Gut microbiota regulates the ALK5/NOX1 axis by altering glutamine metabolism to inhibit ferroptosis of intrahepatic cholangiocarcinoma cells.

Intrahepatic cholangiocarcinoma (ICC) is a kind of hepatobiliary tumor that is increasing in incidence and mortality. The gut microbiota plays a role in the onset and progression of cancer, however, the specific mechanism by which the gut microbiota acts on ICC remains unclear. In this study, feces and plasma from healthy controls and ICC patients were collected for 16S rRNA sequencing or metabolomics analysis. Gut microbiota analysis showed that gut microbiota abundance and biodiversity were altered in ICC patients compared with controls. Plasma metabolism analysis showed that the metabolite glutamine content of the ICC patient was significantly higher than that of the controls. KEGG pathway analysis showed that glutamine plays a vital role in ICC. In addition, the use of antibiotics in ICC animals further confirmed that changes in gut microbiota affect changes in glutamine. Further experiments showed that supplementation with glutamine inhibited ferroptosis and downregulated ALK5 and NOX1 expression in HuCCT1 cells. ALK5 overexpression or NOX1 overexpression increased NOX1, p53, PTGS2, ACSL4, LPCAT3, ROS, MDA and Fe2+ and decreased FTH1, SLC7A11 and GSH. Knockdown of NOX1 suppressed FIN56-induced ferroptosis. In vivo, supplementation with glutamine promoted tumor growth. Overexpression of ALK5 repressed tumor growth and induced ferroptosis in nude mice, which could be reversed by the addition of glutamine. Our results suggested that the gut microbiota altered glutamine metabolism to inhibit ferroptosis in ICC by regulating the ALK5/NOX1 axis.

The inhibition of ß-catenin activity by luteolin isolated from Paulownia flowers leads to growth arrest and apoptosis in cholangiocarcinoma.

To develop an inhibitor targeting the Wnt/ß-catenin signaling pathway, flavonoid monomer that can interact with ß-catenin was isolated from Paulownia flowers. Luteolin may form stable hydrogen bonds with ß-catenin by molecular docking. Fluorescence quenching analysis determined the physical interaction between luteolin and ß-catenin. The binding of luteolin to ß-catenin caused a loss of α-helical structure and induced a conformational change through circular dichroism spectroscopy. Luteolin inhibits the activity of the Wnt signaling, causing cholangiocarcinoma (CCA) cell cycle arrest in the G2/M phase, leading to cell apoptosis and inhibition of cell migration. In addition, transcriptome and proteomics analysis showed that the differentially expressed proteins were significantly enriched in the Wnt/ß-catenin pathway. ß-catenin protein in the nucleus was significantly decreased, while C-Myc and cyclin D1 in the CCA cells were significantly decreased after luteolin treatment. Additionally, activation of the Wnt/ß-catenin signaling reversed the inhibitory effect of luteolin on the migration of CCA cells. Therefore, luteolin can directly interact with ß-catenin and act as an inhibitor of ß-catenin, inhibiting proliferation and reducing the migration ability of CCA cells by inhibiting the Wnt/ß-catenin pathway. This study provides a scientific basis for the development of Wnt/ß-catenin pathway inhibitors and the prevention and treatment of CCA.

Triptolide inhibits intrahepatic cholangiocarcinoma growth by suppressing glycolysis via the AKT/mTOR pathway.

