Development Of CCA Research Articles

Targeting Glycolytic Reprogramming in Cholangiocarcinoma: A Novel Approach for Metabolic Therapy.

Cholangiocarcinoma (CCA) is a highly aggressive and poorly prognostic tumor. Due to the lack of early symptoms, diagnosing CCA remains challenging, often occurring at an advanced stage. Therefore, exploring the underlying mechanisms of CCA development and identifying potential biomarkers and therapeutic targets is crucial. Recently, metabolic reprogramming in cancer cells has emerged as a hallmark of the disease. Glycolysis has been identified as a central component of metabolic reprogramming in CCA, with multiple signaling pathways and key enzymes playing significant roles. Additionally, non-coding RNAs (ncRNAs) and post-translational modifications of proteins are also involved in regulating glycolysis in CCA. In this review, we provide a comprehensive summary of the alterations in cancer metabolism and the diverse signaling pathways involved, as they might exert an impact on the development of CCA. Overall, targeting glycolysis holds considerable promise as a crucial strategy for enhancing the therapeutic outcomes of CCA. In addition, we performed a bioinformatic analysis of the relationship between CCA and glycolysis to identify and investigate potential targets. The purpose of this study is to provide a theoretical basis for the development of CCA targets.

Feedback loop LINC00511-YTHDF2-SOX2 regulatory network drives cholangiocarcinoma progression and stemness.

Cholangiocarcinoma (CCA) was identified as a malignant tumor with rising incidence and mortality rates, and the roles of long noncoding RNA (lncRNA) in CCA remained not entirely clear. In this study, LINC00511 had high expression in CCA, which was closely related to poor prognosis. Knockdown of LINC00511 significantly inhibited cell malignant biological behaviors. It also affected the stemness of CCA, evidenced by decreased SOX2 protein expression. Moreover, the study revealed the interaction of LINC00511, YTHDF2, and SOX2 in CCA. Specifically, LINC00511 facilitated the formation of a complex with YTHDF2 on SOX2 mRNA, which uniquely enhances the mRNA's stability through m6A methylation sites. This stabilization appears crucial for maintaining malignant behaviors in CCA cells. Additionally, LINC00511 modulated SOX2 expression via the PI3K/AKT signaling pathway. Meanwhile, SOX2 can also promote LINC00511 expression as an upstream transcription factor, thereby confirming a positive feedback loop formed by LINC00511, YTHDF2, and SOX2, which plays a significant role in the occurrence and development of CCA. Finally, the study successfully constructed two patient-derived xenograft models, revealing the vital role of LINC00511 in CCA development. In summary, this research provides a comprehensive understanding of the role of LINC00511 in the pathogenesis of CCA.

Notch-Driven Cholangiocarcinogenesis Involves the Hippo Pathway Effector TAZ via METTL3-m6A-YTHDF1

Background and AimsNotch and TAZ are implicated in cholangiocarcinogenesis, but whether and how these oncogenic molecules interact remain unknown. MethodsThe development of CCA was induced by hydrodynamic tail vein (HDTV) injection of oncogenes (NICD/AKT) to the FVB/NJ mice. CCA xenograft was developed by inoculation of human CCA cells into the livers of SCID mice. Tissues and cells were analyzed using qRT-PCR, Western blotting analyses, Immunohistochemistry, ChIP-qPCR and WST-1 cell proliferation Assay. ResultsOur experimental findings show that TAZ is indispensable in NICD-driven cholangiocarcinogenesis. Notch activation induces the expression of METTL3 (Methyltransferase like-3) which catalyzes N6-methyladenosine (m6A) modification of TAZ mRNA and that this mechanism plays a central role in the crosstalk between Notch and TAZ in CCA cells. Mechanistically, Notch regulates the expression of METTL3 through the binding of NICD to its downstream transcription factor CSL in the promoter region of METTL3. METTL3 in turn mediates m6A modification of TAZ mRNA which is recognized by the m6A reader YTHDF1 to enhance TAZ protein translation. We observed that inhibition of Notch signaling decreased the protein levels of both MELLT3 and TAZ. Depletion of METTL3 by shRNAs or by the next generation GapmeR antisense oligonucleotides (ASOs) decreased the level of TAZ protein and inhibited the growth of human CCA cells in vitro and in mice. ConclusionThis study describes a novel Notch-METTL3-TAZ signaling cascade which is important in CCA development and progression. Our experimental results provide new insight into how the Notch pathway cooperates with TAZ signaling in CCA, and the findings may have important therapeutic implications.

