Advances in the treatment of intrahepatic cholangiocarcinoma: An overview of the current and future therapeutic landscape for clinicians.

Intrahepatic cholangiocarcinoma (ICC) is the second most common primary liver tumor and remains a fatal malignancy in the majority of patients. Approximately 20%-30% of patients are eligible for resection, which is considered the only potentially curative treatment; and, after resection, a median survival of 53 months has been reported when sequenced with adjuvant capecitabine. For the 70%-80% of patients who present with locally unresectable or distant metastatic disease, systemic therapy may delay progression, but survival remains limited to approximately 1 year. For the past decade, doublet chemotherapy with gemcitabine and cisplatin has been considered the most effective first-line regimen, but results from the recent use of triplet regimens and even immunotherapy may shift the paradigm. More effective treatment strategies, including those that combine systemic therapy with locoregional therapies like radioembolization or hepatic artery infusion, have also been developed. Molecular therapies, including those that target fibroblast growth factor receptor and isocitrate dehydrogenase, have recently received US Food and Drug Administration approval for a defined role as second-line treatment for up to 40% of patients harboring these actionable genomic alterations, and whether they should be considered in the first-line setting is under investigation. Furthermore, as the oncology field seeks to expand indications for immunotherapy, recent data demonstrated that combining durvalumab with standard cytotoxic therapy improved survival in patients with ICC. This review focuses on the current and future strategies for ICC treatment, including a summary of the primary literature for each treatment modality and an algorithm that can be used to drive a personalized and multidisciplinary approach for patients with this challenging malignancy.

Discovery of lirafugratinib (RLY-4008), a highly selective irreversible small-molecule inhibitor of FGFR2.

Fibroblast growth factor receptor (FGFR) kinase inhibitors have been shown to be effective in the treatment of intrahepatic cholangiocarcinoma and other advanced solid tumors harboring FGFR2 alterations, but the toxicity of these drugs frequently leads to dose reduction or interruption of treatment such that maximum efficacy cannot be achieved. The most common adverse effects are hyperphosphatemia caused by FGFR1 inhibition and diarrhea due to FGFR4 inhibition, as current therapies are not selective among the FGFRs. Designing selective inhibitors has proved difficult with conventional approaches because the orthosteric sites of FGFR family members are observed to be highly similar in X-ray structures. In this study, aided by analysis of protein dynamics, we designed a selective, covalent FGFR2 inhibitor. In a key initial step, analysis of long-timescale molecular dynamics simulations of the FGFR1 and FGFR2 kinase domains allowed us to identify differential motion in their P-loops, which are located adjacent to the orthosteric site. Using this insight, we were able to design orthosteric binders that selectively and covalently engage the P-loop of FGFR2. Our drug discovery efforts culminated in the development of lirafugratinib (RLY-4008), a covalent inhibitor of FGFR2 that shows substantial selectivity over FGFR1 (~250-fold) and FGFR4 (~5,000-fold) in vitro, causes tumor regression in multiple FGFR2-altered human xenograft models, and was recently demonstrated to be efficacious in the clinic at doses that do not induce clinically significant hyperphosphatemia or diarrhea.

Futibatinib for FGFR2-Rearranged Intrahepatic Cholangiocarcinoma.

