The tumorigenic liver fluke Opisthorchis viverrini--multiple pathways to cancer

A multidisciplinary analysis of over 53,000 fascioliasis patients along the 1995-2019 countrywide spread in Vietnam defines a new epidemiological baseline for One Health approaches

Fascioliasis, only foodborne trematodiasis of worldwide distribution, is caused by Fasciola hepatica and F. gigantica, liver flukes transmitted by freshwater snails. Southern and southeastern Asia is an emerging hot spot of F. gigantica, despite its hitherto less involvement in human infection. In Vietnam, increasing cases have been reported since 1995, whereas only sixteen throughout 1800-1994. A database was created to include epidemiological data of fascioliasis patients from the 63 Vietnam provinces throughout 1995-2019. Case profiles were based on serology, symptoms, eosinophilia, imaging techniques, stool egg finding, and post-specific-treatment recovery. Radio broadcasting about symptoms and costless diagnosis/treatment led patients to hospitals after symptom onset. Yearly case numbers were modelled and spatio-temporally analyzed. Missing data and confounders were assessed. The countrywide spread has no precedent. It started in the central coast, including 53,109 patients, mostly adults and females. Seasonality, linked to vegetable consumption, peaks in June, although the intensity of this peak differs according to relief/climatic zones. Incidence data and logistic regression curves are obtained for the first time in human fascioliasis. Fasciolid hybrids accompanying the spreading F. gigantica flukes, and climate change assessed by risk index correlations, are both ruled out as outbreak causes. Human-guided movements of livestock from an original area prove to be the way used by fasciolids and lymnaeid vectors to expand geographically. Radix viridis, a highly efficient transmitting and colonizing vector, played a decisive role in the spread. The use of irrigated crop fields, widely inhabited by R. viridis, for livestock grazing facilitated the transmission and spread of the disease. General physician awareness and diagnostic capacity improvement proved the successful impact of such knowledge transfer in facilitating and increasing patient infection detection. Information, education and communication to the public by radio broadcasting demonstrated to be very helpful. Fasciola gigantica is able to cause epidemic and endemic situations similar to F. hepatica. The magnitude of the human outbreak in Vietnam is a health wake-up call for southern and southeastern countries of Asia which present the highest human population densities with increasing food demands, uncontrolled livestock inter-country exchange, foreign import practices, and monsoon's increasing climate change impact.

MicroRNAs in opisthorchiids and their definitive hosts: Current Status and Perspectives

Opisthorchis felineus, Opisthorchis viverrini, and Clonorchis sinensis (family Opisthorchiidae) are parasitic flatworms that pose serious threats to humans in certain countries and cause opisthorchiasis/clonorchiasis. Opisthorchiid flukes parasitize the biliary tract of the host, causing cholangitis, cholecystitis, cholelithiasis and cholangiocarcinoma. In this review, we primarily focus on recent microRNAs (miRNAs) studies of opisthorchiid flukes and their definitive hosts. Many miRNAs are conserved and expressed in a developmentally stage specific manner in the three opisthorchiid flukes, which play important roles in the growth and development of Opisthorchiidae spp., as well as host-pathogen interactions. Some miRNAs might be potential biomarkers related to carcinogenesis of cholangiocarcinoma. Therefore, this review provides the basis for further investigating the roles of miRNAs in opisthorchiid flukes and their definitive hosts, as well as promoting the development of novel approaches to prevent and treat opisthorchiasis/clonorchiasis.

Mechanistic insights into liver-fluke-induced bile-duct cancer

Liver fluke infection is a major risk for cholangiocarcinoma (CCA). It has been established that the Asian liver flukes, Clonorchis sinensis and Opisthorchis viverrini secrete growth factors, digestive enzymes, and extracellular vesicles (EVs) which contribute to abnormal cell development in the bile ducts where the worms reside. These secretions - combined with aberrant inflammation and repeated cycles of chronic wounding at the site of parasite attachment and grazing on the epithelium - promote biliary hyperplasia and fibrosis and ultimately malignant transformation. Application of post-genomic and gene-editing tools to the study of liver fluke immunobiology and pathogenesis has accelerated the discovery of essential virulence factors to which targeted therapies and diagnostics can be directed.

Spatial prediction of the probability of liver fluke infection in water resource within sub-basin using an optimized geographically-weighted regression model

Introduction

Infection with liver flukes (Opisthorchis viverrini) is partly attributed to their ability to thrive in sub-basin habitats, causing the intermediate host to remain within the watershed system throughout the year. It is crucial to conduct spatial monitoring of fluke infection at a small basin analysis scale as it helps in studying the spatial factors influencing these infections. The number of infected individuals was obtained from local authorities, converted into a percentage, and visually represented as raster data through a heat map. This approach generates continuous data with dependent variables.

Methods

The independent set comprises nine variables, including both vector and raster data, that establish a connection between the location of an infected person and their village. Design spatial units optimized for geo-weighted modeling by utilizing a clustering and overlay approach, thereby facilitating the optimal prediction of alternative models for infection.

Results and discussion

The Model-3 demonstrated the strongest correlation between the variables X5 (stream) and X7 (ndmi), which are associated with the percentage of infected individuals. The statistical analysis showed t-statistics values of -2.045 and 0.784, with corresponding p-values of 0.016 and 0.085. The RMSE was determined to be 2.571%, and the AUC was 0.659, providing support for these findings. Several alternative models were tested, and a generalized mathematical model was developed to incorporate the independent variables. This new model improved the accuracy of the GWR model by 5.75% and increased the R 2 value from 0.754 to 0.800. Additionally, spatial autocorrelation confirmed the difference in predictions between the modeled and actual infection values. This study demonstrates that when using GWR to create spatial models at the sub-basin level, it is possible to identify variables that are associated with liver fluke infection.

Burden and risk factors of suspected cholangiocarcinoma in high Opisthorchis viverrini endemic rural communities in southern Lao PDR

INTRODUCTION

Cholangiocarcinoma (CCA) is a major contributor to hepatobiliary mortality in the Lao People's Democratic Republic (Lao PDR). Infection with the carcinogenic trematode Opisthorchis viverrini (OV), acquired through consumption of insufficiently-cooked river fish, is a known risk factor for the development of CCA. Together with OV, other risk factors contribute to the pathogenesis of CCA. We conducted this study to identify the burden of CCA and identify risk factors in high-risk communities in Lao PDR.

METHOD

A cross-sectional study was performed in Champasack and Savannakhet provinces, southern Lao PDR, where OV infection is highly endemic. We assessed hepatobiliary morbidity with abdominal ultrasound (US). In addition, multiple risk factors known or suspected to be associated with CCA were assessed such as OV infection (examined by Kato-Katz technique for stool examination), lifestyle risks (e.g. smoking and alcohol consumption by face-to-face questionnaire), co-morbidity (e.g. diabetes mellitus) and hepatitis B infection status, both serologically tested.

RESULTS

In 3,400 participants, the overall prevalence of suspected CCA was 7.2% (95% confidence interval [95% CI] 5.4-9.6). The suspected CCA prevalence increased with age, and was higher in men at all ages. Almost all participants (88.3%) were infected with OV. In the multivariate regression analysis, suspected CCA was positively associated with OV infection (adjusted odds ratio [aOR] 3.4, 95% CI 1.7-6.5), and a history of cholecystectomy (aOR 2.7, 95% CI 1.5-4.9).

CONCLUSION

Our CCA screening in high OV prevalence rural areas of Lao PDR uncovers a high public health burden, primarily driven by elevated OV infection rates. Urgent interventions are needed to curb OV infection in these communities. Age and gender disparities in suspected CCA prevalence highlight the need for targeted efforts. Beyond OV, notable factors like a history of cholecystectomy offer valuable insights for preventive strategies. This research enhances our understanding of hepatobiliary morbidity and informs public health initiatives in Lao PDR.

