCA cases compared with normal tissues based on the results derived from GEPIA. Western blot results exhibited PLK1 protein expression in both CCA cell lines. Molecular dynamics simulations and free energy calculations based on MM/GBSA method revealed that BI6727-PLK1 and GSK461364A-PLK1 complexes were stable in an aqueous environment, and their complexation was mainly driven by Van der Waals interaction. BI6727 and GSK461364A clearly suppressed CCA cell proliferation and induced G2/M arrest, accompanied with upregulation of cyclin B1 and phosphorylated Histone H3 at Ser10 (pS10H3), specific markers of mitosis. Furthermore, both compounds triggered mitotic catastrophe followed by cell apoptosis via activation of PARP and Caspase 3, as well as downregulation of Mcl-1 anti-apoptotic protein in both CCA cell lines. In conclusion, pharmacologic PLK1 inhibition by BI6727 and GSK461364A blocked survival of CCA cells by several mechanisms. Our study provides evidence that BI6727 and GSK461364A could be alternative drugs and have potential implications at the clinical level for CCA therapy.

Diminishing acetyl-CoA carboxylase 1 attenuates CCA migration via AMPK-NF-κB-snail axis

Cholangiocarcinoma (CCA), a cancer of the biliary tract, is a significant health problem in Thailand. Reprogramming of cellular metabolism and upregulation of lipogenic enzymes have been revealed in CCA, but the mechanism is unclear. The current study highlighted the importance of acetyl-CoA carboxylase 1 (ACC1), a rate-limiting enzyme in de novo lipogenesis, on CCA migration. ACC1 expression in human CCA tissues was determined by immunohistochemistry. The results demonstrated that increased ACC1 was related to the shorter survival of CCA patients. Herein, ACC1-deficient cell lines (ACC1-KD) were generated by the clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 9 (cas9) system and were used for the comparative study. The ACC1 levels in ACC1-KD were 80-90 % lower than in parental cells. Suppression of ACC1 significantly reduced intracellular malonyl-CoA and neutral lipid contents. Two-fold growth retardation and 60-80 % reduced CCA cell migration and invasion were observed in ACC1-KD cells. The reduced 20-40 % of intracellular ATP levels, AMPK activation, lowered NF-κB p65 nuclear translocation, and snail expression were emphasized. Migration of ACC1-KD cells was restored by supplementation with palmitic acid and malonyl-CoA. Altogether, the importance of rate-limiting enzyme in de novo fatty acid synthesis, ACC1, and AMPK-NF-κB-snail axis on CCA progression was suggested herein. These might be the novel targets for CCA drug design. (ACC1, AMPK, Cholangiocarcinoma, De novo lipogenesis, NF-κB, Palmitic acid).

Establishment and characterization of a novel cancer stem-like cell of cholangiocarcinoma

Cholangiocarcinoma (CCA) is an aggressive malignant tumor of bile duct epithelia. Recent evidence suggests the impact of cancer stem cells (CSC) on the therapeutic resistance of CCA; however, the knowledge of CSC in CCA is limited due to the lack of a CSC model. In this study, we successfully established a stable sphere-forming CCA stem-like cell, KKU-055-CSC, from the original CCA cell line, KKU-055. The KKU-055-CSC exhibits CSC characteristics, including 1) the ability to grow stably and withstand continuous passage for a long period of culture in the stem cell medium, 2) high expression of stem cell markers, 3) low responsiveness to standard chemo-drugs, 4) multi-lineage differentiation, and 5) faster and constant expansive tumor formation in xenograft mouse models. To identify the CCA-CSC-associated pathway, we have performed a global proteomics and functional cluster/network analysis. Proteomics identified the 5925 proteins in total, and the significantly upregulated proteins in CSC compared with FCS-induced differentiated CSC and its parental cells were extracted. Network analysis revealed that high mobility group A1 (HMGA1) and Aurora-A signaling via the STAT-3 pathways were enriched in KKU-055-CSC. Knockdown of HMGA1 in KKU-055-CSC suppressed the expression of stem cell markers, induced the differentiation followed by cell proliferation, and enhanced sensitivity to chemo drugs including Aurora A inhibitors. In silico analysis demonstrated that the expression of HMGA1 was correlated with Aurora-A expressions and poor survival of CCA patients. In conclusion, we have established a unique CCA stem-like cell model and identified the HMGA1-Aurora-A signaling as an important pathway for CSC-CCA.

Abstract 6588: Systems biology-based drug repositioning and biomarker discovery for Thai liver fluke-associated cholangiocarcinoma

Our group has recently reported the successful use of comprehensive drug response and pan-omic profiling for identifying repurposable drug shortlists in Asian cholangiocarcinoma. We also developed the CCA45 gene-expression signature that could accurately predict the prognosis of CCA patients, especially those with Asian ethnic backgrounds. To further explore therapeutic candidates and potential resistance mechanisms, we have established CCA1 cell lines resistant to their subgroup-specific drug candidates: MEK and SRC inhibitors. Reverse-phase protein arrays (RPPA)-based proteomic profiling revealed upregulation of cell cycle, apoptosis, MAPK, and mTOR-related proteins in both MEKi- and SRCi-resistant cells. Src pathway activity was found to be more significantly reduced in SRCi-resistant cells. We identified CDK4/6 inhibitors as the second-line therapeutic candidates for MEK inhibitor-resistant cells by systematic drug screening. SRCi-resistant cells unexpectedly developed cross-resistance to MEK inhibitors and showed sensitivity to only a few CDK4/6 inhibitors. These data are beneficial for the clinical translation of our proposed drug candidates for Asian CCA, preparing the alternate regimens after drug resistance. We also adopted the DSP-based spatial transcriptomic platform to compare the tumor microenvironment between chemotherapy-sensitive and chemotherapy-resistant CCA patients. While the CTA panel showed consistent patterns of normalized gene expression to those of the WTA panel, the CTA panel can only measure 17 of the 45 genes required for our CCA45 signature. Out of these 17 genes, ITGB4, FGFR3, VEGFC, NOTCH1, and RRAD showed significant gene expression changes with reducing tumor percentage. The microenvironment of gemcitabine/cisplatin responder (R) non-responder (NR) exhibited negative regulation of ERK1/2 and MAPK, high WNT pathway activity, and high tumor-infiltrating lymphocyte (TIL). In contrast, the microenvironment of the non-responder (NR) subgroup showed high neutrophil-related activity, high NFκB, high Treg, and the exhausted immune phenotype. Overall, our study contributes toward realizing the precision medicine concept for CCA patients.

Citation Format: Supawan Jamnongsong, Patipark Kueanjinda, Piyathida Tawornparcha, Kulthida Vaeteewoottacharn, Seiji Okada, Siwanon Jirawatnotai, Ananya Pongpaibul, Krittiya Korphaisarn, Somponnat Sampattavanich. Systems biology-based drug repositioning and biomarker discovery for Thai liver fluke-associated cholangiocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6588.

Dense GM-CSFRα-expressing immune infiltration is allied with longer survival of intrahepatic cholangiocarcinoma patients

Background

Intrahepatic cholangiocarcinoma (iCCA) is a cancer arising from intrahepatic bile duct epithelium. An iCCA incidence is increasing worldwide; however, the outcome of the disease is dismal. The linkage between chronic inflammation and iCCA progression is well established, but the roles of granulocyte-macrophage colony-stimulating factor (GM-CSF) remain unrevealed. Thus, a better understanding of GM-CSF functions in CCA may provide an alternative approach to CCA treatment.

Methods

Differential GM-CSF and GM-CSFRα mRNA expressions in CCA tissues were investigated by Gene Expression Profiling Interactive Analysis (GEPIA) based on The Cancer Genome Atlas (TCGA) database. The protein expressions and localizations of GM-CSF and its cognate receptor (GM-CSFRα) in iCCA patients' tissues were demonstrated by the immunohistochemistry (IHC) techniques. The survival analyses were performed using Kaplan-Meier survival analysis with log-rank test and Cox proportional hazard regression model for multivariate analysis. The GM-CSF productions and GM-CSFRα expressions on CCA cells were assessed by ELISA and flow cytometry. The effects of GM-CSF on CCA cell proliferation and migration were evaluated after recombinant human GM-CSF treatment. The relationship between GM-CSF or GM-CSFRα level and related immune cell infiltration was analyzed using the Tumor Immune Estimation Resource (TIMER).

