Clonorchis sinensis, an oriental liver fluke, as a human biological agent of cholangiocarcinoma: a brief review

Expression of Transposable Elements throughout the Fasciola hepatica Trematode Life Cycle

BACKGROUND

Transposable elements (TEs) are major components of eukaryotic genomes. The extensive body of evidence suggests that although they were once considered "genomic parasites", transposons and their transcripts perform specific functions, such as regulation of early embryo development. Understanding the role of TEs in such parasites as trematodes is becoming critically important. Fasciola hepatica, a parasite affecting humans and livestock, undergoes a complex life cycle in diverse environments and hosts, and knowledge about its life cycle regulation is scarce so far.

METHODS

We summarized the data regarding the repetitive elements in F. hepatica and conducted bulk RNA-seq analysis across its life cycle stages. TE expression profiles were analyzed, focusing on differential expression and potential homology with previously described long non-coding RNAs (lncRNAs).

RESULTS

Differential expression analysis revealed stage-specific TE transcription patterns, notably peaking during egg and metacercariae stages. Some TEs showed homology with known lncRNAs and contained putative transcription factor binding sites. Interestingly, TE transcription levels were highest in eggs and metacercariae compared to adults, suggesting regulatory roles in trematode life cycle transitions.

CONCLUSIONS

These findings suggest that TEs may play roles in regulating trematode life cycle transitions. Moreover, TE homology with lncRNAs underscores their significance in gene regulation.

Infection with Clonorchis sinensis (Cobbold, 1875) Metacercariae in Fish from the East Lake of Wuhan: Freshwater Fish in Urban Lakes May Act as Infection Sources of Liver Fluke

The liver fluke disease caused by Clonorchis sinensis is one of the most serious food-borne parasitic diseases in China. Many freshwater fish and shrimps can be infected with C. sinensis metacercariae as the second intermediate hosts in endemic regions. Owing to the lack of infected humans and the good administration of pet dogs and cats in cities of non-endemic regions, few fish are expected to be infected with C. sinensis metacercariae in urban lakes. To determine the infection of C. sinensis metacercariae in freshwater fish and shrimps in urban lakes, a total of 18 fish species and one shrimp species were investigated in the East Lake of Wuhan City. Metacercariae were isolated by artificial digestive juice and identified using morphology and rDNA-ITS2 sequences. Five species of fish, Pseudorasbora parva, Ctenogobius giurinus, Squalidus argentatus, Hemiculter leuciclus, and Rhodeus spp., were infected with C. sinensis metacercariae. The overall prevalence of C. sinensis was 32.5%. The highest prevalence was found in P. parva with 57.9%, while S. argentatus exhibited the highest mean abundance (13.9). Apart from the C. sinensis metacercariae, four species of other trematode metacercariae were also identified across twelve fish species in total. Owing to the consumption of undercooked fish and feeding cats with small fish caught by anglers, there is a potential risk that the small fish infected with C. sinensis metacercariae may act as an infection source to spread liver fluke. Given the complete life cycle of C. sinensis, stray cats and rats were inferred to act as the important final hosts of C. sinensis in urban lakes in non-endemic areas.

The crosstalk between cholangiocytes and hepatic stellate cells promotes the progression of epithelial-mesenchymal transition and periductal fibrosis during Clonorchis sinensis infection

ABSTRACT: BACKGROUND: Clonorchis sinensis infection is one of the risk factors that provokes chronic inflammation, epithelial hyperplasia, periductal fibrosis and even cholangiocarcinoma (CCA). Disrupted or aberrant intercellular communication among liver-constituting cells leads to pathological states that cause various hepatic diseases. This study was designed to investigate the pathological changes caused by C. sinensis excretory-secretory products (ESPs) in non-cancerous human cell lines (cholangiocytes [H69 cell line] and human hepatic stellate cells [LX2 cell line]) and their intercellular crosstalk, as well the pathological changes in infected mouse liver tissues.

METHODS

The cells were treated with ESPs, following which transforming growth factor beta 1 (TGF-β1) and interleukin-6 (IL-6) secretion levels and epithelial-mesenchymal transition (EMT)- and fibrosis-related protein expression were measured. The ESP-mediated cellular motility (migration/invasion) between two cells was assessed using the Transwell and three-dimensional microfluidic assay models. The livers of C. sinensis-infected mice were stained using EMT and fibrotic marker proteins.

RESULTS

Treatment of cells with ESPs increased TGF-β1 and IL-6 secretion and the expression of EMT- and fibrosis-related proteins. The ESP-mediated mutual cell interaction further affected the cytokine secretion and protein expression levels and promoted cellular motility. N-cadherin overexpression and collagen fiber deposition were observed in the livers of C. sinensis-infected mice.

CONCLUSIONS

These findings suggest that EMT and biliary fibrosis occur through intercellular communication between cholangiocytes and hepatic stellate cells during C. sinensis infection, promoting malignant transformation and advanced hepatobiliary abnormalities.

Natural variables separate the endemic areas of Clonorchis sinensis and Opisthorchis viverrini along a continuous, straight zone in Southeast Asia

BACKGROUND

Clonorchiasis and opisthorchiasis, caused by the liver flukes Clonorchis sinensis and Opisthorchis viverrini respectively, represent significant neglected tropical diseases (NTDs) in Asia. The co-existence of these pathogens in overlapping regions complicates effective disease control strategies. This study aimed to clarify the distribution and interaction of these diseases within Southeast Asia.

METHODS

We systematically collated occurrence records of human clonorchiasis (n = 1809) and opisthorchiasis (n = 731) across the Southeast Asia countries. Utilizing species distribution models incorporating environmental and climatic data, coupled machine learning algorithms with boosted regression trees, we predicted and distinguished endemic areas for each fluke species. Machine learning techniques, including geospatial analysis, were employed to delineate the boundaries between these flukes.

RESULTS

Our analysis revealed that the endemic range of C. sinensis and O. viverrini in Southeast Asia primarily spans across part of China, Vietnam, Thailand, Laos, and Cambodia. During the period from 2000 to 2018, we identified C. sinensis infections in 84 distinct locations, predominantly in southern China (Guangxi Zhuang Autonomous Region) and northern Vietnam. In a stark contrast, O. viverrini was more widely distributed, with infections documented in 721 locations across Thailand, Laos, Cambodia, and Vietnam. Critical environmental determinants were quantitatively analyzed, revealing annual mean temperatures ranging between 14 and 20 °C in clonorchiasis-endemic areas and 24-30 °C in opisthorchiasis regions (P < 0.05). The machine learning model effectively mapped a distinct demarcation zone, demonstrating a clear separation between the endemic areas of these two liver flukes with AUC from 0.9 to1. The study in Vietnam delineates the coexistence and geographical boundaries of C. sinensis and O. viverrini, revealing distinct endemic zones and a transitional area where both liver fluke species overlap.

CONCLUSIONS

Our findings highlight the critical role of specific climatic and environmental factors in influencing the geographical distribution of C. sinensis and O. viverrini. This spatial delineation offers valuable insights for integrated surveillance and control strategies, particularly in regions with sympatric transmission. The results underscore the need for tailored interventions, considering regional epidemiological variations. Future collaborations integrating eco-epidemiology, molecular epidemiology, and parasitology are essential to further elucidate the complex interplay of liver fluke distributions in Asia.

Clonorchis sinensis infection in a non‑endemic area: A case report

Non-endemic Clonorchis sinensis infection is challenging to diagnose. The present study reports the case of a 40-year-old female patient with severe epigastric pain, initially suspected to be a liver lesion, who was admitted to The Affiliated Hospital of Zunyi Medical University (Zunyi, China). A combination of diagnostic procedures, including computed tomography and magnetic resonance imaging, revealed an abnormality in the left hepatic lobe. Postoperative evaluation and the epidemiologic history of the patient (consumption of raw fish slices) revealed characteristics of Clonorchis sinensis infection, including chronic bile duct inflammation and eosinophilic liver infiltration. The present case highlights the unexpected emergence of this disease outside of recognized endemic areas and advocates clinical vigilance. Even in non-endemic areas, individuals should be reminded not to eat raw fish and shrimp.

High-resolution mapping of age- and gender-specific risk of Clonorchis sinensis infection risk in Guangdong, China: a geostatistical modeling study

BACKGROUND

The latest national survey on the distribution of human parasites in China demonstrated that Guangdong was among the endemic provinces with the highest Clonorchis sinensis infection rates. High-resolution, age- and gender-specific risk maps of the temporal and spatial distributions are essential for the targeted control work.

METHODS

Disease data on the prevalence of C. sinensis infection from 1990 onwards, either age- and gender-specific or aggregated across age and gender, were collected through systematic review and four large-scale surveys in Guangdong Province. Environmental and socioeconomic variables were obtained from open-access databases and employed as potential predictors. A Bayesian geostatistical model was developed to estimate the C. sinensis infection risk at high spatial resolution.