BACKGROUND: High levels of glycolysis supply large quantities of energy and biological macromolecular raw materials for cell proliferation. Triptolide (TP) is a kind of epoxy diterpene lactone extracted from the roots, flowers, leaves, or grains of the Celastraceae plant, Tripterygium wilfordii. TP has multiple biological activities, including anti-inflammatory, immunologic suppression, and anti-cancer effects. Nevertheless, it is little known regarding its anti-intrahepatic cholangiocarcinoma (ICC) growth, and the mechanism still require exploration. PURPOSE: This research explored the effect of TP on ICC growth and investigated whether TP inhibits glycolysis via the AKT/mTOR pathway. METHODS: Cell proliferation was analyzed by Cell Counting Kit-8 (CCK-8), clonogenic assay, and flow cytometry. The underlying molecular mechanism was identified by determining glucose consumption, ATP production, lactate production, hexokinase (HK) and pyruvate kinase (PK) activity, and Western blot analysis. A rapid ICC model of AKT/YapS127A oncogene coactivation in mice was used to clarify the effect of TP treatment on tumor growth and glycolysis. RESULTS: The results showed that TP treatment significantly inhibited ICC cell proliferation and glycolysis in a dose- and time-dependent manner(P < 0.05). Further analysis suggested that TP suppressed ICC cell glycolysis by targeting AKT/mTOR signaling. Additionally, we found that TP inhibits tumor growth and glycolysis in AKT/YapS127A mice(P < 0.05). CONCLUSION: Taken together, we revealed that TP suppressed ICC growth by suppressing glycolysis via the AKT/mTOR pathway and may provide a potential therapeutic target for ICC treatment.

Transmembrane protein KIRREL1 regulates Hippo signaling via a feedback loop and represents a therapeutic target in YAP/TAZ-active cancers.

The Hippo tumor-suppressor pathway is frequently dysregulated in human cancers and represents a therapeutic target. However, strategies targeting the mammalian Hippo pathway are limited because of the lack of a well-established cell-surface regulator. Here, we show that transmembrane protein KIRREL1, by interacting with both SAV1 and LATS1/2, promotes LATS1/2 activation by MST1/2 (Hippo kinases), and LATS1/2 activation, in turn, inhibits activity of YAP/TAZ oncoproteins. Conversely, YAP/TAZ directly induce the expression of KIRREL1 in a TEAD1-4-dependent manner. Indeed, KIRREL1 expression positively correlates with canonical YAP/TAZ target gene expression in clinical tumor specimens and predicts poor prognosis. Moreover, transgenic expression of KIRREL1 effectively blocks tumorigenesis in a mouse intrahepatic cholangiocarcinoma model, indicating a tumor-suppressor role of KIRREL1. Hence, KIRREL1 constitutes a negative feedback mechanism regulating the Hippo pathway and serves as a cell-surface marker and potential drug target in cancers with YAP/TAZ dependency.

In Silico Target Identification of Galangin, as an Herbal Flavonoid against Cholangiocarcinoma.

Cholangiocarcinoma (CCA) is a heterogenous group of malignancies in the bile duct, which proliferates aggressively. CCA is highly prevalent in Northeastern Thailand wherein it is associated with liver fluke infection, or Opisthorchis viverrini (OV). Most patients are diagnosed in advanced stages, when the cancer has metastasized or severely progressed, thereby limiting treatment options. Several studies investigate the effect of traditional Thai medicinal plants that may be potential therapeutic options in combating CCA. Galangin is one such herbal flavonoid that has medicinal properties and exhibits anti-tumor properties in various cancers. In this study, we investigate the role of Galangin in inhibiting cell proliferation, invasion, and migration in OV-infected CCA cell lines. We discovered that Galangin reduced cell viability and colony formation by inducing apoptosis in CCA cell lines in a dose-dependent manner. Further, Galangin also effectively inhibited invasion and migration in OV-infected CCA cells by reduction of MMP2 and MMP9 enzymatic activity. Additionally, using proteomics, we identified proteins affected post-treatment with Galangin. Enrichment analysis revealed that several kinase pathways were affected by Galangin, and the signature corroborated with that of small molecule kinase inhibitors. Hence, we identified putative targets of Galangin using an in silico approach which highlighted c-Met as candidate target. Galangin effectively inhibited c-Met phosphorylation and subsequent signaling in in vitro CCA cells. In addition, Galangin was able to inhibit HGF, a mediator of c-Met signaling, by suppressing HGF-stimulated invasion, as well as migration and MMP9 activity. This shows that Galangin can be a useful anti-metastatic therapeutic strategy in a subtype of CCA patients.