BACKGROUND: Alterations in fibroblast growth factor receptor 2 (FGFR2) have emerged as promising drug targets for intrahepatic cholangiocarcinoma, a rare cancer with a poor prognosis. Futibatinib, a next-generation, covalently binding FGFR1-4 inhibitor, has been shown to have both antitumor activity in patients with FGFR-altered tumors and strong preclinical activity against acquired resistance mutations associated with ATP-competitive FGFR inhibitors. METHODS: In this multinational, open-label, single-group, phase 2 study, we enrolled patients with unresectable or metastatic FGFR2 fusion-positive or FGFR2 rearrangement-positive intrahepatic cholangiocarcinoma and disease progression after one or more previous lines of systemic therapy (excluding FGFR inhibitors). The patients received oral futibatinib at a dose of 20 mg once daily in a continuous regimen. The primary end point was objective response (partial or complete response), as assessed by independent central review. Secondary end points included the response duration, progression-free and overall survival, safety, and patient-reported outcomes. RESULTS: Between April 16, 2018, and November 29, 2019, a total of 103 patients were enrolled and received futibatinib. A total of 43 of 103 patients (42%; 95% confidence interval, 32 to 52) had a response, and the median duration of response was 9.7 months. Responses were consistent across patient subgroups, including patients with heavily pretreated disease, older adults, and patients who had co-occurring TP53 mutations. At a median follow-up of 17.1 months, the median progression-free survival was 9.0 months and overall survival was 21.7 months. Common treatment-related grade 3 adverse events were hyperphosphatemia (in 30% of the patients), an increased aspartate aminotransferase level (in 7%), stomatitis (in 6%), and fatigue (in 6%). Treatment-related adverse events led to permanent discontinuation of futibatinib in 2% of the patients. No treatment-related deaths occurred. Quality of life was maintained throughout treatment. CONCLUSIONS: In previously treated patients with FGFR2 fusion or rearrangement-positive intrahepatic cholangiocarcinoma, the use of futibatinib, a covalent FGFR inhibitor, led to measurable clinical benefit. (Funded by Taiho Oncology and Taiho Pharmaceutical; FOENIX-CCA2 ClinicalTrials.gov number, NCT02052778.).

FGFR2 Inhibition in Cholangiocarcinoma.

Biliary tract cancer (BTC) is the second most common primary liver cancer after hepatocellular carcinoma and accounts for 2% of cancer-related deaths. BTCs are classified according to their anatomical origin into intrahepatic (iCCA), perihilar, or distal cholangiocarcinoma, as well as gall bladder carcinoma. While the mutational profiles in these anatomical BTC subtypes overlap to a large extent, iCCA is notable for the high frequency of IDH1/2 mutations (10-22%) and the nearly exclusive occurrence of FGFR2 fusions in 10-15% of patients. In recent years, FGFR2 fusions have become one of the most promising targets for precision oncology targeting BTC, with FGFR inhibitors already approved in Europe and the United States for patients with advanced, pretreated iCCA. While the therapeutic potential of nonfusion alterations is still under debate, it is expected that the field of FGFR2-directed therapies will be subject to rapid further evolution and optimization. The scope of this review is to provide an overview of oncogenic FGFR signaling in iCCA cells and highlight the pathophysiology, diagnostic testing strategies, and therapeutic promises and challenges associated with FGFR2-altered iCCA.

Heterogeneity, crosstalk, and targeting of cancer-associated fibroblasts in cholangiocarcinoma.

Cholangiocarcinoma (CCA) comprises diverse tumors of the biliary tree and is characterized by late diagnosis, short-term survival, and chemoresistance. CCAs are mainly classified according to their anatomical location and include diverse molecular subclasses harboring inter-tumoral and intratumoral heterogeneity. Besides the tumor cell component, CCA is also characterized by a complex and dynamic tumor microenvironment where tumor cells and stromal cells crosstalk in an intricate network of interactions. Cancer-associated fibroblasts, one of the most abundant cell types in the tumor stroma of CCA, are actively involved in cholangiocarcinogenesis by participating in multiple aspects of the disease including extracellular matrix remodeling, immunomodulation, neo-angiogenesis, and metastasis. Despite their overall tumor-promoting role, recent evidence indicates the presence of transcriptional and functional heterogeneous CAF subtypes with tumor-promoting and tumor-restricting properties. To elucidate the complexity and potentials of cancer-associated fibroblasts as therapeutic targets in CCA, this review will discuss the origin of cancer-associated fibroblasts, their heterogeneity, crosstalk, and role during tumorigenesis, providing an overall picture of the present and future perspectives toward cancer-associated fibroblasts targeting CCA.