RESULTS

The final dataset included 606 surveys at 463 unique locations for C. sinensis infection. Our findings suggested that following an initial increase and stabilization, the overall population-adjusted prevalence had declined to 2.2% (95% Bayesian credible interval: 1.7-3.0%) in the period of 2015 onwards. From 2015 onwards, moderate and high infection risks were found in the northern regions (e.g. Heyuan and Shaoguan cities) and the southern Pearl River Delta (e.g. Foshan, Zhongshan, Zhuhai and Jiangmen cities), respectively. Age- and gender-specific risk maps revealed that males had a higher infection risk than females, and the infection risk was higher in adults compared to children.

CONCLUSIONS

Our high-resolution risk maps of C. sinensis infection in Guangdong Province identified the spatial, temporal, age and gender heterogeneities, which can provide useful information assisting tailored control strategies.

Oxidative Stress and Redox-Dependent Pathways in Cholangiocarcinoma

Cholangiocarcinoma (CCA) is a primary liver tumor that accounts for 2% of all cancer-related deaths worldwide yearly. It can arise from cholangiocytes of biliary tracts, peribiliary glands, and possibly from progenitor cells or even hepatocytes. CCA is characterized by high chemoresistance, aggressiveness, and poor prognosis. Potentially curative surgical therapy is restricted to a small number of patients with early-stage disease (up to 35%). Accumulating evidence indicates that CCA is an oxidative stress-driven carcinoma resulting from chronic inflammation. Oxidative stress, due to enhanced reactive oxygen species (ROS) production and/or decreased antioxidants, has been recently suggested as a key factor in cholangiocyte oncogenesis through gene expression alterations and molecular damage. However, due to different experimental models and conditions, contradictory results regarding oxidative stress in cholangiocarcinoma have been reported. The role of ROS and antioxidants in cancer is controversial due to their context-dependent ability to stimulate tumorigenesis and support cancer cell proliferation or promote cell death. On these bases, the present narrative review is focused on illustrating the role of oxidative stress in cholangiocarcinoma and the main ROS-driven intracellular pathways. Heterogeneous data about antioxidant effects on cancer development are also discussed.

From the discovery of helminths to the discovery of their carcinogenic potential

Cancer involves a major aberration in the normal behaviour of cells, making them divide continuously, which interferes with the normal physiology of the body. The link between helminths and their cancer-inducing potential has been proposed in the last century. The exact pathway is still not clear but chronic inflammation in response to the deposited eggs, immune response against soluble egg antigens, and co-infection with a third party (a bacteria, a virus, or infection leading to a change in microbiome) seems to be the reasons for cancer induction. This review looks into the historical outlook on helminths along with their epidemiology, morphology, and life cycle. It then focuses on providing correlations between helminth infection and molecular mechanism of carcinogenesis by elaborating upon epidemiological, clinical, and surgical studies. While the cancer-inducing potential has been convincingly established only for a few helminths and studies point out towards possible cancer-inducing ability of the rest of the helminths elucidated in this work, however, more insights into the immunobiology of helminths as well as infected patients are required to conclusively comment upon this ability of the latter.

ASPSCR-1 and Sirt-5 alleviate Clonorchis liver fluke rCsNOSIP-induced oxidative stress, proliferation, and migration in cholangiocarcinoma cells

BACKGROUND

Clonorchiasis, caused by the infection of Clonorchis sinensis (C. sinensis), is a kind of neglected tropical disease, but it is highly related to cholangiocarcinoma. It has been well known that NO from chronic inflammation responses are thought to be a major component of the damage and ultimate carcinogenesis ESPs such as nitric oxide synthase interacting protein (NOSIP) are thought to enhance the damage. The objective of this study was to identify the protein candidates interact with recombinant CsNOSIP (rCsNOSIP) and explore their role involved in CCA development or progression.

METHODS

We applied HuProt microarray containing 21,000 probe sets for a systematic identification of rCsNOSIP-binding proteins and grouped binding hits by gene function. Pull-down assays were used to confirm the interaction of rCsNOSIP with alveolar soft part sarcoma (ASPSCR-1) and sirtuins 5 (Sirt-5). ASPSCR-1/Sirt-5 over-expression and siRNA knockdown experiments were employed for obtain of ASPSCR-1/Sirt-5 high or low expression (ASP-oe/Sirt5-oe or ASP-si/Sirt5-si) cholangiocarcinoma cell line (CCLP-1) cells. Nitric oxide (NO) and reactive oxygen species assay (ROS) as well as cell proliferation and wound-healing assays were performed to observe the effect of rCsNOSIP on ASP-oe/Sirt5-oe or ASP-si/Sirt5-si CCLP-1 cells.

RESULTS

Seventy candidate proteins protein "hits" were detected as rCsNOSIP-binding proteins by HuProt microarray and bioinformatics analysis. Pull down assay showed that ASPSCR-1 and Sirt-5 could interact with rCsNOSIP. In addition, endotoxin-free-rCsNOSIP could increase the production of NO and ROS and promote the migration of CCLP-1 cells, while its effect on enhancing cell proliferation was not significant. Furthermore, ROS/NO production, proliferation, or migration were increased in ASP-si or Sirt5-si CCLP-1 cells but decreased in Asp-oe or Sirt5-oe CCLP-1 cells when stimulated with rCsNOSIP.

CONCLUSIONS

Our findings suggest that CsNOSIP as a component of CsESPs might promote the development and invasion of CCA and Sirt5/ ASPSCR1 as host molecules might play a novel protective role against adverse stimulus during C. sinensis infection. This work supports the idea that CsESPs induce the occurrence and progression of CCA through ROS/RNS-induced oxidative and nitrative DNA damage.

Clonorchis sinensis calcium-binding protein Cs16 causes acute hepatic injury possibly by reprogramming the metabolic pathway of bone marrow-derived monocytes

Introduction

Clonorchis sinensis infection results in various complications in the liver and biliary systems and is a neglected tropical disease in Eastern Asia. In this study, we report that C. sinensis calcium-binding protein Cs16 activates host immune cells and induces immunopathology in liver.

Methods

Immunohistochemistry was used to detect the localization of Cs16 in C. sinensis adult worms. ELISA was used to detect the serum levels of anti-Cs16 IgG antibody in infected humans and mice. Bile duct injection model was used to figure out the role of Cs16 in vivo. RT-qPCR and ELISA were used to detect the cytokine production from Cs16-treated BMMs in vitro. Seahorse assay was used to detect the metabolic pathway of Cs16-treated BMMs in vitro.

Result

Cs16 localizes in the tegument and gut of C. sinensis. Humans and mice with C. sinensis infection exhibited increased levels of anti-Cs16-specific antibody. Using the bile duct injection technique, we found that Cs16 induced obvious inflammation and hepatic necrosis in vivo. Cs16 treatment caused the upregulation of inflammatory cytokines in innate immune cells. Moreover, Cs16-treated monocytes relied more on the glycolytic metabolic pathway.

Discussion

Our findings suggest that Cs16 is a potential pathogenic factor derived from C. sinensis adult worm. By reprogramming the metabolic pathway of innate immune cells, Cs16 triggers pro-inflammatory responses in the liver, and therefore, Cs16 is a potential target for the prevention and treatment of clonorchiasis.

Spatio-temporal disparities of Clonorchis sinensis infection in animal hosts in China: a systematic review and meta-analysis

BACKGROUND

Clonorchis sinensis, one of the most important food-borne zoonotic trematodes, remains prevalent in China. Understanding its infection status in animals is crucial for controlling human clonorchiasis. Here we conducted a systematic review and meta-analysis to focus on the spatio-temporal disparities of C. sinensis infection in animals in China.

METHODS

Data on C. sinensis prevalence in snails, the second intermediate hosts, or animal reservoirs in China were extracted from electronic databases including PubMed, Embase, Web of Science, Chinese Wanfang database, CNKI, VIP, and China Biomedical Literature database. A random-effects meta-analysis model was utilized to estimate the pooled prevalence in each of the above animal hosts. Subgroup analysis and multivariable meta-regression were performed to explore potential sources of heterogeneity across studies and compare the temporal disparity of infection rates between high and low epidemic areas. Scatter plots were used to depict the biogeographical characteristics of regions reporting C. sinensis infection in animals.

RESULTS

The overall pooled prevalence of C. sinensis was 0.9% (95% CI: 0.6-1.2%) in snails, 14.2% (12.7-15.7%) in the second intermediate host, and 14.3% (11.4-17.6%) in animal reservoirs. Prevalence in low epidemic areas (with human prevalence < 1%) decreased from 0.6% (0.2-1.2%) before 1990 to 0.0% (0.0-3.6%) after 2010 in snails (P = 0.0499), from 20.3% (15.6-25.3%) to 8.8% (5.6-12.6%) in the second intermediate hosts (P = 0.0002), and from 18.3% (12.7-24.7%) to 4.7% (1.0-10.4%) in animal reservoirs. However, no similar decrease in prevalence was observed in high epidemic areas (with human prevalence ≥ 1.0%). C. sinensis infections were predominantly reported in areas with altitudes below 2346 m and annual cumulative precipitation above 345 mm and were mostly concentrated in eastern China.