YY1-induced DLEU1/miR-149-5p Promotes Malignant Biological Behavior of Cholangiocarcinoma through Upregulating YAP1/TEAD2/SOX2.

Cholangiocarcinoma is an extremely malignant cancer with poor prognosis. Finding efficient diagnosis and treatment is the indispensable way to improve the prognosis of CCA patients. Therefore, exploring molecular abnormalities in CCA development is urgently needed. DLEU1 is a potential tumor-related lncRNA and abnormally expressed in multiple cancers. In this study, TCGA data analysis showed upregulation of DLEU1 expression in CCA. Furthermore, we confirmed that DLEU1 expression was increased in CCA tissues and cells compared with corresponding controls. Upregulated DLEU1 was related to poor clinicopathological characteristics. Functionally, silencing DLEU1 inhibited CCA proliferation, invasion, stemness maintenance and chemo-resistance, whereas amplifying DLEU1 promoted malignant biological behavior of CCA cells. Mechanistically, DLEU1 expression was transcriptionally facilitated by transcription factor YY1. Moreover, DLEU1 promoted oncogene YAP1 expression by functioning as a sponge to competitively bind to miR-149-5p. YAP1 promoted CCA proliferation, invasion and stemness maintenance, whereas miR-149-5p inhibited malignant biological behavior of CCA. Rescue experiments confirmed that the cancer-promoting effect of DLEU1 was saved by interfering miR-149-5p or YAP1. Furthermore, YAP1 promoted tumor stemness maintenance partly by acting as a transcriptional coactivator to promote TEAD2-induced SOX2 expression. These findings indicated that YY1-induced DLEU1 played a crucial role in CCA progression via miR-149-5p/YAP1/TEAD2/SOX2 axis.

Brusatol suppresses the growth of intrahepatic cholangiocarcinoma by PI3K/Akt pathway.

BACKGROUND: Intrahepatic cholangiocarcinoma (ICC) is a malignancy with a hidden onset, high metastasis recurrence rate, and poor prognosis. Research on effective drugs for ICC is important for improving the prognosis of patients in the clinic. Brusatol is a quassinoid extracted from the seeds of Brucea sumatrana and has been shown to have the potential to inhibit tumor metastasis and proliferation. There has been no scientific research on the therapeutic effect of brusatol on ICC. Our study offers a novel strategy for the therapy of ICC. PURPOSE: Explore effects of brusatol treatment on ICC and clarify the possible mechanism. STUDY DESIGN: Various cell functional experiments and basic experimental techniques were applied to ICC cell lines to explore the influences of brusatol on ICC cells; this conclusion was further verified in animal models. METHODS: The anti-cancer effects of the drug on the cell, protein, and RNA level were verified by cell functional experiments, WB blotting and transcriptome sequencing experiments, respectively. Finally, the experimental results were verified using subcutaneous tumor experiments in nude mice. RESULTS: The consequences exhibited that the levels of epithelial markers of ICC cells increased after brusatol treatment, and the levels of interstitial indicators decreased, suppressing the epithelial-mesenchymal transition (EMT) process. Brusatol inhibited proliferation, induced apoptosis, and suppressed the migration and invasion abilities of Hucc-T1 and RBE oncocytes via activating PI3K/Akt pathway. It also suppressed the growth of Hucc-T1 xenografts in nude mice. CONCLUSION: Brusatol inhibits the proliferation and EMT process in ICC oncocytes by the PI3K/Akt pathway and promotes apoptosis in oncocytes.

YY1 and eIF4A3 are mediators of the cell proliferation, migration and invasion in cholangiocarcinoma promoted by circ-ZNF609 by targeting miR-432-5p to regulate LRRC1.