Risk factors of cholangiocarcinoma in areas not endemic for liver fluke infection.

Thailand has the world's highest prevalence of cholangiocarcinoma (CCA), especially in the endemic area of liver fluke Opisthorchis viverrini infection. However, other regions of Thailand still have relatively high CCA prevalence. We aimed to determine CCA risk factors in areas not endemic for OV infection. A case--control study was performed at a referral center during December 2016-December 2017. We collected blood samples and information from CCA patients and identified them as cases. The control group comprised patients who visited a gastrointestinal clinic for colorectal cancer screening colonoscopy. Logistic regression analysis was used to determine risk factors for CCA. Of 138 participants, O. viverrini infection rate was higher in the case than in the control group (57.1% vs. 36.1%, P = 0.023). Male, O. viverrini infection, smoking, alcohol consumption, and biliary tract diseases were independent risk factors, whereas diabetes, obesity, and cirrhosis were not associated with CCA. By age and sex-adjusted analysis, chronic biliary tract diseases, especially choledochal cysts and smoking, were risk factors for CCA, with adjusted odds ratio (aOR) of 12.7 (95% confidence interval [CI]: 1.4-116.9) and 3.8 (95% CI: 1.3-11.8), respectively, while O. viverrini infection became insignificant risk for CCA (aOR 1.8, 95% CI: 0.8-4.1). In contrast with endemic areas for O. viverrini infection, chronic biliary tract diseases and smoking are major risk factors, whereas O. viverrini infection has trivial contribution to the development of CCA.

Association between incretin-based drugs and risk of cholangiocarcinoma among patients with type 2 diabetes: A large population-based matched cohort study

AimTo examine the association between the use of incretin-based drugs [glucagon-like peptide-1 receptor agonists (GLP-1RAs), dipeptidyl peptidase-4 inhibitors (DPP-4Is)] and the risk of cholangiocarcinoma (CCA) in the United States. MethodsThis large population-based, retrospective cohort study using the TriNetX datasets included adult patients with type 2 diabetes mellitus (T2DM) who were new users of GLP-1RAs, DPP-4Is, or other second- or third-line antidiabetic drugs between 2010 and 2021. The primary outcome was the incidence of CCA. ResultsA total of 3,816,071 patients were included (mean age, 61.4 years, female, 49.3 %). A 51 % and 23 % risk reduction in CCA after 1 year of exposure to GLP-1RAs (hazard ratio 0.49; 95 % CI 0.40–0.60) and DPP4Is (0.77, 95 % CI 0.67–0.90), respectively compared to new second-or third-line users. Results were consistent at 3, 5, and 7 years of follow-up (0.66, 0.71, and 0.72 for GLP-1RAs and 0.84, 0.87, and 0.85 for DPP-4Is, respectively). Compared to new metformin users, GLP-1RA users were associated with a 42 % lower risk of developing CCA, whereas DPP-4I group was not associated with an increased risk. ConclusionsGLP-1RAs and DPP-4Is were not associated with a significantly increased risk of CCA. GLP-1RAs even showed a reduced risk of CCA development. They can be considered as safe and effective treatment options for patients with T2DM at risk of CCA.

RBM39 Enhances Cholangiocarcinoma Growth Through EZH2-mediated WNT7B/β-catenin Pathway

Background and aimsThe RNA-binding motif protein 39 (RBM39) functions as both an RNA-binding protein and a splicing factor in a variety of cancer types. However, the function of RBM39 in cholangiocarcinoma (CCA) remains undefined. In this study, we aimed to investigate the role of RBM39 in CCA and explore its potential as a therapeutic target. MethodsThe expression of RBM39 in CCA was investigated by analyzing human CCA tumor specimens. CRISPR/Cas9 or shRNA-mediated depletion of RBM39 was performed in vitro and in vivo to document the oncogenic role of RBM39 in CCA. The anti-tumor effect of the RBM39 inhibitor Indisulam in combination with the EZH2 degrader MS177 was assessed in vitro and in vivo. ResultsRBM39 is significantly increased in human CCA tissues and associated with a poor prognosis in CCA patients. Depletion of RBM39 by CRISPR/Cas9 or shRNA inhibited CCA cell proliferation in vitro and prevented CCA development and tumor growth in mice. Mechanistically, our results showed that depletion of RBM39 suppressed EZH2 expression via disrupting its mRNA splicing. RBM39-regulated EZH2 controls WNT7B/β-catenin activity. Pharmacological co-targeting of RBM39 (with Indisulam) and EZH2 (with MS177) resulted in a synergistic antitumor effect, both in vitro and in vivo. ConclusionThis study discloses a novel RBM39-EZH2-β-catenin signaling axis that is crucial for CCA growth. Our findings suggest that simultaneous inhibition of RBM39 and EZH2 presents a promising therapeutic strategy for CCA treatment.

