miRNA profiling of biliary intraepithelial neoplasia reveals stepwise tumorigenesis in distal cholangiocarcinoma via the miR-451a/ATF2 axis

Preoperative systemic inflammatory response index as a prognostic marker for distal cholangiocarcinoma after pancreatoduodenectomy

BACKGROUND

The relationship between preoperative inflammation status and tumorigenesis as well as tumor progression is widely acknowledged.

AIM

To assess the prognostic significance of preoperative inflammatory biomarkers in patients with distal cholangiocarcinoma (dCCA) who underwent pancreatoduodenectomy (PD).

METHODS

This single-center study included 216 patients with dCCA after PD between January 1, 2011, and December 31, 2022. The individuals were categorized into two sets based on their systemic inflammatory response index (SIRI) levels: A low SIRI group (SIRI < 1.5, n = 123) and a high SIRI group (SIRI ≥ 1.5, n = 93). Inflammatory biomarkers were evaluated for predictive accuracy using receiver operating characteristic curves. Both univariate and multivariate Cox proportional hazards analyses were performed to estimate SIRI for overall survival (OS) and recurrence-free survival (RFS).

RESULTS

The study included a total of 216 patients, with 58.3% being male and a mean age of 65.6 ± 9.6 years. 123 patients were in the low SIRI group and 93 were in the high SIRI group after PD for dCCA. SIRI had an area under the curve value of 0.674 for diagnosing dCCA, showing better performance than other inflammatory biomarkers. Multivariate analysis indicated that having a SIRI greater than 1.5 independently increased the risk of dCCA following PD, leading to lower OS [hazard ratios (HR) = 1.868, P = 0.006] and RFS (HR = 0.949, P < 0.001). Additionally, survival analysis indicated a significantly better prognosis for patients in the low SIRI group (P < 0.001).

CONCLUSION

It is determined that a high SIRI before surgery is a significant risk factor for dCCA after PD.

Morphomolecular Pathology and Genomic Insights into the Cells of Origin of Cholangiocarcinoma and Combined Hepatocellular-Cholangiocarcinoma

Cholangiocarcinomas are a highly heterogeneous group of malignancies that, despite recent progress in the understanding of their molecular pathogenesis and clinical management, continue to pose a major challenge to public health. The traditional view posits that cholangiocarcinomas derive from the neoplastic transformation of cholangiocytes lining the biliary tree. However, increasing genetic and experimental evidence has recently pointed to a more complex, and nuanced, scenario for the potential cell of origin of cholangiocarcinomas. Hepatocytes as well as hepatic stem/progenitor cells are being considered as additional potential sources, depending on microenvironmental contexts, including liver injury. The hypothesis of potentially diverse cells of origin for cholangiocarcinoma, albeit controversial, is certainly not surprising given the plasticity of the cells populating the liver as well as the existence of liver cancer subtypes with mixed histologic and molecular features. This review carefully examines the current pathologic, genomic, and experimental evidence supporting the existence of multiple cells of origin of liver and biliary tract cancers, with particular focus on cholangiocarcinoma and combined hepatocellular-cholangiocarcinoma.

Human umbilical cord mesenchymal stem cell-derived exosomes loaded miR-451a targets ATF2 to improve rheumatoid arthritis

OBJECTIVE

Rheumatoid arthritis (RA) is an autoimmune disease characterized by chronic joint inflammation, with synovial fibroblasts (SFs) playing a pivotal role in its pathogenesis. Dysregulation of microRNA (miRNA) expression in SFs contributes to RA development. Exosomes (Exos) have emerged as effective carriers for therapeutic molecules, facilitating miRNA transfer between cells. This study explores the therapeutic potential of Exos derived from human umbilical cord mesenchymal stem cells (hUCMSCs), loaded with miR-451a, to modulate ATF2 expression, aiming to address RA in both in vivo and in vitro settings.

