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.

Integrative genomic analyses of European intrahepatic cholangiocarcinoma: Novel ROS1 fusion gene and PBX1 as prognostic marker.

BACKGROUND: Cholangiocarcinoma (CCA) is a fatal cancer of the bile duct with a poor prognosis owing to limited therapeutic options. The incidence of intrahepatic CCA (iCCA) is increasing worldwide, and its molecular basis is emerging. Environmental factors may contribute to regional differences in the mutation spectrum of European patients with iCCA, which are underrepresented in systematic genomic and transcriptomic studies of the disease. METHODS: We describe an integrated whole-exome sequencing and transcriptomic study of 37 iCCAs patients in Germany. RESULTS: We observed as most frequently mutated genes ARID1A (14%), IDH1, BAP1, TP53, KRAS, and ATM in 8% of patients. We identified FGFR2::BICC1 fusions in two tumours, and FGFR2::KCTD1 and TMEM106B::ROS1 as novel fusions with potential therapeutic implications in iCCA and confirmed oncogenic properties of TMEM106B::ROS1 in vitro. Using a data integration framework, we identified PBX1 as a novel central regulatory gene in iCCA. We performed extended screening by targeted sequencing of an additional 40 CCAs. In the joint analysis, IDH1 (13%), BAP1 (10%), TP53 (9%), KRAS (7%), ARID1A (7%), NF1 (5%), and ATM (5%) were the most frequently mutated genes, and we found PBX1 to show copy gain in 20% of the tumours. According to other studies, amplifications of PBX1 tend to occur in European iCCAs in contrast to liver fluke-associated Asian iCCAs. CONCLUSIONS: By analyzing an additional European cohort of iCCA patients, we found that PBX1 protein expression was a marker of poor prognosis. Overall, our findings provide insight into key molecular alterations in iCCA, reveal new targetable fusion genes, and suggest that PBX1 is a novel modulator of this disease.

Expression and clinical significance of interleukin-6 pathway in cholangiocarcinoma.

Background: Cholangiocarcinoma (CCA) is a typical inflammation-induced malignancy, and elevated serum interleukin-6 (IL-6) levels have been reported to be linked to the onset and progression of CCA. We aim to investigate the potential prognostic value of the IL-6 pathway for CCA. Methods: We detected the expressions of IL-6, IL-6R, glycoprotein (gp130), C-reactive protein (CRP), Janus kinase 2 (JAK2), and signal transducer and activator of transcription 3 (STAT3) in CCA tissue microarray using multiplex immunofluorescence. Furthermore, the clinical associations and prognostic values were assessed. Finally, single-cell transcriptome analysis was performed to evaluate the expression level of IL-6 pathway genes in CCA. Results: The results revealed that the expression of IL-6 was lower, while the expression of STAT3 was higher in tumor tissues compared to normal tissues. Especially in tumor microenvironment, the expression of IL-6 pathway genes was generally downregulated. Importantly, gp130 was strongly correlated with JAK2 in tumor tissues, while it was moderately correlated with JAK2 in normal tissue. Although none of the gene expressions were directly associated with overall survival and disease-free survival, our study found that IL-6, IL-6R, CRP, gp130, and JAK2 were inversely correlated with vascular invasion, which is a risk factor for poor prognosis in patients with CCA. Conclusion: The findings from this study suggest that the IL-6 signaling pathway may have a potential prognostic value for CCA. Further investigation is needed to understand the underlying molecular mechanisms of the IL-6 pathway in 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.

Possibility of Cell Block Specimens from Overnight-Stored Bile for Next-Generation Sequencing of Cholangiocarcinoma.