A novel biomarker GATM suppresses proliferation and malignancy of cholangiocarcinoma cells by modulating the JNK/c-Jun signalling pathways

BackgroundCholangiocarcinoma (CCA) is the second most common primary malignancy of the liver and is associated with poor prognosis. Despite the emerging role of glycine amidinotransferase (GATM) in cancer development, its function in CCA remains elusive. This study investigated the biological significance and molecular mechanisms of GATM in CCA. MethodGATM expression was measured using immunohistochemistry and western blotting. Cell proliferation, migration, and invasion were assessed through CCK-8, EdU, clone formation, wound healing, and Transwell assays. Rescue experiments were performed to determine whether the JNK/c-Jun pathway is involved in GATM-mediated CCA development. Immunoprecipitation and mass spectrometry were performed to screen for proteins that interact with GATM. The role of GATM in vivo was investigated according to the xenograft experiment. ResultGATM expression was downregulated in CCA tissues and cells (p < 0.05) and had a significant suppressive effect on CCA cell proliferation, migration, and invasion in vitro as well as on tumour growth in vivo (p < 0.05); conversely, GATM knockdown promoted these phenotypes (p < 0.05). Notably, GATM inhibited the JNK/c-Jun pathway, and JNK activation abrogated GATM's antitumor effects (p < 0.05). Isocitrate dehydrogenase 1 (IDH1) interacts with GATM, and IDH1 knockdown significantly attenuated GATM protein degradation. Overexpression of IDH1 restored the biological function of CCA by reversing the inhibition of JNK/c-Jun pathway phosphorylation by GATM (p < 0.05). ConclusionGATM acts as a tumour suppressor in CCA by regulating the phosphorylation of the JNK/c-Jun pathway. IDH1 interacted with GATM to regulate CCA progression.

AMDHD1 acts as a tumor suppressor and contributes to activation of TGF-β signaling pathway in cholangiocarcinoma.

Cholangiocarcinoma (CCA) is a malignant tumor of the digestive system, characterized by its aggressive behavior and the absence of effective therapeutic biomarkers. Although recent studies have implicated AMDHD1 in tumor formation, its role in CCA development has been insufficiently explored. We utilized multiple bioinformatic datasets alongside 108 clinical samples to examine AMDHD1 expression in CCA. Then, in vitro and in vivo experiments were conducted to assess its impact on tumor growth and metastasis. Furthermore, proteomic analysis and immunoprecipitation mass spectrometry were employed to identify the downstream effectors of AMDHD1. We discovered that AMDHD1 was down-regulated in CCA and this down-regulation was associated with adverse clinicopathological features and prognosis. We also demonstrated that overexpression of AMDHD1 hindered G1/S progression in the cell cycle and promoted apoptosis, thereby inhibiting tumor growth and metastasis. Mechanistically, we found that AMDHD1 operated in a TGF-β-dependent manner and the inhibition of TGF-β signaling abrogated the effect of AMDHD1 overexpression on CCA cells. Specifically, AMDHD1 inhibited the ubiquitination and degradation of the SMAD4 protein through binding to the MH2 domain and synergistically enhanced SMAD2/3 phosphorylation, which activated of TGF-β signaling pathway and resulted in the suppression of CCA cell proliferation and migration. Our study identifies AMDHD1 as a significant prognostic biomarker and a tumor suppressor in CCA. It underscores the pivotal role of the AMDHD1/TGF-β signaling pathway in the development and progression of CCA.

Knockdown of long noncoding RNA AL161431.1 inhibits malignant progression of cholangiocarcinoma.