PTPN9 dephosphorylates FGFR2 pY656/657 through interaction with ACAP1 and ameliorates pemigatinib effect in cholangiocarcinoma.

ABSTRACT AND AIM: Cholangiocarcinoma (CCA) is a highly aggressive and lethal cancer that originates from the biliary epithelium. Systemic treatment options for CCA are currently limited, and the first targeted drug of CCA, pemigatinib, emerged in 2020 for CCA treatment by inhibiting FGFR2 phosphorylation. However, the regulatory mechanism of FGFR2 phosphorylation is not fully elucidated. APPROACH AND RESULTS: Here we screened the FGFR2-interacting proteins and showed that protein tyrosine phosphatase (PTP) N9 interacts with FGFR2 and negatively regulates FGFR2 pY656/657 . Using phosphatase activity assays and modeling the FGFR2-PTPN9 complex structure, we identified FGFR2 pY656/657 as a substrate of PTPN9, and found that sec. 14p domain of PTPN9 interacts with FGFR2 through ACAP1 mediation. Coexpression of PTPN9 and ACAP1 indicates a favorable prognosis for CCA. In addition, we identified key amino acids and motifs involved in the sec. 14p-APCP1-FGFR2 interaction, including the "YRETRRKE" motif of sec. 14p, Y471 of PTPN9, as well as the PH and Arf-GAP domain of ACAP1. Moreover, we discovered that the FGFR2 I654V substitution can decrease PTPN9-FGFR2 interaction and thereby reduce the effectiveness of pemigatinib treatment. Using a series of in vitro and in vivo experiments including patient-derived xenografts (PDX), we showed that PTPN9 synergistically enhances pemigatinib effectiveness and suppresses CCA proliferation, migration, and invasion by inhibiting FGFR2 pY656/657 . CONCLUSIONS: Our study identifies PTPN9 as a negative regulator of FGFR2 phosphorylation and a synergistic factor for pemigatinib treatment. The molecular mechanism, oncogenic function, and clinical significance of the PTPN9-ACAP1-FGFR2 complex are revealed, providing more evidence for CCA precision treatment.

Chemotherapy with or without selective internal radiation therapy for intrahepatic cholangiocarcinoma: Data from clinical trials.

BACKGOUND AND AIMS: In advanced, liver-only intrahepatic cholangiocarcinoma (iCCA), selective internal radiation therapy (SIRT) has been suggested as promising in nonrandomized studies. We aimed to compare data from patients with advanced, liver-only iCCA treated in the first line in clinical trials with either chemotherapy alone or the combination with SIRT. APPROACH AND RESULTS: We collected individual patients' data from the ABC-01, ABC-02, ABC-03, BINGO, AMEBICA, and MISPHEC prospective trials. Data from patients with liver-only iCCA treated in chemotherapy-only arms of the first 5 trials were compared with data from patients treated with SIRT and chemotherapy in MISPHEC. Emulated target trial paradigm and Inverse Probability of Treatment Weighting (IPTW methods) using the propensity score were used to minimize biases. We compared 41 patients treated with the combination with 73 patients treated with chemotherapy alone, the main analysis being in 43 patients treated with cisplatin-gemcitabine or gemcitabine-oxaliplatin. After weighting, overall survival was significantly higher in patients treated with SIRT: median 21.7 months (95% CI: 14.1; not reached) versus 15.9 months(95% CI: 9.8; 18.9), HR = 0.59 (95% CI: 0.34; 0.99), p = 0.049. Progression-free survival was significantly improved: median 14.3 months (95% CI: 7.8; not reached) versus 8.4 months (95% CI: 5.9; 12.1), HR = 0.52 (95% CI: 0.31; 0.89), p < 0.001. Results were confirmed in most sensitivity analyses. CONCLUSIONS: This analysis derived from prospective clinical trials suggests that SIRT combined with chemotherapy might improve outcomes over chemotherapy alone in patients with advanced, liver-only iCCA. Randomized controlled evidence is needed to confirm these findings.