Cholangiocarcinoma is a highly aggressive malignant tumor, and its incidence is increasing all over the world. More and more evidences show that the aberrant expression of circular RNAs play important roles in tumorigenesis and progression. Current studies on the expression and function of circRNAs in cholangiocarcinoma are scarce. In this study, circ-ZNF609 was discovered as a novel circRNA highly expressed in cholangiocarcinoma for the first time. The circ-ZNF609 expression is connected with the advanced TNM stage, lymphatic invasion and survival time in cholangiocarcinoma patients, and can be used as an independent prognostic factor for the patients. Circ-ZNF609 can promote the cholangiocarcinoma cells proliferation, migration and invasion in vitro, it can also catalyze the xenograft growth in vivo. The promoting effect of circ-ZNF609 on cholangiocarcinoma is achieved via oncogene LRRC1 up-regulation through targeting miR-432-5p by endogenous competitive RNA mechanism. In addition, transcription factor YY1 can bind to the promoter of ZNF609 to further facilitate the transcription of circ-ZNF609. RNA binding protein eIF4A3 can bind to the pre-mRNA of circ-ZNF609 which promotes the circ-ZNF609 circular formation. Overall, YY1/eIF4A3/circ-ZNF609/miR-432-5p/LRRC1 have a significant role in progression of cholangiocarcinoma, and circ-ZNF609 is expected to become a novel biomarker for targeted therapy and prognosis evaluation of cholangiocarcinoma.

The synergistic effect of Canady Helios cold atmospheric plasma and a FOLFIRINOX regimen for the treatment of cholangiocarcinoma in vitro.

Cholangiocarcinoma (CCA) is a rare biliary tract cancer with a low five-year survival rate and high recurrence rate after surgical resection. Currently treatment approaches include systemic chemotherapeutics such as FOLFIRINOX, a chemotherapy regimen is a possible treatment for severe CCA cases. A limitation of this chemotherapy regimen is its toxicity to patients and adverse events. There exists a need for therapies to alleviate the toxicity of a FOLFIRINOX regimen while enhancing or not altering its anticancer properties. Cold atmospheric plasma (CAP) is a technology with a promising future as a selective cancer treatment. It is critical to know the potential interactions between CAP and adjuvant chemotherapeutics. In this study the aim is to characterize the efficacy of FOLFIRINOX and CAP in combination to understand potential synergetic effect on CCA cells. FOLFIRINOX treatment alone at the highest dose tested (53.8 µM fluorouracil, 13.7 µM Leucovorin, 5.1 µM Irinotecan, and 3.7 µM Oxaliplatin) reduced CCA cell viability to below 20% while CAP treatment alone for 7 min reduced viability to 3% (p < 0.05). An analysis of cell viability, proliferation, and cell cycle demonstrated that CAP in combination with FOLFIRINOX is more effective than either treatment alone at a lower FOLFIRINOX dose of 6.7 µM fluorouracil, 1.7 µM leucovorin, 0.6 µM irinotecan, and 0.5 µM oxaliplatin and a shorter CAP treatment of 1, 3, or 5 min. In conclusion, CAP has the potential to reduce the toxicity burden of FOLFIRINOX and warrants further investigation as an adjuvant therapy.

Atractylodin inhibited the migration and induced autophagy in cholangiocarcinoma cells via PI3K/AKT/mTOR and p38MAPK signalling pathways.

OBJECTIVES: The effects of atractylodin (ATD), the bioactive compound from Atractylodes lancea, on migration and autophagy status of cholangiocarcinoma cell line were investigated. METHODS: Cytotoxic activity and effects on cell migration and invasion were evaluated by MTT and trans-well assay, respectively. Autophagy and underlying molecular mechanisms were investigated using flow cytometry and western blot analysis. KEY FINDINGS: ATD regulated the activity of PI3K/AKT/mTOR and p38MAPK signalling pathways which contributed to autophagy induction. HuCCT-1 cell growth was inhibited by ATD in a time- and dose-dependent manner. ATD inhibited the migration and invasion of HuCCT1 cells in a concentration-dependent manner. It also induced autophagy in HuCCT1 cells in a time- and dose-dependent manner. The SB202190 (autophagy inducer) and 3-MA (autophagy inhibitor) significantly increased and decreased the rate of ATD-induced autophagy, respectively. The 24 h exposure of ATD inhibited the phosphorylation of phosphatidylinositol-3-kinase (PI3K), protein kinase B (AKT), mammalian target of rapamycin (mTOR), mitogen-activated protein kinase (p38MAPK) and increased Beclin-1 expression and LC3 conversion. It also reduced p-AKT/AKT, p-mTOR/mTOR and p-p38MAPK/p38MAPK. CONCLUSIONS: ATD inhibits the proliferation and induces CCA cell autophagy via regulating PI3K/AKT/mTOR and p38MAPK signalling pathways.