Cholangiocarcinoma (CCA) is one of the most deadly cancers in the world. It usually has a bad prognosis and is challenging to identify in its early stages. Long noncoding RNAs (lncRNAs) have been shown in an increasing number of studies to be important in the control of signaling pathways, cell behaviors, and epigenetic modification that contribute to the growth of tumors. The purpose of this work was to examine the relationship between CCA and lncRNA AL161431.1. Using TCGA clinical survival data, we evaluated the association between AL161431.1 expression and patient prognosis. Using the program cluster Profiler R, enrichment analysis was performed. Additionally, the association between immune cell infiltration and AL161431.1 expression was evaluated by a review of the TCGA database. Next, to ascertain if AL161431.1 influences tumor growth, migration, and invasion in CCA, functional in vitro assays were conducted. Quantitative real-time polymerase chain reaction (qPCR) was employed to gauge AL161431.1 expression levels in CCA cells. Western blot was used to measure protein levels. In CCA, AL161431.1 was extremely expressed. The patients in the high-risk group had a significantly poorer overall survival (OS) than the patients in the low-risk group. A more thorough look at the TCGA data showed a relationship between high expression levels of AL161431.1 and increased infiltration of T cells, T helper cells, and NK CD56dim cells. Furthermore, AL161431.1 knockdown in CCA cells impeded invasion, migration, and proliferation and also lowered the expression of phosphorylated Smad2/Smad3 to restrain the TGFβ/SMAD signaling pathway. Our results indicate that the lncRNA AL161431.1 activates the TGFβ/SMAD signaling pathway to enhance CCA development and metastasis. AL161431.1 could be a novel target for cholangiocarcinoma treatment or a diagnostic marker.

Huaier inhibits cholangiocarcinoma cells through the twist1/FBP1/Wnt/β-catenin axis.

Although Huaier granules can be used as prospective anti-cholangiocarcinoma drugs, the mechanism of action of Huaier granules in cholangiocarcinoma is not clear. The anti-cholangiocarcinoma effect of Huaier granules was validated in cell line research. In vitro experiments were conducted to investigate the signalling pathways affected by Huaier in CCA cells. Real-time quantitative PCR (RT‒qPCR) and Western blot analysis were performed to analyse gene expression in CCA cells. MTT assays, scratch tests, and Transwell assays were used to explore the effects on the proliferation and metastasis of CCA cells. Chromatin immunoprecipitation assays were performed to reveal the potential underlying mechanisms involved. Twist1 was upregulated in human CCA tissues. In addition, its expression levels were negatively related to FBP1 expression levels. Mechanistically, Twist1 can bind to the region of the FBP1 promoter to reduce its expression. Huaier plays an indispensable role in suppressing Twist1 expression to inhibit the Twist1/FBP1/Wnt/β-catenin axis. Then, we verified the effect of Huaier in vitro. These findings suggested that Huaier granules were capable of inhibiting CCA development through regulating the Twist1/FBP1/Wnt/β-catenin signalling axis and provided a novel orientation for the development of novel anti-CCA drugs.

Role of Gut Microbial Metabolites in the Pathogenesis of Primary Liver Cancers.

Hepatobiliary malignancies, which include hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA), are the sixth most common cancers and the third leading cause of cancer-related death worldwide. Hepatic carcinogenesis is highly stimulated by chronic inflammation, defined as fibrosis deposition, and an aberrant imbalance between liver necrosis and nodular regeneration. In this context, the gut-liver axis and gut microbiota have demonstrated a critical role in the pathogenesis of HCC, as dysbiosis and altered intestinal permeability promote bacterial translocation, leading to chronic liver inflammation and tumorigenesis through several pathways. A few data exist on the role of the gut microbiota or bacteria resident in the biliary tract in the pathogenesis of CCA, and some microbial metabolites, such as choline and bile acids, seem to show an association. In this review, we analyze the impact of the gut microbiota and its metabolites on HCC and CCA development and the role of gut dysbiosis as a biomarker of hepatobiliary cancer risk and of response during anti-tumor therapy. We also discuss the future application of gut microbiota in hepatobiliary cancer management.

Characterization of a Syngeneic Orthotopic Model of Cholangiocarcinoma by [18F]FDG-PET/MRI.