METHODS

In this study, hUCMSC and RA SFs were isolated and identified, and hUCMSC-Exos were extracted and characterized. The influence of hUCMSC-Exos on RA SFs was detected. And hUCMSC-Exos targeting RA SFs was traced. HUCMSCKD-AGO2 was prepared by knocking down AGO2 in hUCMSC. HUCMSCKD-AGO2-Exos was extracted and characterized,and their influence on RA SFs was detected. The miRNA profiles before and after hUCMSC-Exos intervention in RA SFs were mapped to identify differential miRNAs. RT-qPCR was used to verify the differential miRNAs, with hsa-miR-451a finally selected as the target gene. The effect of miR-451a on SFs was detected. The latent binding of miR-451a to activating transcription factor 2 (ATF2) was analyzed. The effect of hUCMSC-ExosmiR-451a on SFs was detected, and the expression of miR-451a and ATF2 was measured by RT-PCR. In vivo, hUCMSC-ExosmiR-451a was injected into the ankle joint of CIA rats, and arthritis index, joint imaging and synovial pathology were assessed. The expression of miR-451a and ATF2 in synovial tissue was detected. Finally, the safety of hUCMSC-ExosmiR-451a in CIA rats was evaluated.

RESULTS

This study revealed that hUCMSC-Exos can inhibit RA SFs proliferation, migration and invasion through miRNAs. High throughput sequencing detected 13 miRNAs that could be transmitted from hUCMSCs to RA SFs via hUCMSC-Exos. miR-451a inhibited RA SFs proliferation, migration and invasion by regulating ATF2. hUCMSC-Exos loaded with miR-451a targeted ATF2 to inhibit RA SFs proliferation, migration and invasion, and improve joint inflammation and imaging findings in CIA rats.

CONCLUSIONS

This study demonstrates that miR-451a carried by hUCMSC-Exos can play a role in inhibiting RA SFs biological traits and improving arthritis in CIA rats by inhibiting ATF2. The findings suggest a promising treatment for RA and provide insights into the mechanism of action of hUCMSC-Exos in RA. Future research directions will continue to explore the potential in this field.

Biliary Tract Cancer: Molecular Biology of Precursor Lesions

Biliary tract cancer is a devastating malignancy of the bile ducts and gallbladder with a dismal prognosis. The study of precancerous lesions has received considerable attention and led to a histopathological classification which, in some respects, remains an evolving field. Consequently, increasing efforts have been devoted to characterizing the molecular pathogenesis of the precursor lesions, with the aim of better understanding the mechanisms of tumor progression, and with the ultimate goal of meeting the challenges of early diagnosis and treatment. This review delves into the molecular mechanisms that initiate and promote the development of precursor lesions of intra- and extrahepatic cholangiocarcinoma and of gallbladder carcinoma. It addresses the genomic, epigenomic, and transcriptomic landscape of these precursors and provides an overview of animal and organoid models used to study them. In conclusion, this review summarizes the known molecular features of precancerous lesions in biliary tract cancer and highlights our fragmentary knowledge of the molecular pathogenesis of tumor initiation.

Circular RNA SMARCA5 inhibits cholangiocarcinoma via microRNA-95-3p/tumor necrosis factor receptor associated factor 3 axis

Enhancing research indicatedthat circular RNA (circRNA) acted a critical part in cholangiocarcinoma (CHOL) development. This research aims to discover the role of circRNA SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin, subfamily a, member 5 (SMARCA5) in CHOL bio-progression, which has been proved to be downregulated in CHOL tissues. In this study, quantitative reverse transcription polymerase chain reaction was used to reveal the level and linkage of circRNA SMARCA5, miRNA-95-3p and TNF receptor-associated factor 3 gene (TRAF3) in CHOL tissues and cancer cells. The target sites of circRNA SMARCA5 and miRNA-95-3p were forecast by Starbase, and Targetscan was conducted to forecast the potential linkage points of TRAF3 and miRNA-95-3p, and which is affirmed by double luciferase reporter assay. CCK-8 and flow cytometry assay was carried to indicate cell viability. And apoptosis-related protein was counted by caspase3 activity and Western blot assay. CircRNA SMARCA5 was downregulated in CHOL cell lines and cancer samples. Besides, over-expression of SMARCA5 inhibited cell growth and promoted apoptotic rate. Dual-luciferase reporter assays presented that miRNA-95-3p could link with circRNA SMARCA5. Moreover, miRNA-95-3p was discovered highly expressed in CHOL. Interference of miRNA-95-3p repressed cell proliferation and raised the apoptosis. Importantly, TRAF3 was validated to be a downstream of miRNA-95-3p. Strengthen of miRNA-95-3p reversed the inhibitory impact of circRNA SMARCA5-plasmid transfection, and the results of miRNA-95-3p inhibitor were reversed by si-TRAF3. CircRNA SMARCA5 is involved in CHOL development by interosculating miRNA-95-3p/TRAF3 axis and may become a novel approach for treating CHOL.

