MAL2 reprograms lipid metabolism in intrahepatic cholangiocarcinoma via EGFR/SREBP-1 pathway based on single-cell RNA sequencing.

Intrahepatic cholangiocarcinoma (ICC) is a highly aggressive cancer characterized by a poor prognosis and resistance to chemotherapy. In this study, utilizing scRNA-seq, we discovered that the tetra-transmembrane protein mal, T cell differentiation protein 2 (MAL2), exhibited specific enrichment in ICC cancer cells and was strongly associated with a poor prognosis. The inhibition of MAL2 effectively suppressed cell proliferation, invasion, and migration. Transcriptomics and metabolomics analyses suggested that MAL2 promoted lipid accumulation in ICC by stabilizing EGFR membrane localization and activated the PI3K/AKT/SREBP-1 axis. Molecular docking and Co-IP proved that MAL2 interacted directly with EGFR. Based on constructed ICC organoids, the downregulation of MAL2 enhanced apoptosis and sensitized ICC cells to cisplatin. Lastly, we conducted a virtual screen to identify sarizotan, a small molecule inhibitor of MAL2, and successfully validated its ability to inhibit MAL2 function. Our findings highlight the tumorigenic role of MAL2 and its involvement in cisplatin sensitivity, suggesting the potential for novel combination therapeutic strategies in ICC.

Iodine-125 seed inhibits proliferation and promotes apoptosis of cholangiocarcinoma cells by inducing the ROS/p53 axis.

With advances in radioactive particle implantation in clinical practice, Iodine-125 (125I) seed brachytherapy has emerged as a promising treatment for cholangiocarcinoma (CCA), showing good prognosis; however, the underlying molecular mechanism of the therapeutic effect of 125I seed is unclear. To study the effects of 125I seed on the proliferation and apoptosis of CCA cells. CCA cell lines, RBE and HCCC-9810, were treated with reactive oxygen species (ROS) scavenger acetylcysteine (NAC) or the p53 functional inhibitor, pifithrin-α hydrobromide (PFTα). Cell counting kit-8 (CCK-8) assay, 5-bromo-2-deoxy-uridine (BrdU) staining, and terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) assay and flow cytometry assay were performed to test the radiation-sensitivity of 125I seed toward CCA cells at different radiation doses (0.4 mCi and 0.8 mCi). 2,7-dichlorofluorescein diacetate (DCF-DA) assay, real-time quantitative polymerase chain reaction (RT-qPCR), and western blot analysis were performed to assess the effect of 125I seed on the ROS/p53 axis. A dose-dependent inhibitory effect of 125I seeds on the proliferation of CCA cells was observed. The 125I seed promoted apoptosis of CCA cells and induced the activation of the ROS/p53 pathway in a dose-dependent manner. NAC or PFTα treatment effectively reversed the stimulatory effect of 125I seed on the proliferation of CCA cells. NAC or PFTα suppressed apoptosis and p53 protein expression induced by the 125I seed. 125I seed can inhibit cell growth mainly through the apoptotic pathway. The mechanism may involve the activation of p53 and its downstream apoptotic pathway by up-regulating the level of ROS in cells.

Digitoxin inhibits ICC cell properties via the NF­κB/ST6GAL1 signaling pathway.

Intrahepatic cholangiocarcinoma (ICC) is a type of liver cancer associated with poor prognosis and increased mortality; the limited treatment strategy highlights the urgent need for investigation. Traditional Chinese Medicine (TCM), used alone or in combination with other treatments, can enhance therapeutic efficacy, improve life quality of patients and extend overall survival. In total, two rounds of screening of a TCM library of 2,538 active compounds were conducted using a Cell Counting Kit­8 assay and ICC cell lines. Cell proliferation and migration abilities were assessed through colony formation, 5­ethynyl­2'­deoxyuridine, would healing and Transwell assays. The impact of digitoxin (DT) on signaling pathways was initially investigated using RNA sequencing and further validated using reverse transcription­quantitative PCR, western blotting, lectin blotting and flow cytometry. ICC cells stably overexpressing ST6 ß­galactoside α­2,6­sialyltransferase 1 (ST6GAL1) were generated through lentiviral transfection. It was shown that DT emerged as a highly effective anti­ICC candidate from two rounds high­throughput library screening. DT could inhibit the proliferation and migration of ICC cells by suppressing NF­κB activation and reducing nuclear phosphorylated­NF­κB levels, along with diminishing ST6GAL1 mRNA and protein expression. The aforementioned biological effects and signal pathways of DT could be counteracted by overexpressing ST6GAL1 in ICC cells. In conclusion, DT suppressed ICC cell proliferation and migration by targeting the NF­κB/ST6GAL1 signaling axis. The findings of the present study indicated the promising therapeutic effects of DT in managing ICC, offering new avenues for treatment strategies.

