Circulating miR-106a is a Novel Prognostic and Lymph Node Metastasis Indicator for Cholangiocarcinoma

Precision oncology in biliary tract cancer: the emerging role of liquid biopsy

Liquid biopsy has already proven effective in aiding diagnosis, risk stratification and treatment personalization in several malignancies, and it could represent a practice-changing tool also in biliary tract cancer, even though clinical applications are currently still limited. It is promising for early diagnosis, especially in high-risk populations, and several studies on circulating free DNA (cfDNA), circulating tumour cells and differential microRNA (miRNA) profiles in this setting are ongoing. Circulating tumour DNA (ctDNA) also appears as a feasible noninvasive biomarker in the curative setting, in detecting minimal residual disease after resection and in monitoring disease recurrence. As of today, it can be particularly valuable in biliary tract cancer for genomic profiling, with a good concordance with tissue samples for most molecular alterations. CtDNA analysis may especially be considered in clinical practice when the tumour tissue is not sufficient for next-generation sequencing, or when urgent therapeutic decisions are needed. Moreover, it offers the possibility of providing a real-time picture to monitor treatment response and dynamically identify resistance mutations, potentially representing a way to optimize treatment strategies.

Cholangiocarcinoma: The era of liquid biopsy

Cholangiocarcinoma (CCA) is a highly aggressive and heterogeneous malignancy arising from the epithelial cells of the biliary tract. The limitations of the current methods in the diagnosis of CCA highlight the urgent need for new, accurate tools for early cancer detection, better prognostication and patient monitoring. Liquid biopsy (LB) is a modern and non-invasive technique comprising a diverse group of methodologies aiming to detect tumour biomarkers from body fluids. These biomarkers include circulating tumour cells, cell-free DNA, circulating tumour DNA, RNA and extracellular vesicles. The aim of this review is to explore the current and potential future applications of LB in CCA management, with a focus on diagnosis, prognostication and monitoring. We examine both its significant potential and the inevitable limitations associated with this technology. We conclude that LB holds considerable promise, but further research is necessary to fully integrate it into precision oncology for CCA.

Surgical management, including the role of transplantation, for intrahepatic and peri-hilar cholangiocarcinoma

Intrahepatic and peri-hilar cholangiocarcinoma are life threatening disease with poor outcomes despite optimal treatment currently available (5-year overall survival following resection 20-35%, and <10% cured at 10-years post resection). The insidious onset makes diagnosis difficult, the majority do not have a resection option and the high recurrence rate post-resection suggests that occult metastatic disease is frequently present. Advances in perioperative management, such as ipsilateral portal vein (and hepatic vein) embolisation methods to increase the future liver remnant volume, genomic profiling, and (neo)adjuvant therapies demonstrate great potential in improving outcomes. However multiple areas of controversy exist. Surgical resection rate and outcomes vary between centres with no global consensus on how 'resectable' disease is defined - molecular profiling and genomic analysis could potentially identify patients unlikely to benefit from resection or likely to benefit from targeted therapies. FDG-PET scanning has also improved the ability to detect metastatic disease preoperatively and avoid futile resection. However tumours frequently invade major vasculo-biliary structures, with resection and reconstruction associated with significant morbidity and mortality even in specialist centres. Liver transplantation has been investigated for very selected patients for the last decade and yet the selection algorithm, surgical approach and both value of both neoadjuvant and adjuvant therapies remain to be clarified. In this review, we discuss the contemporary management of intrahepatic and peri-hilar cholangiocarcinoma.

Overview of miR-106a Regulatory Roles: from Cancer to Aging

MicroRNAs (miRNAs) comprise a class of non-coding RNA with extensive regulatory functions within cells. MiR-106a is recognized for its super-regulatory roles in vital processes. Hence, the analysis of its expression in association with diseases has attracted considerable attention for molecular diagnosis and drug development. Numerous studies have investigated miR-106 target genes and shown that this miRNA regulates the expression of some critical cell cycle and apoptosis factors, suggesting miR-106a as an ideal diagnostic and prognostic biomarker with therapeutic potential. Furthermore, the reported correlation between miR-106a expression level and cancer drug resistance has demonstrated the complexity of its functions within different tissues. In this study, we have conducted a comprehensive review on the expression levels of miR-106a in various cancers and other diseases, emphasizing its target genes. The promising findings surrounding miR-106a suggest its potential as a valuable biomolecule. However, further validation assessments and overcoming existing limitations are crucial steps before its clinical implementation can be realized.

Tumor Microenvironment Remodeling in Gastrointestinal Cancer: Role of miRNAs as Biomarkers of Tumor Invasion

Gastrointestinal (GI) cancers are the most frequent neoplasm, responsible for half of all cancer-related deaths. Metastasis is the leading cause of death from GI cancer; thus, studying the processes that regulate cancer cell migration is of paramount importance for the development of new therapeutic strategies. In this review, we summarize the mechanisms adopted by cancer cells to promote cell migration and the subsequent metastasis formation by highlighting the key role that tumor microenvironment components play in deregulating cellular pathways involved in these processes. We, therefore, provide an overview of the role of different microRNAs in promoting tumor metastasis and their role as potential biomarkers for the prognosis, monitoring, and diagnosis of GI cancer patients. Finally, we relate the possible use of nutraceuticals as a new strategy for targeting numerous microRNAs and different pathways involved in GI tumor invasiveness.

Small but mighty: How microRNAs drive the deadly progression of cholangiocarcinoma

Cholangiocarcinoma, also referred to as CCA, is a highly complex epithelial malignancy that can impact various organs and regions of the body, including the perihilar, intrahepatic, and distal organs. This cancer is characterized by the malignant growth of the epithelial lining in the bile ducts, which spans the entire biliary tree and is accountable for disease progression. The current state of affairs concerning CCA is concerning, with poor prognoses, high recurrence rates, and dismal long-term survival rates significantly burden healthcare facilities worldwide. Studies have identified numerous signaling pathways and molecules involved in the development and progression of CCA, including microRNAs, an important class of non-coding RNAs that have the ability to modulate these cellular signaling pathways significantly. In addition, microRNAs may serve as an innovative target for developing novel therapeutic approaches for CCA. In this review, we explore the underlying mechanisms and signaling pathways implicated in the initiation and progression of CCA, focusing on the future direction of utilizing microRNAs as a promising treatment option for this challenging malignancy.

The interplay of signaling pathways with miRNAs in cholangiocarcinoma pathogenicity and targeted therapy

Cholangiocarcinoma (CCA), the second most frequent liver cancer after hepatocellular carcinoma, has been rising worldwide in recent epidemiological research. This neoplasia's pathogenesis is poorly understood. Yet, recent advances have illuminated the molecular processes of cholangiocyte malignancy and growth. Late diagnosis, ineffective therapy, and resistance to standard treatments contribute to this malignancy's poor prognosis. So, to develop efficient preventative and therapy methods, the molecular pathways that cause this cancer must be better understood. MicroRNAs (miRNAs) are non-coding ribonucleic acids (ncRNAs) that influence gene expression. Biliary carcinogenesis involves abnormally expressed miRNAs that act as oncogenes or tumor suppressors (TSs). The miRNAs regulate multiple gene networks and are involved in cancer hallmarks like reprogramming of cellular metabolism, sustained proliferative signaling, evasion of growth suppressors, replicative immortality, induction/access to the vasculature, activation of invasion and metastasis, and avoidance of immune destruction. In addition, numerous ongoing clinical trials are demonstrating the efficacy of therapeutic strategies based on miRNAs as powerful anticancer agents. Here, we will update the research on CCA-related miRNAs and explain their regulation involved in the molecular pathophysiology of this malignancy. Eventually, we will disclose their potential as clinical biomarkers and therapeutic tools in CCA.