The identification of anticancer therapies using next-generation sequencing (NGS) is necessary for the treatment of cholangiocarcinoma. NGS can be easily performed when cell blocks (CB) are obtained from bile stored overnight. We compared NGS results of paired CB and surgically resected specimens (SRS) from the same cholangiocarcinoma cases. Of the prospectively collected 64 bile CBs from 2018 to 2023, NGS was performed for three cases of cholangiocarcinoma that could be compared with the SRS results. The median numbers of DNA and RNA reads were 95,077,806 [CB] vs. 93,161,788 [SRS] and 22,101,328 [CB] vs. 24,806,180 [SRS], respectively. We evaluated 588 genes and found that almost all genetic alterations were attributed to single-nucleotide variants, insertions/deletions, and multi-nucleotide variants. The coverage rate of variants in SRS by those found in CB was 97.9-99.2%, and the coverage rate of SRS genes by CB genes was 99.6-99.7%. The NGS results of CB fully covered the variants and genetic alterations observed in paired SRS samples. As bile CB is easy to prepare in general hospitals, our results suggest the potential use of bile CB as a novel method for NGS-based evaluation of cholangiocarcinoma.

Overexpression of TBX3 suppresses tumorigenesis in experimental and human cholangiocarcinoma.

TBX3 behaves as a tumor suppressor or oncoprotein across cancer. However, TBX3 function remains undetermined in intrahepatic cholangiocarcinoma (iCCA), a deadly primary liver malignancy with few systemic treatment options. This study sought to investigate the impact of TBX3 on iCCA. We found that overexpression of TBX3 strongly inhibited human iCCA cell growth. In the Akt/FBXW7ΔF mouse iCCA model, overexpression of Tbx3 reduced cholangiocarcinogenesis in vivo, while inducible genetic knockout of Tbx3 accelerated iCCA growth. RNA-seq identified MAD2L1 as a downregulated gene in TBX3-overexpressing cells, and ChIP confirmed that TBX3 binds to the MAD2L1 promoter. CRISPR-mediated knockdown of Mad2l1 significantly reduced the growth of two iCCA models in vivo. Finally, we found that TBX3 expression is upregulated in ~20% of human iCCA samples, and its high expression is associated with less proliferation and better survival. MAD2L1 expression is upregulated in most human iCCA samples and negatively correlated with TBX3 expression. Altogether, our findings suggest that overexpression of TBX3 suppresses CCA progression via repressing MAD2L1 expression.

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.

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.

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.

Combined hepatocellular-cholangiocarcinoma: from genesis to molecular pathways and therapeutic strategies.

Hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC) are the most common primary liver cancers. Little is known about the combined hepatocellular-cholangiocarcinoma (cHCC-ICC) variant and the proper therapeutic strategies. Out of over 1200 available studies about cHCC-ICC, we selected the most representative ones that reflected updated information with application to individualized therapy. Based on literature data and own experience, we hypothesize that two molecular groups of cHCC-ICC can be identified. The proposed division might have a significant therapeutic role. Most cases develop, like HCC, on a background of cirrhosis and hepatitis and share characteristics with HCC; thus, they are named HCC-type cHCC-ICC and therapeutic strategies might be like those for HCC. This review also highlights a new carcinogenic perspective and identifies, based on literature data and the own experience, a second variant of cHCC-ICC called ICC-type cHCC-ICC. Contrary to HCC, these cases show a tendency for lymph node metastases and ICC components in the metastatic tissues. No guidelines have been established yet for such cases. Individualized therapy should be, however, oriented toward the immunoprofile of the primary tumor and metastatic cells, and different therapeutic strategies should be used in patients with HCC- versus ICC-type cHCC-ICC.

Bmi1 facilitates the progression of cholangiocarcinoma by inhibiting Foxn2 expression dependent on a histone H2A ubiquitination manner.