Cholangiocarcinoma (CCA) is a type of primary liver cancer originating from the biliary tract epithelium, characterized by limited treatment options for advanced cases and low survival rates. This study aimed to establish an orthotopic mouse model for CCA and monitor tumor growth using PET/MR imaging. Murine CCA cells were implanted into the liver lobe of male C57BL/6J mice. The imaging groups included contrast-enhanced (CE) MR, CE-MR with static [18F]FDG-PET, and dynamic [18F]FDG-PET. Tumor volume and FDG uptake were measured weekly over four weeks. Early tumor formation was visible in CE-MR images, with a gradual increase in volume over time. Dynamic FDG-PET revealed an increase in the metabolic glucose rate (MRGlu) over time. Blood analysis showed pathological changes in liver-related parameters. Lung metastases were observed in nearly all animals after four weeks. The study concludes that PET-MR imaging effectively monitors tumor progression in the CCA mouse model, providing insights into CCA development and potential treatment strategies.

The Tumor Immune Microenvironment plays a Key Role in Driving the Progression of Cholangiocarcinoma.

Cholangiocarcinoma (CCA) is an epithelial cancer distinguished by bile duct cell differentiation and is also a fibroproliferative tumor. It is characterized by a dense mesenchyme and a complex tumor immune microenvironment (TME). The TME comprises both cellular and non-cellular components. The celluar component includes CCA cells, immune cells and mesenchymal cells represented by the cancer-associated fibroblasts (CAFs), while the non-cellular component is represented by mesenchymal elements such as the extracellular matrix (ECM). Recent studies have demonstrated the important role of the TME in the development, progression, and treatment resistance of CCA. These cell-associated prognostic markers as well as intercellular connections, may serve as potential therapeutic targets and could inspire new treatment approaches for CCA in the future. This paper aims to summarize the current understanding of CCA's immune microenvironment, focusing on immune cells, mesenchymal cells, ECM, intercellular interactions, and metabolism within the microenvironment.

Epigenetic silencing of miR-125a-3p promotes the progress of human cholangiocarcinoma via increasing CAC1 expression

We aimed to investigate the dysregulation of the microRNAs(miRNAs) in cholangiocarcinoma (CCA), including its impact on the homeostasis of the transcriptome and cellular behavior. MiRNAs serve as potent epigenetic regulators of transcriptional output, targeting various signaling pathways. This study aimed to investigate the expression level, epigenetic mechanism and function of miR-125a-3 in CCA. The study data showed that the expression level of miR125a-3p was decreased in CCA tissue samples and cell lines, and it was closely related to lymph node metastasis, tissue differentiation and TNM stage. The data demonstrate a strong association between decreased miR-125a-3p expression and poorer prognosis in cholangiocarcinoma patients. miR-125a-3p acts as a tumor suppressor by inhibiting the viability, migration and invasion of CCA cells. There are CpG islands in the promoter region of miR-125a-3p gene, and the methylation of the promoter region of miR-125a-3p gene leads to the transcriptional repression of miR-125a-3p. In addition, miR125a-3p can target and regulate CAC1 mRNA and protein expression in the downstream mechanism, and the high expression of CAC1 can promote the proliferation, migration and invasion of cholangiocarcinoma cells. These data demonstrate that miR-125a-3p promoter methylation leads to silencing of its expression. Mechanically, miR-125a-3p acts as a tumor suppressor and participates in the occurrence and development of CCA through targeting CAC1 gene expression. Therefore, miR-125a-3p may serve as a new target for the diagnosis, prognostic assessment or molecular therapy of CCA.

The Diagnostic and Prognostic Potentials of Non-Coding RNA in Cholangiocarcinoma.

Cholangiocarcinoma (CCA) is a rare biliary tract tumor with high malignancy. CCA is the second most common primary hepatobiliary cancer after hepatocarcinoma. Despite its rarity, the incidence of CCA is steadily increasing globally. Most patients with CCA are asymptomatic in the early stages, resulting in a late-stage diagnosis and poor prognosis. Finding reliable biomarkers is essential to improve CCA's early diagnosis and survival rate. Non-coding RNAs (ncRNAs) are non-protein coding RNAs produced by genomic transcription. This includes microRNAs, long non-coding RNAs, and circular RNAs. ncRNAs have multiple functions in regulating gene expression and are crucial for maintaining normal cell function and developing diseases. Many studies have shown that aberrantly expressed ncRNAs can regulate the occurrence and development of CCA. ncRNAs can be easily extracted and detected through tumor tissue and liquid biopsies, representing a potential tool for diagnosing and prognosis CCA. This review will provide a detailed update on the diagnostic and prognostic potentials of lncRNAs and cirRNAs as biomarkers in CCA.