Targeting Angiogenesis in the Era of Biliary Tract Cancer Immunotherapy: Biological Rationale, Clinical Implications, and Future Research Avenues

Although biliary tract cancers are traditionally considered rare in Western countries, their incidence and mortality rates are rising worldwide. A better knowledge of the genomic landscape of these tumor types has broadened the number of molecular targeted therapies, including angiogenesis inhibitors. The role of immune checkpoint inhibitors (ICIs) could potentially change the first-line therapeutic approach, but monotherapy with ICIs has shown disappointing results in CCA. Several clinical trials are evaluating combination strategies that include immunotherapy together with other anticancer agents with a synergistic activity. The tumor microenvironment (TME) composition plays a pivotal role in the prognosis of BTC patients. The accumulation of immunosuppressive cell types, such as tumor-associated macrophages (TAMs) and regulatory T-cells, together with the poor infiltration of cytotoxic CD8+ T-cells, is known to predispose to a poor prognosis owing to the establishment of resistance mechanisms. Likewise, angiogenesis is recognized as a major player in modulating the TME in an immunosuppressive manner. This is the mechanistic rationale for combination treatment schemes blocking both immunity and angiogenesis. In this scenario, this review aims to provide an overview of the most recent completed or ongoing clinical trials combining immunotherapy and angiogenesis inhibitors with/without a chemotherapy backbone.

The multidisciplinary management of cholangiocarcinoma

Cholangiocarcinoma is a lethal malignancy of the biliary epithelium that can arise anywhere along the biliary tract. Surgical resection confers the greatest likelihood of long-term survivability. However, its insidious onset, difficult diagnostics, and resultant advanced presentation render the majority of patients unresectable, highlighting the importance of early detection with novel biomarkers. Developing liver-directed therapies and emerging targeted therapeutics may offer improved survivability for patients with unresectable or advanced disease. In this article, the authors review the current multidisciplinary standards of care in resectable and unresectable cholangiocarcinoma, with an emphasis on novel biomarkers for early detection and nonsurgical locoregional therapy options.

Heart failure and cancer: From active exposure to passive adaption

The human body seems like a "balance integrator." On the one hand, the body constantly actively receives various outside stimuli and signals to induce changes. On the other hand, several internal regulations would be initiated to adapt to these changes. In most cases, the body could keep the balance in vitro and in vivo to reach a healthy body. However, in some cases, the body can only get to a pathological balance. Actively exposed to unhealthy lifestyles and passively adapting to individual primary diseases lead to a similarly inner environment for both heart failure and cancer. To cope with these stimuli, the body must activate the system regulation mechanism and face the mutual interference. This review summarized the association between heart failure and cancer from active exposure to passive adaption. Moreover, we hope to inspire researchers to contemplate these two diseases from the angle of overall body consideration.

Prioritizing key synergistic circulating microRNAs for the early diagnosis of biliary tract cancer

Biliary tract cancer (BTC) is a highly aggressive malignant tumor. Serum microRNAs (ser-miRNAs) serve as noninvasive biomarkers to identify high risk individuals, thereby facilitating the design of precision therapies. The study is to prioritize key synergistic ser-miRNAs for the diagnosis of early BTC. Sampling technology, significant analysis of microarrays, Pearson Correlation Coefficients, t-test, decision tree, and entropy weight were integrated to develop a global optimization algorithm of decision forest. The source code is available at https://github.com/SuFei-lab/GOADF.git. Four key synergistic ser-miRNAs were prioritized and the synergistic classification performance was better than the single miRNA’ s. In the internal feature evaluation dataset, the area under the receiver operating characteristic curve (AUC) for each single miRNA was 0.8413 (hsa-let-7c-5p), 0.7143 (hsa-miR-16-5p), 0.8571 (hsa-miR-17-5p), and 0.9365 (hsa-miR-26a-5p), respectively, whereas the synergistic AUC value increased to 1.0000. In the internal test dataset, the single AUC was 0.6500, 0.5125, 0.6750, and 0.7500, whereas the synergistic AUC increased to 0.8375. In the independent test dataset, the single AUC was 0.7280, 0.8313, 0.8957, and 0.8303, and the synergistic AUC was 0.9110 for discriminating between BTC patients and healthy controls. The AUC for discriminating BTC from pancreatic cancer was 0.9000. Hsa-miR-26a-5p was a predictor of prognosis, patients with high expression had shorter survival than those with low expression. In conclusion, hsa-let-7c-5p, hsa-miR-16-5p, hsa-miR-17-5p, and hsa-miR-26a-5p may act as key synergistic biomarkers and provide important molecular mechanisms that contribute to pathogenesis of BTC.

Molecular diagnostics and biomarkers in cholangiocarcinoma

Regardless of anatomic origin, cholangiocarcinoma is generally an aggressive malignancy with a relatively high case fatality. Surgical resection with curative intent remains the best opportunity to achieve meaningful long-term survival. Most patients present, however, with advanced disease and less than 20% of patients are candidates for surgical resection. Unfortunately, even patients who undergo resection have a 5-year survival that ranges from 20 to 40%. Biomarkers are indicators of normal, pathologic, or biologic responses to an intervention and can range from a characteristic (i.e., blood pressure reading which can detect hypertension) to specific genetic mutations or proteins (i.e., carcinoembryonic antigen level). Novel biomarkers and improved molecular diagnostics represent an attractive opportunity to improve detection as well as to identify novel therapeutic targets for patients with cholangiocarcinoma. We herein review the latest advances in molecular diagnostics and biomarkers related to the early detection and treatment of patients with cholangiocarcinoma.

Liquid biopsy in biliary tract cancer from blood and bile samples: current knowledge and future perspectives

Biliary tract cancer (BTC) is an aggressive tumor characterized by a poor prognosis. In the latest years, targetable genetic alterations have been discovered in BTC patients, leading to the approval of new targeted therapies. Liquid biopsy, which is a non-invasive method for detecting tumor biomarkers from fluid samples, is a useful tool for diagnosis and molecular characterization, but also for prognosis assessment and monitoring of treatment response. In this review, recent works on liquid biopsy in BTC patients were analyzed, focusing on some relevant aspects for clinical use and trying to depict the future role of this technique. Moreover, differences between plasma and bile samples were pointed out, in light of the peculiar biology of BTC and the possibility of using bile as an alternative source of cell-free DNA (cfDNA) for genomic analysis. In the era of precision oncology, the increasing adoption of liquid biopsy in BTC patients will certainly improve the management of this disease.