Investigation of a Serine Protease Inhibitor Active in the Infectious Stage of the Human Liver Fluke Opisthorchis viverrini

Serine protease inhibitors (serpins) participate in the regulation of inflammation, blood coagulation, and complement activation in humans. This research aimed to identify and characterize such inhibitors of the human liver fluke Opisthorchis viverrini. Parasite proteins that might contribute to the modulation of host physiology are of particular interest, especially as chronic opisthorchiasis increases the risk of developing biliary cancer. BLAST was used to find hypothetical serpins predicted from the parasite genome data. RNA extraction and reverse transcriptase PCR were used to isolate a serpin cDNA and to determine developmental transcript abundance. The evolutionary relation to other trematode serpins was revealed by phylogenetic analysis. Recombinant serpin was expressed in Escherichia coli and used to test the immunoreactivity of human opisthorchiasis sera and the inhibition of human serine proteases. A substantial serpin family with high sequence divergence among the members was found in the genus Opisthorchis. A serpin, different from previously analyzed trematode serpins, was cloned. The transcript was only detected in metacercariae and newly excysted juveniles. Human opisthorchiasis sera showed statistically significant reactivity to recombinant serpin. The serpin caused moderate inhibition of thrombin and low inhibition of kallikrein and chymotrypsin. This parasite serpin could be further evaluated as a diagnostic tool for early infection. Kallikrein and thrombin are involved in fibrinolysis; therefore, further research should explore the effects of the parasite serpin on this process.

Advancing vaccine development against Opisthorchis viverrini: A synergistic integration of omics technologies and advanced computational tools

The liver fluke O. viverrini (Opisthorchis viverrini), a neglected tropical disease (NTD), endemic to the Great Mekong Subregion (GMS), mainly afflicts the northeastern region of Thailand. It is a leading cause of cholangiocarcinoma (CCA) in humans. Presently, the treatment modalities for opisthorchiasis incorporate the use of the antihelminthic drug praziquantel, the rapid occurrence of reinfection, and the looming threat of drug resistance highlight the urgent need for vaccine development. Recent advances in "omics" technologies have proven to be a powerful tool for such studies. Utilizing candidate proteins identified through proteomics and refined via immunoproteomics, reverse vaccinology (RV) offers promising prospects for designing vaccines targeting essential antibody responses to eliminate parasite. Machine learning-based computational tools can predict epitopes of candidate protein/antigens exhibiting high binding affinities for B cells, MHC classes I and II, indicating strong potential for triggering both humoral and cell-mediated immune responses. Subsequently, these vaccine designs can undergo population-specific testing and docking/dynamics studies to assess efficacy and synergistic immunogenicity. Hence, refining proteomics data through immunoinformatics and employing computational tools to generate antigen-specific targets for trials offers a targeted and efficient approach to vaccine development that applies to all domains of parasite infections. In this review, we delve into the strategic antigen selection process using omics modalities for the O. viverrini parasite and propose an innovative framework for vaccine design. We harness omics technologies to revolutionize vaccine development, promising accelerated discoveries and streamlined preclinical and clinical evaluations.

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.

Network pharmacology- and cell-based assessments identify the FAK/Src pathway as a molecular target for the antimetastatic effect of momordin Ic against cholangiocarcinoma

Previous studies have indicated the efficacy of momordin Ic (MIc), a plant-derived triterpenoid, against several types of cancers, implying its potential for further development. However, comprehensive insights into the molecular mechanisms and targets of MIc in cholangiocarcinoma (CCA) are lacking. This study aimed to investigate the actions of MIc against CCA at the molecular level. Network pharmacology analysis was first employed to predict the mechanisms and targets of MIc. The results unveiled the potential involvement of MIc in apoptosis and cell migration, pinpointing Src and FAK as key targets. Subsequently, cell-based assays, in accordance with FAK/Src-associated metastasis, were conducted, demonstrating the ability of MIc to attenuate the metastatic behaviours of KKU-452 cells. The in vitro results further indicated the capability of MIc to suppress the epithelial-mesenchymal transition (EMT) process, notably by downregulating EMT regulators, including N-cadherin, vimentin, ZEB2 and FOXC1/2 expression. Furthermore, MIc suppressed the activation of the FAK/Src signalling pathway, influencing critical downstream factors such as MMP-9, VEGF, ICAM-1, and c-Myc. Molecular docking simulations also suggested that MIc could interact with FAK and Src domains and restrain kinases from being activated by hindering ATP binding. In conclusion, this study employs a comprehensive approach encompassing network pharmacology analysis, in vitro assays, and molecular docking to unveil the mechanisms and targets of MIc in CCA. MIc mitigates metastatic behaviours and suppresses key pathways, offering a promising avenue for future therapeutic strategies against this aggressive cancer.

The Parasitism and Tumors Carcinogenesis: A Review Subject

BACKGROUND

Multi-factorial reasons are an induction to cause cancer. Different infections and infestations with viruses, bacteria, and parasites have been detected for many years to be related to human carcinogenesis.

PURPOSE

The study aimed to review all ideas of tumor carcinogenesis and its associations with parasitic infections and infestations.

METHODS

We reviewed several articles (published and imprinted) by selecting, extracting, and synthesizing data about the relationship between cancers and parasites.

RESULTS

Several helminths infections as schistosomiasis, are highly carcinogenic agents for bladder cancer, whereas trypanosomiasis has a bi-model role in cancer development. Leishmaniasis may be a cause of hepatocarcinoma, skin cancer, and lymphomas. In addition, malaria appears to be causative in the carcinogenesis of some cancers; as Burkitt lymphoma. Also, data from previous studies suggested that Strongyloides stercoralis may be a relevant co-factor in lymphomas.

CONCLUSION

There are different mechanisms of parasitic infection to be enhancing in carcinogenesis of cancer in human.

Animal granulins: In the GRN scheme of things

Granulins are conserved in nearly all metazoans, with an intriguing loss in insects. These pleiotropic peptides are involved in numerous physiological and pathological processes yet have been overwhelmingly examined in mammalian systems. While work in other animal models has been informative, a richer understanding of the proteins should be obtained by integrating knowledge from all available contexts. The main bodies of work described here include 1) the structure-function relationships of progranulin and its cleavage products, 2) the role of expanded granulin gene families and different isoforms in fish immunology, 3) the release of granulin peptides to promote host angiogenesis by parasitic worms, 4) a diversity of molluscan uses for granulins, including immune activation in intermediate hosts to trematodes, 5) knowledge gained on lysosomal functions from C. elegans and the stress-related activities of granulins. We provide an overview of functional reports across the Metazoa to inform much-needed future research.

Deciphering the Dual Role of Heligmosomoides polygyrus Antigens in Macrophage Modulation and Breast Cancer Cell Growth

In our study, we explored how parasitic nematodes, specifically Heligmosomoides polygyrus, influence the immune response, focusing on their potential role in tumor growth. The study aimed to understand the mechanisms by which these parasites modify immune cell activation, particularly in macrophages, and how this might create an environment conducive to tumor growth. Our methods involved analyzing the effects of H. polygyrus excretory-secretory antigens on macrophage activation and their subsequent impact on breast cancer cell lines EMT6 and 4T1. We observed that these antigens significantly increased the expression of genes associated with both pro-inflammatory and anti-inflammatory molecules, such as inducible nitric oxide synthase, TNF-α, (Tumor Necrosis Factor) Il-6 (Interleukin), and arginase. Additionally, we observed changes in the expression of macrophage surface receptors like CD11b, F4/80, and TLR4 (Toll-like receptor 4). Our findings indicate that the antigens from H. polygyrus markedly alter macrophage behavior and increase the proliferation of breast cancer cells in a laboratory setting. This study contributes to a deeper understanding of the complex interactions between parasitic infections and cancer development, highlighting the need for further research in this area to develop potential new strategies for cancer treatment.