CONCLUSIONS

There are spatio-temporal disparities in the animal infections of C. sinensis in different areas of China. Animal infections are primarily concentrated in regions with low altitude and high precipitation. The results suggest that implementing One Health-based comprehensive measures targeting both humans and animals, especially in high epidemic areas, is essential for successful eradication of C. sinensis in China.

Modelling morbidity for neglected tropical diseases: the long and winding road from cumulative exposure to long-term pathology

Reducing the morbidities caused by neglected tropical diseases (NTDs) is a central aim of ongoing disease control programmes. The broad spectrum of pathogens under the umbrella of NTDs lead to a range of negative health outcomes, from malnutrition and anaemia to organ failure, blindness and carcinogenesis. For some NTDs, the most severe clinical manifestations develop over many years of chronic or repeated infection. For these diseases, the association between infection and risk of long-term pathology is generally complex, and the impact of multiple interacting factors, such as age, co-morbidities and host immune response, is often poorly quantified. Mathematical modelling has been used for many years to gain insights into the complex processes underlying the transmission dynamics of infectious diseases; however, long-term morbidities associated with chronic or cumulative exposure are generally not incorporated into dynamic models for NTDs. Here we consider the complexities and challenges for determining the relationship between cumulative pathogen exposure and morbidity at the individual and population levels, drawing on case studies for trachoma, schistosomiasis and foodborne trematodiasis. We explore potential frameworks for explicitly incorporating long-term morbidity into NTD transmission models, and consider the insights such frameworks may bring in terms of policy-relevant projections for the elimination era. This article is part of the theme issue 'Challenges and opportunities in the fight against neglected tropical diseases: a decade from the London Declaration on NTDs'.

Associations of Liver Fluke Infection and Cholangiocarcinoma: A Scoping Review

Cholangiocarcinoma (CCa) is a highly lethal malignancy of biliary tract epithelial cells. Liver fluke infection is one of the well-known causes of CCa in endemic areas of Southeast Asian and Western Pacific regions. Multistep processes underlie carcinogenesis induced by chronic infection with the fish-borne liver fluke. Mechanical injury from fluke feeding and migrating in the bile duct causes damage to the bile duct epithelial cells. The excretory or secretory product of a parasite called OvGRN-1 is internalized by human cholangiocytes and induces changes in gene and protein expression associated with wound healing and cancer pathways. Inflammatory cytokines and their gene polymorphisms may also be linked to biliary pathologies. High plasma levels of interleukin 6 (IL-6) increase the risk of developing advanced periductal fibrosis (APF) and CCa by promoting CCa cell line proliferation. Anti-helminthic drugs can help decrease the risk of CCa caused by flukes. Surgical resection of the tumor and liver transplantation might be helpful too. Chemotherapy is considered for patients with advanced CCa when they cannot undergo surgery or when other treatment options fail to show improvement. Improvements in hygiene, health education, screening for fluke infection, and anti-helminthic therapy can help prevent liver fluke infection and thus the occurrence of CCa.

Prediction of regional lymph node metastasis in intrahepatic cholangiocarcinoma: it's not all about size

OBJECTIVES

Lymph node metastases (LNM) are frequent in patients with intrahepatic cholangiocarcinoma (iCC) and worsen their prognosis even after surgery. Our aim was to investigate the predictive value of lymph node (LN) short axis, the most common discriminator for identifying LNM in tumor-imaging and to develop a predictive model for regional LNM in iCC taking computed tomography (CT) features of extranodal disease into account.

MATERIALS AND METHODS

We enrolled 102 patients with pathologically proven iCC who underwent CT prior to hepatic resection and hilar lymph node dissection (LND) from 2005 to 2021. Two blinded radiologists assessed various imaging characteristics and LN diameters, which were analyzed by bivariate and multivariate logistic regression to develop a prediction model for LNM.

RESULTS

Prevalence of LNM was high (42.4 %) and estimated survival was shorter in LN-positive patients (p = 0.07). An LN short axis diameter of ≥ 9 mm demonstrated the highest predictive power for LNM. Three additional, statistically significant imaging features, presence of intrahepatic metastasis (p = 0.003), hilar tumor infiltration (p = 0.003), and tumor growth along the liver capsule (p = 0.004), were integrated into a prediction model, which substantially outperformed use of LN axis alone in ROC analysis (AUC 0.856 vs 0.701).

CONCLUSIONS

LN diameter alone proved to be a relevant but unreliable imaging-marker for LNM prediction in iCC. Our proposed prognostic model, which additionally considers intrahepatic metastases and hilar and capsular infiltration, significantly improves discriminatory power. Hilar and capsular involvement might indicate direct tumor extension to lymphatic liver structures.

Rapid, sensitive, and visual detection of Clonorchis sinensis with an RPA-CRISPR/Cas12a-based dual readout portable platform

Clonorchis sinensis is a food-borne parasite that parasitizes the liver and bile ducts of humans and many animals. This parasite exerts a high burden due to diverse hepatobiliary morbidities (e.g., cholangitis, cholecystitis, cholelithiasis, and cholangiocarcinoma), and an effective detection strategy is urgently needed. CRISPR/Cas12a exhibits nonspecific trans-cleavage activity upon binding to its specific target and has been widely used for nucleic acid detection. In this study, an RPA-CRISPR/Cas12a-based dual readout portable detection platform was established, which shows high sensitivity (one copy/μl) and specificity (no cross-reactivity with common pathogens) by rapid preamplification and combines lateral flow strips and visual fluorescence for visualization of results by the naked eye within 1 h. Moreover, 50 human fecal swabs and 50 fish flesh samples were detected by this platform and nested PCR. The CRISPR/Cas12a-based dual readout portable platform showed 10.0 % (5/50) C. sinensis-positive samples in human fecal swabs and 28.0 % (14/50) in fish flesh, which was consistent with the results of nested PCR. The results demonstrate that our portable platform has the advantages of stability, sensitivity, accuracy, and low equipment requirements. Furthermore, we provide novel point-of-care testing (POCT) for clinical use in remote rural and resource-constrained areas.

Current status and progress in the omics of Clonorchis sinensis

Clonorchis sinensis (C. sinensis) is a fish-borne trematode that inhabits the bile duct of mammals including humans, cats, dogs, rats, and so on. In the complex life cycle of C. sinensis, the worm develops successively in two intermediate hosts in fresh water and one definitive host. What's more, it undergoes eight developmental stages with a distinct morphology. Clonorchiasis, caused by C. sinensis infection, is an important food-borne parasitic disease and one of the most common zoonoses. C. sinensis infection could result in hyperplasia of the bile duct epithelium, obstructive jaundice, gall-stones, cholecystitis and cholangitis, even liver cirrhosis and cholangiocarcinoma. Thus, clonorchiasis is a serious public health problem in endemic areas. Integrated strategies should be adopted in the prevention and control of clonorchiasis due to the epidemiological characteristics. The recent advances in high-throughput technologies have made available the profiling of multiple layers of a biological system, genomics, transcriptomics, proteomics, and metabolomics. These data can help us to get more information about the development, physiology, metabolism, and reproduction of the parasite as well as pathogenesis and parasite-host interactions in clonorchiasis. In the present study, we summarized recent progresses in omics studies on C. sinensis providing insights into the studies and future directions on treating and preventing C. sinensis associated diseases.

Diagnosis of Indolent Clonorchis sinensis and Opisthorchis viverrini Infections as Risk Factors for Cholangiocarcinoma: An Unmet Medical Need

Background

Cholangiocarcinoma is a highly aggressive cancer of the biliary tract epithelium. This form of cancer is prevalent in Asia, and recent reports show that its incidence is relatively rare but increasing in the United States. Although risk factors for cholangiocarcinoma have yet to be elucidated, a growing body of literature suggests chronic infection of genetically susceptible individuals with the food-borne zoonotic trematodes Clonorchis sinensis (C sinensis) and Opisthorchis viverrini (O viverrini) may play a role.

Observations

Although most infected people remain asymptomatic, untreated indolent infections with C sinensis and O viverrini may persist in peripheral intrahepatic bile ducts for almost 30 years. During this period, the trematodes' feeding activities and their excretory-secretory products may damage the bile duct epithelium and promote local inflammation. These pathological processes could then provoke epithelial desquamation, adenomatous hyperplasia, goblet cell metaplasia, periductal fibrosis, and granuloma formation that are conducive to the initiation and progression of cholangiocarcinoma in genetically susceptible people. The International Agency for Research on Cancer has determined that there is sufficient evidence in humans for the carcinogenicity of chronic infections with C sinensis and O viverrini.