Micro-RNA in Cholangiocarcinoma: Implications for Diagnosis, Prognosis, and Therapy

Bile-duct cancers (BDC) are a group of solid tumors arising from the biliary tree. Despite their classification as rare cancers, the incidence of BDC is increasing worldwide. Poor prognosis is a common feature of this type of cancer and is mainly determined by the following factors: late diagnosis, lack of effective therapeutic approaches, and resistance to conventional treatments. In the past few years, next-generation sequencing technologies has allowed us to study the genome, exome, and transcriptome of BDC deeper, revealing a previously underestimated class of RNA: the noncoding RNA (ncRNA). MicroRNAs (miRNAs) are small ncRNAs that play an important regulatory role in gene expression. The aberrant expression of miRNAs and their pivotal role as oncogenes or tumor suppressors in biliary carcinogenesis has been widely described in BDC. Due to their ability to regulate multiple gene networks, miRNAs are involved in all cancer hallmarks, including sustaining proliferative signaling, evading growth suppressors, resisting cell death, enabling replicative immortality, inducing/accessing vasculature, activating invasion and metastasis, reprogramming cellular metabolism, and avoiding immune destruction. Their use as diagnostic, prognostic, and predictive biomarkers has been widely explored in several human cancers, including BDC. Furthermore, miRNA-based therapeutic strategies are currently the subject of numerous clinical trials that are providing evidence of their efficacy as potent anticancer agents. In this review, we will provide a detailed update of miRNAs affecting BDC, discussing their regulatory function in processes underlying the molecular pathology of BDC. Finally, an overview of their potential use as biomarkers or therapeutic tools in BDC will be further addressed.

Methylation of Tumor Suppressive miRNAs in Plasma from Patients With Pancreaticobiliary Diseases

BACKGROUND/AIM

We previously reported the usefulness of aberrant methylation of tumor suppressive miRNAs in bile to discriminate pancreaticobiliary cancers (PBCs) from benign pancreaticobiliary diseases (BD). Here we performed a methylation analysis of plasma miRNAs to identify miRNAs specific for PBCs.

PATIENTS AND METHODS

Plasma was collected from 80 patients with pancreatic cancer (PC); 18 with biliary tract cancer (BTC) and 28 with BD. Sequences encoding 3 tumor suppressive miRNAs (miR-200a, -200b, and -1247) were PCR amplified and sequenced, and their methylation rates were determined.

RESULTS

The methylation rate of miR-1247 was significantly higher in patients with BTC than in those with BD, and tended to be higher in patients with PC than in those with BD. Furthermore, it was significantly higher in three patients with stages I/II BTC than in those with BD.

CONCLUSION

Methylation of miR-1247 in plasma may be useful to distinguish BTC from BD.

Prognostic and Predictive Molecular Markers in Cholangiocarcinoma

Cholangiocarcinoma (CCA) is the second most common primary liver cancer and subsumes a heterogeneous group of malignant tumors arising from the intra- or extrahepatic biliary tract epithelium. A rising mortality from CCA has been reported worldwide during the last decade, despite significant improvement of surgical and palliative treatment. Over 50% of CCAs originate from proximal extrahepatic bile ducts and constitute the most common CCA entity in the Western world. Clinicopathological characteristics such as lymph node status and poor differentiation remain the best-studied, but imperfect prognostic factors. The identification of prognostic molecular markers as an adjunct to traditional staging systems may not only facilitate the selection of patients who would benefit the most from surgical, adjuvant or palliative treatment strategies, but may also be helpful in defining the aggressiveness of the disease and identifying patients at high-risk for tumor recurrence. The purpose of this review is to provide an overview of currently known molecular prognostic and predictive markers and their role in CCA.

Biliary Tract Cancers: Treatment Updates and Future Directions in the Era of Precision Medicine and Immuno-Oncology

The effective management of biliary tract cancers (BTCs) has been hampered by limited options for systemic therapy. In recent years, the focus on precision medicine has made technologies such as next-generation sequencing (NGS) accessible to clinicians to identify targetable mutations in BTCs in tumor tissue (primarily) as well as blood, and to treat them with targeted therapies when possible. It has also expanded our understanding of functional pathways associated with genetic alterations and opened doors for identifying novel targets for treatment. Recent advances in the precision medicine approach allowed us to identify new molecular markers in BTCs, such as epigenetic changes (methylation and histone modification) and non-DNA markers such as messenger RNA, microRNA, and long non-coding RNA. It also made detecting these markers from non-traditional sources such as blood, urine, bile, and cytology (from fine-needle aspiration and biliary brushings) possible. As these tests become more accessible, we can see the integration of different molecular markers from all available sources to aid physicians in diagnosing, assessing prognosis, predicting tumor response, and screening BTCs. Currently, there are a handful of approved targeted therapies and only one class of immunotherapy agents (immune checkpoint inhibitors or ICIs) to treat BTCs. Early success with new targets, vascular endothelial growth factor receptor (VEGFR), HER2, protein kinase receptor, and Dickkopf-1 (DKK1); new drugs for known targets, fibroblast growth factor receptors (FGFRs) such as futabatinib, derazantinib, and erdafitinib; and ICIs such as durvalumab and tremelimumab is encouraging. Novel immunotherapy agents such as bispecific antibodies (bintrafusp alfa), arginase inhibitors, vaccines, and cellular therapy (chimeric antigen receptor-T cell or CAR-T, natural killer cells, tumor-infiltrating lymphocytes) have the potential to improve outcomes of BTCs in the coming years.

Biliary Strictures and Cholangiocarcinoma - Untangling a Diagnostic Conundrum

Cholangiocarcinoma is an uncommon and highly aggressive biliary tract malignancy with few manifestations until late disease stages. Diagnosis is currently achieved through a combination of clinical, biochemical, radiological and histological techniques. A number of reported cancer biomarkers have the potential to be incorporated into diagnostic pathways, but all lack sufficient sensitivity and specificity limiting their possible use in screening and early diagnosis. The limitations of standard serum markers such as CA19-9, CA125 and CEA have driven researchers to identify multiple novel biomarkers, yet their clinical translation has been slow with a general requirement for further validation in larger patient cohorts. We review recent advances in the diagnostic pathway for suspected CCA as well as emerging diagnostic biomarkers for early detection, with a particular focus on non-invasive approaches.

Potential utility of liquid biopsies in the management of patients with biliary tract cancers: A review

Biliary tract cancer, comprising gallbladder cancer, cholangiocarcinoma and ampullary cancer, represents a more uncommon entity outside high-endemic areas, though global incidence is rising. The majority of patients present at a late stage, and 5-year survival remains poor. Advanced stage disease is incurable, and though palliative chemotherapy has been shown to improve survival, further diagnostic and therapeutic options are required in order to improve patient outcomes. Although certain subtypes of biliary tract cancer are relatively rich in targetable mutations, attaining tumour tissue for histological diagnosis and treatment monitoring is challenging due to locoregional anatomical constraints and patient fitness. Liquid biopsies offer a safe and convenient alternative to invasive procedures and have great potential as diagnostic, predictive and prognostic biomarkers. In this review, the current standard of care for patients with biliary tract cancer, future treatment horizons and the possible utility of liquid biopsies within a variety of contexts will be discussed. Circulating tumour DNA, circulating microRNA and circulating tumour cells are discussed with an overview of their potential applications in management of biliary tract cancer. A summary is also provided of currently recruiting clinical trials incorporating liquid biopsies within biliary tract cancer research.

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.

Next-Generation Biomarkers for Cholangiocarcinoma

Simple Summary

Early and non-invasive diagnosis of cholangiocarcinoma (CCA) is still challenging, thus largely contributing to the increased mortality rates observed worldwide. Consequently, several efforts have been made in order to report novel biomarkers for CCA, that would aid on diagnosis and also to predict prognosis and therapy response. We herein aim to provide an in-depth and critical revision on the next-generation biomarkers for CCA that have been recently proposed.