Bile exosomal miR-182/183-5p increases cholangiocarcinoma stemness and progression by targeting HPGD and increasing PGE2 generation.

BACKGROUND AIMS: Cholangiocarcinoma (CCA) is a highly lethal malignancy originating from the biliary ducts. Current CCA diagnostic and prognostic assessments cannot satisfy the clinical requirement. Bile detection is rarely performed, and herein, we aim to estimate the clinical significance of bile liquid biopsy by assessing bile exosomal concentrations and components. APPROACH RESULTS: Exosomes in bile and sera from CCA, pancreatic cancer, and common bile duct stone were identified and quantified by transmission electronmicroscopy, nanoparticle tracking analysis, and nanoFCM. Exosomal components were assessed by liquid chromatography with tandem mass spectrometry and microRNA sequencing (miRNA-seq). Bile exosomal concentration in different diseases had no significant difference, but miR-182-5p and miR-183-5p were ectopically upregulated in CCA bile exosomes. High miR-182/183-5p in both CCA tissues and bile indicates a poor prognosis. Bile exosomal miR-182/183-5p is secreted by CCA cells and can be absorbed by biliary epithelium or CCA cells. With xenografts in humanized mice, we showed that bile exosomal miR-182/183-5p promotes CCA proliferation, invasion, and epithelial-mesenchymal transition (EMT) by targeting hydroxyprostaglandin dehydrogenase in CCA cells and mast cells (MCs), and increasing prostaglandin E2 generation, which stimulates PTGER1 and increases CCA stemness. In single-cell mRNA-seq, hydroxyprostaglandin dehydrogenase is predominantly expressed in MCs. miR-182/183-5p prompts MC to release VEGF-A release from MC by increasing VEGF-A expression, which facilitates angiogenesis. CONCLUSIONS: CCA cells secret exosomal miR-182/183-5p into bile, which targets hydroxyprostaglandin dehydrogenase in CCA cells and MCs and increases prostaglandin E2 and VEGF-A release. Prostaglandin E2 promotes stemness by activating PTGER1. Our results reveal a type of CCA self-driven progression dependent on bile exosomal miR-182/183-5p and MCs, which is a new interplay pattern of CCA and bile.

Telomere length and risk of cirrhosis, hepatocellular carcinoma, and cholangiocarcinoma in 63,272 individuals from the general population.

BACKGROUND AND AIMS: Inherited short telomeres are associated with a risk of liver disease, whereas longer telomeres predispose to cancer. The association between telomere length and risk of HCC and cholangiocarcinoma remains unknown. APPROACH AND RESULTS: We measured leukocyte telomere length using multiplex PCR in 63,272 individuals from the Danish general population. Telomere length and plasma ALT concentration were not associated (ß = 4 ×10 -6 , p -value = 0.06) in a linear regression model, without any signs of a nonlinear relationship. We tested the association between telomere length and risk of cirrhosis, HCC, and cholangiocarcinoma using Cox regression. During a median follow-up of 11 years, 241, 76, and 112 individuals developed cirrhosis, HCC, and cholangiocarcinoma, respectively. Telomere length and risk of cirrhosis were inversely and linearly associated ( p -value = 0.004, p for nonlinearity = 0.27). Individuals with telomeres in the shortest vs. longest quartile had a 2.25-fold higher risk of cirrhosis. Telomere length and risk of HCC were nonlinearly associated ( p -value = 0.009, p -value for nonlinearity = 0.01). This relationship resembled an inverted J-shape, with the highest risk observed in individuals with short telomeres. Individuals with telomeres in the shortest versus longest quartile had a 2.29-fold higher risk of HCC. Telomere length was inversely and linearly associated with the risk of cholangiocarcinoma. Individuals with telomeres in the shortest versus longest quartile had a 1.86-fold higher risk of cholangiocarcinoma. CONCLUSIONS: Shorter telomere length is associated with a higher risk of cirrhosis, HCC, and cholangiocarcinoma.