Nanoliposomal irinotecan and fluorouracil plus leucovorin versus fluorouracil plus leucovorin in patients with cholangiocarcinoma and gallbladder carcinoma previously treated with gemcitabine-based therapies (AIO NALIRICC): a multicentre, open-label, randomised, phase 2 trial.

BACKGROUND: There is an unmet need for effective therapies in pretreated advanced biliary tract cancer. We aimed to evaluate the efficacy of nanoliposomal irinotecan and fluorouracil plus leucovorin compared with fluorouracil plus leucovorin as second-line treatment for biliary tract cancer. METHODS: NALIRICC was a multicentre, open-label, randomised, phase 2 trial done in 17 German centres for patients aged 18 years or older, with an Eastern Cooperative Oncology Group performance status of 0-1, metastatic biliary tract cancer, and progression on gemcitabine-based therapy. Patients were randomly assigned (1:1) to receive intravenous infusions of nanoliposomal irinotecan (70 mg/m2), fluorouracil (2400 mg/m2), and leucovorin (400 mg/m2) every 2 weeks (nanoliposomal irinotecan group) or fluorouracil (2400 mg/m2) plus leucovorin (400 mg/m2) every 2 weeks (control group). Randomisation was by permutated block randomisation in block sizes of four, stratified by primary tumour site. Investigator-assessed progression-free survival was the primary endpoint, which was evaluated in all randomly assigned patients. Secondary efficacy outcomes were overall survival, objective response rate, and quality of life. Safety was assessed in all randomly assigned patients who received at least one dose of the study treatment. Enrolment for this trial has been completed, and it is registered with ClinicalTrials.gov, NCT03043547. FINDING: Between Dec 4, 2017, and Aug 2, 2021, 49 patients were randomly assigned to the nanoliposomal irinotecan group and 51 patients to the control group. Median age was 65 years (IQR 59-71); 45 (45%) of 100 patients were female. Median progression-free survival was 2·6 months (95% CI 1·7-3·6) in the nanoliposomal irinotecan group and 2·3 months (1·6-3·4) in the control group (hazard ratio [HR] 0·87 [0·56-1·35]). Median overall survival was 6·9 months (95% CI 5·3-10·6) in the nanoliposomal irinotecan group and 8·2 months (5·4-11·9) in the control group (HR 1·08 [0·68-1·72]). The objective response rate was 14% (95% CI 6-27; seven patients) in the nanoliposomal irinotecan group and 4% (1-14; two patients) in the control group. The most common grade 3 or worse adverse events in the nanoliposomal irinotecan group were neutropenia (eight [17%] of 48 vs none in the control group), diarrhoea (seven [15%] vs one [2%]), and nausea (four [8%] vs none). In the control group, the most common grade 3 or worse adverse events were cholangitis (four [8%] patients vs none in the nanoliposomal irinotecan group) and bile duct stenosis (four [8%] vs three [6%]). Treatment-related serious adverse events occurred in 16 (33%) patients in the nanoliposomal irinotecan group (grade 2-3 diarrhoea in five patients; one case each of abdominal infection, acute kidney injury, pancytopenia, increased blood bilirubin, colitis, dehydration, dyspnoea, infectious enterocolitis, ileus, oral mucositis, and nausea). One (2%) treatment-related serious adverse event occurred in the control group (worsening of general condition). Median duration until deterioration of global health status, characterised by the time from randomisation to the initial observation of a score decline exceeding 10 points, was 4·0 months (95% CI 2·2-not reached) in the nanoliposomal irinotecan group and 3·7 months (2·7-not reached) in the control group. INTERPRETATION: The addition of nanoliposomal irinotecan to fluorouracil plus leucovorin did not improve progression-free survival or overall survival and was associated with higher toxicity compared with fluorouracil plus leucovorin. Further research is necessary to define the role of irinotecan-based combinations in second-line treatment of biliary tract cancer. FUNDING: Servier and AIO-Studien.

Liraglutide exhibits potential anti-tumor effects on the progression of intrahepatic cholangiocarcinoma, in vitro and in vivo.