Results

GEPIA analysis indicated GM-CSF and GM-CSFRα expressions were higher in CCA tissues than in normal counterparts, and high GM-CSFRα was related to the longer disease-free survival of the patients (p < 0.001). IHC analysis revealed that CCA cells differentially expressed GM-CSF, while GM-CSFRα was expressed on cancer-infiltrating immune cells. The patient whose CCA tissue contained high GM-CSF expressed CCA, and moderate to dense GM-CSFRα-expressing immune cell infiltration (ICI) acquired longer overall survival (OS) (p = 0.047), whereas light GM-CSFRα-expressing ICI contributed to an increased hazard ratio (HR) to 1.882 (95% CI [1.077-3.287]; p = 0.026). In non-papillary subtype, an aggressive CCA subtype, patients with light GM-CSFRα-expressing ICI had shorter median OS (181 vs. 351 days; p = 0.002) and the HR was elevated to 2.788 (95% CI [1.299-5.985]; p = 0.009). Additionally, TIMER analysis demonstrated GM-CSFRα expression was positively correlated with neutrophil, dendritic cell, and CD8+ T cell infiltrations, though it was conversely related to M2-macrophage and myeloid-derived suppressor cell infiltration. However, the direct effects of GM-CSF on CCA cell proliferation and migration were not observed in the current study.

Conclusions

Light GM-CSFRα-expressing ICI was an independent poor prognostic factor for iCCA patients. Anti-cancer functions of GM-CSFRα-expressing ICI were suggested. Altogether, the benefits of acquired GM-CSFRα-expressing ICI and GM-CSF for CCA treatment are proposed herein and require elucidation.

CRISPR Cas9-mediated ablation of pyruvate carboxylase gene in colon cancer cell line HT-29 inhibits growth and migration, induces apoptosis and increases sensitivity to 5-fluorouracil and glutaminase inhibitor

Pyruvate carboxylase (PC) is an important anaplerotic enzyme that replenishes the tricarboxylic acid cycle (TCA) intermediates. It prevents the collapse of the TCA cycle upon its intermediates are removed during high anabolic demand. We have recently shown that overexpression of PC protein was associated with staging, metastasis and poor survival of colorectal cancer patients. Herein, we generated the PC knockout (PC KO) colon cancer cell lines, HT-29, by CRISPR-Cas9 technique, as a model to understand the role of this enzyme in colorectal cancer. The PC KO HT-29 cell lines had no detectable PC protein and did not show abnormal cellular or nuclear structures. However, PC KO HT-29 cells showed a 50-60% reduction in their growth rate and a 60-70% reduction in migration. The deficient growth phenotype of PC KO HT-29 cells was associated with apoptotic induction with no apparent cell cycle disruption following five days of growth. Down-regulation of key lipogenic enzymes, including acetyl-CoA carboxylase-1 and fatty acid synthase, was also associated with growth inhibition, suggesting that the de novo lipogenesis is impaired. Furthermore, PC KO HT-29 cells were 50% and 60% more sensitive to 5-fluorouracil and glutaminase inhibitor, CB-839, at their IC50 concentrations, respectively, following 48 h exposure. The increased cytotoxicity of CB-839 to PC KO HT-29 cells was associated with increased poly (ADP-ribose) polymerase cleavage. However, this was not observed with PC KO cells exposed to 5-fluorouracil, suggesting that PC KO HT-29 cells were prone to CB-839-induced apoptosis. Collectively, these findings indicate that ablation of PC expression in HT-29 cells disrupts the metabolic homeostasis of cells and inhibits proliferation and migration, accompanied by apoptotic induction. This study highlights the crucial role of PC in supporting the survival of HT-29 cells during exposure to chemotherapeutic drugs.

Low Dose Berberine Suppresses Cholangiocarcinoma Cell Progression as a Multi-Kinase Inhibitor

BACKGROUND

Berberine (BBR), a natural isoquinoline alkaloid, possesses diverse pharmacological properties and anti-cancer effects that have been demonstrated in many in vitro and in vivo studies. In this study, the inhibitory effects and molecular mechanism of low dose BBR on EMT-induced cell migration, and invasion capability of cholangiocarcinoma (CCA) cell lines were demonstrated.

METHODS

The commercially available BBR chloride powder with purity ≥ 95% was used in this study. Effects of BBR on cell growth of two human CCA cell lines, KKU-213A and KKU-213B were measured using MTT assay. The progressive phenotypes-cell adhesion, migration, and invasion were evaluated using cell adhesion, wound healing, and Boyden chamber assays. Molecular docking analysis was performed to assess the possible binding mode of BBR against EGFR, Erk, STAT3 and Akt. The effects of BBR on the activations of EGF/EGFR and its downstream effectors were demonstrated using Western blotting.

RESULTS

BBR inhibited growth of CCA cells in a dose dependent manner. At sub-cytotoxic dose, BBR significantly inhibited cell adhesion, migration, invasion and decreased expression of vimentin, slug, and VEGFA of both CCA cell lines. Molecular docking suggested the simultaneous inhibitory activity of BBR on EGFR, Erk, STAT3 and Akt. The Western blot analyses revealed that upon the EGF/EGFR activation, BBR considerably attenuated the activations of EGFR, Erk, STAT3 and Akt.

CONCLUSION

Low dose of BBR suppresses EMT and thus aggressiveness of CCA cells, in part by its multi-kinase inhibitor property on EGFR and its downstream pathways.  BBR might be beneficial for therapy of human CCA.

COMPREHENSIVE DRUG RESPONSE PROFILING AND PAN-OMIC ANALYSIS IDENTIFIED THERAPEUTIC CANDIDATES AND PROGNOSTIC BIOMARKERS FOR ASIAN CHOLANGIOCARCINOMA

Cholangiocarcinoma (CCA) is rare cancer with the highest incidence in Eastern and Southeast Asian countries. Advanced CCA patients rely on chemotherapeutic regimens that offer unsatisfied clinical outcomes. We developed a comprehensive drug response profiling to investigate potential new drugs using CCA cell lines from Thai and Japanese patients against 100 approved anti-cancer drugs. We identified two major CCA subgroups that displayed unique molecular pathways from our integrative pan-omic and ligand-induced pathway activation analyses. MEK and Src inhibitors specifically killed the CCA1 subgroup without causing cytotoxicity to the normal cholangiocyte. Next, we developed the CCA45 signature to classify CCA patients based on their transcriptomic data. Our CCA45 signature could accurately predict prognosis, especially for Asian CCA patients. Our study provides a comprehensive public resource for drug repurposing in CCA and introduces analytical strategies for prioritizing cancer therapeutic agents for other rare cancer.

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Drug-response profiling separated Asian CCA cell lines into CCA1 and CCA2 subgroups

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Drug potency and subgroup specificity enabled therapeutic candidate shortlist

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Pan-omic profiling revealed the molecular uniqueness of CCA1 and CCA2 subgroups

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CCA45 gene signature predicted poor prognosis in Asian CCA patients

Multiple actions of NMS-P715, the monopolar spindle 1 (MPS1) mitotic checkpoint inhibitor in liver fluke-associated cholangiocarcinoma cells

AIM

NMS-P715 is a potent inhibitor of monopolar spindle 1 (MPS1) mitotic checkpoint kinase. Overexpression of MPS1 is associated with short survival times in patients with cholangiocarcinoma (CCA). This study investigated the anti-cancer effects of NMS-P715 in human CCA cell lines.

MAIN METHODS

KKU-100 and KKU-213A CCA cell lines were treated with NMS-P715 and cell viability was determined using MTT and colony formation assays. Inhibitory effects of NMS-P715 on cell cycle and apoptosis were evaluated using flow cytometry. Expression of underlying mechanism-related proteins was examined by Western blotting. Mitotic catastrophe was assessed by counting abnormal nuclei. Transwell assays were used to examine cell migration and invasion.

KEY FINDINGS

Molecular docking showed that the NMS-P715/MPS1 complex was driven by an induced-fit mechanism. We provide new evidence that NMS-P715 potently inhibited cell proliferation and colony formation in both CCA cell lines. This was accompanied by induction of G2/M arrest and the consequent induction of mitotic catastrophe, a process that occurs during defective mitosis. The recent study showed that NMS-P715 activated caspase-dependent apoptosis and autophagosome formation with an increase of LC3 A/B-II protein expression in CCA cell lines. NMS-P715 also greatly impeded cell migration and invasion in CCA cell lines. The combination of NMS-P715 and gemcitabine or cisplatin showed synergistic effects on CCA cell proliferation.

SIGNIFICANCE

This study revealed for the first time that NMS-P715 is a promising candidate for combating CCA owing via multiple actions and may be suitable for further development in a clinical study.