Direct Reprogramming of Hepatocytes Into JAK/Stat-Dependent LGR5+ Liver Cells Able to Initiate Intrahepatic Cholangiocarcinoma.

Somatic cells that have been partially reprogrammed by the factors Oct4, Sox2, Klf4, and cMyc (OSKM) have been demonstrated to be potentially tumorigenic in vitro and in vivo due to the acquisition of cancer-associated genomic alterations and the absence of OSKM clearance over time. In the present study, we obtained partially reprogrammed, SSEA1-negative cells by transducing murine hepatocytes with Δ1Δ3-deleted adenoviruses that expressed the 4 OSKM factors. We observed that, under long-term 2D and 3D culture conditions, hepatocytes could be converted into LGR5-positive cells with self-renewal capacity that was dependent on 3 cross-signaling pathways: IL6/Jak/Stat3, LGR5/R-spondin, and Wnt/ß-catenin. Following engraftment in syngeneic mice, LGR5-positive cells that expressed the cancer markers CD51, CD166, and CD73 were capable of forming invasive and metastatic tumors reminiscent of intrahepatic cholangiocarcinoma (ICC): they were positive for CK19 and CK7, featured associations of cord-like structures, and contained cuboidal and atypical cells with dissimilar degrees of pleomorphism and mitosis. The LGR5+-derived tumors exhibited a highly vascularized stroma with substantial fibrosis. In addition, we identified pro-angiogenic factors and signaling pathways involved in neo-angiogenesis and vascular development, which represent potential new targets for anti-angiogenic strategies to overcome tumor resistance to current ICC treatments.

Integrated analyses of the genetic and clinicopathological features of cholangiolocarcinoma: cholangiolocarcinoma may be characterized by mismatch-repair deficiency.

Cholangiolocarcinoma (CLC) is a primary liver carcinoma that resembles the canals of Hering and that has been reported to be associated with stem cell features. Due to its rarity, the nature of CLC remains unclear, and its pathological classification remains controversial. To clarify the positioning of CLC in primary liver cancers and identify characteristics that could distinguish CLC from other liver cancers, we performed integrated analyses using whole-exome sequencing (WES), immunohistochemistry, and a retrospective review of clinical information on eight CLC cases and two cases of recurrent CLC. WES demonstrated that CLC includes IDH1 and BAP1 mutations, which are characteristic of intrahepatic cholangiocarcinoma (iCCA). A mutational signature analysis showed a pattern similar to that of iCCA, which was different from that of hepatocellular carcinoma (HCC). CLC cells, including CK7, CK19, and EpCAM, were positive for cholangiocytic differentiation markers. However, the hepatocytic differentiation marker AFP and stem cell marker SALL4 were completely negative. The immunostaining patterns of CLC with CD56 and epithelial membrane antigen were similar to those of the noncancerous bile ductules. In contrast, mutational signature cluster analyses revealed that CLC formed a cluster associated with mismatch-repair deficiency (dMMR), which was separate from iCCA. Therefore, to evaluate MMR status, we performed immunostaining of four MMR proteins (PMS2, MSH6, MLH1, and MSH2) and detected dMMR in almost all CLCs. In conclusion, CLC had highly similar characteristics to iCCA but not to HCC. CLC can be categorized as a subtype of iCCA. In contrast, CLC has characteristics of dMMR tumors that are not found in iCCA, suggesting that it should be treated distinctly from iCCA. © 2024 The Pathological Society of Great Britain and Ireland.

Proteome Landscapes of Human Hepatocellular Carcinoma and Intrahepatic Cholangiocarcinoma.