MicroRNA-27a-3p targets FoxO signalling to induce tumour-like phenotypes in bile duct cells

BACKGROUND & AIMS

Cholangiocarcinoma (CCA) is a heterogeneous and lethal malignancy, the molecular origins of which remain poorly understood. MicroRNAs (miRs) target diverse signalling pathways, functioning as potent epigenetic regulators of transcriptional output. We aimed to characterise miRNome dysregulation in CCA, including its impact on transcriptome homeostasis and cell behaviour.

METHODS

Small RNA sequencing was performed on 119 resected CCAs, 63 surrounding liver tissues, and 22 normal livers. High-throughput miR mimic screens were performed in three primary human cholangiocyte cultures. Integration of patient transcriptomes and miRseq together with miR screening data identified an oncogenic miR for characterization. MiR-mRNA interactions were investigated by a luciferase assay. MiR-CRISPR knockout cells were generated and phenotypically characterized in vitro (proliferation, migration, colony, mitochondrial function, glycolysis) and in vivo using subcutaneous xenografts.

RESULTS

In total, 13% (140/1,049) of detected miRs were differentially expressed between CCA and surrounding liver tissues, including 135 that were upregulated in tumours. CCA tissues were characterised by higher miRNome heterogeneity and miR biogenesis pathway expression. Unsupervised hierarchical clustering of tumour miRNomes identified three subgroups, including distal CCA-enriched and IDH1 mutant-enriched subgroups. High-throughput screening of miR mimics uncovered 71 miRs that consistently increased proliferation of three primary cholangiocyte models and were upregulated in CCA tissues regardless of anatomical location, among which only miR-27a-3p had consistently increased expression and activity in several cohorts. FoxO signalling was predominantly downregulated by miR-27a-3p in CCA, partially through targeting of FOXO1. MiR-27a knockout increased FOXO1 levels in vitro and in vivo, impeding tumour behaviour and growth.

CONCLUSIONS

The miRNomes of CCA tissues are highly remodelled, impacting transcriptome homeostasis in part through regulation of transcription factors like FOXO1. MiR-27a-3p arises as an oncogenic vulnerability in CCA.

IMPACT AND IMPLICATIONS

Cholangiocarcinogenesis entails extensive cellular reprogramming driven by genetic and non-genetic alterations, but the functional roles of these non-genetic events remain poorly understood. By unveiling global miRNA upregulation in patient tumours and their functional ability to increase proliferation of cholangiocytes, these small non-coding RNAs are implicated as critical non-genetic alterations promoting biliary tumour initiation. These findings identify possible mechanisms for transcriptome rewiring during transformation, with potential implications for patient stratification.

Downregulation of miR-451 in cholangiocarcinoma help the diagnsosi and promotes tumor progression

Background

Cholangiocarcinoma is a kind of invasive malignant tumor followed by hepatocellular carcinoma. miR-451 was suggested to function as regulator in various human tumors, but its role in mediating tumor progression and predicting the prognosis of cholangiocarcinoma remains unknown. The clinical significance and biological function of miR-451 in cholangiocarcinoma were assessed in this study.