Modeling the persistence of Opisthorchis viverrini worm burden after mass-drug administration and education campaigns with systematic adherence

Opisthorchis viverrini is a parasitic liver fluke contracted by consumption of raw fish, which affects over 10 million people in Southeast Asia despite sustained control efforts. Chronic infections are a risk factor for the often fatal bile duct cancer, cholangiocarcinoma. Previous modeling predicted rapid elimination of O. viverrini following yearly mass drug administration (MDA) campaigns. However, field data collected in affected populations shows persistence of infection, including heavy worm burden, after many years of repeated interventions. A plausible explanation for this observation is systematic adherence of individuals in health campaigns, such as MDA and education, with some individuals consistently missing treatment. We developed an agent-based model of O. viverrini which allows us to introduce various heterogeneities including systematic adherence to MDA and education campaigns at the individual level. We validate the agent-based model by comparing it to a previously published population-based model. We estimate the degree of systematic adherence to MDA and education campaigns indirectly, using epidemiological data collected in Lao PDR before and after 5 years of repeated MDA, education and sanitation improvement campaigns. We predict the impact of interventions deployed singly and in combination, with and without the estimated systematic adherence. We show how systematic adherence can substantially increase the time required to achieve reductions in worm burden. However, we predict that yearly MDA campaigns alone can result in a strong reduction of moderate and heavy worm burden, even under systematic adherence. We predict latrines and education campaigns to be particularly important for the reduction in overall prevalence, and therefore, ultimately, elimination. Our findings show how systematic adherence can explain the observed persistence of worm burden; while emphasizing the benefit of interventions for the entire population, even under systematic adherence. At the same time, the results highlight the substantial opportunity to further reduce worm burden if patterns of systematic adherence can be overcome.

Preclinical evidence for preventive and curative effects of resveratrol on xenograft cholangiocarcinogenesis

Cholangiocarcinoma (CCA), the malignant tumor of bile duct epithelial cells, is a relatively rare yet highly lethal cancer. In this work, we tested the ability of Resveratrol (RV) to prevent and cure CCA xenograft in nude mice and investigated molecular mechanisms underpinning such anticancer effect. Human CCA cells were xenografted in mice that were or not treated prior to or after to transplantation with RV. Tumor growth was monitored and analyzed for the markers of cell proliferation, apoptosis, and autophagy. TCGA was interrogated for the molecules possibly targeted by RV. RV could inhibit the growth of human CCA xenograft when administered after implantation and could reduce the growth or even impair the implantation of the tumors when administered prior the transplantation. RV inhibited CCA cell proliferation, induced apoptosis with autophagy, and strongly reduced the presence of CAFs and production of IL-6. Interrogation of CCA dataset in TCGA database revealed that the expression of IL-6 Receptor (IL-6R) inversely correlated with that of MAP-LC3 and BECLIN-1, and that low expression of IL-6R and of MIK67, two pathways downregulated by RV, associated with better survival of CCA patients. Our data demonstrate that RV elicits a strong preventive and curative anticancer effect in CCA by limiting the formation of CAFs and their release of IL-6, and this results in up-regulation of autophagy and apoptosis in the cancer cells. These findings support the clinical use of RV as a primary line of prevention in patients exposed at risk and as an adjuvant therapeutics in CCA patients.

Inflammatory responses to Opisthorchis viverrini infection in animal models: A comparison between susceptible and nonsusceptible hosts in different anatomical locations

Background

Inflammation caused by Opisthorchis viverrini infection increases the risk of cholangitis, cholecystitis, and leads to bile duct cancer (cholangiocarcinoma or CCA). However, only certain infected individuals are susceptible to CCA, suggesting the involvement of host factors in cancer development. In addition, there are reports indicating differences in the locations of CCA.

Aim

This study aims to investigate cellular inflammatory responses in the common bile duct (CB), intrahepatic bile duct (IHB), and gallbladder (GB) in susceptible and non-susceptible hosts following O. viverrini infection.

Methods

Thirty Syrian golden hamsters (a susceptible host) and 30 BALB/c mice (a non-susceptible host) infected with O. viverrini were studied at six time points (five animals per group). Histopathological evaluations were conducted on samples from the IHB, CB, and GB. Inflammatory cell infiltration was quantitatively assessed and compared between groups and time points. Statistical analysis was performed using one-way ANOVA, with a significance level of p < 0.05.

Results

Inflammation was significantly more pronounced in the IHB compared to the other two biliary locations. In comparison between susceptible and non-susceptible hosts, the intensity of inflammation was higher in the OV+H group than in the OV+M group (p < 0.05).

Conclusion

This study highlights the association between host response to inflammation, tissue location, and host susceptibility, with the IHB showing particular susceptibility to inflammation and pathological changes. These findings contribute to our understanding of the increased risk of CCA in susceptible hosts.

Trematode Genomics and Proteomics

Trematode infections stand out as one of the frequently overlooked tropical diseases, despite their wide global prevalence and remarkable capacity to parasitize diverse host species and tissues. Furthermore, these parasites hold significant socio-economic, medical, veterinary and agricultural implications. Over the past decades, substantial strides have been taken to bridge the information gap concerning various "omic" tools, such as proteomics and genomics, in this field. In this edition of the book, we highlight recent progress in genomics and proteomics concerning trematodes with a particular focus on the advances made in the past 5 years. Additionally, we present insights into cutting-edge technologies employed in studying trematode biology and shed light on the available resources for exploring the molecular facets of this particular group of parasitic helminths.

Liver Flukes: Clonorchis and Opisthorchis

Clonorchis sinensis, Opisthorchis viverrini and O. felineus are liver flukes of human and animal pathogens occurring across much of Europe and Asia. Nevertheless, they are often underestimated compared to other, better known neglected diseases in spite of the fact that many millions of people are infected and hundreds of millions are at risk. This is possibly because of the chronic nature of the infection and disease and that it takes several decades prior to a life-threatening pathology to develop. Several studies in the past decade have provided more information on the molecular biology of the liver flukes which clearly lead to better understanding of parasite biology, systematics and population genetics. Clonorchiasis and opisthorchiasis are characterized by a chronic infection that induces hepatobiliary inflammation, especially periductal fibrosis, which can be detected by ultrasonography. These chronic inflammations eventually lead to cholangiocarcinoma (CCA), a usually fatal bile duct cancer that develops in some infected individuals. In Thailand alone, opisthorchiasis-associated CCA kills up to 20,000 people every year and is therefore of substantial public health importance. Its socioeconomic impacts on impoverished families and communities are considerable. To reduce hepatobiliary morbidity and CCA, the primary intervention measures focus on control and elimination of the liver fluke. Accurate diagnosis of liver fluke infections in both human and other mammalian, snail and fish intermediate hosts is important for achieving these goals. While the short-term goal of liver fluke control can be achieved by praziquantel chemotherapy, a comprehensive health education package targeting school children is believed to be more beneficial for a long-term goal/solution. It is recommended that transdisciplinary research or multisectoral control approach including one health and/or eco health intervention strategy should be applied to combat the liver flukes and hence contribute to reduction of CCA in endemic areas.