Annexin A1 Is a Potential Prognostic Marker for, and Enhances the Metastasis of, Cholangiocarcinoma

OBJECTIVE

Annexin A1 (ANXA1) is a calcium-dependent phospholipid-binding protein which contributes to proliferation, cancer progression and metastasis. Overexpression of ANXA1 is closely associated with metastasis in numerous types of cancer. Cholangiocarcinoma (CCA) is a bile-duct cancer which has high rates of metastasis. Previously, we demonstrated up-regulation of ANXA1 in a highly metastatic CCA cell line (KKU-213AL5). Here, we investigated the functions of ANXA1 in the progression of CCA cell lines and evaluated its clinical impacts in human CCA tissues.  Methods: Effects of ANXA1 on metastatic potential of CCA cell lines were evaluated using cell-proliferation, clonogenic, migration and invasion assays. The expression of ANXA1 in 44 intrahepatic human CCA tissues was investigated using immunohistochemistry (IHC). The association of ANXA1 with clinicopathological features of CCA patients was analyzed.

RESULTS

Silencing of ANXA1 expression using siRNA significantly decreased cell proliferation, colony formation, cell migration and invasion in the KKU-213AL5 cell line. IHC results showed low expression of ANXA1 in normal bile ducts in the non-tumor area. In contrast, high expression of ANXA1 in human CCA tissues was associated with advanced tumor stage, tumor size and presence of lymph-node metastasis.

CONCLUSION

These findings strongly imply that ANXA1 contributes to the progression of CCA. ANXA1 can serve as a potential prognostic marker for CCA. Ablation of ANXA1 action may be an alternative strategy to prevent metastasis of CCA.

Intracellular IL-33 Attenuates Extracellular IL-33-induced Cholangiocarcinoma Cell Proliferation and Invasion via NF-κB and GSK-3β Pathways

BACKGROUND/AIM

The functions of interleukin 33 (IL-33) in cholangiocarcinoma (CCA) are unclear. This study aimed to evaluate the roles of IL-33 in CCA progression.

MATERIALS AND METHODS

The effect of intracellular IL-33 using shIL-33 knocked down KKU-055 (IL-33KD-KKU-055) compared to parental (Pa) KKU-055 and extracellular IL-33 using recombinant human IL-33 (rhIL-33) treatment on the proliferation and invasion of CCA cells grown in 3D cultures was studied. Relevant markers were determined by western blot or ELISA.

RESULTS

IL-33KD-KKU-055 cells showed increased proliferation and invasion in 3D cultures compared to Pa-KKU-055 cells, with NF-κB and IL-6 up-regulation. Treatment with 2 ng/ml rhIL-33 promoted Pa-KKU-055 cell proliferation by inducing NF-κB and IL-6 expressions. Upon GSK-3β inactivation and increased nuclear full-length IL-33 (flIL-33), 20 ng/ml rhIL-33 had no effect on proliferation. Both 2 and 20 ng/ml rhIL-33 induced proliferation and invasion of IL-33-negative KKU-213 cells in 3D cultures, as well as NF-κB and IL-6 up-regulation.

CONCLUSION

Intracellular and extracellular IL-33 have distinct roles in the mechanisms of CCA progression.

Mucin-producing hamster cholangiocarcinoma cell line, Ham-2, possesses the aggressive cancer phenotypes with liver and lung metastases

Cholangiocarcinoma (CCA) is an aggressive bile duct cancer. Opisthorchis viverrini (O. viverrini) infection is a significant cause of CCA in the Greater Mekong subregion. Currently, there is no standard chemotherapeutic regimen for CCA. A unique hamster carcinogenesis model of O. viverrini-associated CCA was established. Molecular targets identified from the hamster CCA-comparative model are valuable for target identification and validation. Hamster CCA was induced by the administration of O. viverrini metacercariae and N-nitrosodimethylamine. Hamster-derived cancer cells were isolated and continuously cultured for more than 6 months. Ham-2 cell line was established and characterized in vitro and in vivo. Ham-2 exhibited chromosome hyperploidy. A comparative study with previously established cell line, Ham-1, demonstrated that Ham-2 acquired slower growth, higher adhesion, higher migration, and resistance to doxorubicin and 5-fluorouracil (5-FU). In BALB/c Rag-2/Jak3 double-deficient (BRJ) mice, Ham-2 subcutaneous transplantation formed mucin-producing cancers, which morphologically resemble human tubular cholangiocarcinoma. Intravenous-injected Ham-2 established the metastatic nodules in the lungs and livers of BRJ mice. Altogether, a new hamster cholangiocarcinoma cell line, Ham-2, which acquired more aggressive phenotypes in vitro and in vivo, was established. This cell line might be a valuable tool for comparative drug target identification and validation.

Five-(Tetradecyloxy)-2-furoic Acid Alleviates Cholangiocarcinoma Growth by Inhibition of Cell-cycle Progression and Induction of Apoptosis

BACKGROUND/AIM

Cholangiocarcinoma (CCA), a biliary cancer, is a health problem worldwide. The major problem in CCA treatment presents limited options. To date, targeting cancer metabolism is a promising anti-cancer strategy. To elucidate the functional importance of lipid metabolism in CCA, de novo lipogenesis was inhibited using 5-(tetradecyloxy)-2-furoic acid (TOFA), an acetyl CoA carboxylase inhibitor.

MATERIALS AND METHODS

Anti-proliferative effects of TOFA were determined both in vitro and in vivo. Its inhibitory effect on cell-cycle and apoptosis was investigated by flow cytometry and western blot analysis of relevant markers.

RESULTS

TOFA inhibited CCA cell growth, induced cell-cycle progression accompanied by apoptosis in a dose-dependent manner. Induction of p21, and caspase-3, -8, and -9 cleavages, while down-regulation of cyclin B1 and cyclin D1 were observed in TOFA-treated cells. The therapeutic potential was demonstrated in vivo.

CONCLUSION

De novo lipogensis is essential for CCA cell growth and is an alternative target for CCA treatment.

Reversine, a selective MPS1 inhibitor, induced autophagic cell death via diminished glucose uptake and ATP production in cholangiocarcinoma cells

Reversine is a selective inhibitor of mitotic kinase monopolar spindle 1 (MPS1) and has been reported as an anticancer agent in various cancers. The effects of reversine on bile duct cancer, cholangiocarcinoma (CCA), a lethal cancer in Northeastern Thailand, were investigated. This study reports that reversine inhibited cell proliferation of CCA cell lines in dose- and time-dependent manners but had less inhibitory effect on an immortalized cholangiocyte cell line. Reversine also triggered apoptotic cell death by decreasing anti-apoptotic proteins, Bcl-XL and Mcl-1, increasing Bax pro-apoptotic protein and activating caspase-3 activity. Moreover, reversine induced autophagic cell death by increasing LC3-II and Beclin 1 while decreasing p62. Reversine activated autophagy via the AKT signaling pathway. Additionally, this study demonstrated for the first time that reversine could diminish the expression of Hypoxia-Inducible Factor 1- alpha (HIF-1α) and glucose transporter 1 (GLUT1), resulting in a reduction of glucose uptake and energy production in CCA cell lines. These findings suggest that reversine could be a good candidate as an alternative or supplementary drug for CCA treatment.

An internal class III PDZ binding motif in HPV16 E6* protein is required for Dlg degradation activity

BACKGROUND

A splice product of the E6 oncoprotein, E6*, is found in cells infected with HPV associated with a high-risk for cervical cancer. Both E6* and E6 promote Dlg degradation, considered a contributing factor for the tumorigenic potential of high-risk HPVs. The full-length E6 utilizes a conserved PDZ binding motif (PBM) at the extreme C-terminus to promote Dlg degradation. In contrast, this PBM is absent in E6*.

METHODS

We performed western blot analysis, site-directed mutagenesis and co-immunoprecipitation to identify the key elements required for Dlg degradation activity of high-risk HPVE6*, using HPV16E6* as a model.

RESULTS

Our data indicate that only one of the two internal putative class III PBMs, located between amino acids 24-27 (HDII) of HPV16E6*, was required to facilitate degradation of Dlg protein. Substitution of the two consensus residues in this region (D25 and I27) to glycine greatly diminished activity. Whereas substitution of the two conserved residues in the putative internal class I PBM (amino acids 16-19) or the second putative class III PBM (amino acids 28-31) was without effect. Interestingly, HPV66E6* which does not promote Dlg degradation can be converted into a form capable of facilitating Dlg degradation through the insertion of nine amino acids (20-28) containing the class III PBM from HPV16E6*. HPV16E6*-induced Dlg degradation appeared independent of E6AP.

CONCLUSIONS

The internal class III PBM of HPV16E6*I required for Dlg degradation is identified.