Results

The tissue and serum expression of miR-451 was decreased in cholangiocarcinoma compared with corresponding normal samples. The downregulation of miR-451 was associated with the progressive TNM stage and positive lymph node metastasis of patients. miR-451 was identified to be an indicator of the diagnosis and prognosis of cholangiocarcinoma distinguishing cholangiocarcinoma patients from healthy volunteers and predicting the poor outcome of patients. miR-451 also served as a tumor suppressor negatively regulating the cellular processes of cholangiocarcinoma.

Conclusions

miR-451 played a vital role in the early detection and risk prediction of cholangiocarcinoma. miR-451 also suppressed the progression of cholangiocarcinoma, which provides a potential therapeutical target for cholangiocarcinoma treatment.

Impact of WTAP in small HCC and paired adjacent non-neoplastic liver tissue on recurrence: A cohort study with external extension analysis

Background: To evaluate prognostic value of WTAP levels in tumor and paired adjacent non-neoplastic liver tissues (PANLT) for cases of hepatitis B virus (HBV)-positive Asian small hepatocellular carcinoma (sHCC) patients who received curative partial hepatectomy. Method: The investigation with two external cohorts were included. Associations between hazard risk of recurrence and continuous WTAP levels were investigated with restricted cubic spline models. Cox and inverse probability weighting models were established for survival analysis. Based on interaction effects, further stratification analysis was performed. Landmark analysis was employed to analyze cases of late recurrence. Finally, sensitivity analysis was performed to assess unmeasured confounders. Findings: In an investigation cohort of 307 patients, restricted cubic spline models indicated that hazard risk of recurrence increases with elevated WTAP levels for sHCC and PANLT. However, using Cox and inverse probability weighting models, no significant differences were observed in recurrence-free survival (RFS) between groups with different WTAP levels in sHCC. Multivariate analysis showed that patients with high PANLT WTAP levels had significantly worse RFS (HR 1.567, 95% CI 1.065-2.307; p = 0.023). Based on the significant interaction effect between WTAP levels in sHCC and PANLT, stratification analysis revealed that recurrence risk is more pronounced in patients with high WTAP levels in both PANLT and sHCC. Landmark analysis showed that late recurrence was more likely to occur in patients with high PANLT WTAP levels (HR 2.058, 95% CI 1.113-3.805; p = 0.021). Moreover, the detrimental effects of elevated PANLT WTAP levels on RFS were validated with two external cohorts. Sensitivity analysis confirmed the robustness of results. Conclusion: Increased PANLT WTAP expression levels independently predict high recurrence risk in HBV-positive Asian sHCC patients. Both tumor tissues and PANLT need to be considered together in future clinical practice to obtain a more comprehensive and accurate evaluation for recurrence risk.

Altered DNA methylation pattern characterizes the peripheral immune cells of patients with autoimmune hepatitis

BACKGROUND AND AIMS

Little is known about the impact of DNA methylation modifications on autoimmune hepatitis (AIH) pathogenesis and therapeutic response. We investigated the potential alterations of DNA methylation in AIH peripheral lymphocytes at diagnosis and remission.

METHODS

Ten AIH patients at diagnosis (time-point 1; AIH-tp1), 8/10 following biochemical response (time-point 2; AIH-tp2), 9 primary biliary cholangitis (PBC) and 10 healthy controls (HC) were investigated. Peripheral CD19(+) and CD4(+) cells were isolated. Global DNA methylation (5^m C)/hydroxymethylation (5^hm C) was studied by ELISAs. mRNA of DNA methylation (DNMT1/3A/3B) and their counteracting hydroxymethylation enzymes (TET1/2/3) was determined by quantitative RT-PCR. Epigenome wide association study (EWAS) was performed in CD4(+) cells (Illumina HumanMethylation 850 K array) in AIH and HC. Total 5^m C/5^hm C was also assessed by immunohistochemistry (IHC) on paraffin-embedded liver sections.