Glucagon-like peptide 1 receptor (GLP-1R) agonist is an emerging anti-diabetic medication whose effects on the risk and progression of cholangiocarcinoma (CCA) are controversial. This study aimed to elucidate the roles of GLP-1R and its agonists on intrahepatic CCA (iCCA) progression. Expressions of GLP-1R in iCCA tissues investigated by immunohistochemistry showed that GLP-1R expressions were significantly associated with poor histological grading (P = 0.027). iCCA cell lines, KKU-055 and KKU-213A, were treated with exendin-4 and liraglutide, GLP-1R agonists, and their effects on proliferation and migration were assessed. Exendin-4 and liraglutide did not affect CCA cell proliferation in vitro, but liraglutide significantly suppressed the migration of CCA cells, partly by inhibiting epithelial-mesenchymal transition. In contrast, liraglutide significantly reduced CCA tumor volumes and weights in xenografted mice (P = 0.046). GLP-1R appeared downregulated when CCA cells were treated with liraglutide in vitro and in vivo. In addition, liraglutide treatment significantly suppressed Akt and STAT3 signaling in CCA cells, by reducing their phosphorylation levels. These results suggested that liraglutide potentially slows down CCA progression, and further clinical investigation would benefit the treatment of CCA with diabetes mellitus.

Real-world outcomes of chemotherapy plus immune checkpoint inhibitors versus chemotherapy alone in advanced, unresectable, and recurrent intrahepatic cholangiocarcinoma.

Background: There are limited treatment options available to improve the prognosis of patients with advanced or metastatic cholangiocarcinoma particularly intrahepatic cholangiocarcinoma (iCCA). This study aimed to evaluate the efficacy and safety of combining chemotherapy plus anti-PD-1/L1 drugs compared to chemotherapy alone in advanced, unresectable, and recurrent intrahepatic cholangiocarcinoma patients. Methods: Patients with advanced, unresectable, or recurrent iCCA who received chemotherapy combined with PD-1/PD-L1 inhibitors or chemotherapy alone were retrospectively screened and analyzed. The primary outcomes were overall survival (OS) and progression-free survival (PFS). The secondary outcomes were overall response rate (ORR), disease control rate (DCR), and safety. Results: 81 eligible patients were included in the study (chemotherapy plus anti-PD-1/L1 group n=51, and chemotherapy-alone group n=30). The median OS was 11 months for the chemotherapy plus anti-PD-1/L1 group, significantly longer than the 8 months in the chemotherapy-alone group, with a hazard ratio (HR) of 0.53 (95% CI 0.30-0.94, P = 0.008). The median PFS of 7 months in the chemotherapy plus anti-PD-1/L1 group was significantly longer than the 4 months in the chemotherapy-alone group, with HR of 0.48 (95% CI 0.27-0.87); P = 0.002). Similarly, the combined therapy group showed a higher ORR (29.4%) and DCR (78.4%) compared to 13.3% and 73.3% in the chemotherapy-alone group, respectively. More grade 3-4 treatment-related adverse effects were recorded in the chemotherapy plus anti-PD-1/L1 group (66.7%) compared to the chemotherapy-alone group (23.3%), however, they were manageable and tolerable. Conclusion: Chemotherapy plus anti-PD-1/L1 represents a more effective and tolerable treatment option for advanced, unresectable, and recurrent iCCA patients compared to chemotherapy alone.

PTEN status determines therapeutic vulnerability to celastrol in cholangiocarcinoma.

BACKGROUND: A balanced protein homeostasis network helps cholangiocarcinoma (CCA) maintain their oncogenic growth, and disrupting proteostasis therapeutically will induce proteotoxic stress. Phosphatase and tensin homolog (PTEN) have been reported to be involved in proteostasis, and PTEN-associated pathways are commonly altered in CCA. Celastrol, a triterpene from plants, exhibits cytotoxic effects in various types of cancer. However, the underlying mechanisms remain unclear. PURPOSE: We investigated the therapeutic effect of celastrol in CCA and identified the molecular characteristics of tumors that were sensitive to celastrol. The target of celastrol was explored. We then evaluated the candidate combination therapeutic strategy to increase the effectiveness of celastrol in celastrol-insensitive CCA tumors. METHODS: Various CCA cells were categorized as either celastrol-sensitive or celastrol-insensitive based on their response to celastrol. The molecular characteristics of cells from different groups were determined by RNA-seq. PTEN status and its role in proteasome activity in CCA cells were investigated. The CMAP analysis, molecular docking, and functional assay were performed to explore the effect of celastrol on proteasome activities. The correlation between PTEN status and clinical outcomes, as well as proteasomal activity, were measured in CCA patients. The synergistic therapeutic effect of autophagy inhibitors on celastrol-insensitive CCA cells were measured. RESULTS: Diverse responses to celastrol were observed in CCA cells. PTEN expression varied among different CCA cells, and its status could impact cell sensitivity to celastrol: PTENhigh tumor cells were resistant to celastrol, while PTENlow cells were more sensitive. Celastrol induced proteasomal dysregulation in CCA cells by directly targeting PSMB5. Cells with low PTEN status transcriptionally promoted proteasome subunit expression in an AKT-dependent manner, making these cells more reliant on proteasomal activities to maintain proteostasis. This caused the PTENlow CCA cells sensitive to celastrol. A negative correlation was found between PTEN levels and the proteasome signature in CCA patients. Moreover, celastrol treatment could induce autophagy in PTENhigh CCA cells. Disrupting the autophagic pathway in PTENhigh CCA cells enhanced the cytotoxic effect of celastrol. CONCLUSION: PTEN status in CCA cells determines their sensitivity to celastrol, and autophagy inhibitors could enhance the anti-tumor effect in PTENhigh CCA.