CP-673451, a Selective Platelet-Derived Growth Factor Receptor Tyrosine Kinase Inhibitor, Induces Apoptosis in Opisthorchis viverrini-Associated Cholangiocarcinoma via Nrf2 Suppression and Enhanced ROS

Platelet-derived growth factors (PDGFs) and PDGF receptors (PDGFRs) play essential roles in promoting cholangiocarcinoma (CCA) cell survival by mediating paracrine crosstalk between tumor and cancer-associated fibroblasts (CAFs), indicating the potential of PDGFR as a target for CCA treatment. Clinical trials evaluating PDGFR inhibitors for CCA treatment have shown limited efficacy. Furthermore, little is known about the role of PDGF/PDGFR expression and the mechanism underlying PDGFR inhibitors in CCA related to Opisthorchis viverrini (OV). Therefore, we examined the effect of PDGFR inhibitors in OV-related CCA cells and investigated the molecular mechanism involved. We found that the PDGF and PDGFR mRNAs were overexpressed in CCA tissues compared to resection margins. Notably, PDGFR-α showed high expression in CCA cells, while PDGFR-β was predominantly expressed in CAFs. The selective inhibitor CP-673451 induced CCA cell death by suppressing the PI3K/Akt/Nrf2 pathway, leading to a decreased expression of Nrf2-targeted antioxidant genes. Consequently, this led to an increase in ROS levels and the promotion of CCA apoptosis. CP-673451 is a promising PDGFR-targeted drug for CCA and supports the further clinical investigation of CP-673451 for CCA treatment, particularly in the context of OV-related cases.

Cost-Effectiveness Analysis of Ultrasound Surveillance for Cholangiocarcinoma in an Endemic Area of Thailand

OBJECTIVE

This research aimed to analyze the cost-effectiveness of ultrasound surveillance for Cholangiocarcinoma (CCA) in a high-risk population residing in the northern region of Thailand and compare these results with the non-surveillance patients who presented with CCA.

METHODS

This was a retrospective descriptive study of two groups monitored and treated for CCA in the same institute, but differing as to whether ultrasound was included in the surveillance. The ultrasound surveillance group comprised those who participated in the cohort study of CCA at Chulabhorn Hospital from 2011 to 2017. Whereas, the non-ultrasound surveillance group consisted of patients treated for CCA at Chulabhorn Hospital from 2009 to 2015 (and not part of the first group). Historical data and societal perspectives were analyzed and interpreted using a decision tree model. The results of one-way sensitivity analyses of probability and cost parameters affecting the change in incremental cost-effectiveness ratio (ICER) were analyzed and presented using tornado diagrams.

RESULT

The ultrasound surveillance group had the quality-adjusted life years gained (QALY gained) of 0.117 years, resulting in the incremental cost-effectiveness ratio (ICER) of 152,985 Thai Baht (THB) or equal to 4,222.6 US-dollars (USD) /QALY gained which is about when compared to the non-ultrasound surveillance group. Moreover, the ICER value was within the willingness to pay (WTP) calculated for Thailand of 4,416.2 USD (160,000 THB) /QALY gained.  The probability of non-diagnostic CCA in non-ultrasound surveillance group and the cost of abdominal ultrasound were found to be major factors affecting the ICER.

CONCLUSION

Ultrasound surveillance of CCA was cost-effective in Thailand. This information can be helpful for national policy planning in regard to Thai populations at high risk of CCA. Further study is recommended to assess cost-effectiveness in other areas with lower incidences of CCA.

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.

Tetraspanins from the liver fluke Opisthorchis viverrini stimulate cholangiocyte migration and inflammatory cytokine production

The liver fluke Opisthorchis viverrini (Poirier, 1886) (Digenea) secretes extracellular vesicles (EVs) bearing CD63-like tetraspanins on their surface. Fluke EVs are actively internalised by host cholangiocytes in the bile ducts, where they drive pathology and promote neoplasia through induction of cellular proliferation and secretion of inflammatory cytokines. We investigated the effects of tetraspanins of the CD63 superfamily by co-culturing recombinant forms of the large extracellular loop (LEL) of O. viverrini tetraspanin-2 (rLEL-Ov-TSP-2) and tetraspanin-3 (rLEL-Ov-TSP-3) with non-cancerous human bile duct (H69) and cholangiocarcinoma (CCA, M213) cell lines. The results showed that cell lines co-cultured with excretory/secretory products from adult O. viverrini (Ov-ES) underwent significantly increased cell proliferation at 48 hours but not 24 hours compared to untreated control cells (P < 0.05), whereas rLEL-Ov-TSP-3 co-culture resulted in significantly increased cell proliferation at both 24 hours (P < 0.05) and 48 hours (P < 0.01) time points. In like fashion, H69 cholangiocytes co-cultured with both Ov-ES and rLEL-Ov-TSP-3 underwent significantly elevated Il-6 and Il-8 gene expression for at least one of the time points assessed. Finally, both rLEL-Ov-TSP-2 and rLEL-Ov-TSP-3 significantly enhanced migration of both M213 and H69 cell lines. These findings indicated that O. viverrini CD63 family tetraspanins can promote a cancerous microenvironment by enhancing innate immune responses and migration of biliary epithelial cells.

Association of MICA Gene Polymorphism in Opisthorchis viverrini-Induced Periductal Fibrosis in Northeastern Thais

OBJECTIVE

Chronic Opisthorchis viverrini (OV) infection is the cause of advanced periductal fibrosis (APF), subsequently leading to cholangiocarcinoma (CCA). Natural killer (NK) cells can kill hepatic stellate cells (HSCs), the initiating cells for fibrosis formation, by using the interaction between the natural killer group 2 member D (NKG2D) receptor and its ligand on the HSCs. This can inhibit the fibrosis formation. Major histocompatibility complex class I chain-related A (MICA) is the ligand of the NKG2D receptor and has highly polymorphic characteristics that are involved in NKG2D binding and NK cell activation. This study aimed to investigate the polymorphism of MICA in OV-induced fibrosis.

METHOD

MICA typing was performed by polymerase chain reaction- sequence specific primer (PCR-SSP) and sequencing in two groups: OV infection without fibrosis (N = 99) and with fibrosis (N = 290).

RESULT

Six alleles were identified and the MICA*010 allele had the highest frequency in both groups. The MICA*00201-02 allele was a protective factor for fibrosis (OR= 0.508, 95%CI= 0.34-0.76, Pc <0.05), while the MICA*019 allele was suggested to be a risk allele for fibrosis (OR=1.95, 95%CI=1.25-3.03, Pc<0.005). In addition, two motifs, glycine (G) at position 14 and glutamine (Q) at position 251, were negatively associated with fibrosis (G14: OR=0.508, 95%CI=0.34-0.76, Pc <0.05 and Q251: OR=0.586, 95%CI=0.41-0.84, Pc <0.05). Moreover, the distribution of the MICA-129 genotype also showed the protective genotype (Pc<0.05, OR=0.319, 95%CI= 0.12-0.54) for fibrosis. The MICA*00201-02 allele encoded all these motifs, and this suggested that it might lead to strong NK cell activation to kill HSCs, subsequently preventing fibrosis formation.

CONCLUSION

This study described initial evidence suggesting that the polymorphism of the MICA gene might be a marker for OV-derived periductal fibrosis.

Neutrophils form extracellular traps in response to Opisthorchis viverrini crude antigens, which are elevated in neutrophils from opisthorchiasis patients with hepatobiliary abnormalities

Opisthorchis viverrini (Ov) infection can cause several disease conditions of the bile duct including hepatobiliary abnormalities (HBAs) and the most severe, cholangiocarcinoma (CCA). Fibrosis occurs when tissues are damaged and normal wound-healing responses are dysregulated. Neutrophils are the first cells to migrate to an infection site to protect the host from intruding extracellular pathogens through a wide range of effector mechanisms such as phagocytosis, production of reactive oxygen species, proteases, or release of neutrophil extracellular traps (NETs). In this work, we used confocal microscopy to assess whether Ov crude antigens can cause release of NETs from neutrophils from Ov-free individuals. We demonstrated for the first time that these antigens could induce release of NETs ex vivo in a dose-dependent manner from neutrophils isolated from Ov-free individuals. Intriguingly, when we measured NETs from neutrophils isolated from Ov-infected patients, we found increased spontaneous production of NETs in patients with HBAs. Interestingly, exposure to Ov crude antigens lowered the level of NETs released by neutrophils from patients with active Ov infection regardless of HBA status. We propose that in the case of acute Ov infection, even when concentration of Ov antigens is relatively low, neutrophils can form NETs. However, when this infection becomes chronic, manifesting as a definite HBA, the levels of NET production are reduced when treated with Ov crude antigens. Excessive production of proinflammatory mediators from these NETs might have effects on the parasites, but may also lead to excessive injury of surrounding tissues resulting in HBAs and may lead eventually to the most severe complications such as CCA.