Circ-LAMP1 contributes to the growth and metastasis of cholangiocarcinoma via miR-556-5p and miR-567 mediated YY1 activation.

Dysregulation of circular RNAs (circRNAs) executes important regulatory roles in carcinogenesis. Nonetheless, few studies focused on the mechanisms of circRNAs in cholangiocarcinoma (CCA). qRT-PCR was applied to verify the dysregulated circRNAs in CCA. Fisher's exact test, Kaplan-Meier analysis and Cox regression model were utilized to investigate the clinical implications of circ-LAMP1 in the patients with CCA. The viability, apoptosis, migration and invasion of CCA cells were detected after silencing/overexpression of circ-LAMP1. Xenograft and lung metastasis assays were performed to verify the in vitro results. The regulatory networks of circ-LAMP1 were unveiled by bioinformatic analysis, RNA immunoprecipitation (RIP), RNA pulldown and luciferase reporter assays. Up-regulation of circ-LAMP1 was found in CCA tissue samples and cell lines. Enhanced level of circ-LAMP1 was linked to clinical severity, high post-operative recurrence and poor prognosis for the patients with CCA. Gain/loss-of-function assays confirmed the oncogenic role of circ-LAMP1 in mediating cell growth, apoptosis, migration and invasion. Nevertheless, the level of circ-LAMP1 had no effect on normal biliary epithelium proliferation and apoptosis. Animal study further verified the in vitro data. Mechanistically, circ-LAMP1 directly sponged miR-556-5p and miR-567, thereby releasing their suppression on YY1 at post-transcriptional level. Rescue assay indicated that the oncogenic role of circ-LAMP1 is partially dependent on its modulation of YY1 in CCA. In summary, this study suggested that circ-LAMP1 might be used as a promising biomarker/therapeutic target for CCA.

PCAT1 induced by transcription factor YY1 promotes cholangiocarcinoma proliferation, migration and invasion by sponging miR-216a-3p to up-regulate oncogene BCL3.

This study was designed to illustrate the function and role of PCAT1 in CCA. The relative expression was confirmed by RT-qPCR and western blot. The biological function of PCAT1 was evaluated by CCK8, EdU, colony formation, wound healing, transwell, and subcutaneous tumor formation assays. Protein levels of EMT markers were measured by western blot. The binding relationship was predicted by JASPAR and starBase. The binding of YY1 to PCAT1 promoter was assessed by ChIP and luciferase reporter. The binding capacity between miR-216a-3p and PCAT1 as well as BCL3 was assessed by luciferase reporter and AGO2-RIP assays. In this study, we found that PCAT1 was up-regulated in CCA tissues and cells, and the PCAT1 overexpression was associated with poor prognosis. Moreover, PCAT1 was assessed as an independent risk factor of prognosis for CCA patients. Amplified PCAT1 was found to promote tumor proliferation, migration, invasion and EMT process, whereas PCAT1 knockdown inhibited these malignant phenotypes. Mechanistically, PCAT1 was predominantly localized in the cytoplasm and competitively bound miR-216a-3p to increase BCL3 expression. In addition, PCAT1 was activated by transcription factor YY1. This study revealed that PCAT1 acted as an oncogene in CCA, and the YY1/PCAT1/miR-216a-3p/BCL3 axis exhibited critical functions in CCA progression.

miR-138 mediates sorafenib-induced cell survival and is associated with poor prognosis in cholangiocarcinoma cells.