First-line hepatic arterial infusion chemotherapy plus lenvatinib and PD-(L)1 inhibitors versus systemic chemotherapy alone or with PD-(L)1 inhibitors in unresectable intrahepatic cholangiocarcinoma.

PURPOSE: Limited treatment options exist for unresectable intrahepatic cholangiocarcinoma (ICC), with systemic chemotherapy (SC) serving as the primary approach. This study aimed to assess the effectiveness of first-line hepatic arterial infusion chemotherapy (HAIC) in combination with lenvatinib and PD-(L)1 inhibitors (HLP) compared to SC combined with PD-(L)1 inhibitors (SCP) or SC alone in treating unresectable ICC. METHODS: Patient with unresectable ICC who underwent first-line treatment with HLP, SCP or SC from January 2016 to December 2022 were retrospectively analyzed. The study evaluated and compared efficacy and safety outcomes across the three treatment groups. RESULTS: The study comprised 42, 49, and 50 patients in the HLP, SCP, and SC groups, respectively. Median progression-free survival (PFS) times were 30.0, 10.2, and 6.5 months for HLP, SCP, and SC groups. While the SC group had a median overall survival (OS) time of 21.8 months, the HLP and SCP groups hadn't reached median OS. The HLP group demonstrated significantly superior PFS (p < 0.001) and OS (p = 0.014) compared to the others. Moreover, the HLP group exhibited the highest objective response rate (ORR) at 50.0% and the highest disease control rate (DCR) at 88.1%, surpassing the SC group (ORR, 6.0%; DCR, 52.0%) and SCP group (ORR, 18.4%; DCR, 73.5%) (p < 0.05). Generally, the HLP group reported fewer grades 3-4 adverse events (AEs) compared with others. CONCLUSION: In contrast to systemic chemotherapy with or without PD-(L)1 inhibitors, the triple combination therapy incorporating HAIC, lenvatinib, and PD-(L)1 inhibitors showcased favorable survival benefits and manageable adverse events for unresectable ICC.

An open-label study of pemigatinib in cholangiocarcinoma: final results from FIGHT-202.

BACKGROUND: Fibroblast growth factor receptor 2 (FGFR2) fusions and rearrangements are clinically actionable genomic alterations in cholangiocarcinoma (CCA). Pemigatinib is a selective, potent, oral inhibitor of FGFR1-3 and demonstrated efficacy in patients with previously treated, advanced/metastatic CCA with FGFR2 alterations in FIGHT-202 (NCT02924376). We report final outcomes from the extended follow-up period. PATIENTS AND METHODS: The multicenter, open-label, single-arm, phase II FIGHT-202 study enrolled patients ≥18 years old with previously treated advanced/metastatic CCA with FGFR2 fusions or rearrangements (cohort A), other FGF/FGFR alterations (cohort B), or no FGF/FGFR alterations (cohort C). Patients received once-daily oral pemigatinib 13.5 mg in 21-day cycles (2 weeks on, 1 week off) until disease progression or unacceptable toxicity. The primary endpoint was objective response rate (ORR) in cohort A assessed as per RECIST v1.1 by an independent review committee; secondary endpoints included duration of response (DOR), progression-free survival (PFS), overall survival (OS), and safety. RESULTS: FIGHT-202 enrolled 147 patients (cohort A, 108; cohort B, 20; cohort C, 17; unconfirmed FGF/FGFR alterations, 2). By final analysis, 145 (98.6%) had discontinued treatment due to progressive disease (71.4%), withdrawal by patient (8.2%), or adverse events (AEs; 6.8%). Median follow-up was 45.4 months. The ORR in cohort A was 37.0% (95% confidence interval 27.9% to 46.9%); complete and partial responses were observed in 3 and 37 patients, respectively. Median DOR was 9.1 (6.0-14.5) months; median PFS and OS were 7.0 (6.1-10.5) months and 17.5 (14.4-22.9) months, respectively. The most common treatment-emergent AEs (TEAEs) were hyperphosphatemia (58.5%), alopecia (49.7%), and diarrhea (47.6%). Overall, 15 (10.2%) patients experienced TEAEs leading to pemigatinib discontinuation; intestinal obstruction and acute kidney injury (n = 2 each) occurred most frequently. CONCLUSIONS: Pemigatinib demonstrated durable response and prolonged OS with manageable AEs in patients with previously treated, advanced/metastatic CCA with FGFR2 alterations in the extended follow-up period of FIGHT-202.