Endoplasmic Reticulum Stress-Mediated Apoptosis Induced by VR12684 Isolated from Mallotus spodocarpus in Cholangiocarcinoma Cell Line

INTRODUCTION

Cholangiocarcinoma (CCA) is a poor prognosis of a malignant tumor that has been unresponsive to conventional chemotherapeutic agents. Effective and novel therapeutic agents are urgently needed. VR12684 (isolated from Mallotus spodocarpus) has been reported to exhibit growth inhibitory activities in cancer cell lines. The present study investigated the growth inhibitory mechanisms of this compound in a human CCA cell line (KKU-M156).

METHODS

The effects of VR12684 on anti‑proliferation, cell cycle arrest and apoptosis induction in CCA cells were demonstrated by SRB assay, flow cytometry, acridine orange/ethidium bromide (AO/EB) staining and western blot analysis.

RESULTS

Treatment with VR12684 decreased cell proliferation in a dose- and time-dependent manner in the KKU-M156 cell line. VR12684 induced cell cycle arrest in the G2 phase in KKU-M156 through down-regulation of cyclin B1 and Cdk1 and up-regulation of p21, p27 and p53 levels. VR12684 induced mitochondria-mediated apoptosis by increasing DNA fragmentation, the Bax/BCL-2 ratio and AIF, and decreasing survivin with subsequent activation of caspase-9 and -3. This compound could induce apoptosis through the endoplasmic reticulum (ER) stress-mediated pathway by up-regulation of GRP78, IRE1α and GADD153 levels leading to down-regulation of Bcl-2 and activation of calpain-1, caspase-7 and -12.

CONCLUSION

These results suggested that VR12684 inhibited KKU-M-156 cell growth by way of cell cycle arrest and induction of apoptosis, at least in part, through the mitochondria- and ER-associated intrinsic pathways. Such compounds warrant evaluation as a candidate for the treatment of human CCA.

Cancerogenic parasites in veterinary medicine: a narrative literature review

Parasite infection is one of the many environmental factors that can significantly contribute to carcinogenesis and is already known to be associated with a variety of malignancies in both human and veterinary medicine. However, the actual number of cancerogenic parasites and their relationship to tumor development is far from being fully understood, especially in veterinary medicine. Thus, the aim of this review is to investigate parasite-related cancers in domestic and wild animals and their burden in veterinary oncology. Spontaneous neoplasia with ascertained or putative parasite etiology in domestic and wild animals will be reviewed, and the multifarious mechanisms of protozoan and metazoan cancer induction will be discussed.

Cystatins from the Human Liver Fluke Opisthorchis viverrini: Molecular Characterization and Functional Analysis

A high incidence of cholangiocarcinoma (bile duct cancer) has been observed in Thailand. This usually rare cancer has been associated with infection with the human liver fluke, Opisthorchis viverrini. Secretions of the parasite that interact with the host are thought to be a major component of its pathogenicity and proteolysis is a key biological activity of the secreted molecules. In this study, we present a molecular analysis of cysteine proteinase inhibitors (cystatins) of Opisthorchis viverrini. Six cDNA coding sequences of Opisthorchis viverrini cystatins, OvCys1-6, were cloned from the adult stage of the parasite using RT-PCR. Based on their sequences, OvCys1 and OvCys2 are classified as type 1 cystatins, while OvCys3-6 are classified as type 2 cystatins, with each containing a signal peptide and only one C-terminal disulfide bond. Their C-terminal region sequences are diverse compared with other cystatin members. Cystatins OvCys1, 3 and 4 were found in crude worm extracts and excretory-secretory (ES) products from the adult parasite using Western blot detection, while the other isoforms were not. Thus, OvCys1, 3 and 4 were selected for inhibition analysis and immune reactivity with Opisthorchis viverrini-infected hamster sera. OvCys1, 3, and 4 inhibited mammalian cathepsin L more effectively than cathepsin B. The pH range for their full activity was very wide (pH 3-9) and they were heat stable for at least 3 h. Unlike Fasciola gigantica cystatins, they showed no immune reactivity with infected hamster sera based on indirect ELISA. Our findings suggest that Opisthorchis viverrini cystatins are not major antigenic components in the ES product of this parasite and that other effects of Opisthorchis viverrini cystatins should be investigated.

Intestinal helminth infections and associated risk factors among adults in the Lao People's Democratic Republic

BACKGROUND

Helminthiases are highly endemic in Southeast Asia, including the Lao People's Democratic Republic (Lao PDR). This study aimed to assess the current intestinal helminth infections and the associated risk factors among adults across the Lao PDR.

METHODS

A cross-sectional survey was conducted in 165 villages across 17 provinces and the Vientiane Capital, Lao PDR. A multi-stage sampling method was employed to select the adult study participants (≥ 18 years). Data collection included (1) interview of the study participants, (2) physical measurements, and (3) a five gram of stool sample from each study participant was collected and preserved in 10% formalin solution for intestinal helminth detection using formalin-ether concentration technique (FECT). Descriptive analysis was used to describe the socio-demographic characteristics of study participants and the prevalence of intestinal helminth infections. Logistic regressions were applied to test the association between intestinal helminth infection and individual risk factors. A P-value below 0.05 was considered statistically significant.

RESULTS

A total of 2800 study participants were enrolled. Their average age was 46.0 years; 57.8% were female. Overall, 30.9%, 8.6% and 1.5% of study participants were infected with one, two, or three different intestinal helminth species, respectively. Among the study participants 21.6% were infected with hookworm, 18.8% with Opisthorchis viverrini-like (Ov-like) infection, 4.8% with Strongyloides stercoralis, 2.3% with Ascaris lumbricoides, 1.5% with Trichuris trichiura, and 3.3% with Taenia spp. Ov-like infection was of high prevalence in the southern (28.8%) and central (21.3%) provinces, while hookworm (26.3%), A. lumbricoides (7.3%), T. trichiura (3.1%), and Taenia spp. (4.2%) were prevalent in the northern provinces. Risk analysis showed that men were more likely to be infected with hookworm [adjusted odds ratio (aOR) = 1.2, P = 0.019]. The Lao-Tai ethnic group had a 5.2-times (P < 0.001) higher chance of having Ov-like infection than the minorities. Possession of toilet facility at home was associated with reduced odds for Ov-like (aOR = 0.4, P < 0.001) and hookworm (aOR = 0.6, P < 0.001) infections.

CONCLUSIONS

Our study provides a nationwide update of the intestinal helminth prevalence among adults in Lao PDR. To the best of our knowledge, this is the first Lao nationwide survey on intestinal helminth infections and risk factors in adults. It provides crucial information for national control programs for intestinal helminth infections in Lao PDR.