Conclusions

Timely serodiagnosis of indolent C sinensis and O viverrini infections is important as these parasites may be a risk factor for cholangiocarcinoma in veterans who served in Vietnam. About 774,000 living Americans served in Vietnam and there is an urgent need to develop sensitive and specific serologic assays to detect both acute and indolent infections. We posit that testing and treatment of high-risk populations could lead to earlier detection and treatment of cholangiocarcinoma, leading to improved overall survival.

Incidence of fish-borne trematode infections and associated factors: results from a cohort study in highly endemic communities in northern Vietnam

Fish-borne trematodes (FiBT) are an important group of zoonotic parasites negatively affecting human health, mainly in Asia. Most studies on FiBT have applied a cross-sectional design, which provides weaker evidence on potential risk factors for transmission than a cohort study. This cohort study aimed to estimate the incidence and identify associated risk factors for FiBT infection in Vietnam. Between April 2018 and May 2019, two communes in Yen Bai province, a highly endemic area for FiBT, were visited for sampling. Participants with a negative stool result for FiBT at baseline, were invited for follow-up and data collection, at months 4, 9, and 13. Stools were examined using Kato-Katz and formalin-ethyl acetate concentration techniques to detect FiBT eggs, whereas a questionnaire was used for interviewing participants to determine the risk factors for FiBT infection during each follow-up period. The incidence risk and the incidence rate were calculated, and univariate and multivariable models were run to identify the risk factors for FiBT. A total of 194 people, negative for FiBT eggs at the baseline survey, were invited to participate in the study, and 111 people agreed to enroll in the follow-up. The incidence risk at months 4, 9, and 13 was 9.0%, 6.4%, and 5.1%, respectively. We finally used data from 95 participants for the risk factor analysis, excluding 16 people lost for the follow-up. Overall, 20 people became infected with FiBT (IR = 21.1%). The incidence rate of FiBT infection was 21.4/100 person-year. In the univariate analysis, consumption of raw fish was the main risk factor (RR = 4.59, 95%CI = 1.95-10.82), followed by being male (RR = 3.41, 95%CI = 1.56-7.45) and drinking alcohol (RR = 3.25, 95%CI = 1.49-7.11). In the multivariable analysis, only consumption of raw-fish dishes was significantly associated with FiBT infection. The people who consumed raw fish were 3.44 (95%CI = 1.11-10.70) times more at risk of infection with FiBT as compared to individuals who did not consume raw fish. It can be concluded that the FiBT incidence is high in the study area. More awareness campaigns are needed to stop eating raw fish in these areas to reduce FBT infection.

New challenges in cholangiocarcinoma candidates for elective surgery: harnessing the microbiome dysbiosis

BACKGROUND

The gut microbiota, composed by several species of microorganisms, works to preserve the liver-gut homeostasis and plays an important role during digestion and absorption of nutrients, and in the immune response of the host. In this review, we analyzed the influence of microbiota in patients with cholangiocarcinoma (CCA) who were candidates for elective surgery.

METHODS

A literature review was conducted to identify papers that provided empiric evidence to support that the altered microbiota composition (dysbiosis) is related also to CCA development.

RESULTS

Bacteria such as Helicobacter pylori, Helicobacter hepaticus, and Opisthorchis viverrini increase the risk of CCA. The most abundant genera were Enterococcus, Streptococcus, Bacteroides, Klebsiella, and Pyramidobacter in CCA's biliary microbiota. Additionally, levels of Bacteroides, Geobacillus, Meiothermus, and Anoxybacillus genera were significantly higher. An enrichment of Bifidobacteriaceae, Enterobacteriaceae, and Enterococcaceae families has also been observed in CCA tumor tissue. Microbiota is related to postoperative outcomes in abdominal surgery. The combination of caloric restriction diets in liver cancer or CCA increases the effect of the chemotherapy treatment.

CONCLUSION

The correct use of nutrition for microbiota modulation according to each patient's needs could be a therapeutic tool in combination with elective surgery and chemotherapy to diminish side effects and improve prognosis. Further investigations are needed to fully understand the mechanisms by which they are related.

Food- and vector-borne parasitic zoonoses: Global burden and impacts

Around 25% of the global population suffer from one or more parasitic infections, of which food- and vector-borne parasitic zoonotic diseases are a major concern. Additionally, zoonoses and communicable diseases, common to man and animals, are drawing increased attention worldwide. Significant changes in climatic conditions, cropping pattern, demography, food habits, increasing international travel, marketing and trade, deforestation, and urbanization play vital roles in the emergence and re-emergence of parasitic zoonoses. Although it is likely to be underestimated, the collective burden of food- and vector-borne parasitic diseases accounts for ∼60 million disability-adjusted life years (DALYs). Out of 20 neglected tropical diseases (NTDs) listed by the World Health Organization (WHO) and the Centres for Disease Control and Prevention (CDC), 13 diseases are of parasitic origin. There are about 200 zoonotic diseases of which the WHO listed eight as neglected zoonotic diseases (NZDs) in the year 2013. Out of these eight NZDs, four diseases, namely cysticercosis, hydatidosis, leishmaniasis, and trypanosomiasis, are caused by parasites. In this review, we discuss the global burden and impacts of food- and vector-borne zoonotic parasitic diseases.

Systematic review of cholangiocarcinoma in Africa: epidemiology, management, and clinical outcomes

BACKGROUND

The prevalence, management, and clinical outcomes of cholangiocarcinoma in Africa are unknown. The aim is to conduct a comprehensive systematic review on the epidemiology, management, and outcomes of cholangiocarcinoma in Africa.

METHODS

We searched PubMed, EMBASE, Web of Science and CINHAL from inception up to November 2019 for studies on cholangiocarcinoma in Africa. The results reported follow PRISMA guidelines. Quality of studies and risk of bias were adapted from a standard quality assessment tool. Descriptive data were expressed as numbers with proportions and Chi-squared test was used to compare proportions. P values < 0.05 were considered significant.

RESULTS

A total of 201 citations were identified from the four databases. After excluding duplicates, 133 full texts were reviewed for eligibility, and 11 studies were included. The 11 studies are reported from 4 countries only: 8 are from North Africa (Egypt 6 and Tunisia 2), and 3 in Sub-Saharan Africa (2 in South Africa, 1 in Nigeria). Ten studies reported management and outcomes, while one study reported epidemiology and risk factors. Median age for cholangiocarcinoma ranged between 52 and 61 years. Despite the proportion with cholangiocarcinoma being higher among males than females in Egypt, this gender disparity could not be demonstrated in other African countries. Chemotherapy is mainly used for palliative care. Surgical interventions are curative and prevent cancer progression. Statistical analyses were performed with Stata 15.1.

CONCLUSION

The known global major risk factors such as primary sclerosing cholangitis, Clonorchis sinensis and Opisthorchis viverrini infestation are rare. Chemotherapy treatment was mainly used for palliative treatment and was reported in three studies. Surgical intervention was described in at least 6 studies as a curative modality of treatment. Diagnostic capabilities such as radiographic imaging and endoscopic are lacking across the continent which most likely plays a role in accurate diagnosis.

A Case of Concurrence of Clonorchis Sinensis and Pancreatic Adenocarcinoma-A Diagnostic Dilemma

Clonorchis Sinensis, a common liver fluke, is known to cause biliary disease and can present with a wide array of symptoms. It's mostly found in Asian countries due to consumption of undercooked or raw fish. Although Cholangiocarcinoma is a known serious complication of this disease, Pancreatic neoplasms are rare and have seldom been reported. Here, we report a case of an 80-year-old man who presents with pancreatic adenocarcinoma associated with Clonorchis Sinensis infection.

Spatial parasitology and the unmapped human helminthiases

Helminthiases are a class of neglected tropical diseases that affect at least 1 billion people worldwide, with a disproportionate impact on resource-poor areas with limited disease surveillance. Geospatial methods can offer valuable insights into the burden of these infections, particularly given that many are subject to strong ecological influences on the environmental, vector-borne or zoonotic stages of their life cycle. In this study, we screened 6829 abstracts and analysed 485 studies that use maps to document, infer or predict transmission patterns for over 200 species of parasitic worms. We found that quantitative mapping methods are increasingly used in medical parasitology, drawing on One Health surveillance data from the community scale to model geographic distributions and burdens up to the regional or global scale. However, we found that the vast majority of the human helminthiases may be entirely unmapped, with research effort focused disproportionately on a half-dozen infections that are targeted by mass drug administration programmes. Entire regions were also surprisingly under-represented in the literature, particularly southern Asia and the Neotropics. We conclude by proposing a shortlist of possible priorities for future research, including several neglected helminthiases with a burden that may be underestimated.

rCsHscB Derived from Clonorchis sinensis: A Carcinogenic Liver Fluke Ameliorates LPS-Induced Acute Hepatic Injury by Repression of Inflammation

Sepsis-associated acute liver injury caused by spillovers of bacteria and endotoxins (lipopolysaccharide, LPS) into the liver remains a public health issue due to the lack of specific therapeutic approaches. Previous studies showed that the recombinant protein HscB (rCsHscB) of Clonorchis sinensis, a carcinogenic liver fluke, had an anti-inflammatory effect and could alleviate inflammatory diseases such as enteritis; however, whether it can prevent sepsis-associated acute liver injury induced by LPS is still unknown. In our current study, the therapeutic effects and the potential mechanisms of rCsHscB on LPS-induced acute liver injury were investigated both in vivo and in vitro. The data showed that rCsHscB prevented LPS-induced liver damage, as demonstrated by histopathological observation and hepatic damage markers (the activities of serum ALT and AST) in a murine model of sepsis-associated acute liver injury. rCsHscB also significantly reversed the high levels of serum IL-6 and MCP-1 induced by LPS. In addition, rCsHscB attenuated the production of LPS-induced proinflammatory cytokines, including IL-6 and TNF-α, in a macrophage cell line-RAW264.7, through possible mediation by the MAPK signaling pathway in vitro. In conclusion, the present study demonstrates that rCsHscB derived from a fluke C. sinensis protects against sepsis-associated acute liver injury induced by LPS, which may be attributed to the inhibition of the MAPK signaling pathway. Our present study provides a potential therapeutic strategy for sepsis-associated acute liver injury.