Liver cancer is among the top leading causes of cancer mortality worldwide. Particularly, hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (CCA) have been extensively investigated from the aspect of tumor biology. However, a comprehensive and systematic understanding of the molecular characteristics of HCC and CCA remains absent. Here, we characterized the proteome landscapes of HCC and CCA using the data-independent acquisition (DIA) mass spectrometry (MS) method. By comparing the quantitative proteomes of HCC and CCA, we found several differences between the two cancer types. In particular, we found an abnormal lipid metabolism in HCC and activated extracellular matrix-related pathways in CCA. We next developed a three-protein classifier to distinguish CCA from HCC, achieving an area under the curve (AUC) of 0.92, and an accuracy of 90% in an independent validation cohort of 51 patients. The distinct molecular characteristics of HCC and CCA presented in this study provide new insights into the tumor biology of these two major important primary liver cancers. Our findings may help develop more efficient diagnostic approaches and new targeted drug treatments.

Regenerative failure of intrahepatic biliary cells in Alagille syndrome rescued by elevated Jagged/Notch/Sox9 signaling.

Despite the robust healing capacity of the liver, regenerative failure underlies numerous hepatic diseases, including the JAG1 haploinsufficient disorder, Alagille syndrome (ALGS). Cholestasis due to intrahepatic duct (IHD) paucity resolves in certain ALGS cases but fails in most with no clear mechanisms or therapeutic interventions. We find that modulating jag1b and jag2b allele dosage is sufficient to stratify these distinct outcomes, which can be either exacerbated or rescued with genetic manipulation of Notch signaling, demonstrating that perturbations of Jag/Notch signaling may be causal for the spectrum of ALGS liver severities. Although regenerating IHD cells proliferate, they remain clustered in mutants that fail to recover due to a blunted elevation of Notch signaling in the distal-most IHD cells. Increased Notch signaling is required for regenerating IHD cells to branch and segregate into the peripheral region of the growing liver, where biliary paucity is commonly observed in ALGS. Mosaic loss- and-gain-of-function analysis reveals Sox9b to be a key Notch transcriptional effector required cell autonomously to regulate these cellular dynamics during IHD regeneration. Treatment with a small-molecule putative Notch agonist stimulates Sox9 expression in ALGS patient fibroblasts and enhances hepatic sox9b expression, rescues IHD paucity and cholestasis, and increases survival in zebrafish mutants, thereby providing a proof-of-concept therapeutic avenue for this disorder.

Genomic and transcriptomic characteristics of 12 novel primary cell lines derived from three patients with cholangiocarcinoma.

Cholangiocarcinoma (CCA) is an aggressive bile duct malignancy with poor prognosis. To improve our understanding of the biological characteristics of CCA and develop effective therapies, appropriate preclinical models are required. Here, we established and characterized 12 novel patient-derived primary cancer cell (PDPC) models using multi-region sampling. At the genomic level of PDPCs, we observed not only commonly mutated genes, such as TP53, JAK3, and KMT2C, consistent with the reports in CCA, but also specific mutation patterns in each cell line. In addition, specific expression patterns with distinct biological functions and pathways involved were also observed in the PDPCs at the transcriptomic level. Furthermore, the drug-sensitivity results revealed that the PDPCs exhibited different responses to the six commonly used compounds. Our findings indicate that the established PDPCs can serve as novel in vitro reliable models to provide a crucial molecular basis for improving the understanding of tumorigenesis and its treatment.

Molecular portraits of patients with intrahepatic cholangiocarcinoma who diverge as rapid progressors or long survivors on chemotherapy.