Abstract

The increasing mortality rates of cholangiocarcinoma (CCA) registered during the last decades are, at least in part, a result of the lack of accurate non-invasive biomarkers for early disease diagnosis, making the identification of patients who might benefit from potentially curative approaches (i.e., surgery) extremely challenging. The obscure CCA pathogenesis and associated etiological factors, as well as the lack of symptoms in patients with early tumor stages, highly compromises CCA identification and to predict tumor development in at-risk populations. Currently, CCA diagnosis is accomplished by the combination of clinical/biochemical features, radiological imaging and non-specific serum tumor biomarkers, although a tumor biopsy is still needed to confirm disease diagnosis. Furthermore, prognostic and predictive biomarkers are still lacking and urgently needed. During the recent years, high-throughput omics-based approaches have identified novel circulating biomarkers (diagnostic and prognostic) that might be included in large, international validation studies in the near future. In this review, we summarize and discuss the most recent advances in the field of biomarker discovery in CCA, providing new insights and future research directions.

Liquid biopsy in cholangiocarcinoma: Current status and future perspectives

Cholangiocarcinoma (CCA) are a heterogeneous group of tumors in terms of aetiology, natural history, morphological subtypes, molecular alterations and management, but all sharing complex diagnosis, management, and poor prognosis. Several mutated genes and epigenetic changes have been detected in CCA, with the potential to identify diagnostic and prognostic biomarkers and therapeutic targets. Accessing tumoral components and genetic material is therefore crucial for the diagnosis, management and selection of targeted therapies; but sampling tumor tissue, when possible, is often risky and difficult to be repeated at different time points. Liquid biopsy (LB) represents a way to overcome these issues and comprises a diverse group of methodologies centering around detection of tumor biomarkers from fluid samples. Compared to the traditional tissue sampling methods LB is less invasive and can be serially repeated, allowing a real-time monitoring of the tumor genetic profile or the response to therapy. In this review, we analysis the current evidence on the possible roles of LB (circulating DNA, circulating RNA, exosomes, cytokines) in the diagnosis and management of patients affected by CCA.

Prognostic biomarkers for cholangiocarcinoma (CCA): state of the art

Introduction:Although advances in understanding the molecular basis of cholangiocarcinoma (CCA) have been made, surgery is the only curative therapy option and the overall prognosis of patients suffering from the disease remains poor. Therefore, estimation of prognosis based on known and novel biomarkers is essential for therapy guidance of CCA in both, curative and palliative settings.Areas covered:An extensive literature search on biomarkers for CCA with special emphasis on prognosis was performed. Based on this, prognostic biomarkers from serum, tumor tissue and other compartments that are currently in use or under evaluation for CCA were summarized in this review. Furthermore, an overview of new biomarkers was provided including those determined from extracellular vesicles (EVs), metabolites and nucleic acids. Finally, prognostic markers associated with potential new therapy options for the treatment of CCA were summed up.Expert opinion:So far, an optimal prognostic biomarker for CCA has not been described. However, based on the increasing knowledge about the molecular basis of CCA but also due to novel, innovative technologies, a plethora of novel prognostic biomarkers is currently under evaluation and will be available for CCA in future.

Development and validation of a CpG island methylator phenotype-related prognostic signature for cholangiocarcinoma

Cholangiocarcinoma (CCA) still has a very unfavorable prognosis with a very high mortality, which is complicated by a lack of prognostic biomarkers. In this study, CCA patients in the Gene Expression Omnibus (GEO) cohort were categorized into two subtypes. Differentially expressed and methylated genes were identified, and the impact of DNA methylation in the trans-regulation of gene expression was investigated. Finally, a CIMP-related methylation signature specific for CCA (CMSC) was trained in GEO and validated in the Tongji cohort. A subset of patients with CIMP-H was identified, which was correlated with an unfavorable prognosis. Gene enrichment analysis implied the potential mechanism of CIMP as a promoter of carcinogenesis by regulating proliferation. The trans-regulation among differentially methylated CpG sites and genes with the same change trends was positively correlated, while the converse situation showed a negative correlation. Notably, CMSC based on four genes could significantly classify CCA patients into low- and high-risk groups in the GEO cohort, and the robustness of CMSC was validated in the Tongji cohort. The results of receiver operating characteristic analysis further indicated that CMSC was capable of highly sensitive and specific prediction of the patient outcomes in CCA. In conclusion, our work highlights the clinical significance of CMSC in the prognosis of CCA.

Pathogenetic Role and Clinical Implications of Regulatory RNAs in Biliary Tract Cancer

Biliary tract cancer (BTC) is characterised by poor prognosis and low overall survival in patients. This is generally due to minimal understanding of its pathogenesis, late diagnosis and limited therapeutics in preventing or treating BTC patients. Non-coding RNA (ncRNA) are small RNAs (mRNA) that are not translated to proteins. ncRNAs were considered to be of no importance in the genome, but recent studies have shown they play essential roles in biology and oncology such as transcriptional repression and degradation, thus regulating mRNA transcriptomes. This has led to investigations into the role of ncRNAs in the pathogenesis of BTC, and their clinical implications. In this review, the mechanisms of action of ncRNA are discussed and the role of microRNAs in BTC is summarised. The scope of this review will be limited to miRNA as they have been shown to play the most significant roles in BTC progression. There is huge potential in miRNA-based biomarkers and therapeutics in BTC, but more studies, research and technological advancements are required before it can be translated into clinical practice for patients.

Cholangiocarcinoma 2020: the next horizon in mechanisms and management

Cholangiocarcinoma (CCA) includes a cluster of highly heterogeneous biliary malignant tumours that can arise at any point of the biliary tree. Their incidence is increasing globally, currently accounting for ~15% of all primary liver cancers and ~3% of gastrointestinal malignancies. The silent presentation of these tumours combined with their highly aggressive nature and refractoriness to chemotherapy contribute to their alarming mortality, representing ~2% of all cancer-related deaths worldwide yearly. The current diagnosis of CCA by non-invasive approaches is not accurate enough, and histological confirmation is necessary. Furthermore, the high heterogeneity of CCAs at the genomic, epigenetic and molecular levels severely compromises the efficacy of the available therapies. In the past decade, increasing efforts have been made to understand the complexity of these tumours and to develop new diagnostic tools and therapies that might help to improve patient outcomes. In this expert Consensus Statement, which is endorsed by the European Network for the Study of Cholangiocarcinoma, we aim to summarize and critically discuss the latest advances in CCA, mostly focusing on classification, cells of origin, genetic and epigenetic abnormalities, molecular alterations, biomarker discovery and treatments. Furthermore, the horizon of CCA for the next decade from 2020 onwards is highlighted.

Analysis of differentially expressed mRNAs and the prognosis of cholangiocarcinoma based on TCGA database

Background

The effective evaluation of cholangiocarcinoma (CCA) is challenging due to a lack of accurate screening tools. Consequently, there is an urgent need to screen out effective biomarkers. Bioinformatics analysis on a substantial amount of transcriptomic data to screen biomolecules allows for the verification of histological samples, and can provide a new method for CCA biomolecule screening in diagnosis and prognosis.

Methods

EdgeR model was used to analyze The Cancer Genome Atlas (TCGA)-extracted CCA data set, and to determine the differential expression of mRNAs. Based on this, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) were used to perform functional and pathway enrichment analysis. Subsequently, a protein interaction network was also established to identify the key differential node genes. Then, the previously determined differential genes were analyzed to establish a link between these genes and clinical prognosis. Finally, we used tissue samples to realize our results via IHC, Western blot and qRT-PCR.