Advanced Cholangiocarcinoma With High Tumor Mutation Burden Achieving Complete Response to Immune Check Point Inhibitor.

BACKGROUND/AIM: Genomic examination of tumor tissue has been clinically accepted, and the identification of actionable mutations for molecular-targeted therapy may provide substantial survival benefit for patients with advanced malignancies. CASE REPORT: A female patient in her 60s showed a stenosis of the afferent loop of the small intestine because of circumferential metastatic tumor 14 months after curative surgery for hilar cholangiocarcinoma. Chemotherapy with gemcitabine plus cisplatin was administered for 18 months. An oncopanel examination was performed during chemotherapy, and a high tumor mutation burden was revealed. At 38 months after surgery, a new recurrent tumor, 2.7 cm in size, was observed in the abdominal wall, which was histologically proven to be metastatic adenocarcinoma. Atezolizumab was administered. After three cycles of treatment, treatment was switched to pembrolizumab because of its acceptance by healthcare insurance. The recurrent tumors in the abdominal wall and small intestine disappeared 6 months after the administration of immune checkpoint inhibitor, and the patient has continued pembrolizumab, surviving for 76 months after surgery without any clinical evidence of tumor. CONCLUSION: Immune checkpoint blockade successfully prolonged the survival of a patient with advanced hilar cholangiocarcinoma with high tumor mutation burden, although the optimal number of mutations for such a successful response needs to be clarified.

Exosomal miR-141-3p Induces Gemcitabine Resistance in Biliary Tract Cancer Cells.

BACKGROUND/AIM: Gemcitabine (GEM)-based chemotherapy has been established as the core multimodal therapy for biliary tract cancer (BTC). However, the prognosis of BTC is unfavorable because of its resistance to GEM. Exosomes play important roles in the regulation of tumor progression and metastasis, immune dysregulation, and chemoresistance. This study investigated the effects of exosomes on GEM resistance in BTC. MATERIALS AND METHODS: The human intrahepatic cholangiocarcinoma cell line CC-LP-1, its GEM-resistant (GR) derivative cell line CC-LP-1-GR, and the human intrahepatic cholangiocarcinoma cell lines HuCCA-1 and HuCCT1, were used. GEM resistance was examined by measuring cell viability in the presence of GEM using an MTS assay. Exosomes were isolated using ultracentrifugation and quantified using ELISA. Comprehensive expression analysis was performed using RNA sequencing. The effects of microRNAs were examined by miRNA mimic transfection. RESULTS: The conditioned medium and exosomes derived from CC-LP-1-GR cells enhanced the GEM resistance of parental CC-LP-1 cells. In the presence of GEM, the p53 pathway was negatively enriched in CC-LP-1-GR and CC-LP-1 cells treated with exosomes from CC-LP-1-GR (rExo) compared to CC-LP-1 cells. The expression of miR-141-3p was higher in rExos than in CC-LP-1 cells. CC-LP-1 cells transfected with miR-141-3p mimic showed significantly (p<0.05) increased viability in the presence of GEM. CONCLUSION: A GEM-resistant human BTC cell line, CC-LP-1-GR, may acquire resistance to GEM by exosomes containing miR-141-3p.

Quantitative proteomics analysis reveals possible anticancer mechanisms of 5'-deoxy-5'-methylthioadenosine in cholangiocarcinoma cells.