Regulation of Hippo–YAP signaling axis by Isoalantolactone suppresses tumor progression in cholangiocarcinoma

Cholangiocarcinoma (CCA) is a devastating malignancy characterized by aggressive tumor growth and limited treatment options. Dysregulation of the Hippo signaling pathway and its downstream effector, Yes-associated protein (YAP), has been implicated in CCA development and progression. In this study, we investigated the effects of Isoalantolactone (IALT) on CCA cells to elucidate its effect on YAP activity and its potential clinical significance. Our findings demonstrate that IALT exerts cytotoxic effects, induces apoptosis, and modulates YAP signaling in SNU478 cells. We further confirmed the involvement of the canonical Hippo pathway by generating LATS1/LATS2 knockout cells, highlighting the dependence of IALT-mediated apoptosis and YAP phosphorylation on the Hippo-LATS signaling axis. In addition, IALT suppressed cell growth and migration, partially dependent on YAP-TEAD activity. These results provide insights into the therapeutic potential of targeting YAP in CCA and provide a rationale for developing of YAP-targeted therapies for this challenging malignancy.

Transcription factor EHF drives cholangiocarcinoma development through transcriptional activation of glioma-associated oncogene homolog 1 and chemokine CCL2.

Cholangiocarcinoma (CCA) is characterized by rapid onset and high chance of metastasis. Therefore, identification of novel therapeutic targets is imperative. E26 transformation-specific homologous factor (EHF), a member of the E26 transformation-specific transcription factor family, plays a pivotal role in epithelial cell differentiation and cancer progression. However, its precise role in CCA remains unclear. In this study, through in vitro and in vivo experiments, we demonstrated that EHF plays a profound role in promoting CCA by transcriptional activation of glioma-associated oncogene homolog 1 (GLI1). Moreover, EHF significantly recruited and activated tumor-associated macrophages (TAMs) through the C-C motif chemokine 2/C-C chemokine receptor type 2 (CCL2/CCR2) axis, thereby remodeling the tumor microenvironment. In human CCA tissues, EHF expression was positively correlated with GLI1 and CCL2 expression, and patients with co-expression of EHF/GLI1 or EHF/CCL2 had the most adverse prognosis. Furthermore, the combination of the GLI1 inhibitor, GANT58, and CCR2 inhibitor, INCB3344, substantially reduced the occurrence of EHF-mediated CCA. In summary, our findings suggest that EHF is a potential prognostic biomarker for patients with CCA, while also advocating the therapeutic approach of combined targeting of GLI1 and CCL2/CCR2-TAMs to inhibit EHF-driven CCA development.

Establishment of a cholangiocarcinoma risk evaluation model based on mucin expression levels.

Cholangiocarcinoma (CCA) is a highly malignant cancer, characterized by frequent mucin overexpression. MUC1 has been identified as a critical oncogene in the progression of CCA. However, the comprehensive understanding of how the mucin family influences CCA progression and prognosis is still incomplete. To investigate the functions of mucins on the progression of CCA and to establish a risk evaluation formula for stratifying CCA patients. Single-cell RNA sequencing data from 14 CCA samples were employed for elucidating the roles of mucins, complemented by bioinformatic analyses. Subsequent validations were conducted through spatial transcriptomics and immunohistochemistry. The construction of a risk evaluation model utilized the least absolute shrinkage and selection operator regression algorithm, which was further confirmed by independent cohorts and diverse data types. CCA tumor cells with elevated levels of MUC1 and MUC4 showed activated nucleotide metabolic pathways and increased invasiveness. MUC5AC-high cells were found to promote CCA progression through WNT signaling. MUC5B-high cells exhibited robust cellular oxidation activities, leading to resistance against antitumoral treatments. MUC13-high cells were observed to secret chemokines, recruiting and transforming macrophages into the M2-polarized state, thereby suppressing antitumor immunity. MUC16-high cells were found to promote tumor progression through interleukin-1/nuclear factor kappa-light-chain-enhancer of activated B cells signaling upon interaction with neutrophils. Utilizing the expression levels of these mucins, a risk factor evaluation formula for CCA was developed and validated across multiple cohorts. CCA samples with higher risk factors exhibited stronger metastatic potential, chemotherapy resistance, and poorer prognosis. Our study elucidates the functional mechanisms through which mucins contribute to CCA development, and provides tools for risk stratification in CCA.