Results

A total of 5,561 differential mRNAs were screened, including 3,473 upregulated genes and 2,088 downregulated genes. GO and KEGG enrichment analysis showed that the upregulated genes had significantly enriched cell adhesion, concentrated chromosomal motility, and microtubule motility. Downregulated genes were significantly enriched in heterologous metabolism and exosomes. Furthermore, we found upregulated genes were significantly enriched in the cancer pathways and cell cycle. Downregulated genes were enriched in the metabolic pathways and biosynthesis of antibiotics. Ten hub genes were screened out through the protein interaction network; among these, the AURKB and PLK1 genes were closely related to the clinical prognosis of patients. Results of the immunohistochemical staining, Western blot and qRT-PCR all showed that the expression of AURKB and PLK1 in cancer tissues was higher than that in the adjacent tissues, and this difference was statistically significant (P<0.05).

Conclusions

The upregulated genes were significantly enriched in the biological processes of cell division, cell cycle, and related cell components. AURKB and PLK1 play a key role in differentially expressed gene nodes. These genes are closely related to the prognosis of patients and can be used as potential diagnostic tools and prognostic biomarkers.

Targeting miRNAs by natural products: A new way for cancer therapy

MicroRNAs (miRNAs) are short non-coding RNAs that regulate gene expression through mRNA degradation or translation inhibition. MiRNAs play important roles in a variety of biological processes, and dysregulation of miRNA expression is highly associated with cancer development. Individual miRNA regulates multiple gene expressions, enabling them to regulate multiple cellular signaling pathways simultaneously. Hence, miRNAs could be served as cancer biomarkers for diagnosis and prognosis, and also therapeutic targets. Recently, more and more evidences showed that natural products such as paclitaxel, curcumin, resveratrol, genistein or epigallocatechin-3-gallate exert their anti-proliferative and/or pro-apoptotic effects through regulating one or more miRNAs, leading to the inhibition of cancer cell growth, induction of apoptosis or enhancement of conventional cancer therapeutic efficacy. Herein, we outlined the recent advances in the regulation of miRNAs expression by the natural products and highlight the importance of these natural drugs as a potential strategy in cancer treatment. This review will help us better understand how natural products modulate miRNAs and contribute to the development of effective and safe natural drugs for therapeutic purposes.

Role of noncoding RNAs in cholangiocarcinoma (Review)

Cholangiocarcinoma (CCA) is a malignant tumour originating from biliary epithelial cells, and is increasing in incidence. Radical surgery is the main treatment. However, the pathogenesis of CCA is unclear. Noncoding RNAs (ncRNAs) are non‑protein‑coding RNAs produced by genomic transcription that include microRNAs (miRNAs), circular RNAs (circRNAs) and long noncoding RNAs (lncRNAs). They play important roles in gene expression, epigenetic modification, cell proliferation, differentiation and reproduction. ncRNAs also serve key roles in cancer development. Numerous studies have been carried out on ncRNAs, and associated publications have shown that ncRNAs are closely associated with the physiological and pathological mechanisms of CCA. The findings of these studies can provide new insights into the diagnosis, treatment and prognosis of CCA. The present review summarizes the pathophysiological mechanisms of different types of ncRNAs, including miRNAs, circRNAs and lncRNAs in CCA, and their applications in the diagnosis and treatment of CCA.

Circulating miR-130b- and miR-21-based diagnostic markers and therapeutic targets for hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) is one of the histological types of primary liver cancer with high recurrence and mortality in the world. The purpose of this study was to explore the diagnostic and therapeutic value for HCC patients.

Methods

In this study, we investigated the circulating miR‐130b‐5p (miR‐130b) and miR‐21‐5p (miR‐21) expression levels in patients with HCC and their association with clinical parameters.

Results

The circulating miR‐130b and miR‐21 were all upregulated in patients with HCC. The upregulated microRNAs (miRNAs) were associated with clinicopathological parameters of tumor capsular infiltration and clinical TNM stage. Also, the poor prognosis of patients with upregulated miRNAs levels suggested that it may be an effective therapeutic target for HCC by suppression of the miRNAs levels. In addition, the combined detection of serum miR‐130b and miR‐21 performed better in the diagnosis of HCC with a sensitivity of 92.16% and an accuracy rate of 77.51%. In vivo, tumors treated with the nanoparticle (NP)/miR‐130b and miR‐21 inhibitor complexes had significantly lower growth than the other groups.

Conclusion

The circulating miR‐130b and miR‐21 can be used as potential tumor biomarkers to diagnose liver cancer, and the combined detection of serum miR‐130b and miR‐21 is superior to the diagnosis of HCC. NP/miR‐130b and miR‐21 inhibitor complexes show good therapeutic effects in vivo and are expected to become therapeutic targets worthy of further study.

Noncoding RNAs in Extracellular Fluids as Cancer Biomarkers: The New Frontier of Liquid Biopsies

The last two decades of cancer research have been devoted in two directions: (1) understanding the mechanism of carcinogenesis for an effective treatment, and (2) improving cancer prevention and screening for early detection of the disease. This last aspect has been developed, especially for certain types of cancers, thanks also to the introduction of new concepts such as liquid biopsies and precision medicine. In this context, there is a growing interest in the application of alternative and noninvasive methodologies to search for cancer biomarkers. The new frontiers of the research lead to a search for RNA molecules circulating in body fluids. Searching for biomarkers in extracellular body fluids represents a better option for patients because they are easier to access, less painful, and potentially more economical. Moreover, the possibility for these types of samples to be taken repeatedly, allows a better monitoring of the disease progression or treatment efficacy for a better intervention and dynamic treatment of the patient, which is the fundamental basis of personalized medicine. RNA molecules, freely circulating in body fluids or packed in microvesicles, have all the characteristics of the ideal biomarkers owing to their high stability under storage and handling conditions and being able to be sampled several times for monitoring. Moreover, as demonstrated for many cancers, their plasma/serum levels mirror those in the primary tumor. There are a large variety of RNA species noncoding for proteins that could be used as cancer biomarkers in liquid biopsies. Among them, the most studied are microRNAs, but recently the attention of the researcher has been also directed towards Piwi-interacting RNAs, circular RNAs, and other small noncoding RNAs. Another class of RNA species, the long noncoding RNAs, is larger than microRNAs and represents a very versatile and promising group of molecules which, apart from their use as biomarkers, have also a possible therapeutic role. In this review, we will give an overview of the most common noncoding RNA species detectable in extracellular fluids and will provide an update concerning the situation of the research on these molecules as cancer biomarkers.

Diagnostic and prognostic biomarkers in cholangiocarcinoma

The high mortality rate of cholangiocarcinoma (CCA) is due, in part, to the lack of non-invasive approaches able to accurately detect this silent tumour at early stages, when therapeutic options can be potentially curative or may at least increase the overall survival of patients. The fact that the majority of CCA tumours are not linked to any known aetiological factor highly compromises the monitoring of patients at risk for tumour development and also their early diagnosis. Combination of clinical/biochemical features, imaging techniques and analysis of non-specific tumour biomarkers in serum are commonly used to help in the diagnosis of CCA, but tumour biopsy is usually required to confirm the diagnosis. Moreover, no prognostic biomarkers are currently used in the clinical setting, deserving more innovative research, and international validation and consensus. Important efforts have been made in the last few years to identify accurate non-invasive biomarkers, by using innovative techniques and high-throughput omics technologies. This review summarizes and discusses the advances in the investigation of novel diagnostic and prognostic biomarkers in CCA and envisions the future directions in this field of research.