GENERAL SIGNIFICANCE

This study highlights that a novel class III PBM as the domain responsible for Dlg degradation activity in high-risk HPVE6*.

High Monopolar Spindle 1 Is Associated with Short Survival of Cholangiocarcinoma Patients and Enhances the Progression Via AKT and STAT3 Signaling Pathways

Cholangiocarcinoma (CCA) is a malignancy of the bile duct epithelium. The major problems of this cancer are late diagnosis and a high rate of metastasis. CCA patients in advanced stages have poor survival and cannot be cured with surgery. Therefore, targeting molecules involved in the metastatic process may be an effective CCA treatment. Monopolar spindle 1 (MPS1) is a kinase protein that controls the spindle assemble checkpoint in mitosis. It is overexpressed in proliferating cells and various cancers. The functional roles of MPS1 in CCA progression have not been investigated. The aims of this study were to examine the roles and molecular mechanisms of MPS1 in CCA progression. Immunohistochemistry results showed that MPS1 was up-regulated in carcinogenesis of CCA in a hamster model, and positive expression of MPS1 in human CCA tissues was correlated to short survival of CCA patients (n = 185). Small interfering RNA (siRNA)-induced knockdown of MPS1 expression reduced cell proliferation via G2/M arrest, colony formation, migration, and invasion. Moreover, MPS1 controlled epithelial to mesenchymal transition (EMT)-mediated migration via AKT and STAT3 signaling transductions. MPS1 was also involved in MMPs-dependent invasion of CCA cell lines. The current research highlights for the first time that MPS1 has an essential role in promoting the progression of CCA via AKT and STAT3 signaling pathways and could be an attractive target for metastatic CCA treatment.

Expression of FOXO4 Inhibits Cholangiocarcinoma Cell Proliferation In Vitro via Induction of G0/G1 Arrest

BACKGROUND/AIM

Forkhead box O4 (FOXO4) has been demonstrated to be a tumor suppressor and proposed as target for treatment of a variety of cancer types. However, the role of FOXO4 in cholangiocarcinoma (CCA), a dangerous cancer of bile-duct epithelium, has rarely been explored.

MATERIALS AND METHODS

The proliferative rate of CCA cell lines KKU-213B, KKU-055 and KKK-D068 was investigated using the sulforhodamine B (SRB) assay. Levels of FOXO4, cyclin E1 (CCNE1), CCNE2, cyclin-dependent kinase 2 (CDK2) and cell division cycle 25A (CDC25A) expression were measured using reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR). The cell-cycle profile was explored using flow cytometry.

RESULTS

The SRB assay demonstrated that KKU-213B expressed low levels of FOXO4 but its proliferative rate was highest of all cell lines tested. Interestingly, ectopic expression of FOXO4 significantly suppressed proliferation of KKU-213B cells. Cell-cycle analysis revealed that the cell population in the G₀/G₁ phase was significantly higher in FOXO4-transfected KKU-213B cells than in controls. RT-qPCR analysis demonstrated that the levels of expression of genes that play a role in the G₁/S transition, namely CCNE1, CCNE2, CDK2 and CDC25A, were significantly lower in FOXO4-transfected KKU-213B cells compared to controls.

CONCLUSION

FOXO4 suppressed CCA cell proliferation partly via down-regulating the expression of genes involved in the G₁/S transition, leading to G₀/G₁ arrest. Our findings suggest that induction of FOXO4 expression might be an alternative approach for the treatment of CCA.

High level of interleukin-33 in cancer cells and cancer-associated fibroblasts correlates with good prognosis and suppressed migration in cholangiocarcinoma

Interleukin 33 (IL-33) promotes cholangiocarcinoma (CCA) genesis in a mouse model, however, its function in human CCA has not been clearly understood. This study was aimed to investigate IL-33 level in CCA tissues and its clinicopathological correlations. The results revealed that IL-33 was found in both cancer cells and stromal cancer-associated fibroblast (CAFs) staining patterns which were divided into high (CH) and low level (CL) in cancer cells; and presence (FP) and absence (FA) in CAFs. Kaplan-Meier analysis showed that patients in the CL group were significantly correlated with a short 2-year survival time (P = 0.027). The CL/FP group had a shorter survival time compared to the other groups with statistical significance for 2-year (P = 0.030) and 5-year (P = 0.023) survivals. In contrast, CH/FP patients had significantly greater 2-year (P = 0.003) and 5-year (P = 0.003) survivals. Univariate and multivariate analysis confirmed that CL/FP was a significantly independent risk factor whereas CH/FP was a significant protective factor in CCA patients. High IL-33 expressing CCA cells had low migration, but they showed increased migration when IL-33 expression was knocked down. The low level of recombinant human IL-33 (rhIL-33) (0.002 - 2 ng/ml) could promote CCA cell migration, in contrast to the suppressive effect at a high dose (20 - 200 ng/ml). In conclusion, the combination of high IL-33 level in cancer cells and CAFs is a potentially good prognosis marker in CCA patients. The in vitro migration suppressive effect of IL-33 may be the potential mechanism supporting its role as a good prognostic marker in CCA patients. The obtained results strengthen IL-33 as a promising predictor and therapeutic target for CCA.

Chromomycin A3 suppresses cholangiocarcinoma growth by induction of S phase cell cycle arrest and suppression of Sp1‑related anti‑apoptotic proteins

Cholangiocarcinoma (CCA) is a cancer of biliary epithelium. Late diagnosis and resistance to conventional chemotherapy are the major obstacles in CCA treatment. Increased expression of anti‑apoptotic proteins are observed in CCA, which might confer chemoresistance. Thus, modulations of anti‑apoptotic proteins leading to apoptotic induction is the focus of this study. Chromomycin A3 (CMA3), an anthraquinone glycoside‑mithramycin A analog, was selected. CMA3 strongly binds to GC‑rich regions in DNA, where specificity protein 1 (Sp1), a common transcription factor of apoptosis‑related proteins, is preferentially bounded. The effects of CMA3 on anti‑proliferation, cell cycle arrest and apoptosis induction in CCA cells were demonstrated by MTT assay, flow cytometry and western blot analysis. The results showed CMA3 suppressed cell proliferation in vitro in the nM range. At low doses, CMA3 inhibited cell cycle progression at S phase, while it promoted caspase‑dependent apoptosis at higher doses. CMA3 induced effects of apoptosis were through the suppression of Sp1‑related anti‑apoptotic proteins, FADD‑like IL‑1β‑converting enzyme‑inhibitory protein, myeloid cell leukemia‑1, X‑linked inhibitor of apoptosis protein, cellular inhibitor of apoptosis and survivin. The anti‑CCA effects of CMA3 were confirmed in the xenograft mouse model. CMA3 retarded xenograft tumor growth. Taken together, CMA3 induced apoptosis in CCA cells by diminishing the Sp1‑related anti‑apoptotic proteins is demonstrated. CMA3 might be useful as a chemosensitizing agent.

Functional and genetic characterization of three cell lines derived from a single tumor of an Opisthorchis viverrini-associated cholangiocarcinoma patient

Three cholangiocarcinoma (CCA) cell line-formerly named, M156, M213 and M214 have been intensively used with discrepancy of their tumor origins. They were assumed to be originated from three different donors without authentication. To verify the origins of these cell lines, the short tandem repeat (STR) analysis of the currently used cell lines, the cell stocks from the establisher and the primary tumor of a CCA patient were performed. Their phenotypic and genotypic originality were compared. The currently used 3 CCA cell lines exhibited similar STR as CCA patient ID-M213 indicating the same origin of these cells. The cell stocks from the establisher, however, revealed the same STR of M213 and M214 cells, but not M156. The misidentification of M214 and M156 is probably due to the mislabeling and cross-contamination of M213 cells during culture. These currently used cell lines were renamed as KKU-213A, -213B and -213C, for the formerly M213, M214 and M156 cells, respectively. These cell lines were established from a male with an intrahepatic mass-forming CCA stage-4B. The tumor was an adenosquamous carcinoma with the liver fluke ova granuloma in evidence. All cell lines had positive CK19 with differential CA19-9 expression. They exhibited aneuploidy karyotypes, distinct cell morphology, cell growth, cytogenetic characteristic and progressive phenotypes. KKU-213C formed a adenosquamous carcinoma, whereas KKU-213A and KKU-213B formed poorly- and well-differentiated squamous cell carcinomas in xenografted mice. mRNA microarray revealed different expression profiles among these three cell lines. The three cell lines have unique characteristics and may resemble the heterogeneity of tumor origin.