Abstract 4367: PTEN/AKT signal promotes cholangiocyte fate in liver tumorigenesis by inducing SOX9 overexpression and crosstalk with Notch activation

Abstract Cholangiocarcinoma (CCA) is the second most dominant primary liver malignancy next to hepatocellular carcinoma (HCC), and among the most mortal among human cancers. The PI3K/AKT signaling pathway was considered a permissive signal for the development of CCA. To explore how the PI3K/AKT signal contributes to CCA development, we deleted Pten, the lipid phosphatase that negatively regulates the PI3K/AKT signal in the liver. The Lv-PTEN (PtenloxP/loxP; Alb-Cre+) mice developed a mixed HCC and CCA tumor phenotype with all mice developing CCA by 12-month age. Treatment of Lv-PTEN mice with DDC at 3 months to obstruct the bile duct leads to an earlier CCA oncogenesis. Deletion of Akt2 in the Lv-PTEN mice (Lv-DM, Akt2loxP/loxP; PtenloxP/loxP; Alb-Cre+) significantly attenuates tumor development. Compared with the Lv-PTEN mice, loss of AKT2 in Lv-DM mice robustly and significantly reduced the expression of SOX9, a cholangiocyte gene. This data suggests that the AKT signal may permit a cholangiocyte fate by inducing SOX9 expression. Supporting the role of PTEN/AKT in permitting a cholangiocyte fate, SOX9 expression is also induced in the livers of mice where Pten deletion is targeted to the hepatocytes via injection of AAV8-TGB-Cre (Hp-PTEN, PtenloxP/loxP; R26RYFP; AAV8-TBG-Cre). Similar to the Lv-PTEN mice, treatment with DDC induced early onset of CCA development in the Hp-PTEN mice. We next explore Notch signal for its crosstalk with PTEN loss that permits CCA development. Notch signal is robustly induced in the tumors of the Lv-PTEN mice and induced with DDC treatment in both Lv-PTEN and Hp-PTEN livers. We showed that exposure to Jag1 ligand-coated extracellular matrix or expression of NICD also induced the expression of SOX9 while DAPT time-dependently attenuated the expression of SOX9. In the Hp-Pten mice treated with DDC, inhibiting the Notch pathway with DAPT attenuated ductal reaction and led to downregulation of SOX9 in the Lv-PTEN livers, suggesting a positive regulatory role of Notch on SOX9. These data support that Notch activation regulates SOX9 and collaborates with PTEN loss to drive cholangiocyte fate and CCA development. Citation Format: Qi Tang, Jingyu Chen, Ni Zeng, Lina He, Shefali Chopra, Diala Alhousari, Phillip Nguyen, Guo Zhang, Bangyan L. Stiles. PTEN/AKT signal promotes cholangiocyte fate in liver tumorigenesis by inducing SOX9 overexpression and crosstalk with Notch activation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4367.

Smad4 restricts injury-provoked biliary proliferation and carcinogenesis.

Cholangiocarcinoma (CCA) is a deadly and heterogeneous type of cancer characterized by a spectrum of epidemiologic associations as well as genetic and epigenetic alterations. We seek to understand how these features inter-relate in the earliest phase of cancer development and through the course of disease progression. For this, we studied murine models of liver injury integrating the most commonly occurring gene mutations of CCA - including Kras, Tp53, Arid1a and Smad4 - as well as murine hepatobiliary cancer models and derived primary cell lines based on these mutations. Among commonly mutated genes in CCA, we found that Smad4 functions uniquely to restrict reactive cholangiocyte expansion to liver injury through restraint of the proliferative response. Inactivation of Smad4 accelerates carcinogenesis, provoking pre-neoplastic biliary lesions and CCA development in an injury setting. Expression analyses of Smad4-perturbed reactive cholangiocytes and CCA lines demonstrated shared enriched pathways, including cell-cycle regulation, MYC signaling and oxidative phosphorylation, suggesting that Smad4 may act via these mechanisms to regulate cholangiocyte proliferation and progression to CCA. Overall, we showed that TGFβ/SMAD4 signaling serves as a critical barrier restraining cholangiocyte expansion and malignant transformation in states of biliary injury.