Usefulness of serum microRNA as a predictive marker of recurrence and prognosis in biliary tract cancer after radical surgery

Biliary tract cancer (BTC) is an aggressive type of malignant tumour. Even after radical resection, the risk of recurrence is still high, resulting in a poor prognosis. Here, we investigated the usefulness of serum miRNAs as predictive markers of recurrence and prognosis for patients with BTC after radical surgery using 66 serum samples that were collected at three time points from 22 patients with BTC who underwent radical surgery. Using microarray analysis, we successfully identified six specific miRNAs (miR-1225-3p, miR-1234-3p, miR1260b, miR-1470, miR-6834-3p, and miR-6875-5p) associated with recurrence and prognosis of BTC after radical surgery. In addition, using a combination of these miRNAs, we developed a recurrence predictive index to predict recurrence in patients with BTC after operation with high accuracy. Patients having higher index scores (≥ cut-off) had significantly worse recurrence-free survival (RFS) and overall survival (OS) than those with lower index scores (<cut-off). Furthermore, the index was an independent factor related to RFS and OS by univariate and multivariate analyses using a Cox hazard proportional model. Overall, our results provided compelling evidence for the potential usefulness of specific serum miRNAs as effective predictive tools for recurrence and prognosis in patients with BTC who underwent radical surgery.

Enhanced plasma miR-142-5p promotes the progression of intrahepatic cholangiocarcinoma via targeting PTEN

The aim of the present study was to evaluate the expression and specific role of microRNA (miR)-142-5p in the progression of intrahepatic cholangiocarcinoma (ICC). Reverse transcription-quantitative polymerase chain reaction was performed to evaluate miR-142-5p expression in patients with ICC and healthy control subjects. The results revealed that plasma miR-142-5p was significantly increased in patients with ICC compared with the control group. Furthermore, miR-142-5p was also increased in ICC tissues compared with adjacent non-neoplastic tissues. Compared with patients with Ta-T1 stage ICC, miR-142-5p was significantly elevated in patients with ICC ≥T2 stage. Patients with ICC at G3 stage had much higher plasma miR-142-5p levels compared with those at G1/2 stage. Receiver operating characteristic analysis indicated that miR-142-5p could be used as a biomarker to differentiate patients with ICC from healthy controls. Kaplan-Meier analysis demonstrated that plasma miR-142-5p was negatively correlated with survival in patients with ICC. A dual luciferase reporter assay indicated that miR-142-5p significantly suppressed the relative luciferase activity of pmirGLO-PTEN-3' untranslated region compared with the control group. In summary, the results of the present study provide novel data indicating that plasma miR-142-5p is significantly upregulated in patients with ICC. miR-142-5p may therefore have potential as a biomarker for screening patients with ICC from healthy controls.

Biomarkers for Stratification in Colorectal Cancer: MicroRNAs

Colorectal cancer (CRC) is one of the most widely recognized and deadly malignancies worldwide. In spite of the fact that the death rates have declined over the previous decade, particularly because of enhanced screening or potential treatment alternatives, CRC still remains the third leading cause of cancer-related mortality in the world, with an estimated incidence of over 1 million new cases and approximately 600 000 deaths estimated yearly. Unlike prostate and lung cancer, CRC is not easily detectable in its early stage, which may also account for its high mortality rate. MicroRNAs (miRNAs) are a class of noncoding RNAs. The roles of these noncoding RNAs have been implicated in cancer pathogenesis, most especially CRC, due to their ability to posttranscriptionally regulate the expression of oncogenes and tumor suppressor genes. Dysregulated expression of many miRNAs regulates the expression of hundreds of growth regulatory genes and pathways that are important in the multistep model of colorectal carcinogenesis. If CRC is detected early, it is a largely treatable disease. Early diagnosis, including the identification of premalignant adenomas, is regarded a major concept for improving patient survival in CRC treatment. Several lines of research suggest that miRNAs are closely implicated in the metastatic process in CRC and some of these miRNAs could be useful as promising clinical tools for identifying specific stages of CRC due to their differential expression. This review discusses the correlation between CRC staging relative to the specific expression of miRNA for early detection, treatment, and disease management.

Diagnostic and prognostic value of microRNAs in cholangiocarcinoma: a systematic review and meta-analysis

Background and aim

Several dysregulated microRNAs (miRNAs) have been implicated in the pathogenesis of cholangiocarcinoma (CCA); however, small sample sizes and invariable research designs are limitations, hindering a thorough analysis of miRNAs as diagnostic and prognostic tools for CCA. This study aimed to systematically summarize the clinical value of miRNAs in human CCA both for all available miRNAs and single miRNA with multiple researches.

Methods

Pooled parameters included the area under the curve (AUC), sensitivity, specificity, and hazard ratios (HRs) to separately determine overall diagnostic and prognostic performance. Subgroup and sensitivity analyses were performed only in the event of heterogeneity. Thirty-four studies including 12 diagnostic studies and 22 prognostic studies were eligible for inclusion in this meta-analysis.

Results

We observed that miR-21, miR-26, miR-483, miR-106a, miR-150, miR-192, and miR-194 were employed for distinguishing patients with CCA from healthy controls. Pooled sensitivity, specificity, and AUC were 0.82 (95% confidence interval [CI] 0.77–0.86), 0.83 (95% CI 0.75–0.89), and 0.88 (95% CI 0.85–0.91), respectively. Abnormal expression of miR-21, miR-26a, miR-192, miR-200c, miR-221, miR-29a, miR-191, miR-181c, miR-34a, miR-106a, miR-203, and miR-373 in patients was confirmed to associate with poor survival rate. Pooled HRs and 95% CIs were calculated using STATA, resulting in the pooled HR of 1.47 (95% CI 0.91–2.37) for overall survival (OS), 0.67 (95% CI 0.16–2.81) for disease-free survival (DFS), 2.31 (95% CI 1.59–3.36) for progression-free survival (PFS), and 2.68 (95% CI 0.88–8.15) for relapse-free survival (RFS). Thus, CCA patients with dysregulated miRNA expression were confirmed to have shorter OS, DFS, PFS, and RFS. Data regarding the diagnostic and prognostic roles of miR-21 suggested pooled diagnostic results of miR-21 for sensitivity, specificity, and AUC were 0.85 (95% CI 0.76–0.91), 0.92 (95% CI 0.81–0.97), and 0.93 (95% CI 0.91–0.95), respectively, suggesting better diagnostic performance of miR-21 compared with other miRNAs. Meanwhile, pooled prognostic result of miR-21 for HR was 1.88 (95% CI 1.41–2.51), indicating miR-21 could more appropriately predict shorter OS in patients with CCA.

Conclusion

miRNAs may provide a new approach for clinical application, and miR-21 may be a promising biomarker for diagnosis and prognosis of CCA.

Circulating Biomarkers for Cholangiocarcinoma

BACKGROUND

Cholangiocarcinoma (CCA) represents the second most common primary liver malignancy. The incidence rate has constantly increased over the last decades and CCA patients face a dismal prognosis with a 5-year survival rate of less than 5% for advanced stage of disease. Surgical tumor resection has remained the only potentially curative treatment option in daily practice but is often not feasible due to advanced disease stage at initial diagnosis.