Cholangiocarcinoma is an aggressive malignancy with rapid invasion, metastasis and poor prognosis, however, the mechanism mediating its cholangiocarcinoma development needs further investigation. Here, we demonstrate that decreased miR-138 in tumor tissues is related to the poor prognosis in patients, and that miR-138 mediates sorafenib-induced cell survival in cholangiocarcinoma cells. Moreover, miR-138 negatively regulates SOX4 expression by specifically targeting its 3' untranslated region (3' UTR). As per our results, overexpression of SOX4 reversed sorafenib-induced changes in cell viability and apoptosis. Furthermore, the elevated levels of SOX4 in the tumor tissues that correlated with poor prognosis. Overall, the present study reveals that miR-138/SOX4 is involved in sorafinib-mediated cell survival in cholangiocarcinoma cells, and is associated with poor prognosis.

The synergistic antitumor effect of Huaier combined with 5-Florouracil in human cholangiocarcinoma cells.

BACKGROUND: 5-Florouracil (5-FU) is a commonly used chemotherapeutic drug for cholangiocarcinoma, whereas it has unsatisfactory effect, and patients often have chemo-resistance to it. The combination of chemotherapeutic agents and traditional Chinese medicine has already exhibited a promising application in oncotherapy. Huaier extract (Huaier) has been used in clinical practice widely, exhibiting good anti-tumor effect. This paper aims to investigate the possibility of combination 5-FU and Huaier as a treatment for cholangiocarcinoma. METHODS: A series of experiments were performed on the Huh28 cells in vitro, which involved cell proliferation, colony formation, apoptosis, cell cycle, migratory and invasive tests. Besides, western blots were also performed to examine the potential mechanism of 5-FU. RESULTS: The combination effect (antagonism, synergy or additive) was assessed using Chou-Talalay method. Using the CCK-8 and Colony formation assay, the anti-proliferation effect of 5-FU combined with Huaier was observed. Apoptosis inducing and cell cycle arrest effect of the combination of two drugs were assessed by flow cytometry. To determine the combined treatment on cell immigration and invasion ability, wound healing and Transwell assay were performed. The above experiment results suggest that the combined 5-FU and Huaier, compared with treatment using either drug alone, exhibited stronger effects in anti-proliferation, cycle arrest, apoptosis-induced and anti-metastasis. Further, western blot results reveal that the inhibition of STAT3 and its target genes (e.g. Ki67, Cyclin D1, Bcl-2 and MMP-2) might be set as the potential therapeutic targets. Besides, the inhibition of combination treatment in proteins expression associated with proliferation, apoptosis, cell cycle and metastasis was consistent with that of previous phenotypic experiments. CONCLUSIONS: Huaier combined with 5-FU exhibited a synergistic anti-tumor effect in Huh28 cell. Furthermore, the mechanisms might be associated with the activation and translocation of STAT3, as well as its downstream genes.

Evaluation of anticancer potential of Thai medicinal herb extracts against cholangiocarcinoma cell lines.

Although cholangiocarcinoma (CCA) has a low incidence globally, this is extremely high in Northeast Thailand. The lack of both early detection measures and effective therapeutic drugs is the major problem for the poor prognosis of CCA patients. Based on regional knowledge, it would be advantageous to search for effective natural phyto-products for the treatment of CCA. Cardiospermum halicacabum L., Gomphrena celosioides Mart. and Scoparia dulcis L., very well-known medicinal herbs in Asian countries, were selected for the investigation of inhibitory effects on CCA cells. Of the three different ethanolic extracts, S. dulcis L extract showed most inhibitory effects on cell growth of CCA cell lines KKU-100 and KKU-213, at percentages of 56.06 and 74.76, respectively, compared to the untreated group after treatment with 250 µg/mL of extracts for 72 hrs. At 400 and 500 µg/mL of the extracts, the inhibitory effect of KKU-213 was indicated by a significant increase in the BAX/Bcl-2 ratio and cell membrane permeability. Moreover, metabolic profiling-based screening employed in the current study revealed a significant positive association between the lignin compound and a decrease in CCA cell viability. Our study suggests, for the first time, that ESD has the ability to inhibit CCA cell growth through the induction of apoptosis.