Tetraspanins from Opisthorchis viverrini stimulate cholangiocyte migration and inflammatory cytokine production

The liver fluke Opsithorchis viverrini secretes extracellular vesicles (EVs) bearing CD63-like tetraspanins on their surface. Fluke EVs are actively internalized by host cholangiocytes in the bile ducts, where they drive pathology and promote neoplasia through induction of cellular proliferation and secretion of inflammatory cytokines. We investigated the effects of tetraspanins of the CD63 superfamily by co-culturing recombinant forms of the large extracellular loop (LEL) of O. viverrini tetraspanin-2 (rLEL- Ov -TSP-2) and tetraspanin-3 (rLEL- Ov -TSP-3) with non-cancerous human bile duct (H69) and cholangiocarcinoma (CCA, M213) cell lines. The results showed that cell lines co-cultured with excretory/secretory products from adult O. viverrini ( Ov- ES) underwent significantly increased cell proliferation at 48 hours but not 24 hours compared to untreated control cells ( P <0.05), whereas rLEL- Ov -TSP-3 co-culture resulted in significantly increased cell proliferation at both 24 hr ( P <0.05) and 48 hr ( P <0.01) time points. In like fashion, H69 cholangiocytes co-cultured with both Ov -ES and rLEL- Ov -TSP-3 underwent significantly elevated Il-6 and Il-8 gene expression for at least one of the time points assessed. Finally, both rLEL- Ov -TSP-and rLEL- Ov -TSP-3 significantly enhanced migration of both M213 and H69 cell lines. These findings indicated that O. viverrini CD63 family tetraspanins can promote a cancerous microenvironment by enhancing innate immune responses and migration of biliary epithelial cells.

Mutational Landscape of Cholangiocarcinoma According to Different Etiologies: A Review

Recent next-generation sequencing (NGS) studies on large cohorts of cholangiocarcinoma (CCA) patients have clearly revealed the extreme intra- and inter-tumoral molecular heterogeneity that characterizes this malignancy. The lack of a stereotyped molecular signature in CCA makes the identification of actionable therapeutic targets challenging, making it mandatory to have a better understanding of the origin of such heterogeneity in order to improve the clinical outcome of these patients. Compelling evidence has shown that the CCA genomic landscape significantly differs according to anatomical subtypes and the underlying etiology, highlighting the importance of conducting molecular studies in different populations of CCA patients. Currently, some risk factors have been recognized in CCA development, while others are emerging from recent epidemiological studies. Nevertheless, the role of each etiologic factor in driving CCA genetic heterogeneity still remains unclear, and available studies are limited. In an attempt to shed more light on this issue, here we review the current literature data on the mutational spectrum of this disease according to different etiologies.

Polymorphism of genes encoding drug-metabolizing and inflammation-related enzymes for susceptibility to cholangiocarcinoma in Thailand

BACKGROUND

Cholangiocarcinoma (CCA) is an intractable cancer, and its incidence in northeastern Thailand is the highest worldwide. Infection with the liver fluke Opisthorchis viverrini (OV) has been associated with CCA risk. However, animal experiments have suggested that OV alone does not induce CCA, but its combination with a chemical carcinogen like nitrosamine can cause experimentally induced CCA in hamsters. Therefore, in humans, other environmental and genetic factors may also be involved.

AIM

To examine relations between risk for CCA and genetic polymorphisms in carcinogen-metabolizing and inflammation-related genes.

METHODS

This hospital-based case-control study enrolled 95 case-control pairs matched by age (± 5 years) and sex. We examined relations between risk for CCA and genetic polymorphisms in carcinogen-metabolizing and inflammation-related genes, serum anti-OV, alcohol consumption, and smoking. Polymorphisms of CYP2E1, IL-6 (-174 and -634), IL-10 (-819), and NF-κB (-94) and their co-occurrence with polymorphisms in the drug-metabolizing enzyme gene GSTT1 or GSTM1 were also analyzed.

RESULTS

Although CCA risk was not significantly associated with any single polymorphism, persons with the GSTT1 wild-type and CYP2E1 c1/c2 + c2/c2 genotype had an increased risk (OR = 3.33, 95%CI: 1.23-9.00) as compared with persons having the GSTT1 wild-type and CYP2E1 c1/c1 wild genotype. The presence of anti-OV in serum was associated with a 7- to 11-fold increased risk, and smoking level was related to an OR of 1.5-1.8 in multivariable analyses adjusted for each of the seven genetic polymorphisms.

CONCLUSION

In addition to infection with OV, gene-gene interactions may be considered as one of the risk factors for CCA development.

Current prevalence and geographic distribution of helminth infections in the parasitic endemic areas of rural Northeastern Thailand

BACKGROUND

Helminth infection is a global health issue that not only causes acute helminthiasis but long-term infection may lead to complicated symptoms as well as severe complications. The World Health Organization cooperated with the Ministry of Public Health in many countries, particularly where high prevalence, spending a lot of resources for limiting the infection. In Thailand, the incidence of parasitic helminth infections was continuously declined in the last few decades according to several campaigns for parasitic elimination. However, the rural community in the northeast of Thailand where the highest prevalence of the country still needs to be monitored. This present study aims to report the current prevalence of parasitic helminth infections in Nakhon Ratchasima and Chaiyaphum provinces where sharing a huge area of the northeastern region of Thailand but only a few studies have been published.

METHODS

The stool specimens were collected from 11,196 volunteers and processed by modified Kato-Katz thick smear, PBS-ethyl acetate concentration techniques, and PCR. The epidemiological data were collected, analyzed, and used for generating of parasitic hotspots.

RESULTS

The results indicated that O. viverrini remains the major parasite in this area with a total prevalence of 5.05% followed by Taenia spp., Hookworms, T. trichiura, and Echinostoma spp., respectively. Mueang district of Chaiyaphum province has the highest prevalence especially O. viverrini with a prevalence of 7.15% that higher than the latest national surveillance. Interestingly, the prevalence of O. viverrini was hugely reported (more than 10%) in five subdistricts. The geographic localization of O. viverrini infections revealed that a lot of water reservoirs such as the lakes or branches of the river in the two-most prevalent subdistricts. Our finding indicated that gender and age were insignificantly different.

CONCLUSION

This finding suggested that the parasitic helminth infection in the rural areas of northeast of Thailand remains high and the housing location is a major contributing factor for the parasitic infection.

The predictive value of lymphocyte to monocyte ratio for overall survival in cholangiocarcinoma patients with hepatic resection

BACKGROUND

There is considerable heterogeneity in clinical behavior and survival outcomes in patients with cholangiocarcinoma (CCA), and the prognosis of CCA patients is poor. We proposed lymphocyte to monocyte ratio (LMR) as a novel prognostic element for CCA patients with hepatic resection in present study.

METHODS

By retrospectively analyzing the clinical data of 145 CCA patients with hepatic resection, we determined the optimal LMR cutoff value according to the receiver operating characteristic (ROC). We comparatively analyzed the clinical features of CAA patients between low LMR group and high LMR group, mainly including overall survival (OS) analysis by using the Kaplan-Meier method, univariate and multivariate Cox regression.

RESULTS

We found there was a longer OS in CCA patients of the high LMR group than the low LMR group. The total median OS of cholangiocarcinoma patients were 13.6 months, and the OS of low LMR group was markedly lower than the high LMR group. The 1-year, 3-year, and 5-year OS of high LMR group were respectively 62.9%, 32.4%, and 16.4%, and were significantly higher the cholangiocarcinoma patients of low LMR group (40.2%, 16.4%, and 0%). Multivariate regression analyses showed that preoperative cholangitis, elevated CEA level and nerve invasion were risk factors for the OS of cholangiocarcinoma patients, while the high LMR level and postoperative treatment were protective factors for the OS of cholangiocarcinoma patients.

CONCLUSIONS

Preoperative LMR was a vital prognostic factor to predict the prognosis of CCA patients with hepatic resection and provided additional prognostic value beyond standard clinicopathological parameters.