Cholangiocarcinoma (CCA), an exceptionally aggressive malignancy originating from the epithelium of the bile duct, poses a formidable challenge in cancer research and clinical management. Currently, attention is focused on exploring the oncogenic role and prognostic implications associated with Bmi1 in the context of CCA. In our study, we assessed the correlation of Bmi1 and Foxn2 expression across all types of CCA and evaluated their prognostic significance. Our results demonstrated that Bmi1 exhibits significantly upregulated expression in CCA tissues, while Foxn2 expression shows an inverse pattern. Simultaneously, the high expression of Bmi1, coupled with the low expression of Foxn2, indicates an unfavorable prognosis. Through in vitro and in vivo experiments, we confirmed the crucial role of Foxn2 in the proliferation, metastasis, and epithelial-mesenchymal transition (EMT) of CCA. Mechanistically, Bmi1 promotes the ubiquitination of histone H2A (H2AUb), leading to chromatin opening attenuation and a decrease in Foxn2 expression, ultimately driving CCA progression. Additionally, we described the potential value of Bmi1 and H2AUb inhibitors in treating CCA through in vitro experiments and orthotopic models. This study is of significant importance in deepening our understanding of the interaction between Bmi1 and Foxn2 in CCA and has the potential to advance the development of precision therapies for CCA.

DCLK1 Expression and its Functional Significance in Intrahepatic Cholangiocarcinoma and Bil-IN Stage.

BACKGROUND/AIM: Although several studies in some neoplasms have reported correlation between the expression levels of Doublecortin-like kinase1(DCLK1) and carcinogenesis, its role in cholangiocarcinoma remains unknown. MATERIALS AND METHODS: DCLK1 expression in normal epithelium (NE), biliary intraepithelial neoplasia (BilIN)1∼3, and intrahepatic cholangiocarcinoma (ICC) were investigated immuno-histochemically. The molecular effects of DCLK1 were investigated by gene silencing using RNAi [DCLK1-tagrgeting (siDCLK1)]. The human ICC cell lines HuCCT1 and HuH28 were transfected with these siRNAs, and used for assays in the presence or absence of DCLK1 inhibitors. RESULTS: The positive ratio of DCLK1 expression in ICC was higher than that in NE, and equally distributed among BilIN1∼3 (NE: BilIN1: BilIN2: BilIN3: ICC=62%: 91%: 97%: 100%: 95%, p<0.05). In the wound healing assay, the migration of the siDCLK1-treated cells was significantly inhibited compared to the NT-treated cells (p<0.05). In the cell invasion assay, the invasion of the siDCLK1-treated cells was significantly inhibited compared to the NT-treated cells (p<0.05). In the presence of the DCLK1 inhibitor, cell proliferative capacity at 24 hours was decreased in a concentration-dependent manner. CONCLUSION: DCLK1 was highly expressed in the early stage of ICC carcinogenesis. Human ICC cell growth was suppressed in vitro by siRNA silencing of DCLK1 or after treatment with the DCLK1 inhibitor, indicating DCLK1 may be molecular target for ICC therapy.

Identification and functional analysis of mitogenic miRNA of the carcinogenic liver fluke Opisthorchis viverrini.

Opisthorchis viverrini is a pathogenic liver fluke that is known to cause cholangiocarcinoma in chronic infections. The underlying mechanism for this carcinogenesis is believed to be multifactorial, with parasite-derived excretory-secretory (ES) products potentially playing major roles. A recent study on these ES products has identified microRNAs (miRNA) that originate from O. viverrini but their influence on carcinogenesis remains understudied. Hence, we aimed to investigate the role of these miRNAs in the carcinogenesis of O. viverrini-associated cholangiocarcinoma. The mature miRNA sequences were retrieved from published data. Bioinformatics analysis was employed to identify miRNA targets and to identify potentially mitogenic miRNAs. An in vitro study was conducted to test the effects of miRNA on the bile duct epithelial cell lines. The miRNA target prediction analysis revealed that Ov_miRNA_EV_36/ovi-miR-3479a targets cancer-associated pathways. Hence, it was selected and used to assess its effect on the cell proliferation rate of H69 and MMNK-1 cholangiocyte cell lines. The results showed that Ov_miRNA_EV_36/ovi-miR-3479a induced significant cell proliferation in both cell lines when compared to negative controls. These results indicate that Ov_miRNA_EV_36/ovi-miR-3479a may play an essential role in the carcinogenesis of O. viverrini and therefore warrant further investigations.