RESULTS

Reduced TET1 and increased DNMT3A mRNA levels characterized CD19(+) and CD4(+)-lymphocytes from AIH-tp1 compared to HC and PBC, respectively, without affecting global DNA 5^m C/5^hm C. In AIH-tp1, CD4(+) DNMT3A expression was negatively correlated with serum IgG (P = .03). In remission, DNMT3A decreased in both CD19(+) and CD4(+) cells compared to AIH-tp1 (P = .02, P = .03 respectively). EWAS in CD4(+) cells from AIH patients confirmed important modifications in genes implicated in immune responses (HLA-DP, TNF, lnRNAs and CD86). IHC showed increased 5^hm C staining of periportal infiltrating lymphocytes in AIH-tp1 compared to HC and PBC.

CONCLUSION

Altered TET1 and DNMT3A expressions, characterize peripheral lymphocytes in AIH. DNMT3A was associated with disease activity and decreased following remission. Gene DNA methylation modifications affect immunological pathways that may play an important role in AIH pathogenesis.

Protein profiling reveals potential isomiR-associated cross-talks among RNAs in cholangiocarcinoma

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Protein profiling identified crucial genes that were used to screen related ncRNAs.

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Both miRNAs and isomiRs were involved in coding-non-coding RNA regulatory network.

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IsomiR-associated ceRNA networks implied the complex interactions among RNAs.

Cholangiocarcinomas (CCAs) are tumors that arise from the cholangiocytes. Although some genes have been shown with important roles in pathological process, interactions or cross-talks among different RNAs are important to understand the detailed molecular mechanisms in cancer development, especially discussing cross-talks among isomiRs and other RNAs. Herein, to characterize crucial genes in CCA, the protein expression profile was performed to survey potential crucial mRNAs and related non-coding RNAs (ncRNAs) in mRNA-ncRNA network, mainly including miRNAs/isomiRs and lncRNAs. Deregulated mRNAs were firstly obtained if consistent expression patterns were found at protein and mRNA levels, and related miRNAs/isomiRs were screened according to regulatory relationships. Diverse isomiRs from a given miRNA locus also contributed to interactions between the small RNAs and target mRNAs, and miRNAs were further used to survey related lncRNAs to expand the interactions. Thus, several groups of RNAs were constructed as candidate competitive endogenous RNA (ceRNA) networks. Finally, we found that RAB11FIP1:miR-101-3p:MIR3142HG may be a potential ceRNA network, and the interactions among them may be more complex due to variety of isomiRs. Simultaneously, RAB11FIP1 and miR-194-5p were also detected other related lncRNAs (FBXL19-AS1, SNHG1 and PVT1) that may be crucial in coding-non-coding RNA regulatory network. Our results show that diverse isomiRs with sequence and expression heterogeneities contribute to ceRNA regulatory network that may have crucial roles in CCA, which will expand our understanding of interactions among diverse RNAs and their contributions in cancer development.

Identification and functional characterization of miR-451a as a novel plasma-based biomarker for occult hepatitis B virus infection

BACKGROUND

Numerous studies have indicated that miRNAs might play significant roles in the development of hepatitis B virus (HBV) infection. while the miRNAs in occult HBV infection (OBI) are still largely unknown.

METHODS

Initially, 15 HBV infection-related miRNAs in plasma of 10 OBI and 10 healthy controls (HCs) was analyzed by qRT-PCR. Significantly dysregulated miRNAs were subsequently validated in another 64 OBI, 20HCs, 31 chronic hepatitis B (CHB) and 20 asymptomatic HBsAg carriers (ASC). Furthermore, the potential biological functions and molecular mechanisms of miR-451a in HBV infection were investigated using HBV-expressing hepatoma cell lines.

RESULTS

Compared to HCs, plasma miR-451a and miR-340-3p were significantly up-regulated in OBI, ASC and CHB patients, while no significant difference was found among OBI, ASC and CHB patients. ROC curve analysis indicated that both plasma miR-451a and miR-340-3p could moderately distinguish OBI from HCs, with AUCs of 0.76 and 0.78, respectively. When combined, the differentiation efficiency of this miRNA panel was better, with an AUC of 0.82. While, they both could not specifically separate the stage of chronic HBV infection. Functional experiments showed that overexpression of miR-451a might suppress HBV replication and gene expression in hepatoma cell lines. Mechanistically, miR-451a might inhibit HBV replication and gene expression by directly targeting ATF2.