SUMMARY

The early detection of cholangiocarcinoma is essential to provide patients with a potentially curative treatment. Furthermore, prognostic biomarkers represent a valuable tool to offer patients a tailored therapeutic approach in accordance to their life expectancy. The clinically most established biomarker carbohydrate antigen 19-9 shows only a limited diagnostic and prognostic power, encouraging the evaluation of novel biomarkers for cholangiocarcinoma in the last years. Key Massage: In this review, we assess currently available and potential future biomarkers for the diagnosis and prognosis of cholangicarcinoma.

MicroRNAs and extracellular vesicles in cholangiopathies

Cholangiopathies encompass a heterogeneous group of disorders affecting biliary epithelial cells (i.e. cholangiocytes). Early diagnosis, prognosis and treatment still remain clinically challenging for most of these diseases and are critical for adequate patient care. In the past decade, extensive research has emphasized microRNAs (miRs) as potential non-invasive biomarkers and tools to accurately identify, predict and treat cholangiopathies. MiRs can be released extracellularly conjugated with lipoproteins or encapsulated in extracellular vesicles (EVs). Research on EVs is also gaining attention since they are present in multiple biological fluids and may represent a relevant source of novel non-invasive biomarkers and be vehicles for new therapeutic approaches. This review highlights the most promising candidate miRs and EV-related biomarkers in cholangiopathies, as well as their relevant roles in biliary pathophysiology. This article is part of a Special Issue entitled: Cholangiocytes in Health and Disease edited by Jesus Banales, Marco Marzioni, Nicholas LaRusso and Peter Jansen.

RESEARCH STRATEGY

PubMed search (April 2017) was done with the following terms: "microRNA", "miRNA", "miR", "extracellular vesicles", "EV", "exosomes", "primary biliary cholangitis", "primary biliary cholangitis", "PBC", "primary sclerosing cholangitis", "PSC", "cholangiocarcinoma", "CCA", "biliary atresia", "BA", "polycystic liver diseases", "PLD", "cholangiopathies", "cholestatic liver disease". Most significant articles in full-text English were selected. The reference lists of selected papers were also considered.

The search for novel diagnostic and prognostic biomarkers in cholangiocarcinoma

The poor prognosis of cholangiocarcinoma (CCA) is in part due to late diagnosis, which is currently achieved by a combination of clinical, radiological and histological approaches. Available biomarkers determined in serum and biopsy samples to assist in CCA diagnosis are not sufficiently sensitive and specific. Therefore, the identification of new biomarkers, preferably those obtained by minimally invasive methods, such as liquid biopsy, is important. The development of innovative technologies has permitted to identify a significant number of genetic, epigenetic, proteomic and metabolomic CCA features with potential clinical usefulness in early diagnosis, prognosis or prediction of treatment response. Potential new candidates must be rigorously evaluated prior to entering routine clinical application. Unfortunately, to date, no such biomarker has achieved validation for these purposes. This review is an up-to-date of currently used biomarkers and the candidates with promising characteristics that could be included in the clinical practice in the next future. This article is part of a Special Issue entitled: Cholangiocytes in Health and Disease edited by Jesus Banales, Marco Marzioni, Nicholas LaRusso and Peter Jansen.

NcRNAs and Cholangiocarcinoma

Cholangiocarcinoma (CCA) is the most common primary biliary malignancy with poor prognosis. Less understanding of its etiology and pathogenesis makes the diagnosis and therapy difficult. Recently, accumulating evidences have demonstrated that deregulated expression of non-coding RNAs (ncRNAs) is closely associated with the etiopathogenesis of CCA. NcRNAs which lack open reading frame are a heterogeneous class of transcribed RNA molecules, including microRNAs, long non-coding RNAs and circular RNAs. Several studies have shown ncRNAs dysregulation is a common central event occurring in CCA and has the potential of being therapy targets. Moreover, ncRNAs can be easily detected in cancer tissues and biofluids, representing valuable tools for diagnosis. In this review, we illustrate the role of ncRNA in the CCA and discuss their potential clinical value.

Serum miR-126 level combined with multi- detector computed tomography in the preoperative prediction of lymph node metastasis of gastric cancer

BACKGROUND

Predicting lymph node metastasis (LNM) accurately is vital to design optimal treatment strategies preoperatively for gastric cancer (GC) patients. However, conventional tumor biomarkers and imaging techniques are not sufficient to predict LNM before surgery. miR-126 has been reported to play important roles in tumor metastasis which may represent a novel tumor biomarker.

OBJECTIVE

To assess the utility of the combination of serum miR-126 and multi-detector computed tomography (MDCT) in predicting LNM preoperatively in GC.

METHODS

Quantitative real-time polymerase chain reaction was performed to examine the serum miR-126 expression levels in 338 GC patients. MDCT was also performed. The cut-off value of preoperative serum miR-126 level for LNM was determined by receiver characteristic curve (ROC) analysis. Logistic regression analysis was used to determine independent predictors for LNM.

RESULTS

The serum miR-126 levels of GC patients with LNM were significantly lower compared with those without LNM (p< 0.05). In addition, the later the N stage was, the lower the serum miR-126 level was in GC patients (p< 0.05). With a cut-off value of 63.4, the sensitivity, specificity, accuracy, positive predictive value and negative predictive value of serum miR-126 for predicating LNM were 83.2%, 79.0%, 81.9%, 90.4% and 66.4%, respectively. The combination of serum miR-126 level and MDCT increased the accuracy of MDCT prediction for LNM from 69.2% to 86.7%. Serum miR-126 was an independent predictor for LNM.

CONCLUSIONS

These results indicate for the first time that the combination of serum miR-126 and MDCT is useful for the prediction of LNM in GC.

miRNA profiling for diagnosis, prognosis and stratification of cancer treatment in cholangiocarcinoma

Cholangiocarcinoma (CCA) is a lethal malignancy originating from the biliary tract epithelium. Most patients are diagnosed at an advanced stage. Even after resection with curative intent, prognosis remains poor. Previous studies have reported the evolving role of miRNAs as novel biomarkers in cancer diagnosis, prognostication and chemotherapy response. Various miRNAs, such as miR-21, miR-26, miR-122 and miR-150, have been identified as possible blood-based biomarkers for noninvasive diagnosis of CCA. Moreover, epithelial-mesenchymal transition (EMT)- and angiogenesis-associated miRNAs have been implicated in tumor cell dissemination and are able to determine clinical outcome. In fact, miRNAs involved in cell survival might even determine chemotherapy response. This review provides an overview of known miRNAs as CCA-specific biomarkers.

Emerging molecular targets and therapy for cholangiocarcinoma

Cholangiocarcinoma (CCA) is a rare cancer arising from the biliary tree with a poor prognosis and limited therapeutic options. Recent large scale molecular characterisation studies have identified recurrent genetic alterations in CCA which may be amenable to therapeutic targeting. In this review we explore the genomic landscape of CCA and examine results from trials of molecularly targeted agents and immunotherapy in this disease. Challenges in CCA diagnosis, treatment and trial design are discussed and we reflect on future directions which may lead to improved outcomes for CCA patients.