OBJECTIVE: Cytotoxic agents are the cornerstone of treatment for patients with advanced intrahepatic cholangiocarcinoma (iCCA), despite heterogeneous benefit. We hypothesised that the pretreatment molecular profiles of diagnostic biopsies can predict patient benefit from chemotherapy and define molecular bases of innate chemoresistance. DESIGN: We identified a cohort of advanced iCCA patients with comparable baseline characteristics who diverged as extreme outliers on chemotherapy (survival <6 m in rapid progressors, RP; survival >23 m in long survivors, LS). Diagnostic biopsies were characterised by digital pathology, then subjected to whole-transcriptome profiling of bulk and geospatially macrodissected tissue regions. Spatial transcriptomics of tumour-infiltrating myeloid cells was performed using targeted digital spatial profiling (GeoMx). Transcriptome signatures were evaluated in multiple cohorts of resected cancers. Signatures were also characterised using in vitro cell lines, in vivo mouse models and single cell RNA-sequencing data. RESULTS: Pretreatment transcriptome profiles differentiated patients who would become RPs or LSs on chemotherapy. Biologically, this signature originated from altered tumour-myeloid dynamics, implicating tumour-induced immune tolerogenicity with poor response to chemotherapy. The central role of the liver microenviroment was confrmed by the association of the RPLS transcriptome signature with clinical outcome in iCCA but not extrahepatic CCA, and in liver metastasis from colorectal cancer, but not in the matched primary bowel tumours. CONCLUSIONS: The RPLS signature could be a novel metric of chemotherapy outcome in iCCA. Further development and validation of this transcriptomic signature is warranted to develop precision chemotherapy strategies in these settings.

Ferroptosis-related gene glutathione peroxidase 4 promotes reprogramming of glucose metabolism via Akt-mTOR axis in intrahepatic cholangiocarcinoma.

The role of the ferroptosis-related gene glutathione peroxidase 4 (GPX4) in oncology has been extensively investigated. However, the clinical implications of GPX4 in patients with intrahepatic cholangiocarcinoma (ICC) remain unknown. This study aimed to evaluate the prognostic impact of GPX4 and its underlying molecular mechanisms in patients with ICC. Fifty-seven patients who underwent surgical resection for ICC between 2010 and 2017 were retrospectively analyzed. Based on the immunohistochemistry, patients were divided into GPX4 high (n = 15) and low (n = 42) groups, and clinical outcomes were assessed. Furthermore, the roles of GPX4 in cell proliferation, migration and gene expression were analyzed in ICC cell lines in vitro and in vivo. The results from clinical study showed that GPX4 high group showed significant associations with high SUVmax on 18F-fluorodeoxyglucose-positron emission tomography (≥8.0, P = 0.017), multiple tumors (P = 0.004), and showed glucose transporter 1 (GLUT1) high expression with a trend toward significance (P = 0.053). Overall and recurrence-free survival in the GPX4 high expression group were significantly worse than those in the GPX4 low expression group (P = 0.038 and P < 0.001, respectively). In the experimental study, inhibition of GPX4 attenuated cell proliferation and migration in ICC cell lines. Inhibition of GPX4 also decreased the expression of glucose metabolism-related genes, such as GLUT1 or HIF1α. Mechanistically, these molecular changes are regulated in Akt-mechanistic targets of rapamycin axis. In conclusion, this study suggested the pivotal value of GPX4 serving as a prognostic marker for patients with ICC. Furthermore, GPX4 can mediate glucose metabolism of ICC.

Degradation of AZGP1 suppresses apoptosis and facilitates cholangiocarcinoma tumorigenesis via TRIM25.

Alpha-2-Glycoprotein 1, Zinc-binding (AZGP1, ZAG) is a secreted protein that is synthesized by adipocytes and epithelial cells; it is downregulated in several malignancies such as breast, prostate, liver and lung cancers. However, its function remains unclear in cholangiocarcinoma (CCA). Here, we evaluated the impact AZGP1 in CCA using Gene Expression Omnibus (GEO) and GEPIA. In addition, we analysed AZGP1 expression using quantitative reverse transcription PCR and western blotting. Expression of AZGP1 was nearly deficient in CCA patients and cell lines and was associated with poor prognosis. AZGP1 overexpression upregulated apoptosis markers. Co-immunoprecipitation experiments showed that AZGP1 interacts with tripartite motif-containing protein 25 (TRIM25), and tissue microarray and bioinformatic analysis showed that AZGP1 is negatively correlated with TRIM25 expression in CCA. Thereafter, TRIM25 knockdown led to AZGP1 upregulation and induced cancer cell apoptosis. TRIM25 targets AZGP1 for degradation by catalysing its ubiquitination. AZGP1 overexpression significantly suppressed tumour growth in a xenograft mouse model. This study findings suggest that AZGP1 is a potential therapeutic target or a diagnostic biomarker for treating patients with CCA.