CONCLUSIONS

A plasma panel, including miR-340-3p and miR-451a that might suppress HBV replication by targeting ATF2, has the potential as biomarkers for HBV infection. In the setting of blood donations, this panel would be more practical to moderately differentiate OBI in HBsAg-negative donors.

MicroRNA-146b-5p suppresses cholangiocarcinoma cells by targeting TRAF6 and modulating p53 translocation

BACKGROUND

In view of the poor prognosis and high mortality of cholangiocarcinoma, there is a need for new therapeutic strategies. This study aims to reveal the biological function of miR-146b-5p in cholangiocarcinoma cell and its possible mechanism.

METHODS

The expression level and prognostic information on miR-146b-5p in cholangiocarcinoma were obtained in TCGA database. The biological function of miR-146b-5p on proliferation and vitality of cholangiocarcinoma cell HUCCT-1 was examined by EdU and MTT assay, and the apoptosis of HUCCT-1 cells transfected with miR-146b-5p mimic, mimic control, inhibitor, inhibitor control was detected by flow cytometry analysis. The western blot was done to evaluate the effect of miR-146b-5p targeting substrate and the expression of p53 in whole-cell protein and mitochondria fractions.

RESULTS

Our finding revealed that miR-146b-5p expression in patients with CHOL was lower than the normal group(p＜0.001). MiR-146b-5p expression was down-regulated in human cholangiocarcinoma HUCCT-1 and RBE cells compared to normal control HIBEC and other cancer cells. The miR-146b-5p mimic could inhibit HUCCT-1 cell proliferation (p＜0.05) and promote HUCCT-1 cell apoptosis significantly (p＜0.05). The results of western blot showed that miR-146b-5p mimic could directly target TRAF6 3'UTR region and up-regulate the expression of p53 in mitochondria and miR-146b-5p inhibitor could down-regulated the level of p53 in mitochondria.

CONCLUSION

MiR-146b-5p is a cholangiocarcinoma suppressor by inhibiting cell proliferation and promoting cell apoptosis with targeting TRAF6, possibly via modulating p53 translocation to mitochondria.

The Role of microRNAs in Cholangiocarcinoma

Cholangiocarcinoma (CCA), an aggressive malignancy, is typically diagnosed at an advanced stage. It is associated with dismal 5-year postoperative survival rates, generating an urgent need for prognostic and diagnostic biomarkers. MicroRNAs (miRNAs) are a class of non-coding RNAs that are associated with cancer regulation, including modulation of cell cycle progression, apoptosis, metastasis, angiogenesis, autophagy, therapy resistance, and epithelial–mesenchymal transition. Several miRNAs have been found to be dysregulated in CCA and are associated with CCA-related risk factors. Accumulating studies have indicated that the expression of altered miRNAs could act as oncogenic or suppressor miRNAs in the development and progression of CCA and contribute to clinical diagnosis and prognosis prediction as potential biomarkers. Furthermore, miRNAs and their target genes also contribute to targeted therapy development and aid in the determination of drug resistance mechanisms. This review aims to summarize the roles of miRNAs in the pathogenesis of CCA, their potential use as biomarkers of diagnosis and prognosis, and their utilization as novel therapeutic targets in CCA.

Programmed Death Ligand-1 (PD-L1) Is an Independent Negative Prognosticator in Western-World Gallbladder Cancer