Cholangiocarcinoma (CCA) is an aggressive cancer originating from bile duct epithelium, particularly prevalent in Asian countries with liver fluke infections. Current chemotherapy for CCA often fails due to drug resistance, necessitating novel anticancer agents. This study investigates the potential of 5'-deoxy-5'-methylthioadenosine (MTA), a naturally occurring nucleoside, against CCA. While MTA has shown promise against various cancers, its effects on CCA remain unexplored. We evaluated MTA's anticancer activity in CCA cell lines and drug-resistant sub-lines, assessing cell viability, migration, invasion, and apoptosis. The potential anticancer mechanisms of MTA were explored through proteomic analysis using LC-MS/MS and bioinformatic analysis. The results show a dose-dependent reduction in CCA cell viability, with enhanced effects on cancer cells compared to normal cells. Moreover, MTA inhibits growth, induces apoptosis, and suppresses cell migration and invasion. Additionally, MTA enhanced the anticancer effects of gemcitabine on drug-resistant CCA cells. Proteomics revealed the down-regulation of multiple proteins by MTA, affecting various molecular functions, biological processes, and cellular components. Network analysis highlighted MTA's role in inhibiting proteins related to mitochondrial function and energy derivation, crucial for cell growth and survival. Additionally, MTA suppressed proteins involved in cell morphology and cytoskeleton organization, important for cancer cell motility and metastasis. Six candidate genes, including ZNF860, KLC1, GRAMD1C, MAMSTR, TANC1, and TTC13, were selected from the top 10 most down-regulated proteins identified in the proteomics results and were subsequently verified through RT-qPCR. Further, KLC1 protein suppression by MTA treatment was confirmed through Western blotting. Additionally, based on TCGA data, KLC1 mRNA was found to be upregulated in the tissue of CCA patients compared to that of normal adjacent tissues. In summary, MTA shows promising anticancer potential against CCA by inhibiting growth, inducing apoptosis, and suppressing migration and invasion, while enhancing gemcitabine's effects. Proteomic analysis elucidates possible molecular mechanisms underlying MTA's anticancer activity, laying the groundwork for future research and development of MTA as a treatment for advanced CCA.

Stage-specificity of STING activation in intrahepatic cholangiocarcinoma determines the efficacy of its agonism.

Intrahepatic cholangiocarcinoma (iCCA) is an aggressive cancer with an extremely poor prognosis, and new treatment options are needed. Recently, immunotherapy has emerged as an efficient treatment against malignant tumors, but less effective in iCCA. Activation of stimulator of interferon genes (STING) signaling could reignite immunologically inert tumors, but the expression and role of STING in iCCA remains to be determined. Here, we show STING is expressed in iCCA, and patients with high expression of STING in early-stage iCCA have a longer overall survival than those have low expression. Increased immune cell infiltration in early-stage iCCA corresponds to elevated STING expression. In mice iCCA models, treatment with the STING agonist MSA-2 show stage-specific inhibitory effects on tumors, with beneficial effects in early-stage tumors but not with advanced-stage cancer. This discrepancy was associated with greater programmed cell death ligand 1 (PD-L1) expression in advanced-stage tumors. Combination therapy targeting PD-L1 and MSA-2 strikingly reduced tumor burden in such tumors compared to either monotherapy. Cumulatively, these data demonstrate that STING agonism monotherapy improves the immune landscape of the tumor microenvironment in early-stage iCCA, while combination therapy ameliorates advanced-stage iCCA.

The combination of gemcitabine plus an anti-FGFR inhibitor can have a synergistic antitumor effect on FGF-activating cholangiocarcinoma.

Anti-FGFR treatment for cholangiocarcinoma (CCA) with fibroblast growth factor receptor (FGFR) alteration is a promising treatment option. Since the antitumor mechanisms of anti-FGFR inhibitors and conventional cytotoxic drugs differ, synergistic effects can be possible. This study aimed to evaluate the efficacy of the combined administration of gemcitabine (GEM) and pemigatinib in CCA cells with FGFR2 alterations. To simulate the treatment for patients with 3 kinds of CCA, chemonaïve CCA with activation of the FGF pathway, chemo-resistant CCA with activation of the FGF pathway, and CCA without FGF pathway activation (as controls), we evaluated 3 different CCA cell lines, CCLP-1 (with a FGFR2 fusion mutation), CCLP-GR (GEM-resistant cells established from CCLP-1), and HuCCT1 (without FGFR mutations). There was no significant difference between CCLP-1 and HuCCT1 in GEM suspensibility (IC50 = 19.3, 22.6 mg/dl, p = 0.1187), and the drug sensitivity to pemigatinib did not differ between CCLP-1 and CCLP-GR (IC50 = 7.18,7.60 nM, p = 0.3089). Interestingly, only CCLP-1 showed a synergistic effect with combination therapy consisting of GEM plus pemigatinib in vitro and in vivo. In a comparison of the reaction to GEM exposure, only CCLP-1 cells showed an increase in the activation of downstream proteins in the FGF pathway, especially FRS2 and ERK. In association with this reaction, cell cycle and mitosis were increased with GEM exposure in CCLP-1, but HuCCT1/CCLP-GR did not show this reaction. Our results suggested that combination therapy with GEM plus pemigatinib is a promising treatment for chemonaïve patients with CCA with activation of the FGF pathway.

Efficacy of dual checkpoint inhibitors in a patient with a mixed hepatocellular cholangiocarcinoma.