The Debate between the Human Microbiota and Immune System in Treating Aerodigestive and Digestive Tract Cancers: A Review

The human microbiota comprises a group of microorganisms co-existing in the human body. Unbalanced microbiota homeostasis may impact metabolic and immune system regulation, shrinking the edge between health and disease. Recently, the microbiota has been considered a prominent extrinsic/intrinsic element of cancer development and a promising milestone in the modulation of conventional cancer treatments. Particularly, the oral cavity represents a yin-and-yang target site for microorganisms that can promote human health or contribute to oral cancer development, such as Fusobacterium nucleatum. Moreover, Helicobacter pylori has also been implicated in esophageal and stomach cancers, and decreased butyrate-producing bacteria, such as Lachnospiraceae spp. and Ruminococcaceae, have demonstrated a protective role in the development of colorectal cancer. Interestingly, prebiotics, e.g., polyphenols, probiotics (Faecalibacterium, Bifidobacterium, Lactobacillus, and Burkholderia), postbiotics (inosine, butyrate, and propionate), and innovative nanomedicines can modulate antitumor immunity, circumventing resistance to conventional treatments and could complement existing therapies. Therefore, this manuscript delivers a holistic perspective on the interaction between human microbiota and cancer development and treatment, particularly in aerodigestive and digestive cancers, focusing on applying prebiotics, probiotics, and nanomedicines to overcome some challenges in treating cancer.

Opisthorchis Felineus Infection is a Risk Factor for Cholangiocarcinoma in Western Siberia: A Hospital-based Case-control Study

BACKGROUND

Cholangiocarcinoma (CCA), a fatal bile duct cancer, has a high incidence in Western Siberia, Russian Federation. In addition, Opisthorchis felineus, a bile duct-dwelling trematode liver fluke is highly endemic. Closely related species have been shown to be cancerogenic agents in Asia. We therefore examined the association between O felineus infection and CCA in Western Siberia.

METHODS

We conducted a hospital-based, individually matched case-control study between January 2017 and August 2020 in Tomsk Oblast and Khanty-Mansiysk Autonomous Okrug, Yugra, Russian Federation. Histologically confirmed CCA patients (cases) were compared with matched age, sex, and place of residence hospital controls. The examination of study participants included the diagnosis of current and past O felineus infection, abdominal ultrasonographical assessment, physical examination, and interview on exposures to potential risk factors.

RESULTS

We identified 40 patients with CCA and 160 controls. Exposures to O felineus infection was strongly associated with CCA (odds ratio [OR], 3.9; 95% confidence interval [CI], 1.4-10.8; P = .008). Also, cases reported more often that they were currently or in the past were infected by O felineus compared with controls (OR, 4.03; 95% CI, 1.7-9.5; P = .001). Furthermore, cases reported river fish consumption and fishing habits significantly more often than controls (OR, 5.5; 95% CI, 1.5-19.8; P = .009 and OR, 3.3; 95% CI, 1.4-7.7; P = .005).

CONCLUSIONS

The study results revealed a strong significantly increased risk for CCA development in O felineus-infected individuals. Elaboration of the guidelines on screening programs for early CCA diagnosis, prevention, and treatment is socially important in endemic regions.

Diagnosis of helminths depends on worm fecundity and the distribution of parasites within hosts

Helminth transmission and morbidity are dependent on the number of mature parasites within a host; however, observing adult worms is impossible for many natural infections. An outstanding challenge is therefore relating routine diagnostics, such as faecal egg counts, to the underlying worm burden. This relationship is complicated by density-dependent fecundity (egg output per worm reduces due to crowding at high burdens) and the skewed distribution of parasites (majority of helminths aggregated in a small fraction of hosts). We address these questions for the carcinogenic liver fluke Opisthorchis viverrini, which infects approximately 10 million people across Southeast Asia, by analysing five epidemiological surveys (n = 641) where adult flukes were recovered. Using a mechanistic model, we show that parasite fecundity varies between populations, with surveys from Thailand and Laos demonstrating distinct patterns of egg output and density-dependence. As the probability of observing faecal eggs increases with the number of mature parasites within a host, we quantify diagnostic sensitivity as a function of the worm burden and find that greater than 50% of cases are misdiagnosed as false negative in communities close to elimination. Finally, we demonstrate that the relationship between observed prevalence from routine diagnostics and true prevalence is nonlinear and strongly influenced by parasite aggregation.

Receptors of immune cells mediates recognition for tumors

Over the last few decades, the immune system has been steered toward eradication of cancer cells with the help of cancer immunotherapy. T cells, B cells, monocytes/macrophages, dendritic cells, T-reg cells, and natural killer (NK) cells are some of the numerous immune cell types that play a significant part in cancer cell detection and reduction of inflammation, and the antitumor response. Briefly stated, chimeric antigen receptors, adoptive transfer and immune checkpoint modulators are currently the subjects of research focus for successful immunotherapy-based treatments for a variety of cancers. This chapter discusses ongoing investigations on the mechanisms and recent developments by which receptors of immune cells especially that of lymphocytes and monocytes/macrophages regulate the detection of immune system leading to malignancies. We will also be looking into the treatment strategies based on these mechanisms.

Epidemiology and Control of Opisthorchis viverrini Infection: Implications for Cholangiocarcinoma Prevention

It is known that Opisthorchis viverrini (OV) is the most significant risk factor for the development of cholangiocarcinoma (CCA); hence, it is also known as carcinogenic parasite. Effective control and elimination of OV infection should significantly reduce O. viverrini-related CCA. This chapter includes details of the three recently developed innovative tools, namely the Isan cohort database software, an OV-RDT for screening of O. viverrini, and an ultrasound telecommunication system. Past and current control programs, i.e., education, medication, and sanitation were discussed and stressed the need for a comprehensive control program which encompasses primary, secondary, and tertiary patient care programs for confirmation and management of suspected CCA cases. The approach of mathematical modeling for control of OV and CCA was also briefly described. Additionally, we highlighted the current progress toward control of OV and CCA in Thailand and potential for expansion into nearby countries in Southeast Asia.

Jagged-1/Notch Pathway and Key Transient Markers Involved in Biliary Fibrosis during Opisthorchis felineus Infection

Chronic opisthorchiasis associated with Opisthorchis felineus infection is accompanied by severe fibrotic complications. It is of high practical significance to elucidate the mechanisms of hepatic fibrosis in chronic infection dynamics. The goal of the study is to investigate the temporal profile of key markers and the Jagged1/Notch signaling pathway in the implementation of fibrosis in a chronic O. felineus infection. For the first time, using histological methods and real-time PCR analysis, we demonstrated the activation of the Jagged1/Notch pathway in liver fibrogenesis, including the activation of the Hes1 and Hey1 target genes during experimental opisthorchiasis in Mesocricetus auratus. Cluster analysis followed by regression analysis of key markers during the infection showed that Jagged1 and Mmp9have the greatest contribution to the development of cholangiofibrosis and periductal fibrosis. Moreover, we detected a significant increase in the number of Jagged1-positive cells in the liver of chronic opisthorchiasis patients compared to that of the control group without infection. The results of the study are extremely informative both in terms of investigation both diverse fibrosis mechanisms as well as potential targets in complex antihelmintic therapy.

Prevalence and Risk Factors of Opisthorchis viverrini Infection in Sakon Nakhon Province, Thailand

Opisthorchiasis is a parasitic infection caused by the liver fluke Opisthorchis viverrini. This parasite is widely distributed and well documented in Thailand, Lao PDR, Southern Vietnam, Cambodia, and Myanmar. However, its prevalence is a major problem in these countries. Thus, the aim of this study was to determine the prevalence and risk factors of O. viverrini infection from 2017 to 2020 in Sakon Nakhon province, Thailand. Questionnaires were used to interview 320 participants (160 cases and 160 controls) in a random selection of 18 districts across Sakon Nakhon province. Univariate logistic regression was used to identify the factors associated with O. viverrini infection. The overall prevalence levels of O. viverrini infection in Sakon Nakhon province for 2018, 2019, and 2020 were 3.60%, 5.21%, and 7.01%, respectively. Raw fish consumption was a positive risk factor for its infection in endemic areas. Factors associated with O. viverrini infection were the habit of consuming unsafely prepared fish (OR = 6.33, 95%CI = 0.32–0.59), the medical history of O. viverrini examination (OR = 8.93, 95%CI = 5.15–15.47), a history of O. viverrini infection (OR = 3.64, 95%CI = 1.17–1.44), and a history of taking praziquantel (OR = 3.64, 95%CI = 1.17–1.44). These results identified gaps in the epidemiological knowledge of O. viverrini in this region that need addressing to identify and develop innovative methods for prevention, control, and support efforts to permanently overcome O. viverrini infection in endemic regions.