Establishment of Patient-Derived Organoids and Drug Screening for Biliary Tract Carcinoma.

Biliary tract carcinomas (BTCs) are among the most aggressive malignancies and have a poor prognosis. Here, we successfully established organoid lines derived from intrahepatic cholangiocarcinoma, gallbladder cancer, and neuroendocrine carcinoma of the ampulla of Vater. These organoids derived from BTCs were cultured stably for >1 year and closely recapitulated the histopathology, gene expression, and genetic alterations evident in the primary tumors. Gene expression profiling of the organoids revealed that SOX2 could be a potential prognostic biomarker for patients with BTC. We screened a compound library consisting of drugs used clinically for their ability to suppress organoids derived from BTCs and found that the antifungal drugs amorolfine and fenticonazole significantly suppressed the growth of organoids derived from BTCs with minimal toxicity to normal biliary epithelial cells. Patient-derived organoids may be a powerful research tool for the clarification of molecular pathogenesis and the discovery of biomarkers and therapeutic drugs for refractory cancers.

Actinidia arguta (Hardy Kiwi) Root Extract Exerts Anti-cancer Effects via Mcl-1-Mediated Apoptosis in Cholangiocarcinoma.

Cholangiocarcinoma (CCA) is a highly aggressive and chemoresistant liver malignancy. Thus, identification of strategies to overcome insensitivity to apoptosis and growth inhibition is a growing focus of research in this malignancy. This study evaluated the potential anti-cancer effects of an ethanol extract from the Actinidia arguta (Hardy Kiwi) root (RAE) on CCA. Our data demonstrated that RAE decreased cell viability and induced apoptosis by activation of Caspase 3, Caspase 8, and Poly (ADP-ribose) polymerase (PARP) in two CCA cell lines. RAE induced a decrease in Mcl-1 in cultured CCA cells and in xenograft CCA tumors. Administration of RAE every other day led to significant growth inhibition in tumor burden xenograft CCA mice. Western blotting analysis of paired human CCA and normal adjacent tissues from the same patient revealed that CCA tissues exhibited significantly higher Mcl-1 expression than normal tissues. Taken together, our findings demonstrated the anti-cancer effects of RAE on CCA both in vitro and in vivo. These data suggest that RAE may be a promising anti-CCA agent and could be beneficial in the treatment of CCA through the targeting of Mcl-1.

Rhinacanthin-C Extracted from Rhinacanthus nasutus (L.) Inhibits Cholangiocarcinoma Cell Migration and Invasion by Decreasing MMP-2, uPA, FAK and MAPK Pathways

Cholangiocarcinoma is a malignant tumor with high metastatic and mortality rates. We investigated the effects of rhinacanthin-C on cell proliferation, migration, invasion and the expression of proteins regulating cancer cell invasion-regulated proteins in a cholangiocarcinoma (KKU-M156) cell line. Cytotoxicity of rhinacanthin-C was determined by the SRB assay. Using wound-migration, chamber-migration and chamber-invasion assays, we assessed the effects of rhinacanthin-C against KKU-M156 cells. The activities of matrix metalloproteinases 2 and 9 (MMP-2, MMP-9) and urokinase-type plasminogen activator (uPA) were determined using gelatinase and uPA zymography assays. The expression of invasion-regulated proteins was investigated using western-blot analysis. After treatment with rhinacanthin-C, KKU-M156 cells exhibited antiproliferative effects in a dose-dependent manner with greater efficacy than in Vero cells: IC50 values were 1.50 and 2.37 µM, respectively. Rhinacanthin-C significantly inhibited cell migration and invasion of KKU-M156 cells in a dose-dependent manner. Consistent with this observation, treatment with rhinacanthin-C was associated with a decrease in the expression levels of FAK, p-FAK, MMP-2, and a decrease in the levels of p38-, JNK1/2- and ERK1/2-MAPK pathways as well as inhibiting NF-κB/p65 expression and translocation of NF-κB/p65 to the nucleus. We have shown for the first time that the anti-metastatic effects of rhinacanthin-C on KKU-M156 cells are mediated via inhibition of the expression of invasion-regulated proteins. Rhinacanthin-C may deserve consideration as a potential agent for the treatment of cholangiocarcinoma.