Unboxing the molecular modalities of mutagens in cancer

The etiology of the majority of human cancers is associated with a myriad of environmental causes, including physical, chemical, and biological factors. DNA damage induced by such mutagens is the initial step in the process of carcinogenesis resulting in the accumulation of mutations. Mutational events are considered the major triggers for introducing genetic and epigenetic insults such as DNA crosslinks, single- and double-strand DNA breaks, formation of DNA adducts, mismatched bases, modification in histones, DNA methylation, and microRNA alterations. However, DNA repair mechanisms are devoted to protect the DNA to ensure genetic stability, any aberrations in these calibrated mechanisms provoke cancer occurrence. Comprehensive knowledge of the type of mutagens and carcinogens and the influence of these agents in DNA damage and cancer induction is crucial to develop rational anticancer strategies. This review delineated the molecular mechanism of DNA damage and the repair pathways to provide a deep understanding of the molecular basis of mutagenicity and carcinogenicity. A relationship between DNA adduct formation and cancer incidence has also been summarized. The mechanistic basis of inflammatory response and oxidative damage triggered by mutagens in tumorigenesis has also been highlighted. We elucidated the interesting interplay between DNA damage response and immune system mechanisms. We addressed the current understanding of DNA repair targeted therapies and DNA damaging chemotherapeutic agents for cancer treatment and discussed how antiviral agents, anti-inflammatory drugs, and immunotherapeutic agents combined with traditional approaches lay the foundations for future cancer therapies.

DNA methylation alterations caused by Leishmania infection may generate a microenvironment prone to tumour development

DNA methylation is an epigenetic signature consisting of a methyl group at the 5’ cytosine of CpG dinucleotides. Modifications in DNA methylation pattern have been detected in cancer and infectious diseases and may be associated with gene expression changes. In cancer development DNA methylation aberrations are early events whereas in infectious diseases these epigenetic changes may be due to host/pathogen interaction. In particular, in leishmaniasis, a parasitic disease caused by the protozoan Leishmania, DNA methylation alterations have been detected in macrophages upon infection with Leishmania donovani and in skin lesions from patients with cutaneous leishmaniasis. Interestingly, different types of cancers, such as cutaneous malignant lesions, lymphoma and hepatocellular carcinoma, have been diagnosed in patients with a history of leishmaniasis. In fact, it is known that there exists an association between cancer and infectious diseases. Leishmania infection may increase susceptibility to develop cancer, but the mechanisms involved are not entirely clear. Considering these aspects, in this review we discuss the hypothesis that DNA methylation alterations induced by Leishmania may trigger tumorigenesis in long term infection since these epigenetic modifications may enhance and accumulate during chronic leishmaniasis.

Relationship between Clonorchis sinensis Infection and Cholangiocarcinoma in Korea

This study provides an overview of the current status of clonorchiasis and cholangiocarcinoma (CCA), and their relationship in Korea during 2012–2020. Data were obtained from the Health Insurance Review & Assessment Service of Korea. Cluster, trend, and correlation analyses were performed. Gyeongsangnam-do and Seoul had the highest average number of cases (1,026 and 4,208) and adjusted rate (306 and 424) for clonorchiasis and CCA, respectively. The most likely clusters (MLC) for clonorchiasis and CCA were Busan/Gyeongsangnam-do/Ulsan/Daegu/Gyeongsangbuk-do (Relative Risk; RR=4.55, Likelihood Ratio; LLR=9,131.115) joint cluster and Seoul (RR=2.29, LLR=7,602.472), respectively. The MLC for clonorchiasis was in the southeastern part of Korea, while that for CCA was in the southern part. Clonorchiasis showed a decreasing trend in the southeastern districts, while increased in the southwestern districts. Cities in the central region had a decreasing trend, while the western districts had an increasing trend. In most adults (30–59), infection rate of clonorchiasis showed a significant decrease until 2018, while thereafter increased, although not significant. CCA showed a sharply decreasing tendency. The incidence of clonorchiasis and CCA were positively correlated. In general, the correlation was weak (r=0.39, P<0.001), but it was strongly positive around the 4 river basins (r=0.74, P<0.001). This study might provide an analytic basis for developing an effective system against clonorchiasis and CCA.

Liver fluke eggs in bile duct brush cytology: An unexpected diagnosis during evaluation of a biliary stricture

Clonorchis sinensis, a liver fluke parasite, infects humans through ingestion of raw or undercooked fish, crabs, or crayfish in endemic areas where the parasite is found. Clonorchis sinensis infects the liver, gallbladder, and bile duct in humans, causing Clonorichiasis. Although the majority of patients are asymptomatic, long-lasting infections may cause severe disease. Without treatment, human infection may persist for the parasite's lifespan (25-30 years). Pathologic diagnosis can be challenging as sampling may demonstrate limited cellularity with minuscule eggs that may be overlooked. Here, we report a rare case of liver fluke eggs diagnosed in bile duct brush cytology.

Roles of microRNAs and Long Non-Coding RNAs Encoded by Parasitic Helminths in Human Carcinogenesis

Infectious agents such as viruses, bacteria, and parasites can lead to cancer development. Infection with the helminthic parasite Schistosoma haematobium can cause cancer of the urinary bladder in humans, and infection with the parasites Clonorchis sinensis and Opisthorchis viverrini can promote cholangiocarcinoma. These three pathogens have been categorized as “group 1: carcinogenic to humans” by the International Agency for Research on Cancer (IARC). Additionally, the parasite Schistosoma japonicum has been associated with liver and colorectal cancer and classified as “group 2B: possibly carcinogenic to humans”. These parasites express regulatory non-coding RNAs as microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), which modulate genic expression in different biological processes. In this review, we discuss the potential roles of miRNAS and lncRNAs encoded by helminthic parasites that are classified by the IARC as carcinogenic and possibly carcinogenic to humans. The miRNAs of these parasites may be involved in carcinogenesis by modulating the biological functions of the pathogen and the host and by altering microenvironments prone to tumor growth. miRNAs were identified in different host fluids. Additionally, some miRNAs showed direct antitumoral effects. Together, these miRNAs show potential for use in future therapeutic and diagnostic applications. LncRNAs have been less studied in these parasites, and their biological effects in the parasite–host interaction are largely unknown.

Liver Fluke Infection Throughout Human Evolution

The species of liver fluke that infect humans are zoonotic parasites that we share with other animals. The complex way in which humans have interacted with their environment, and the animals that live alongside them, has affected our ancestors' risk of infection by these helminths for millions of years. Here, we describe the range of flukes that can survive in the human liver and the health consequences that result from infection. Our focus is on Clonorchis sinensis (Chinese liver fluke), Fasciola hepatica (sheep liver fluke), F. gigantica (giant liver fluke), Opisthorchis viverrini (Southeast Asian liver fluke), O. felineus (cat liver fluke), and Dicrocoelium dendriticum (lancet liver fluke). We use our knowledge of where different kinds of liver flukes are endemic to estimate when and where human ancestors would have been exposed to infection over deep time. DNA evidence is used to investigate the evolutionary origins of the major species of liver flukes. The archaeological evidence for different species of fluke helps to show in which periods of human history they were most common. These flukes spread to humans from wild animals in early prehistory because of our ancestor's hunter-gatherer lifestyle and later from farm animals after the development of agriculture. We explore when and how some species have been able to spread across the world, whereas others are limited to particular geographic regions because of the endemic distribution of snail and vertebrate intermediate hosts. It is clear that human activity and migrations have played a key role in the expanding geographical range where we find liver flukes endemic today.