Novel Analytical Platform For Robust Identification of Cell Migration Inhibitors

Wound healing assay is a simple and cost-effective in vitro assay for assessing therapeutic impacts on cell migration. Its key limitation is the possible confoundment by other cellular phenotypes, causing misinterpretation of the experimental outcome. In this study, we attempted to address this problem by developing a simple analytical approach for scoring therapeutic influences on both cell migration and cell death, while normalizing the influence of cell growth using Mitomycin C pre-treatment. By carefully mapping the relationship between cell death and wound closure rate, contribution of cell death and cell migration on the observed wound closure delay can be quantitatively separated at all drug dosing. We showed that both intrinsic cell motility difference and extrinsic factors such as cell seeding density can significantly affect final interpretation of therapeutic impacts on cellular phenotypes. Such discrepancy can be rectified by using the actual wound closure time of each treatment condition for the calculation of phenotypic scores. Finally, we demonstrated a screen for strong pharmaceutical inhibitors of cell migration in cholangiocarcinoma cell lines. Our approach enables accurate scoring of both migrastatic and cytotoxic effects, and can be easily implemented for high-throughput drug screening.

CD147 augmented monocarboxylate transporter-1/4 expression through modulation of the Akt-FoxO3-NF-κB pathway promotes cholangiocarcinoma migration and invasion

PURPOSE

Cholangiocarcinoma (CCA) is an aggressive type of cancer. The major obstacles for treatment are its late presentation and the occurrence metastases. Targeting the metastatic process may serve as a treatment option. CD147 is a membrane protein that promotes CCA metastasis. High lactate levels in CCA are predicted to result from lactate dehydrogenase A expression and sensitivity to monocarboxylate transporter (MCT) inhibitors. An involvement of CD147 in MCT maturation has been reported, but the exact role of MCT in CCA is not clear. Here, we aimed to assess the mechanism of CD147-promoted CCA progression through MCT regulation.

METHODS

The expression levels of CD147 and MCT-1/4 in human CCA tissues were determined by immunohistochemistry. Two CD147 knockout (CD147 KO) CCA cell (KKU-213) clones were established using the CRISPR/Cas9 system. Cell migration and invasion were determined using a Boyden chamber assay. Temporal protein levels were modified by siRNA, specific inhibitors and/or activators. The expression of target proteins was determined using Western blot analyses.

RESULTS

CD147 and MCT-1/4 were found to be overexpressed in CCA tissues compared to normal bile duct tissues. In addition, we found that CD147 knockdown significantly alleviated CCA cell migration and invasion, concomitant with decreased pAkt, pFoxO3, pNF-κB (pp65) and MCT-1/4 levels. Conversely, we found that FoxO3 knockdown led to recovered migration/invasion abilities and increased pp65 and MCT-1/4 expression levels. The involvement of Akt in the regulation of MCT-1/4 expression through CD147 was established by inhibition and activation of Akt phosphorylation.

CONCLUSION

Our data indicate that CD147 promotes the malignant progression of CCA cells by activating the Akt-FoxO3-NF-κB-MCT-1/4 axis. As such, CD147 may serve as a possible target for advanced CCA treatment.

Dependency of Cholangiocarcinoma on Cyclin D-Dependent Kinase Activity

Cholangiocarcinoma (CCA) is a bile duct cancer with a very poor prognosis. Currently, there is no effective pharmacological treatment available for it. We showed that CCA ubiquitously relies on cyclin-dependent kinases 4 and 6 (CDK4/6) activity to proliferate. Primary CCA tissues express high levels of cyclin D1 and the specific marker of CDK4/6 activity, phospho-RB Ser780. Treatment of a 15-CCA cell line collection by pharmacological CDK4/6 inhibitors leads to reduced numbers of cells in the S-phase and senescence in most of the CCA cell lines. We found that expression of retinoblastoma protein (pRB) is required for activity of the CDK4/6 inhibitor, and that loss of pRB conferred CDK4/6 inhibitor-drug resistance. We also identified that sensitivity of CCA to CDK4/6 inhibition is associated with the activated KRAS signature. Effectiveness of CDK4/6 inhibition for CCA was confirmed in the three-dimensional spheroid-, xenograft-, and patient-derived xenograft models. Last, we identified a list of genes whose expressions can be used to predict response to the CDK4/6 inhibitor. Conclusion: We investigated a ubiquitous dependency of CCA on CDK4/6 activity and the universal response to CDK4/6 inhibition. We propose that the CDK4/6-pRB pathway is a suitable therapeutic target for CCA treatment.

Application of Highly Immunocompromised Mice for the Establishment of Patient-Derived Xenograft (PDX) Models

Patient-derived xenograft (PDX) models are created by engraftment of patient tumor tissues into immunocompetent mice. Since a PDX model retains the characteristics of the primary patient tumor including gene expression profiles and drug responses, it has become the most reliable in vivo human cancer model. The engraftment rate increases with the introduction of Non-obese diabetic Severe combined immunodeficiency (NOD/SCID)-based immunocompromised mice, especially the NK-deficient NOD strains NOD/SCID/interleukin-2 receptor gamma chain(IL2Rγ)null (NOG/NSG) and NOD/SCID/Jak3(Janus kinase 3)null (NOJ). Success rates differ with tumor origin: gastrointestinal tumors acquire a higher engraftment rate, while the rate is lower for breast cancers. Subcutaneous transplantation is the most popular method to establish PDX, but some tumors require specific environments, e.g., orthotropic or renal capsule transplantation. Human hormone treatment is necessary to establish hormone-dependent cancers such as prostate and breast cancers. PDX mice with human hematopoietic and immune systems (humanized PDX) are powerful tools for the analysis of tumor-immune system interaction and evaluation of immunotherapy response. A PDX biobank equipped with patients' clinical data, gene-expression patterns, mutational statuses, tumor tissue architects, and drug responsiveness will be an authoritative resource for developing specific tumor biomarkers for chemotherapeutic predictions, creating individualized therapy, and establishing precise cancer medicine.

Antitumor effects of flavopiridol, a cyclin-dependent kinase inhibitor, on human cholangiocarcinoma in vitro and in an in vivo xenograft model

Flavopiridol, a pan-cyclin-dependent kinase (CDK) inhibitor, was recently identified as an effective antitumor agent for several cancers. We investigated the antitumor effect of flavopiridol on cholangiocarcinoma (CCA), in vitro and in vivo. A methylthiotetrazole assay revealed that the proliferation of certain CCA cells was inhibited by flavopiridol, which induced the caspase-dependent apoptosis of CCA cells. Although increased cell cycle arrest was observed at the G2/M phase, caspase activation occurred earlier than 24 h, indicating that caspase-dependent apoptosis is the major pathway for the suppression of cell proliferation. Flavopiridol potently reduced the CCA tumor growth in a xenograft model without observable adverse effects. These findings indicated that flavopiridol could be a potential antitumor agent for the treatment of CCA.

O-GlcNAc-induced nuclear translocation of hnRNP-K is associated with progression and metastasis of cholangiocarcinoma

O‐GlcNAcylation is a key post‐translational modification that modifies the functions of proteins. Associations between O‐GlcNAcylation, shorter survival of cholangiocarcinoma (CCA) patients, and increased migration/invasion of CCA cell lines have been reported. However, the specific O‐GlcNAcylated proteins (OGPs) that participate in promotion of CCA progression are poorly understood. OGPs were isolated from human CCA cell lines, KKU‐213 and KKU‐214, using a click chemistry‐based enzymatic labeling system, identified using LC‐MS/MS, and searched against an OGP database. From the proteomic analysis, a total of 21 OGPs related to cancer progression were identified, of which 12 have not been previously reported. Among these, hnRNP‐K, a multifaceted RNA‐ and DNA‐binding protein known as a pre‐mRNA‐binding protein, was one of the most abundantly expressed, suggesting its involvement in CCA progression. O‐GlcNAcylation of hnRNP‐K was further verified by anti‐OGP/anti‐hnRNP‐K immunoprecipitations and sWGA pull‐down assays. The perpetuation of CCA by hnRNP‐K was evaluated using siRNA, which revealed modulation of cyclin D1, XIAP, EMT markers, and MMP2 and MMP7 expression. In native CCA cells, hnRNP‐K was primarily localized in the nucleus; however, when O‐GlcNAcylation was suppressed, hnRNP‐K was retained in the cytoplasm. These data signify an association between nuclear accumulation of hnRNP‐K and the migratory capabilities of CCA cells. In human CCA tissues, expression of nuclear hnRNP‐K was positively correlated with high O‐GlcNAcylation levels, metastatic stage, and shorter survival of CCA patients. This study demonstrates the significance of O‐GlcNAcylation on the nuclear translocation of hnRNP‐K and its impact on the progression of CCA.