Identification of circulating microRNA signatures as potential noninvasive biomarkers for prediction and prognosis of lymph node metastasis in gastric cancer

Circulating microRNAs (miRNAs) are emerging as novel noninvasive biomarkers for prediction of lymph node metastasis (LNM) in cancer. The aim of this study was to identify serum miRNA signatures for prediction and prognosis of LNM in gastric cancer (GC). MiSeq sequencing was performed for an initial screening of serum miRNAs in 10 GC patients with LNM, 10 patients without LNM and 10 healthy controls. Reverse transcription quantitative real-time PCR was applied to confirm concentration of candidate miRNAs using a training cohort (n = 279) and a validation cohort (n = 180). We identified a four-miRNA panel (miR-501-3p, miR-143-3p, miR-451a, miR-146a) by multivariate logistic regression model that provided high predictive accuracy for LNM with an area under the receiver operating characteristic curve (AUC) of 0.891 (95% CI, 0.840 to 0.930) in training set. Prospective evaluation of this panel revealed an AUC of 0.822 (95% CI, 0.758 to 0.875, specificity = 87.78%, sensitivity = 63.33%) in validation set. Moreover, Kaplan-Meier analysis showed that LNM patients with low miR-451a and miR-146a levels had worse overall survival (OS) (p < 0.05). In Cox regression analysis, miR-451a was independently associated with OS of LNM (p = 0.028). Our results suggested that use of serum miRNAs seems promising in estimating the probability GC patients harbor LNM and providing prognostic information for LNM.

Role of circulating microRNAs in liver diseases

MicroRNAs (miRNAs) are small RNAs regulate gene expression by inhibiting the turnover of their target mRNAs. In the last years, it became apparent that miRNAs are released into the circulation and circulating miRNAs emerged as a new class of biomarkers for various diseases. In this review we summarize available data on the role of circulating miRNAs in the context of acute and chronic liver diseases including hepatocellular and cholangiocellular carcinoma. Data from animal models are compared to human data and current challenges in the field of miRNAs research are discussed.

Identification of microRNAs as biomarkers for cholangiocarcinoma detection: A diagnostic meta-analysis

BACKGROUND

Cholangiocarcinoma (CCA) is a common biliary malignancy that results in high mortality and poor survival rates. The diagnostic capacity of miRNAs in CCA detection is still controversial. Current meta-analysis evaluate the evidence on the capacity of miRNAs for CCA diagnosis.

METHODS

A systematic literature search for relevant articles in PubMed, Embase and Web of science database up to 10 April 2016 was conducted. The pooled sensitivity, specificity, positive and negative likelihood ratios (PLR and NLR, respectively), diagnostic odds ratio (DOR) and area under the curve (AUC) were pooled to assess the overall diagnostic value of miRNA. Subgroup analysis was further applied to explore the between-study heterogeneity. Publication bias was assessed with Deeks' funnel plot. Statistical analysis was carried out using RevMan 5.2 and MetaDisc 1.4.

RESULTS

A total of 501 patients and 248 controls from 14 studies in 8 articles were included in this meta-analysis. The pooled sensitivity and specialty were 0.83 (0.80-0.86) and 0.79 (0.75-0.83), respectively. The pooled PLR was 3.96 (2.64-5.94), NLR was 0.25 (0.19-0.34), DOR was 18.1 (9.79-33.5) and pooled AUC was 0.88 (0.85-0.90). Subgroup analyses indicated that the serum miRNA assays showed highly accurate CCA diagnosis. The diagnostic capacity was more accurate in Caucasians than in Asians.

CONCLUSIONS

The miRNA assays are promising diagnostic tools for CCA detection with moderate accuracy. However, further prospective studies were needed to confirm this results before clinical application.

Targeting Angiogenesis in Biliary Tract Cancers: An Open Option

Biliary tract cancers (BTCs) are characterized by a bad prognosis and the armamentarium of drugs for their treatment is very poor. Although the inflammatory status of biliary tract represents the first step in the cancerogenesis, the microenvironment also plays a key role in the pathogenesis of BTCs, promoting tumor angiogenesis, invasion and metastasis. Several molecules, such as vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF), are involved in the angiogenesis process and their expression on tumor samples has been explored as prognostic marker in both cholangiocarcinoma and gallbladder cancer. Recent studies evaluated the genomic landscape of BTCs and evidenced that aberrations in several genes enrolled in the pro-angiogenic signaling, such as FGF receptor-2 (FGFR-2), are characteristic of BTCs. New drugs targeting the signaling pathways involved in angiogenesis have been tested in preclinical studies both in vitro and in vivo with promising results. Moreover, several clinical studies tested monoclonal antibodies against VEGF and tyrosine kinase inhibitors targeting the VEGF and the MEK/ERK pathways. Herein, we evaluate both the pathogenic mechanisms of BTCs focused on angiogenesis and the preclinical and clinical data available regarding the use of new anti-angiogenic drugs in these malignancies.

A case of concomitant colitic cancer and intrahepatic cholangiocarcinoma during follow-up for ulcerative colitis

Colitis-associated colorectal cancer (CAC) is known to occur in long-standing and extensive ulcerative colitis (UC). Furthermore, UC is known to complicate primary sclerosing cholangitis (PSC), which subsequently results in an increased risk of developing cholangiocarcinoma. We report a case of colitis-associated rectal cancer (CARC) accompanied by intrahepatic cholangiocarcinoma (ICC) based on UC and PSC. A 73-year-old man had suffered from UC for 19 years. During surveillance colonoscopy, a tumor was found in the rectum that was pathologically diagnosed as CARC from the resected specimen. Abdominal computed tomography also revealed a localized dilation of the intrahepatic bile duct, and endoscopic retrograde cholangiography revealed a band-like stricture. This remarkable tumor lesion was not observed in the hepatic duct. Left hepatectomy was performed because of the suspicion of possible ICC at the stenosis of the hepatic duct. The presence of ICC was confirmed at the lesion causing the stricture. The pathological diagnosis from the resected specimen was ICC based on PSC. Adjuvant chemotherapy for ICC was performed for 6 months. Neither cancer has recurred for 2.5 years after hepatectomy. Patients with PSC concomitant with UC should be considered a high-risk group for CAC and ICC.

Cell-free microRNAs in blood and other body fluids, as cancer biomarkers

The discovery of cell-free microRNAs (miRNAs) in serum, plasma and other body fluids has yielded an invaluable potential source of non-invasive biomarkers for cancer and other non-malignant diseases. miRNAs in the blood and other body fluids are highly stable in biological samples and are resistant to environmental conditions, such as freezing, thawing or enzymatic degradation, which makes them convenient as potential biomarkers. In addition, they are more easily sampled than tissue miRNAs. Altered levels of cell-free miRNAs have been found in every type of cancer analysed, and increasing evidence indicates that they may participate in carcinogenesis by acting as cell-to-cell signalling molecules. This review summarizes the biological characteristics and mechanisms of release of cell-free miRNAs that make them promising candidates as non-invasive biomarkers of cancer.

The Emerging Role of miRNAs and Their Clinical Implication in Biliary Tract Cancer

Biliary tract cancers are aggressive malignancies that include gallbladder cancer and tumors of intra- and extrahepatic ducts and have a poor prognosis. Surgical resection remains the main curative therapy. Nevertheless, numerous patients experience recurrence even after radical surgery. This scenario drives the research to identify biliary tract cancer biomarkers despite the limited progress that has been made. Recently, a large number of studies have demonstrated that deregulated expression of microRNAs is closely associated with cancer development and progression. In this review, we highlight the role and importance of microRNAs in biliary tract cancers with an emphasis on utilizing circulating microRNAs as potential biomarkers. Additionally, we report several single-nucleotide polymorphisms in microRNA genes that are associated with the susceptibility of biliary tract tumors.