Downregulation of JAM3 occurs in cholangiocarcinoma by hypermethylation: A potential molecular marker for diagnosis and prognosis.

Junctional adhesion molecular 3 (JAM3) is downregulated by hypermethylation in cancers but is unclear in cholangiocarcinoma. The JAM3 expression level was checked in cholangiocarcinoma cell lines and tissues. Methylated JAM3 was detected in cell lines, tissues and plasma cell-free DNAs (cfDNA). The roles of JAM3 in cholangiocarcinoma were studied by transfection of siRNA and pCMV3-JAM3. The survival analysis was based on the Gene Set Cancer Analysis (GSCA) database. JAM3 was downregulated in HCCC-9810 and HuCCT1 cell lines and tissues by hypermethylation. Methylated JAM3 was detected in cfDNAs with 53.3% sensitivity and 96.6% specificity. Transfection of pCMV3-JAM3 into HCCC-9810 and HuCCT1 induced apoptosis and suppressed cell proliferation, migration and invasion. The depletion of JAM3 in RBE cells using siRNA decreased apoptosis and increased cell proliferation, migration and invasion. Hypermethylation of JAM3 was associated with tumour differentiation, metastasis and TNM stage. Downregulation and hypermethylation of JAM3 were related to poor progression-free survival. Junctional adhesion molecular 3 may function as a tumour suppressor in cholangiocarcinoma. Methylated JAM3 DNA may represent a non-invasive molecular marker for the early detection of cholangiocarcinoma and prognosis.

CircPCNXL2 promotes tumor growth and metastasis by interacting with STRAP to regulate ERK signaling in intrahepatic cholangiocarcinoma.

BACKGROUND: circular RNAs (circRNAs) have been reported to exert important effects in the progression of numerous cancers. However, the functions of circRNAs in intrahepatic cholangiocarcinoma (ICC) are still unclear. METHODS: circPCNXL2 (has_circ_0016956) were identified in paired ICC by circRNA microarray. Then, we assessed the biological functions of circPCNXL2 by CCK8, EdU, clone formation, transwell, wound healing assays, and xenograft models. RNA pull-down, mass spectrometry, and RNA immunoprecipitation (RIP) were applied to explore the interaction between cirrcPCNXL2 and serine-threonine kinase receptor-associated protein (STRAP). RNA pull-down, RIP and luciferase reporter assays were used to investigate the sponge functions of circPCNXL2. In the end, we explore the effects of circPCNXL2 and trametinib (a MEK1/2 inhibitor) in vivo. RESULTS: circPCNXL2 was upregulated in ICC tissues and cell lines, which promoted the proliferation and metastasis of ICC in vitro and in vivo. In terms of the mechanisms, circPCNXL2 could directly bind to STRAP and induce the interaction between STRAP and MEK1/2, resulting in the tumor promotion in ICC by activation of ERK/MAPK pathways. Besides, circPCNXL2 could regulate the expression of SRSF1 by sponging miR-766-3p and subsequently facilitated the growth of ICC. Finally, circPCNXL2 could partially inhibit the anti-tumor activity of trametinib in vivo. CONCLUSION: circPCNXL2 played a crucial role in the progression of ICC by interacting with STRAP to activate the ERK signaling pathway, as well as by modulating the miR-766-3p/SRSF1 axis. These findings suggest that circPCNXL2 may be a promising biomarker and therapeutic target for ICC.