FOXM1 modulates 5-fluorouracil sensitivity in cholangiocarcinoma through thymidylate synthase (TYMS): implications of FOXM1-TYMS axis uncoupling in 5-FU resistance

Fluorouracil (5-FU) is the first-line chemotherapeutic drug for cholangiocarcinoma (CCA), but its efficacy has been compromised by the development of resistance. Development of 5-FU resistance is associated with elevated expression of its cellular target, thymidylate synthase (TYMS). E2F1 transcription factor has previously been shown to modulate the expression of FOXM1 and TYMS. Immunohistochemical (IHC) analysis revealed a strong correlated upregulation of FOXM1 (78%) and TYMS (48%) expression at the protein levels in CCA tissues. In agreement, RT-qPCR and western blot analyses of four human CCA cell lines at the baseline level and in response to high doses of 5-FU revealed good correlations between FOXM1 and TYMS expression in the CCA cell lines tested, except for the highly 5-FU-resistant HuCCA cells. Consistently, siRNA-mediated knockdown of FOXM1 reduced the clonogenicity and TYMS expression in the relatively sensitive KKU-D131 but not in the highly resistant HuCCA cells. Interestingly, silencing of TYMS sensitized both KKU-D131 and HuCCA to 5-FU treatment, suggesting that resistance to very high levels of 5-FU is due to the inability of the genotoxic sensor FOXM1 to modulate TYMS expression. Consistently, ChIP analysis revealed that FOXM1 binds efficiently to the TYMS promoter and modulates TYMS expression at the promoter level upon 5-FU treatment in KKU-D131 but not in HuCCA cells. In addition, E2F1 expression did not correlate with either FOXM1 or TYMS expression and E2F1 depletion has no effects on the clonogenicity and TYMS expression in the CCA cells. In conclusion, our data show that FOXM1 regulates TYMS expression to modulate 5-FU resistance in CCA and that severe 5-FU resistance can be caused by the uncoupling of the regulation of TYMS by FOXM1. Our findings suggest that the FOXM1–TYMS axis can be a novel diagnostic, predictive and prognostic marker as well as a therapeutic target for CCA.

Artesunate and chloroquine induce cytotoxic activity on cholangiocarcinoma cells via different cell death mechanisms

Chemotherapy for cholangiocarcinoma (CCA) is not quite successful. In this study, we revisited the possibility of artesunate (ART) and chloroquine (CQ), the antimalarial drugs, as therapeutic agents against CCA. The possible mechanisms of these drugs to exert cytotoxicity on CCA cells were also explored. The effects of ART and CQ on proliferation and death patterns of two CCA cell lines, KKU-214 and its highly metastatic subtype KKU-214L5, were examined using water soluble tetrazolium (WST) assay and time-lapse photometry, respectively. To differentiate and verify the death patterns between necrosis and apoptosis, lactate dehydrogenase (LDH) release, and caspase 3 activity were measured. CellROXTM green reagent staining method was used to assess reactive oxygen species (ROS) production in ART- and CQ-treated cells. ART and CQ significantly inhibited proliferation of CCA cells. Both drugs kill malarial parasites via similar mechanism depending on ROS formation, however, ART induced necrotic cell death and CQ induced apoptotic cell death in CCA cells. ART induced LDH release, whereas CQ activated caspase 3, confirming induction of necrotic and apoptotic cell deaths by ART and CQ, respectively. ART treatment induced higher ROS production than CQ. ART and CQ induce CCA cells death via different death pathways. ART should be suitable for necrosis-sensitive CCA, whereas CQ is more suitable for apoptosis-sensitive CCA.

O-GlcNAcylation mediates metastasis of cholangiocarcinoma through FOXO3 and MAN1A1

The leading cause of death in cancer patients is metastasis, for which an effective treatment is still necessary. During metastasis, cancer cells aberrantly express several glycans that are correlated with poor patient outcome. This study was aimed toward exploring the effects of O-GlcNAcylation on membranous N-glycans that are associated with the progression of cholangiocarcinoma (CCA). Global O-GlcNAcylation in CCA cells was depleted using specific siRNA against O-GlcNAc transferase (OGT), which transfers GlcNAc to the acceptor proteins. Using an HPLC-Chip/Time-of-Flight (Chip/TOF) MS system, the N-glycans associated with O-GlcNAcylation were identified by comparing the membranous N-glycans of siOGT-treated cells with those of scramble siRNA-treated cells. In parallel, the membranous N-glycans of the parental cells (KKU-213 and KKU-214) were compared with those of the highly metastatic cells (KKU-213L5 and KKU-214L5). Together, these data revealed that high mannose (Hex₉HexNAc₂) and biantennary complex (Hex₅HexNAc₄Fuc₁NeuAc₁) N-linked glycans correlated positively with metastasis. We subsequently demonstrate that suppression of O-GlcNAcylation decreased the expression of these two N-glycans, suggesting that O-GlcNAcylation mediates their levels in CCA. In addition, the ability of highly metastatic cells to migrate and invade was reduced by the presence of Pisum Sativum Agglutinin (PSA), a mannose-specific lectin, further indicating the association of high mannose type N-glycans with CCA metastasis. The molecular mechanism of O-GlcNAc-mediated progression of CCA was shown to proceed via a series of signaling events, involving the activation of Akt/Erk (i), an increase in FOXO3 phosphorylation (ii), which results in the reduction of MAN1A1 expression (iii) and thus the accumulation of Hex₉HexNAc₂ N-glycans (iv). This study demonstrates for the first time the association between O-GlcNAcylation, high mannose type N-glycans, and the progression of CCA metastasis, suggesting a novel therapeutic target for treatment of metastatic CCA.

Anthocyanin complex exerts anti-cholangiocarcinoma activities and improves the efficacy of drug treatment in a gemcitabine-resistant cell line

Cholangiocarcinoma (CCA) is a deleterious bile duct tumor with poor prognosis and is relatively resistant to chemotherapy. Therefore, alternative or supplementary agents with anticancer and chemosensitizing activities may be useful for the treatment of CCA. A novel anthocyanin complex (AC) nanoparticle, developed from extracts of cobs of purple waxy corn and petals of blue butterfly pea, has exhibited chemopreventive potential in vivo. In the present study, the anti-CCA activities of AC and their underlying molecular mechanisms were investigated further in vitro using a CCA cell line (KKU213). The potential use of AC as a chemosensitizer was also evaluated in a gemcitabine-resistant CCA cell line (KKU214GemR). It was demonstrated that AC treatment suppressed proliferation of KKU213 CCA cells in dose- and time-dependent manners. AC treatment also induced apoptosis and mitochondrial superoxide production, decreased clonogenicity of CCA cells, and downregulated forkhead box protein M1 (FOXM1), nuclear factor-κB (NF-κB) and pro-survival protein B-cell lymphoma-2 (Bcl-2). The expression of endoplasmic reticulum (ER) stress-response proteins, including protein kinase RNA-like ER kinase, phosphorylated eIF2α, eukaryotic initiation factor 2α and activating transcription factor 4, also decreased following AC treatment. It was also identified that AC treatment inhibited KKU214GemR cell proliferation in dose- and time-dependent manners. Co-treatment of KKU214GemR cells with low doses of AC together with gemcitabine significantly enhanced efficacy of the latter against this cell line. Therefore, it is suggested that AC treatment is cytotoxic to KKU213 cells, possibly via downregulation of FOXM1, NF-κB, Bcl-2 and the ER stress response, and by induction of mitochondrial superoxide production. AC also sensitizes KKU214GemR to gemcitabine treatment, which may have potential for overcoming drug resistance of CCA.

The microRNA-15a-PAI-2 axis in cholangiocarcinoma-associated fibroblasts promotes migration of cancer cells

BACKGROUND

Cholangiocarcinoma (CCA) has an abundance of tumor stroma which plays an important role in cancer progression via tumor-promoting signals. This study aims to explore the microRNA (miRNA) profile of CCA-associated fibroblasts (CCFs) and the roles of any identified miRNAs in CCA progression.

METHODS

miRNA expression profiles of CCFs and normal skin fibroblasts were compared by microarray. Identified downregulated miRNAs and their target genes were confirmed by real-time PCR. Their binding was confirmed by a luciferase reporter assay. The effects of conditioned-media (CM) of miRNA mimic- and antagonist-transfected CCFs were tested in CCA migration in wound healing assays. Finally, the levels of miRNA and their target genes were examined by real-time PCR and immunohistochemistry in clinical CCA samples.