A woman in her 60s was diagnosed with a metastatic, unresectable rare histological type of liver cancer; combined hepatocellular cholangiocarcinoma. She had palliative chemotherapy, initially with gemcitabine and cisplatin, and then with oxaliplatin, L-folinic acid and fluorouracil. Both treatment strategies demonstrated disease progression, and somatic mutation profiling revealed no actionable mutations. The patient was started on immuno-oncology (IO) with nivolumab and ipilimumab, followed by maintenance nivolumab. She has achieved a sustained ongoing partial response since the start of this therapy for at least 12 months. The outcome in this patient is in keeping with the growing evidence of the role that IO agents have in metastatic biliary tract cancer and also serves to highlight their importance in mixed histology liver tumours.

Unveiling the promise of PD1/PD-L1: A new dawn in immunotherapy for cholangiocarcinoma.

Cholangiocarcinoma (CCA), a rare yet notably aggressive cancer, has experienced a surge in incidence in recent years. Presently, surgical resection remains the most effective curative strategy for CCA. Nevertheless, a majority of patients with CCA are ineligible for surgical removal at the time of diagnosis. For advanced stages of CCA, the combination of gemcitabine and cisplatin is established as the standard chemotherapy regimen. Despite this, treatment efficacy is often hindered by the development of resistance. In recent times, immune checkpoint inhibitors, particularly those that block programmed death 1 and its ligand (PD1/PD-L1), have emerged as promising strategies against a variety of cancers and are being increasingly integrated into the therapeutic landscape of CCA. A growing body of research supports that the use of PD1/PD-L1 monoclonal antibodies in conjunction with chemotherapy may significantly improve patient outcomes. This article seeks to meticulously review the latest studies on PD1/PD-L1 involvement in CCA, delving into their expression profiles, prognostic significance, contribution to oncogenic processes, and their potential clinical utility.

SRC inhibition enables formation of a growth suppressive MAGI1-PP2A complex in isocitrate dehydrogenase-mutant cholangiocarcinoma.

Intrahepatic cholangiocarcinoma (ICC) is an aggressive bile duct malignancy that frequently exhibits isocitrate dehydrogenase (IDH1/IDH2) mutations. Mutant IDH (IDHm) ICC is dependent on SRC kinase for growth and survival and is hypersensitive to inhibition by dasatinib, but the molecular mechanism underlying this sensitivity is unclear. We found that dasatinib reduced p70 S6 kinase (S6K) and ribosomal protein S6 (S6), leading to substantial reductions in cell size and de novo protein synthesis. Using an unbiased phosphoproteomic screen, we identified membrane-associated guanylate kinase, WW, and PDZ domain containing 1 (MAGI1) as an SRC substrate in IDHm ICC. Biochemical and functional assays further showed that SRC inhibits a latent tumor-suppressing function of the MAGI1-protein phosphatase 2A (PP2A) complex to activate S6K/S6 signaling in IDHm ICC. Inhibiting SRC led to activation and increased access of PP2A to dephosphorylate S6K, resulting in cell death. Evidence from patient tissue and cell line models revealed that both intrinsic and extrinsic resistance to dasatinib is due to increased phospho-S6 (pS6). To block pS6, we paired dasatinib with the S6K/AKT inhibitor M2698, which led to a marked reduction in pS6 in IDHm ICC cell lines and patient-derived organoids in vitro and substantial growth inhibition in ICC patient-derived xenografts in vivo. Together, these results elucidated the mechanism of action of dasatinib in IDHm ICC, revealed a signaling complex regulating S6K phosphorylation independent of mTOR, suggested markers for dasatinib sensitivity, and described a combination therapy for IDHm ICC that may be actionable in the clinic.

Unveiling the role of HP1α-HDAC1-STAT1 axis as a therapeutic target for HP1α-positive intrahepatic cholangiocarcinoma.