Molecular Mechanisms Linking Risk Factors to Cholangiocarcinoma Development

The poor prognosis of cholangiocarcinoma in humans is related to several factors, such as (i) the heterogeneity of the disease, (ii) the late onset of symptoms and (iii) the limited comprehension of the carcinogenic pathways determining neoplastic changes, which all limit the pursuit of appropriate treatment. Several risk factors have been recognized, including different infective, immune-mediated, and dysmorphogenic disorders of the biliary tree. In this review, we report the details of possible mechanisms that lead a specific premalignant pathological condition to become cholangiocarcinoma. For instance, during liver fluke infection, factors secreted from the worms may play a major role in pathogenesis. In primary sclerosing cholangitis, deregulation of histamine and bile-acid signaling may determine important changes in cellular pathways. The study of these molecular events may also shed some light on the pathogenesis of sporadic (unrelated to risk factors) forms of cholangiocarcinoma, which represent the majority (nearly 75%) of cases.

Treatment of Intrahepatic Cholangiocarcinoma-A Multidisciplinary Approach

Simple Summary

This review discusses multimodality treatment strategies for intrahepatic cholangiocarcinoma (iCC). Surgical resection remains the only potentially curative therapeutic option and the central cornerstone of treatment. Adjuvant systemic treatment will be recommended after resection or in the palliative setting. Increasing knowledge of phenotypic subclassification and molecular profiling allows investigation of targeted therapies as (neo-)adjuvant treatment. High-dose brachytherapy, internal radiation therapy, and transarterial chemoembolization are among the interventional treatment options being evaluated for unresectable iCC. Given the multiple options of multidisciplinary management, any treatment strategy should be discussed in a multidisciplinary tumor board and treatment should be directed by a specialized treatment center.

Abstract

Intrahepatic cholangiocarcinoma (iCC) is distinguished as an entity from perihilar and distal cholangiocarcinoma and gallbladder carcinoma. Recently, molecular profiling and histopathological features have allowed further classification. Due to the frequent delay in diagnosis, the prognosis for iCC remains poor despite major technical advances and multimodal therapeutic approaches. Liver resection represents the therapeutic backbone and only curative treatment option, with the functional residual capacity of the liver and oncologic radicality being deciding factors for postoperative and long-term oncological outcome. Furthermore, in selected cases and depending on national guidelines, liver transplantation may be a therapeutic option. Given the often advanced tumor stage at diagnosis or the potential for postoperative recurrence, locoregional therapies have become increasingly important. These strategies range from radiofrequency ablation to transarterial chemoembolization to selective internal radiation therapy and can be used in combination with liver resection. In addition, adjuvant and neoadjuvant chemotherapies as well as targeted therapies and immunotherapies based on molecular profiles can be applied. This review discusses multimodal treatment strategies for iCC and their differential use.

Clonorchis sinensis Granulin Promotes Malignant Transformation of Hepatocyte Through EGFR-Mediated RAS/MAPK/ERK and PI3K/Akt Signaling Pathways

The biological functions of growth factor, such as granulins, have been explored in parasites, and we elucidated that Clonorchis sinensis granulin (CsGRN) promoted the metastasis of hepatocellular carcinoma in our previous study. However, it is still unclear for the malignant transformation role of CsGRN in normal human hepatocytes. In this study, by transfecting pEGFP-C1-CsGRN eukaryotic expression plasmid, a cell line with stable overexpression of CsGRN in normal hepatocyte (LO2-GRN cells) was constructed. The effects on cell proliferation were detected by carrying out cell counting kit-8 (CCK8) assay and colony formation assay. Additionally, we conducted flow cytometry analysis to determine whether the proliferation of CsGRN was due to cell cycle arrest. Subsequently, the migration ability and the invasion ability of LO2-GRN cells were evaluated through wound-healing assay and transwell assay. Meanwhile, the levels of the markers of RAS/MAPK/ERK and PI3K/Akt signaling pathways activation in LO2-GRN cells were assessed by quantitative RT-PCR and Western blot. Our results indicated that CsGRN promoted the proliferation of LO2 cells by regulating the expression of cell-cycle-related genes. Moreover, the overexpression of CsGRN regulates malignant metastasis of liver cells by inducing the upregulation of epithelial-mesenchymal transition (EMT) marker proteins. Furthermore, both mRNA and protein expression levels of p-EGFR, RAS, p-ERK, p-AKT, p-PI3K, and p-braf have been enhanced by CsGRN. These results showed that CsGRN promoted the malignant transformation of hepatocytes by regulating epidermal growth factor receptor (EGFR)-mediated RAS/MAPK/ERK and PI3K/Akt signaling pathways, which suggested that CsGRN could serve as a novel oncoprotein during Clonorchis sinensis-associated malignant transformation of hepatocytes.

Pathogen-Induced Epigenetic Modifications in Cancers: Implications for Prevention, Detection and Treatment of Cancers in Africa

Cancer is a major public health burden worldwide. Tumor formation is caused by multiple intrinsic and extrinsic factors. Many reports have demonstrated a positive correlation between the burden of infectious pathogens and the occurrence of cancers. However, the mechanistic link between pathogens and cancer development remains largely unclear and is subject to active investigations. Apart from somatic mutations that have been widely linked with various cancers, an appreciable body of knowledge points to alterations of host epigenetic patterns as key triggers for cancer development. Several studies have associated various infectious pathogens with epigenetic modifications. It is therefore plausible to assume that pathogens induce carcinogenesis via alteration of normal host epigenetic patterns. Thus, Africa with its disproportionate burden of infectious pathogens is threatened by a dramatic increase in pathogen-mediated cancers. To curb the potential upsurge of such cancers, a better understanding of the role of tropical pathogens in cancer epigenetics could substantially provide resources to improve cancer management among Africans. Therefore, this review discusses cancer epigenetic studies in Africa and the link between tropical pathogens and cancer burden. In addition, we discuss the potential mechanisms by which pathogens induce cancers and the opportunities and challenges of tropical pathogen-induced epigenetic changes for cancer prevention, detection and management.

Subcellular localization of HMGB1 in human cholangiocarcinoma: correlation with tumor stage

Cholangiocarcinoma (CCA) is a malignant disease with a poor prognosis, and several studies have been conducted using different molecular markers as a tool for CCA diagnosis, including Clonorchis sinensis (CS)-CCA. We initially identified the expression profiles of the three markers of interest, HMGB1, SOX9, and YAP1, using GSE (GSE76297 and GSE32958) datasets. Upregulated levels of these three proteins were detected in CCA samples compared to those in normal samples. To clarify this issue, 24 human CCA tissues with paired adjacent normal tissues were evaluated using immunohistochemical staining. Of the three markers, the total cellular staining intensities were scanned, and subcellular localization was scored in the nuclear and cytoplasmic regions. The intensities of HMGB1, SOX9, and YAP1 were elevated in CCA tissues than the adjacent normal tissues. Individual scoring of subcellular localization revealed that the expression levels of HMGB1 (nucleus) and YAP1 (nucleus and cytoplasm) were significantly different from the pathologic M stage. Moreover, the translocation pattern was categorized using "site-index", and the results demonstrated that the overexpression of HMGB1 and SOX9 was mostly observed in both the nucleus and cytoplasm, whereas YAP1 was predominantly expressed in the cytoplasm of tumor cells. Interestingly, the site index of HMGB1 was moderately correlated with the tumor stage (r = 0.441, p = 0.031). These findings imply that the overexpression of subcellular HMGB1 could be associated with the metastatic status of patients with CS-CCA, which was shown to be effective for CS-CCA prognosis.

Tissue Pathogens and Cancers: A Review of Commonly Seen Manifestations in Histo- and Cytopathology

Tissue pathogens are commonly encountered in histopathology and cytology practice, where they can present as either benign mimickers of malignancy or true malignancies. The aim of this review is to provide a timely synthesis of our understanding of these tissue pathogens, with an emphasis on pertinent diagnostic conundrums associated with the benign mimickers of malignancy that can be seen with viral infections and those which manifest as granulomas. The oncogenic pathogens, including viruses, bacteria, and parasites, are then discussed with relationship to their associated malignancies. Although not exhaustive, the epidemiology, clinical manifestations, pathogenesis, and histological findings are included, along with a short review of emerging therapies.

Identification of a novel mutation gene signature HAMP for cholangiocarcinoma through comprehensive TCGA and GEO data mining

Cholangiocarcinoma (CHOL), the second most common malignant liver tumor, is clinically heterogeneous. In this study, we used gene expression profiles of CHOL obtained from The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) databases to identify novel mutation signatures in CHOL. Hepcidin antimicrobial peptide (HAMP) was identified as a novel diagnostic biomarker for CHOL using the intersection of mutation analysis and receiver operating characteristic (ROC) analysis. We then explored the expression signatures of HAMP in CHOL. HAMP-related differentially expressed genes (DEGs) were selected for the identification of hub genes related to HAMP and for prognostic prediction model analysis. Gene set enrichment analysis (GSEA) showed that the HAMP-related DEGs were mainly enriched for signaling pathways related to cholangiocarcinoma development. Through immunohistochemistry validation, clinical cohorts analysis, and TCGA analysis, we investigated the association between HAMP and clinical parameters and found that decreased HAMP expression was correlated with advanced pathological grade and poor prognosis. Besides, we estimated the immune infiltration level in CHOL and its relationship with HAMP expression. The proportion of tumor-infiltrating cells revealed that gamma delta T cells and monocytes were positively correlated with HAMP expression. Besides, HAMP was also correlated with chemokine, CCL16. This evidence suggested that HAMP might contribute to immune activation in the CHOL microenvironment. Therefore, HAMP may play a synergistic role with these immune cells and chemokines to inhibit CHOL development. HAMP serves as a valuable biomarker in CHOL and is closely correlated with its progression.

