Function of mast cell and bile-cholangiocarcinoma interplay in cholangiocarcinoma microenvironment.

OBJECTIVE: The correlation between cholangiocarcinoma (CCA) progression and bile is rarely studied. Here, we aimed to identify differential metabolites in benign and malignant bile ducts and elucidate the generation, function and degradation of bile metabolites. DESIGN: Differential metabolites in the bile from CCA and benign biliary stenosis were identified by metabonomics. Biliary molecules able to induce mast cell (MC) degranulation were revealed by in vitro and in vivo experiments, including liquid chromatography-mass spectrometry (MS)/MS and bioluminescence resonance energy transfer assays. Histamine (HA) receptor expression in CCA was mapped using a single-cell mRNA sequence. HA receptor functions were elucidated by patient-derived xenografts (PDX) in humanised mice and orthotopic models in MC-deficient mice. Genes involved in HA-induced proliferation were screened by CRISPR/Cas9. RESULTS: Bile HA was elevated in CCA and indicated poorer prognoses. Cancer-associated fibroblasts (CAFs)-derived stem cell factor (SCF) recruited MCs, and bile N,N-dimethyl-1,4-phenylenediamine (DMPD) stimulated MCs to release HA through G protein-coupled receptor subtype 2 (MRGPRX2)-Gαq signalling. Bile-induced MCs released platelet-derived growth factor subunit B (PDGF-B) and angiopoietin 1/2 (ANGPT1/2), which enhanced CCA angiogenesis and lymphangiogenesis. Histamine receptor H1 (HRH1) and HRH2 were predominantly expressed in CCA cells and CAFs, respectively. HA promoted CCA cell proliferation by activating HRH1-Gαq signalling and hastened CAFs to secrete hepatocyte growth factor by stimulating HRH2-Gαs signalling. Solute carrier family 22 member 3 (SLC22A3) inhibited HA-induced CCA proliferation by importing bile HA into cells for degradation, and SLC22A3 deletion resulted in HA accumulation. CONCLUSION: Bile HA is released from MCs through DMPD stimulation and degraded via SLC22A3 import. Different HA receptors exhibit a distinct expression profile in CCA and produce different oncogenic effects. MCs promote CCA progression in a CCA-bile interplay pattern.

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.

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.

Advances in molecular and cell therapy for immunotherapy of cholangiocarcinoma.

Cholangiocarcinoma (CCA) is a highly malignant tumor of the hepatobiliary system that has failed to respond to many traditional therapies to a certain extent, including surgery, chemotherapy and radiotherapy. In recent years, the new therapeutic schemes based on immunology have fundamentally changed the systemic treatment of various malignant tumors to a certain extent. In view of the immunogenicity of CCA, during the occurrence and development of CCA, some immunosuppressive substances are released from cells and immunosuppressive microenvironment is formed to promote the escape immune response of its own cells, thus enhancing the malignancy of the tumor and reducing the sensitivity of the tumor to drugs. Some immunotherapy regimens for cholangiocarcinoma have produced good clinical effects. Immunotherapy has more precise characteristics and less adverse reactions compared with traditional treatment approaches. However, due to the unique immune characteristics of CCA, some patients with CCA may not benefit in the long term or not benefit at all after current immunotherapy. At present, the immunotherapy of CCA that have been clinically studied mainly include molecular therapy and cell therapy. In this article, we generalized and summarized the current status of immunotherapy strategies including molecular therapy and cell therapy in CCA in clinical studies, and we outlined our understanding of how to enhance the clinical application of these immunotherapy strategies.

The role of extracellular vesicles in cholangiocarcinoma tumor microenvironment.

Cholangiocarcinoma (CCA) is a highly aggressive malignant tumor that originates from the biliary system. With restricted treatment options at hand, the challenging aspect of early CCA diagnosis leads to a bleak prognosis. Besides the intrinsic characteristics of tumor cells, the generation and progression of CCA are profoundly influenced by the tumor microenvironment, which engages in intricate interactions with cholangiocarcinoma cells. Of notable significance is the role of extracellular vesicles as key carriers in enabling communication between cancer cells and the tumor microenvironment. This review aims to provide a comprehensive overview of current research examining the interplay between extracellular vesicles and the tumor microenvironment in the context of CCA. Specifically, we will emphasize the significant contributions of extracellular vesicles in molding the CCA microenvironment and explore their potential applications in the diagnosis, prognosis assessment, and therapeutic strategies for this aggressive malignancy.

Research progress of bile biomarkers and their immunoregulatory role in biliary tract cancers.

Biliary tract cancers (BTCs), including cholangiocarcinoma and gallbladder carcinoma, originate from the biliary epithelium and have a poor prognosis. Surgery is the only choice for cure in the early stage of disease. However, most patients are diagnosed in the advanced stage and lose the chance for surgery. Early diagnosis could significantly improve the prognosis of patients. Bile has complex components and is in direct contact with biliary tract tumors. Bile components are closely related to the occurrence and development of biliary tract tumors and may be applied as biomarkers for BTCs. Meanwhile, arising evidence has confirmed the immunoregulatory role of bile components. In this review, we aim to summarize and discuss the relationship between bile components and biliary tract cancers and their ability as biomarkers for BTCs, highlighting the role of bile components in regulating immune response, and their promising application prospects.

Wnt-TCF7-SOX9 axis promotes cholangiocarcinoma proliferation and pemigatinib resistance in a FGF7-FGFR2 autocrine pathway.

Cholangiocarcinoma (CCA) is a type of highly malignant tumor originating from bile ducts. The prognosis of CCA is poor and the treatment options are limited. The biomarker study of CCA has made little progresses in recent years because of the difficulty to obtain CCA specimens. SOX9 is an important regulator of cholangiocyte proliferation and differentiation. We performed mRNA sequencing of CCA, retrieved TCGA data, and detected SOX9 expression in a large CCA cohort. With WNT3A stimulation, SOX9 expression and transcription was elevated by TCF7. Moreover, SOX9 was substantially up-regulated in CCA tissues and was identified as a prognostic biomarker of CCA. With mRNA sequencing and in vitro/vivo validation, we demonstrated that SOX9 enhanced the transcription and expression of FGF7 and FGFR2. FGF7 was significantly up-regulated in the bile and serum of CCA patients, and may promote CCA proliferation by activating FGFR2 in an autocrine pathway. co-expression of FGF7 and FGFR2 was a more sensitive marker for poor prognosis. SOX9-induced overexpression of FGF7 and FGFR2 was the key reason of SOX9-involved pemigatinib resistance. In conclusion, SOX9 and FGF7 were prognostic biomarkers of CCA. WNT3A-TCF7-SOX9 axis could induce pemigatinib resistance in two independent pathways: (1)SOX9 directly promotes FGFR2 transcription and expression; (2)SOX9 elevates FGF7 expression, which could be secreted from CCA cells and activates FGFR2 phosphorylation in an autocrine pathway.