BACKGROUND: Intrahepatic cholangiocarcinoma (ICCA) is a heterogeneous group of malignant tumors characterized by high recurrence rate and poor prognosis. Heterochromatin Protein 1α (HP1α) is one of the most important nonhistone chromosomal proteins involved in transcriptional silencing via heterochromatin formation and structural maintenance. The effect of HP1α on the progression of ICCA remained unclear. METHODS: The effect on the proliferation of ICCA was detected by experiments in two cell lines and two ICCA mouse models. The interaction between HP1α and Histone Deacetylase 1 (HDAC1) was determined using Electrospray Ionization Mass Spectrometry (ESI-MS) and the binding mechanism was studied using immunoprecipitation assays (co-IP). The target gene was screened out by RNA sequencing (RNA-seq). The occupation of DNA binding proteins and histone modifications were predicted by bioinformatic methods and evaluated by Cleavage Under Targets and Tagmentation (CUT & Tag) and Chromatin immunoprecipitation (ChIP). RESULTS: HP1α was upregulated in intrahepatic cholangiocarcinoma (ICCA) tissues and regulated the proliferation of ICCA cells by inhibiting the interferon pathway in a Signal Transducer and Activator of Transcription 1 (STAT1)-dependent manner. Mechanistically, STAT1 is transcriptionally regulated by the HP1α-HDAC1 complex directly and epigenetically via promoter binding and changes in different histone modifications, as validated by high-throughput sequencing. Broad-spectrum HDAC inhibitor (HDACi) activates the interferon pathway and inhibits the proliferation of ICCA cells by downregulating HP1α and targeting the heterodimer. Broad-spectrum HDACi plus interferon preparation regimen was found to improve the antiproliferative effects and delay ICCA development in vivo and in vitro, which took advantage of basal activation as well as direct activation of the interferon pathway. HP1α participates in mediating the cellular resistance to both agents. CONCLUSIONS: HP1α-HDAC1 complex influences interferon pathway activation by directly and epigenetically regulating STAT1 in transcriptional level. The broad-spectrum HDACi plus interferon preparation regimen inhibits ICCA development, providing feasible strategies for ICCA treatment. Targeting the HP1α-HDAC1-STAT1 axis is a possible strategy for treating ICCA, especially HP1α-positive cases.

Antitumor Activity of Tasurgratinib as an Orally Available FGFR1-3 Inhibitor in Cholangiocarcinoma Models With FGFR2-fusion.

BACKGROUND/AIM: Cholangiocarcinoma (CCA) is an aggressive tumor with limited treatment options especially in 2nd line or later treatments. Targeting fibroblast growth factor receptor (FGFR) 2 has recently emerged as a promising treatment option for patients with CCA harboring FGFR2-fusion. This study investigated the antitumor activities of tasurgratinib as an orally available FGFR1-3 inhibitor, in preclinical FGFR2-driven CCA models. MATERIALS AND METHODS: Antitumor activities of tasurgratinib were examined in vitro and in vivo using NIH/3T3 cells expressing FGFR2-fusion as FGFR2-driven CCA models, and in vivo using a CCA patient-derived xenograft model. The molecular mechanism of action of tasurgratinib was elucidated through co-crystal structure analysis with FGFR1, manual complex model analysis with FGFR2, and binding kinetics analysis with FGFR2. Furthermore, the cell-based inhibitory activities against acquired resistant FGFR2 mutations in patients with CCA treated with FGFR inhibitors were evaluated. RESULTS: Tasurgratinib showed antitumor activity in preclinical FGFR2-driven CCA models by inhibiting the FGFR signaling pathway in vitro and in vivo. Furthermore, cell-based target engagement assays indicated that tasurgratinib had potent inhibitory activities against FGFR2 mutations, such as N549H/K, which are the major acquired mutations in CCA. We also confirmed that tasurgratinib exhibited fast association and slow dissociation kinetics with FGFR2, binding to the ATP-binding site and the neighboring region, and adopting an Asp-Phe-Gly (DFG)-"in" conformation. CONCLUSION: These data demonstrate the therapeutic potential of tasurgratinib in FGFR2-driven CCA and provide molecular mechanistic insights into its unique inhibitory profile against secondary FGFR2 resistance mutations in patients with CCA treated with FGFR inhibitors.

SERPINE1: Role in Cholangiocarcinoma Progression and a Therapeutic Target in the Desmoplastic Microenvironment.

A heterogenous population of inflammatory elements, other immune and nonimmune cells and cancer-associated fibroblasts (CAFs) are evident in solid malignancies where they coexist with the growing tumor mass. In highly desmoplastic malignancies, CAFs are the prominent mesenchymal cell type in the tumor microenvironment (TME), where their presence and abundance signal a poor prognosis. CAFs play a major role in the progression of various cancers by remodeling the supporting stroma into a dense, fibrotic matrix while secreting factors that promote the maintenance of cancer stem-like characteristics, tumor cell survival, aggressive growth and metastasis and reduced sensitivity to chemotherapeutics. Tumors with high stromal fibrotic signatures are more likely to be associated with drug resistance and eventual relapse. Identifying the molecular underpinnings for such multidirectional crosstalk among the various normal and neoplastic cell types in the TME may provide new targets and novel opportunities for therapeutic intervention. This review highlights recent concepts regarding the complexity of CAF biology in cholangiocarcinoma, a highly desmoplastic cancer. The discussion focuses on CAF heterogeneity, functionality in drug resistance, contributions to a progressively fibrotic tumor stroma, the involved signaling pathways and the participating genes.