Novel mechanism of hepatobiliary system damage and immunoglobulin G4 elevation caused by Clonorchis sinensis infection

Clonorchis sinensis infection is still a major public health problem. It is estimated that more than 15 million people worldwide are infected, especially in Northeast China, Taiwan, South Korea, and North Vietnam. The detection of Clonorchis sinensis eggs in feces and bile is still the only gold standard for the diagnosis of Clonorchis sinensis infection, and new detection methods are needed to improve the detection rate. After Clonorchis sinensis invades the human body, it mainly parasitizes the hepatobiliary tract. Therefore, it is closely related to hepatobiliary diseases such as cholangitis, bile duct stones, liver fibrosis, and cholangiocarcinoma. The increase in immunoglobulin G4 (IgG4) caused by Clonorchis sinensis infection is rare and there are few reports about the relevant mechanism. It may be related to the inflammatory factors interleukin (IL)-4, IL-10, and IL-13 produced by human phagocytes, T cells, B cells, and other immune cells in the process of resisting the invasion of Clonorchis sinensis. However, this finding still needs further clarification and confirmation. This article reviews the epidemiology, clinical manifestations, serology, imaging, pathogenic mechanism, and control measures of Clonorchis sinensis infection to help establish the diagnostic process for Clonorchis sinensis. We report novel mechanisms of IgG4 elevation due to Clonorchis sinensis infection to provide more experience and a theoretical basis for clinical diagnosis and treatment of this infection.

Pathogens and Carcinogenesis: A Review

Cancer is a global health problem associated with genetics and unhealthy lifestyles. Increasingly, pathogenic infections have also been identified as contributors to human cancer initiation and progression. Most pathogens (bacteria, viruses, fungi, and parasites) associated with human cancers are categorized as Group I human carcinogens by the International Agency for Research on Cancer, IARC. These pathogens cause carcinogenesis via three known mechanisms: persistent infection that cause inflammation and DNA damage, initiation of oncogene expression, and immunosuppression activity of the host. In this review, we discuss the carcinogenesis mechanism of ten pathogens, their implications, and some future considerations for better management of the disease. The pathogens and cancers described are Helicobacter pylori (gastric cancer), Epstein-Barr virus (gastric cancer and lymphoma), Hepatitis B and C viruses (liver cancer), Aspergillus spp. (liver cancer), Opisthorchis viverrine (bile duct cancer), Clonorchis sinensis (bile duct cancer), Fusobacterium nucleatum (colorectal cancer), Schistosoma haematobium (bladder cancer); Human Papillomavirus (cervical cancer), and Kaposi's Sarcoma Herpes Virus (Kaposi's sarcoma).

A review of molecular identification tools for the opisthorchioidea

The superfamily Opisthorchioidea encompasses the families Cryptogonimidae, Opisthorchiidae and Heterophyidae. These parasites depend on the aquatic environment and include marine and freshwater species. Some species, such as Clonorchis sinensis and Opisthorchis viverrini, have a high impact on public health with millions of infected people worldwide and have thus been the object of many studies and tool developments. However, for many species, tools for identification and detection are scarce. Although morphological descriptions have been used and are still important, they are often not efficient on the immature stages of these parasites. Thus, during the past few decades, molecular approaches for parasite identification have become commonplace. These approaches are efficient, quick and reliable. Nonetheless, for some parasites of the superfamily Opisthorchioidea, reference genomic data are limited. This study reviews available genetic data and molecular tools for the identification and/or the detection of this superfamily. Molecular data on this superfamily are mostly based on mitochondrial and ribosomal gene sequence analyses, especially on the cytochrome c oxidase subunit 1 gene and internal transcribed spacer regions respectively.

The Overactivation of NADPH Oxidase during Clonorchis sinensis Infection and the Exposure to N-Nitroso Compounds Promote Periductal Fibrosis

Clonorchis sinensis, a high-risk pathogenic human liver fluke, provokes various hepatobiliary complications, including epithelial hyperplasia, inflammation, periductal fibrosis, and even cholangiocarcinogenesis via direct contact with worms and their excretory-secretory products (ESPs). These pathological changes are strongly associated with persistent increases in free radical accumulation, leading to oxidative stress-mediated lesions. The present study investigated C. sinensis infection- and/or carcinogen N-nitrosodimethylamine (NDMA)-associated fibrosis in cell culture and animal models. The treatment of human cholangiocytes (H69 cells) with ESPs or/and NDMA increased reactive oxidative species (ROS) generation via the activation of NADPH oxidase (NOX), resulting in augmented expression of fibrosis-related proteins. These increased expressions were markedly attenuated by preincubation with a NOX inhibitor (diphenyleneiodonium chloride) or an antioxidant (N-acetylcysteine), indicating the involvement of excessive NOX-dependent ROS formation in periductal fibrosis. The immunoreactive NOX subunits, p47^phox and p67^phox, were observed in the livers of mice infected with C. sinensis and both infection plus NDMA, concomitant with collagen deposition and immunoreactive fibronectin elevation. Staining intensities are proportional to lesion severity and infection duration or/and NDMA administration. Thus, excessive ROS formation via NOX overactivation is a detrimental factor for fibrogenesis during liver fluke infection and exposure to N-nitroso compounds.

Clinical Characteristics of Clonorchis sinensis-Associated Cholangiocarcinoma: A Large-Scale, Single-Center Study

Background:Clonorchis sinensis (CS) infection is considered a group 1 carcinogen of cholangiocarcinoma (CCA). There were very few studies regarding clinical characteristics of CS-associated CCA (CACC). This study aimed to investigate clinical characteristics of patients with CCA with or without CS infection.

Methods: A total of 367 patients diagnosed with CCA who underwent diagnostic tests for CS infection were enrolled. CS infection was defined as follows: at least one positive serum ELISA test, skin test, stool microscopy, or bile microscopy.

Results: There were 95 (26%) patients with CS infections. The median follow-up duration was 14.9 months (range, 6.07–36.17). The following significant differences were noted among patients with CACC compared to non-CACC; diagnosis at younger age (median 62 years vs. 65 years, p = 0.018), higher male to female ratio (83.2 vs. 61.8%, p < 0.001), and residence in CS-endemic area (46.3 vs. 25.4%, p = 0.014). Univariate analysis of prognostic factors indicated that tumor location, curative resection, tumor stage, and laboratory tests including CA 19-9, CEA, and bilirubin were significantly associated with overall survival, but CS infection was not. In multivariate analysis, tumor location, CEA, curative resection and tumor stage were identified as independent prognostic factors. Among patients under age 64, CACC group had lower survival rate than non-CACC group (p = 0.022).

Conclusions: CACC had the following significant characteristics compared to non-CACC; diagnosis at younger age, higher male to female ratio, higher prevalence in CS endemic areas and poorer overall survival in patients under age 64.

Transcriptomic profiling of three-dimensional cholangiocyte spheroids long term exposed to repetitive Clonorchis sinensis excretory-secretory products

Background

Biliary tract infection with the carcinogenic human liver fluke, Clonorchis sinensis, provokes chronic inflammation, epithelial hyperplasia, periductal fibrosis, and even cholangiocarcinoma. Complications are proportional to the intensity and duration of the infection. In addition to mechanical irritation of the biliary epithelia from worms, their excretory-secretory products (ESPs) cause chemical irritation, which leads to inflammation, proliferation, and free radical generation.

Methods

A three-dimensional in vitro cholangiocyte spheroid culture model was established, followed by ESP treatment. This allowed us to examine the intrinsic pathological mechanisms of clonorchiasis via the imitation of prolonged and repetitive in vivo infection.

Results

Microarray and RNA-Seq analysis revealed that ESP-treated cholangiocyte H69 spheroids displayed global changes in gene expression compared to untreated spheroids. In ESP-treated H69 spheroids, 185 and 63 probes were found to be significantly upregulated and downregulated, respectively, corresponding to 209 genes (p < 0.01, fold change > 2). RNA-Seq was performed for the validation of the microarray results, and the gene expression patterns in both transcriptome platforms were well matched for 209 significant genes. Gene ontology analysis demonstrated that differentially expressed genes were mainly classified into immune system processes, the extracellular region, and the extracellular matrix. Among the upregulated genes, four genes (XAF1, TRIM22, CXCL10, and BST2) were selected for confirmation using quantitative RT-PCR, resulting in 100% similar expression patterns in microarray and RNA-Seq.