RESULTS

miR-15a was identified as a downregulated miRNA in CCFs. Moreover, PAI-2 was identified as a novel target gene of miR-15a. Recombinant PAI-2 promoted migration of CCA cells. Moreover, CM from miR-15a mimic-transfected CCFs suppressed migration of CCA cells. Lower expression of miR-15a and higher expression of PAI-2 were observed in human CCA samples compared with normal liver tissues. Importantly, PAI-2 expression correlated with poor prognosis in CCA patients.

CONCLUSIONS

These findings highlight the miR-15a/PAI-2 axis as a potential therapeutic target in CCA patients.

Clinical significance of GalNAcylated glycans in cholangiocarcinoma: Values for diagnosis and prognosis

Cancer cells exhibited the aberrant cancer-associated glycans that are potential biomarkers for diagnosis and monitoring of the cancer. In this study, Sophora japonica agglutinin (SJA) was used to detect SJA-specific N-acetylgalactosamine-associated glycans (SNAG) in liver tissues and sera from cholangiocarcinoma (CCA) patients. Whether SNAG could be the diagnostic and prognostic markers for CCA was evaluated. SJA-histochemistry revealed that SNAG was undetec2 in normal bile ducts but was highly expressed in hyperplastic/dysplastic bile ducts and CCA. SNAG was negative in hepatocytes and hepatoma tissues indicating SNAG as a differential marker of CCA and hepatoma. SJA-histochemistry of CCA hamster tissues revealed the involvement of SNAG in the early pathogenesis of bile duct epithelia and CCA development. A SJA-based ELISA was successfully developed to determine SNAG in serum. Serum-SNAG from CCA patients was significantly higher than those of non-CCA control groups with the diagnostic values of 59.5% sensitivity and 73.6% specificity, comparable to those of serum CA19-9. High levels of serum SNAG (≥69AU/ml) indicated poor survival of CCA patients. Taken together, SNAG was first demonstrated here to be a glycobiomarker for diagnosis and prognosis of CCA. Association of SNAG with pathogenesis of bile ducts and CCA development were suggested. (198).

Inhibitory Effect of Aspirin on Cholangiocarcinoma Cells

Aspirin and other non-steroidal anti-inflammatory drugs reduce the risk of cancer due to their anti-proliferative and apoptotic effects, which are the important mechanisms for their anti-tumor activity. Here, the effect of aspirin on human cholangiocarcinoma cells (KKU-214) and the underlying mechanisms of its action were explored. Cell proliferation was measured by sulforhodamine B (SRB) assay, while cell cycle distribution and apoptosis were determined by flow cytometry. Western blotting was used to explore protein expression underlying molecular mechanisms of anti-cancer treatment of aspirin. Aspirin reduced cell proliferation in a dose- and time-dependent manner, and altered the cell cycle phase distribution of KKU-214 cells by increasing the proportion of cells in the G0/G1 phase and reducing the proportion in the S and G2/M phases. Consistent with its effect on the cell cycle, aspirin also reduced the expression of cyclin D1 and cyclin-dependent kinase 4 (Cdk-4), which are important for G0/G1 cell cycle progression. Treatment with aspirin led to increased induction of apoptosis in a dose-dependent manner. Further analysis of the mechanism underlying the effect of this drug showed that aspirin induced the expression of the tumor-suppressor protein p53 while inhibiting the anti-apoptotic protein B-cell lymphoma-2 (Bcl-2). Correspondingly, the activation of caspase-9 and -3 was also increased. These findings suggest that aspirin causes cell cycle arrest and apoptosis, both of which could contribute to its anti-proliferative effect.

Upregulation of CD147 Promotes Metastasis of Cholangiocarcinoma by Modulating the Epithelial-to-Mesenchymal Transitional Process

CD147 is a transmembrane protein that can induce the expression and activity of matrix metalloproteinases (MMPs). Expression of CD147 has been shown to potentiate cell migration, invasion, and metastasis of cancer. In this study, the critical role of CD147 in metastasis was elucidated using CD147-overexpressing cholangiocarcinoma (CCA) cells in vitro and in vivo. The molecular mechanism, demonstrated herein, supported the hypothesis that metastasis increased in CD147-overexpressing cells. Five CD147-overexpressing clones (Ex-CD147) were established from a low CD147-expressing CCA cell line, KKU-055, using lentivirus containing pReceiver-Lenti-CD147. The metastatic capability was determined using the tail vein injection mouse model and an in vitro 3D invasion assay. Liver colonization was assessed using anti-HLA class I immunohistochemistry. Adhesion abilities, cytoskeletal arrangements, MMP activities, the expressions of adhesion molecules, and epithelial-mesenchymal transitional markers were analyzed. All Ex-CD147 clones exhibited a high CD147 expression and high liver colonization in the tail vein-injected mouse model, whereas parental cells lacked this ability. Ex-CD147 clones exhibited metastatic phenotypes (i.e., an increase in F-actin rearrangement) and cell invasion and a decrease in cell adhesion. The molecular mechanisms were shown to be via the induction of MMP-2 activity and enhancement of epithelial-mesenchymal transitions. An increase in mesenchymal markers Slug, vimentin, and N-cadherin, and a decrease in epithelial markers E-cadherin and claudin-1, together with suppression of the adhesion molecule ICAM-1, were observed in the Ex-CD147 clones. Moreover, suppression of CD147 expression using siCD147 in two CCA cell lines with high CD147 expression significantly decreased cell migration and invasion of these CCA cells. These findings emphasize the essential role of CD147 in CCA metastasis and suggest CD147 as a promising target for the effective treatment of CCA.

Activation of Vimentin Is Critical to Promote a Metastatic Potential of Cholangiocarcinoma Cells

Cholangiocarcinoma (CCA) is a highly metastatic tumor, and the majority of patients with CCA have a short survival time because there are no available effective treatments. Hence, a better understanding regarding CCA metastasis may provide an opportunity to improve the strategies for treatment. A comparison study between the highly metastatic cells and their parental cells is an approach to uncover the molecular mechanisms underlying the metastatic process. In the present study, a lung metastatic CCA cell line, KKU-214L5, was established by the in vivo selection of the tail vein-injected mouse model. KKU-214L5 cells possessed mesenchymal spindle-like morphology with higher migration and invasion abilities in vitro than the parental cells (KKU-214). KKU-214L5 also exhibited extremely aggressive lung colonization in the tail vein-injected metastatic model. Epithelial–mesenchymal transition (EMT) was clearly observed in KKU-214L5 cells. Significant downregulation of epithelial markers (ZO-1 and claudin-1), with unique upregulation of E-cadherin and mesenchymal markers (vimentin, β-catenin, and slug), was observed in KKU-214L5. Increasing MMP-2 and MMP-9 activities and CD147 expression reflected the high invasion activity in KKU-214L5 cells. Suppression of vimentin using siRNA significantly decreased the migration and invasion capabilities of KKU-214L5 to almost the basal levels of the parental cells without any change on the expression levels of other EMT markers and the activities of MMPs. These results suggest that vimentin activation is essential to potentiate the metastatic characters of CCA cells, and suppression of vimentin expression could be a potential strategy to improve the treatment of CCA, a highly metastatic cancer.

High glucose levels boost the aggressiveness of highly metastatic cholangiocarcinoma cells via O-GlcNAcylation

Increased glucose utilization is a feature of cancer cells to support cell survival, proliferation, and metastasis. An association between diabetes mellitus and cancer progression was previously demonstrated in cancers including cholangiocarcinoma (CCA). This study was aimed to determine the effects of high glucose on protein O-GlcNAcylation and metastatic potentials of CCA cells. Two pairs each of the parental low metastatic and highly metastatic CCA sublines were cultured in normal (5.6 mM) or high (25 mM) glucose media. The migration and invasion abilities were determined and underlying mechanisms were explored. Results revealed that high glucose promoted migration and invasion of CCA cells that were more pronounced in the highly metastatic sublines. Concomitantly, high glucose increased global O-GlcNAcylated proteins, the expressions of vimentin, hexokinase, glucosamine-fructose-6-phosphate amidotransferase (GFAT) and O-GlcNAc transferase of CCA cells. The glucose level that promoted migration/invasion was shown to be potentiated by the induction of GFAT, O-GlcNAcylation and an increase of O-GlcNAcylated vimentin and vimentin expression. Treatment with a GFAT inhibitor reduced global O-GlcNAcylated proteins, vimentin expression, and alleviated cell migration. Altogether, these results suggested the role of high glucose enhanced CCA metastasis via modulation of O-GlcNAcylation, through the expressions of GFAT and vimentin.