Dihydroartemisinin induces apoptosis and autophagy-dependent cell death in cholangiocarcinoma through a DAPK1-BECLIN1 pathway.

Cholangiocarcinoma (CCA) is a very aggressive cancer arising from the malignant transformation of cholangiocytes. Intrahepatic CCA is associated with reactive inflammation and intense fibrosis of the hepatobiliary tract. Dihydroartemisinin (DHA), the active compound found in Artemisia annua, has been shown to possess anti-tumor activity in a variety of human cancers, including hepatoma. Here, we tested the ability of DHA to specifically kill CCA cells and have investigated the underlying mechanisms. DHA induced both apoptosis and autophagy-dependent caspase-independent cell death in many CCA cell lines, while being slightly toxic to immortalized cholangiocytes. DHA induced the expression of many apoptosis- and autophagy-related genes in CCA cells. In particular, it greatly induced the expression of DAPK1, and reduced the interaction of BECLIN1 with BCL-2 while promoting its interaction with PI3KC3. Genetic silencing of DAPK1 prevented DHA-induced autophagy. Pharmacologic and genetic inhibition of BECLIN1 function prevented autophagy and cell death induced by DHA in CCA cells. These data unravel a novel pathway of DHA cancer toxicity and open the possibility to introduce DHA in the therapeutic regimen for the treatment of CCA.

Synergistic Effect of Forbesione From Garcinia hanburyi in Combination with 5-Fluorouracil on Cholangiocarcinoma

Background: Chemotherapy for advanced cholangiocarcinoma (CCA) is largely ineffective; thus innovative combinations of chemotherapeutic agents and natural compounds represent a promising strategy. This study aimed to investigate the synergistic effects of forbesione combined with 5-fluorouracil (5-FU) in hamster cholangiocarcinoma (Ham-1) cells both in vitro and in vivo. The anti-tumor effects of 5-FU combined with forbesione in vitro were determined using the Sulforhodamine B (SRB) assay and the effects in vivo were assessed in transplanted Ham-1 allograph models. Using ethidium bromide/acridine orange (EB/AO) staining, the morphological changes of apoptotic cells was investigated. The expressions of apoptosis-related molecules after combined treatment with forbesione and 5-FU were determined using real-time RT-PCR and western blot analysis. Forbesione or 5-FU alone inhibited proliferation of Ham-1 cells in a dose-dependent manner and their combination showed a synergistic proliferation inhibitory effect in vitro. In vivo studies, forbesione in combination with 5-FU exhibited greater inhibition of the tumor in the hamster model compared with treatment using either drug alone. Forbesione combined with 5-FU exerted stronger apoptotic induction in Ham-1 cells than did single drug treatment. The combination of drugs strongly suppressed the expression of B-cell lymphoma 2 (Bcl-2) and procaspase-3 while enhancing the expression of p53, Bcl-2-associated X protein (Bax), apoptotic protease activating factor-1 (Apaf-1), caspase-9 and caspase-3, compared with single drug treatments. These results explained the decreased expression of cytokeratin 19 (CK19) positive cells and proliferation cell nuclear antigen (PCNA) positive cells in Ham-1 cell tumor tissues of the treated hamsters. There was no apparent systemic toxicity observed in the treated animals compared with the control groups. Forbesione combined with 5-FU strongly induced apoptosis in Ham-1 cells. The growth inhibitory effect of combined treatment using these two drugs was much greater than treatment with either drug alone, both in vitro and in vivo.