Conclusions

These findings broaden our understanding of the pathological pathways of liver fluke-associated hepatobiliary disorders and suggest a novel therapeutic strategy for this infectious cancer.

Graphic abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-021-04717-2.

High-quality reference genome for Clonorchis sinensis

The Chinese liver fluke, Clonorchis sinensis, causes the disease clonorchiasis, affecting ~35 million people in regions of China, Vietnam, Korea and the Russian Far East. Chronic clonorchiasis causes cholangitis and can induce a malignant cancer, called cholangiocarcinoma, in the biliary system. Control in endemic regions is challenging, and often relies largely on chemotherapy with one anthelmintic, called praziquantel. Routine treatment carries a significant risk of inducing resistance to this anthelmintic in the fluke, such that the discovery of new interventions is considered important. It is hoped that the use of molecular technologies will assist this endeavour by enabling the identification of drug or vaccine targets involved in crucial biological processes and/or pathways in the parasite. Although draft genomes of C. sinensis have been published, their assemblies are fragmented. In the present study, we tackle this genome fragmentation issue by utilising, in an integrated way, advanced (second- and third-generation) DNA sequencing and informatic approaches to build a high-quality reference genome for C. sinensis, with chromosome-level contiguity and curated gene models. This substantially-enhanced genome provides a resource that could accelerate fundamental and applied molecular investigations of C. sinensis, clonorchiasis and/or cholangiocarcinoma, and assist in the discovery of new interventions against what is a highly significant, but neglected disease-complex.

Spirocerca lupi Proteomics and Its Role in Cancer Development: An Overview of Spirocercosis-Induced Sarcomas and Revision of Helminth-Induced Carcinomas

Spirocerca lupi is a parasitic nematode of canids that induces a myriad of clinical manifestations in its host and, in 25% of infections, leads to the formation of sarcomas. The description of the protein composition of the excretory and secretory products (Sl-ESP) of S. lupi has shed light on its possible interactions with the host environment, including migration within the host and mechanisms of immunomodulation. Despite this, the process by which S. lupi induces cancer in the dog remains poorly understood, and some hypotheses have arisen regarding these possible mechanisms. In this review, we discuss the role of specific ESP from the carcinogenic helminths Clonorchis sinensis, Opisthorchis viverrini and Schistosoma haematobium in inducing chronic inflammation and cancer in their host’s tissues. The parasitic worms Taenia solium, Echinococcus granulosus, Heterakis gallinarum, Trichuris muris and Strongyloides stercoralis, which have less-characterized mechanisms of cancer induction, are also analyzed. Based on the pathological findings in spirocercosis and the mechanisms by which other parasitic helminths induce cancer, we propose that the sustained inflammatory response in the dog´s tissues produced in response to the release of Sl-ESP homologous to those of other carcinogenic worms may lead to the malignant process in infected dogs.

Aspirin inhibits cholangiocarcinoma cell proliferation via cell cycle arrest in vitro and in vivo

Cholangiocarcinoma is the most common biliary duct malignancy and the second most common primary liver cancer, accounting for 10-20% of hepatic malignancies. With high mortality and poor prognosis, the 5-year survival rate of cholangiocarcinoma is only 10%. A previous study demonstrated a significant association between aspirin use and a decreased risk of cholangiocarcinoma. However, the effect of aspirin on cholangiocarcinoma remains unknown. Therefore, the aim of the present study was to investigate the effects of aspirin on cholangiocarcinoma in vitro and in vivo. Three cholangiocarcinoma cell lines were used to analyze the effect of aspirin on cell proliferation, cell cycle progression, apoptosis, and the regulation of microRNAs. MicroRNAs are known to regulate the development and progression of various types of cancer. An HuCCT-1 xenograft model was used for the in vivo study. It was determined that aspirin inhibited the proliferation of human cholangiocarcinoma cells (except TKKK cells). Aspirin induced cell cycle arrest in the G₀/G₁ phase and regulated cell-cycle related proteins in cholangiocarcinoma cells (HuCCT-1 cells) but did not induce apoptosis. The expression of miR-340-5p was significantly upregulated after treatment, and overexpression of miR-340-5p inhibited the proliferation of HuCCT-1 cells and decreased the levels of cyclin D1. TKKK cells had low miR-340-5p expression, which may explain why aspirin had no effect on their proliferation. In vivo, aspirin reduced the growth of xenografted tumors. In conclusion, the present study indicated that aspirin partially inhibited cholangiocarcinoma cell proliferation and tumor growth by inducing G₀/G₁ phase cell cycle arrest, potentially through the miR-340-5p/cyclin D1 axis.

Estimates of Cancer Mortality Attributable to Carcinogenic Infections in Italy

Several infectious agents are ascertained causes of cancer, but the burden of cancer mortality attributable to carcinogenic infections in Italy is still unknown. To tackle this issue, we calculated the rate and regional distribution of cancer deaths due to infections sustained by seven pathogens ranked as group 1 carcinogenic agents in humans by the International Agency for Research on Cancer. Population attributable fractions related to these agents were applied to annual statistics of cancer deaths coded according to the 10th International Classification of Diseases. The estimated burden of cancer mortality attributable to carcinogenic infections in Italy during the period 2011-2015 was 8.7% of all cancer deaths registered yearly, on average. Approximately 60% of deaths occurred in men, and almost the whole burden was due to four infectious agents (Helicobacter pylori, hepatitis C virus, high-risk human papillomavirus, and hepatitis B virus). The analysis of regional distribution showed a higher number of infection-related cancer deaths in the northern regions, where the estimates reached 30 (Liguria) and 28 (Friuli Venezia Giulia) deaths per 100,000 inhabitants in 2015. Since one-twelfth of cancer deaths were attributable to these modifiable risk factors, the implementation of appropriate prevention and treatment interventions may help to reduce the impact of these infections on cancer mortality.

Microbiota Effects on Carcinogenesis: Initiation, Promotion, and Progression

Carcinogenesis is a multistep process by which normal cells acquire genetic and epigenetic changes that result in cancer. In combination with host genetic susceptibility and environmental exposures, a prominent procarcinogenic role for the microbiota has recently emerged. In colorectal cancer (CRC), three nefarious microbes have been consistently linked to cancer development: (a) Colibactin-producing Escherichia coli initiates carcinogenic DNA damage, (b) enterotoxigenic Bacteroides fragilis promotes tumorigenesis via toxin-induced cell proliferation and tumor-promoting inflammation, and (c) Fusobacterium nucleatum enhances CRC progression through two adhesins, Fap2 and FadA, that promote proliferation and antitumor immune evasion and may contribute to metastases. Herein, we use these three prominent microbes to discuss the experimental evidence linking microbial activities to carcinogenesis and the specific mechanisms driving this stepwise process. Precisely defining mechanisms by which the microbiota impacts carcinogenesis at each stage is essential for developing microbiota-targeted strategies for the diagnosis, prognosis, and treatment of cancer.

Recombinant CsHscB of carcinogenic liver fluke Clonorchis sinensis induces IL-10 production by binding with TLR2

BACKGROUND

Clonorchis sinensis, a fluke dwelling in the intrahepatic bile ducts causes clonorchiasis, which affect about 15 million people wide-distributed in eastern Asia. During C. sinensis infection, worm-host interaction results in activation of patterns recognition receptors (PRRs) such as Toll-like receptors (TLRs) and further triggers immune responses, which determines the outcome of the infection. However, the mechanisms by which pathogen-associated molecules patterns from C. sinensis interact with TLRs were poorly understood. In the present study, we assumed that the molecules from C. sinensis may regulate host immune responses via TLR2 signaling pathway.

METHODOLOGY/PRINCIPAL FINDINGS

In the present study, we have identified a ~34 kDa CsHscB from C. sinensis which physically bound with TLR2 as demonstrated by molecular docking and pull-down assay. We also found that recombinant CsHscB (rCsHscB) potently activates macrophage to express various proteins including TLR2, CD80, MHCII, and cytokines like IL-6, TNF-α, and IL-10, but rCsHscB failed to induce IL-10 in macrophages from Tlr2-/- mice. Moreover, ERK1/2 activation was required for rCsHscB-induced IL-10 production in macrophages. In vivo study revealed that rCsHscB triggered a high production of IL-10 in the wild-type (WT) but not in Tlr2-/- mice. Consistently, the phosphorylation of ERK1/2 was also attenuated in Tlr2-/- mice compared to the WT mice, after the treatment with rCsHscB.

CONCLUSIONS/SIGNIFICANCE

Our data thus demonstrate that rCsHscB from C. sinensis interacts with TLR2 to be endowed with immune regulatory activities, and may have some therapeutic implications in future beyond parasitology.