In Vitro and In Vivo Inhibitory Effects of α-Mangostin on Cholangiocarcinoma Cells and Allografts

We investigated the anti-cholangiocarcinoma effect of α-mangostin from Garcinia mangostana pericarp extract (GM) in a human cholangiocarcinoma (CCA) cell line and a hamster CCA allograft model. In vitro, human CCA cells were treated with GM at various concentrations and for different time periods; then cell-cycle arrest and apoptosis were evaluated using flow cytometry, and metastatic potential with wound healing assays. In vivo, hamster allografts were treated with GM, gemcitabine (positive control) and a placebo (negative control) for 1 month; tumor weight and volume were then determined. Histopathological features and immunostaining (CK19 and PCNA) characteristics were examined by microscopy. The present study found that α-mangostin could: inhibit CCA cell proliferation by inducing apoptosis through the mitochondrial pathway; induce G1 cell-cycle arrest; and inhibit metastasis. Moreover, α-mangostin could inhibit CCA growth, i.e. reduce tumor mass (weight and size) and alter CCA pathology, as evidenced by reduced positive staining for CK19 and PCNA. The present study thus suggested that α-mangostin is a promising anti-CCA compound whose ready availability in tropical countries might indicate use for prevention and treatment of CCA.

Thymosin β10 as a predictive biomarker of response to 5-fluorouracil chemotherapy in cholangiocarcinoma

 Introduction and aim. 5-Fluorouracil (5-FU) is the most commonly used chemotherapeutic drug in the treatment of cholangiocarcinoma (CCA). Since development of drug resistance to 5-FU in CCA patients is the primary cause of treatment failure, a better understanding of the mechanism of drug resistance of this cancer is essential to improve the efficacy of 5-FU in CCA therapy.

MATERIAL AND METHODS

A 5-FU resistant CCA cell line (M214-5FUR) for a comparative chemo-resistance study was established. Real time RT-PCR was used to determine gene expression levels. Cell cytotoxicity was measured by the MTT assay. Protein expression levels were detected by the immunofluorescene method.

RESULTS

It was found that 5-FU resistance was associated with the overexpression of T?10 in CCA cell lines. 5-FU treatment at various concentrations induced the expressions of T?10 and ABC transporters (ABCB1, ABCG2 ABCA3) in two CCA cell lines, KKU-M055 and KKU-M214. M214-5FUR, a 5-FU-resistant cell line, exhibited a 5-FU resistant phenotype with a 16-fold extremely high expression of T?10 and ABC transporters, as compared to the parental cells, KKU-M214. siRNA targeted to T?10 significantly reduced expression of ABC transporters tested in the M214-5FUR cells (P < 0.05).

CONCLUSIONS

The present novel findingsof T?10 connected with drug resistance as shown in this study provides a new insight for the therapeutic value of T?10 as a predictive biomarker of 5-FU chemoresistance. Inhibiting T?10 may be a valuable adjunct for suppression of ABC transporters and sensitizing chemotherapy treatment, especially 5-FU in CCA patients.

Repurposing cimetidine for cholangiocarcinoma: Antitumor effects in vitro and in vivo

Cimetidine is a histamine type-2 (H₂) receptor antagonist that has been demonstrated to have antitumor effects on various types of malignancy. However, its effect on cholangiocarcinoma (CCA), a chemotherapy-resistant bile duct tumor, has yet to be investigated. In the present study, the antitumor activity of cimetidine in vitro and in vivo was evaluated. A methylthiotetrazole assay revealed that the proliferation of certain CCA cell lines was inhibited by cimetidine, which induced the caspase-dependent apoptosis of CCA cells via suppression of the protein kinase B signaling pathway. Suppression of Akt phosphorylation, caspase-3, -8 and -9 activation, phosphotidylserine exposure determined by Annexin V binding assay and the presence of a sub-G1 population were demonstrated by western blotting and flow cytometry analysis. In a CCA xenograft mouse model cimetidine inhibited the growth of CCA cells without observable adverse effects. These results suggest that cimetidine has the potential to be an effective antitumor agent for the treatment of CCA.

Inhibition of NF-κB Activity Enhances Sensitivity to Anticancer Drugs in Cholangiocarcinoma Cells

Cholangiocarcinoma (CCA) is a dismal cancer. At present, there is no effective chemotherapeutic regimen for CCA. This may be due to the marked resistance of CCA to chemotherapy drugs, for which a mechanism remains unknown. Nuclear factor-κB (NF-κB) is constitutively activated in a variety of cancer cells, including CCA. It has been shown to play roles in growth, metastasis, and chemoresistance of cancer. In the present study, we examined whether NF-κB is involved in the chemoresistance of CCA and whether dehydroxymethylepoxyquinomicin (DHMEQ), an effective NF-κB inhibitor, can overcome the drug resistance of CCA. Two CCA cell lines, KKU-M213 and KKU-M214, were treated with DHMEQ and/or chemotherapeutic drugs. Cell viability, apoptosis, and the expressions of the ATP-binding cassette (ABC) transporters were compared. The combination of chemotherapy drugs, 5-fluorouracil, cisplatin, and doxorubicin, with DHMEQ significantly enhanced the cytotoxicity of all chemotherapeutic drugs compared to DHMEQ or drug alone. Furthermore, the mRNA level of ABCB1, a multidrug-resistant protein, was significantly decreased in the 5-fluorouracil combined with DHMEQ-treated cells. These findings suggest that the inhibition of NF-κB by DHMEQ enhanced the chemoresponsiveness of CCA cells, possibly by reducing the expression of ABC transporter. Inhibition of NF-κB may be a potential chemodrug-sensitizing strategy for chemoresistant cancer such as CCA.

Antitumor effect of forbesione isolated from Garcinia hanburyi on cholangiocarcinoma in vitro and in vivo

Cholangiocarcinoma (CCA) is a malignancy with no effective therapy and poor prognosis. Forbesione, a caged xanthone isolated from Garcinia hanburyi, has been reported to inhibit proliferation and to induce apoptosis in human CCA cell lines. The present study aimed to further explore the potential anticancer properties of forbesione by testing its effects against the hamster CCA cell line Ham-1 in vitro and in vivo. It was observed that forbesione inhibited the growth of Ham-1 cells in vitro and suppressed Ham-1 growth as allograft in hamsters by inducing cell cycle arrest at the S phase. This was mediated by decreasing the protein expression of cyclin E, cyclin A and cyclin-dependent kinase 2. In addition, increased expression of p21 and p27 was detected, which could possibly explain the reduced expression of proliferating cell nuclear antigen and of the bile duct cell marker cytokeratin 19 observed in forbesione-treated Ham-1 cells in vitro and in tumor tissues of forbesione-treated hamsters. Furthermore, forbesione induced apoptosis through multiple pathways. The death receptor pathway was activated by increased expression of Fas, Fas-associated death domain and activated caspase-3, along with decreased expression of procaspase-8 and procaspase-3. The mitochondrial pathway was driven by increased expression of B-cell lymphoma (Bcl)-2-like protein 4, activated caspase-9 and inhibitor of κB-α, along with decreased expression of Bcl-2, survivin, procaspase-9 and nuclear factor-κB/p65. The endoplasmic reticulum pathway was stimulated by increased expression of activated caspase-12 and decreased expression of procaspase-12. No side effects or toxicity were observed in forbesione-treated hamsters. Thus, forbesione is a potential drug candidate for cancer therapy that deserves further investigation.

Overexpression of lactate dehydrogenase A in cholangiocarcinoma is correlated with poor prognosis

Lactate dehydrogenase A (LDHA), a key metabolic enzyme, plays a crucial role in the final step of anaerobic glycolysis. Overexpression of LDHA is observed in many human malignancies in association with tumor progression. The purpose of this study was to investigate LDHA expression pattern during carcinogenesis, its clinico-pathological association, and evaluate the prognostic value of LDHA in CCA patients. LDHA expression was investigated using immunohistochemistry technique in both hamster- (n=60) and human-CCA tissues (n=82). Plasma LDH from healthy control (n=40) and CCA patients (n=29) were determined using an enzymatic based assay. The association of LDHA expression with clinico-pathological findings and prognostic value were evaluated by statistical analysis. In the CCA hamster model, an increase of LDHA expression was associated with the progression of CCA-genesis. Higher LDHA overexpression was associated with shorter survival of CCA patients. Multivariate analysis indicated that LDHA expression including histological type and N stage of tumor were independent prognostic risk factor of patient's survival. However, there was no difference in plasma LDH level between CCA patients and healthy controls. LDHA expression is involved in cholangiocarcinogenesis. Overexpression of LDHA can be a marker of poor prognosis in CCA patients and it might be a potential target for CCA treatment.