Inhibition of the programmed cell death protein-1/ligand-1 (PD-1/PD-L1) axis has opened a new era in the treatment of solid cancers. However, there is no data on the expression and relevance of PD-L1 in Western gallbladder cancer (GBC). We assessed PD-L1 immunohistochemically in 131 GBC patients as Tumor Proportion Score (TPS), Immune Cell Score (IC) and Combined Positivity Score (CPS). Tumor cells expressed PD-L1 in a subset of 14.7% GBC patients at a TPS cut-off of 1%. Higher PD-L1 levels above 10% and 25% TPS were reached in 4.7% and 3.1% of GBC cases, respectively. At a 10% cut-off, TPS was associated with distinct histomorphological subtypes and correlated with poor tumor differentiation. Survival analysis revealed a TPS above 10% to be a highly significant and independent negative prognosticator in GBC. PD-L1 expression was associated with increased CD4+, CD8+ and PD-1+ immune cell densities. In 14.8% of the cases, scattered immune cells expressed T-cell immunoreceptor with Ig and ITIM domains (TIGIT), which was correlated to tumoral expression of its ligand CD155. We here show that a high PD-L1 expression confers a negative prognostic value in Western-world GBC and highlight the TIGIT/CD155 immune checkpoint as a potential new target for GBC immunotherapy.

Targeted therapies for extrahepatic cholangiocarcinoma: preclinical and clinical development and prospects for the clinic

Introduction: Until recently, cholangiocarcinoma (CCA) was a largely overlooked disease, and among CCAs, extrahepatic CCA (eCCA) was even more neglected. Despite the growing impact of molecularly targeted therapies and immunotherapy, prognosis of eCCA is dismal. Therefore, unraveling the complex molecular landscape of eCCA has become an urgent need. Deep phenotyping studies have revealed that eCCA is a heterogeneous tumor, harboring specific alterations categorizable into four classes, 'Mesenchymal', 'Proliferation', 'Immune', 'Metabolic'. Molecular alterations convey the activation of several pro-oncogenic pathways, where either actionable drivers or outcome predictors can be identified.Areas covered: We offer insights on perturbed pathways, molecular profiling, and actionable targets in eCCA and present a perspective on the potential stepping-stones to future progress. A systematic literature search in PubMed/ClinicalTrials.gov websites was performed by authors from different disciplines according to their specific topic knowledge to identify the newest and most relevant advances in precision medicine of eCCA.Expert opinion: eCCA is a distinct entity with unique features in terms of molecular classes, oncogenic drivers, and tumor microenvironment. Since more prevalent mutations are currently undruggable, and immunotherapy can be offered only to a minority of patients, international collaborations are instrumental to improve the understanding of the molecular underpins of this disease.

Intraductal Papillary Neoplasm of Bile Duct: Updated Clinicopathological Characteristics and Molecular and Genetic Alterations

Intraductal papillary neoplasm of the bile duct (IPNB), a pre-invasive neoplasm of the bile duct, is being established pathologically as a precursor lesion of invasive cholangiocarcinoma (CCA), and at the time of surgical resection, approximately half of IPNBs show stromal invasion (IPNB associated with invasive carcinoma). IPNB can involve any part of the biliary tree. IPNB shows grossly visible, exophytic growth in a dilated bile duct lumen, with histologically villous/papillary neoplastic epithelia with tubular components covering fine fibrovascular stalks. Interestingly, IPNB can be classified into four subtypes (intestinal, gastric, pancreatobiliary and oncocytic), similar to intraductal papillary mucinous neoplasm of the pancreas (IPMN). IPNBs are classified into low-grade and high-grade based on lining epithelial features. The new subclassification of IPNB into types 1 (low-grade dysplasia and high-grade dysplasia with regular architecture) and 2 (high-grade dysplasia with irregular architecture) proposed by the Japan–Korea pathologist group may be useful in the clinical field. The outcome of post-operative IPNBs is more favorable in type 1 than type 2. Recent genetic studies using next-generation sequencing have demonstrated the existence of several groups of mutations of genes: (i) IPNB showing mutations in KRAS, GNAS and RNF43 belonged to type 1, particularly the intestinal subtype, similar to the mutation patterns of IPMN; (ii) IPNB showing mutations in CTNNB1 and lacking mutations in KRAS, GNAS and RNF43 belonged to the pancreatobiliary subtype but differed from IPMN. IPNB showing mutation of TP53, SMAD4 and PIK3CA might reflect complicated and other features characterizing type 2. The recent recognition of IPNBs may facilitate further clinical and basic studies of CCA with respect to the pre-invasive and early invasive stages.