Curcumin-loaded nanocomplexes ameliorate the severity of nonalcoholic steatohepatitis in hamsters infected with Opisthorchis viverrini

Background

Comorbidity of Opisthorchis viverrini (OV) infection and nonalcoholic fatty-liver disease (NAFLD) enhances NAFLD progression to nonalcoholic steatohepatitis (NASH) by promoting severe liver inflammation and fibrosis. Here, we investigated the effect of supplementation with curcumin-loaded nanocomplexes (CNCs) on the severity of NASH in hamsters.

Methodology

Hamsters were placed in experimental groups as follows: fed standard chow diet (normal control, NC); fed only high-fat and high-fructose (HFF) diet; O. viverrini-infected and fed HFF diet (HFFOV); group fed with blank nanocomplexes (HFFOV+BNCs); groups fed different doses of CNCs (25, 50 and 100 mg/kg body weight: HFFOV+CNCs25; HFFOV+CNCs50; HFFOV+CNCs100, respectively) and a group given native curcumin (HFFOV+CUR). All treatment were for three months.

Results

The HFF group revealed NAFLD as evidenced by hepatic fat accumulation, ballooning, mild inflammation and little or no fibrosis. These changes were more obvious in the HFFOV group, indicating development of NASH. In contrast, in the HFFOV+CNCs50 group, histopathological features indicated that hepatic fat accumulation, cell ballooning, cell inflammation and fibrosis were lower than in other treatment groups. Relevantly, the expression of lipid-uptake genes, including fatty-acid uptake (cluster of differentiation 36), was reduced, which was associated with the lowering of alanine aminotransferase, total cholesterol and triglyceride (TG) levels. Reduced expression of an inflammation marker (high-mobility group box protein 1) and a fibrosis marker (alpha smooth-muscle actin) were also observed in the HFFOV+CNCs50 group.

Conclusion

CNCs treatment attenuates the severity of NASH by decreasing hepatic steatosis, inflammation, and fibrosis as well as TG synthesis. CNCs mitigate the severity of NASH in this preclinical study, which indicates promise for future use in patients.

Similarities and differences among the Opisthorchiidae liver flukes: insights from Opisthorchis felineus

The foodborne liver trematode Opisthorchis felineus (Rivolta, 1884) is a member of the triad of phylogenetically related epidemiologically important Opisthorchiidae trematodes, which also includes O. viverrini (Poirier, 1886) and Clonorchis sinensis (Loos, 1907). Despite similarity in the life cycle, Opisthorchiidae liver flukes also have marked differences. Two species (O. viverrini and C. sinensis) are recognized as Group 1A biological carcinogens, whereas O. felineus belongs to Group 3A. In this review, we focus on these questions: Are there actual differences in carcinogenicity among these 3 liver fluke species? Is there an explanation for these differences? We provide a recent update of our knowledge on the liver fluke O. felineus and highlight its differences from O. viverrini and C. sinensis. In particular, we concentrate on differences in the climate of endemic areas, characteristics of the life cycle, the range of intermediate hosts, genomic and transcriptomic features of the pathogens, and clinical symptoms and morbidity of the infections in humans. The discussion of these questions can stimulate new developments in comparative studies on the pathogenicity of liver flukes and should help to identify species-specific features of opisthorchiasis and clonorchiasis pathogenesis.

Knockout of liver fluke granulin, Ov-grn-1, impedes malignant transformation during chronic infection with Opisthorchis viverrini

Infection with the food-borne liver fluke Opisthorchis viverrini is the principal risk factor for cholangiocarcinoma (CCA) in the Mekong Basin countries of Thailand, Lao PDR, Vietnam, Myanmar and Cambodia. Using a novel model of CCA, involving infection with gene-edited liver flukes in the hamster during concurrent exposure to dietary nitrosamine, we explored the role of the fluke granulin-like growth factor Ov-GRN-1 in malignancy. We derived RNA-guided gene knockout flukes (ΔOv-grn-1) using CRISPR/Cas9/gRNA materials delivered by electroporation. Genome sequencing confirmed programmed Cas9-catalyzed mutations of the targeted genes, which was accompanied by rapid depletion of transcripts and the proteins they encode. Gene-edited parasites colonized the biliary tract of hamsters and developed into adult flukes. However, less hepatobiliary tract disease manifested during chronic infection with ΔOv-grn-1 worms in comparison to hamsters infected with control gene-edited and mock-edited parasites. Specifically, immuno- and colorimetric-histochemical analysis of livers revealed markedly less periductal fibrosis surrounding the flukes and less fibrosis globally within the hepatobiliary tract during infection with ΔOv-grn-1 genotype worms, minimal biliary epithelial cell proliferation, and significantly fewer mutations of TP53 in biliary epithelial cells. Moreover, fewer hamsters developed high-grade CCA compared to controls. The clinically relevant, pathophysiological phenotype of the hepatobiliary tract confirmed a role for this secreted growth factor in malignancy and morbidity during opisthorchiasis.

General overview of the current status of human foodborne trematodiasis

Foodborne trematodes (FBT) of public health significance include liver flukes (Clonorchis sinensis, Opisthorchis viverrini, O. felineus, Fasciola hepatica and F. gigantica), lung flukes (Paragonimus westermani and several other Paragonimus spp.) and intestinal flukes, which include heterophyids (Metagonimus yokogawai, Heterophyes nocens and Haplorchis taichui), echinostomes (Echinostoma revolutum, Isthmiophora hortensis, Echinochasmus japonicus and Artyfechinostomum malayanum) and miscellaneous species, including Fasciolopsis buski and Gymnophalloides seoi. These trematode infections are distributed worldwide but occur most commonly in Asia. The global burden of FBT diseases has been estimated at about 80 million, however, this seems to be a considerable underestimate. Their life cycle involves a molluscan first intermediate host, and a second intermediate host, including freshwater fish, crustaceans, aquatic vegetables and freshwater or brackish water gastropods and bivalves. The mode of human infection is the consumption of the second intermediate host under raw or improperly cooked conditions. The major pathogenesis of C. sinensis and Opisthorchis spp. infection includes inflammation of the bile duct which leads to cholangitis and cholecystitis, and in a substantial number of patients, serious complications, such as liver cirrhosis and cholangiocarcinoma, may develop. In lung fluke infections, cough, bloody sputum and bronchiectasis are the most common clinical manifestations. However, lung flukes often migrate to extrapulmonary sites, including the brain, spinal cord, skin, subcutaneous tissues and abdominal organs. Intestinal flukes can induce inflammation in the intestinal mucosa, and they may at times undergo extraintestinal migration, in particular, in immunocompromised patients. In order to control FBT infections, eating foods after proper cooking is strongly recommended.

The role of helminths in the development of non-communicable diseases

Non-communicable diseases (NCDs) like cardiovascular disease, chronic respiratory diseases, cancers, diabetes, and neuropsychiatric diseases cause significant global morbidity and mortality which disproportionately affect those living in low resource regions including low- and middle-income countries (LMICs). In order to reduce NCD morbidity and mortality in LMIC it is imperative to understand risk factors associated with the development of NCDs. Certain infections are known risk factors for many NCDs. Several parasitic helminth infections, which occur most commonly in LMICs, have been identified as potential drivers of NCDs in parasite-endemic regions. Though understudied, the impact of helminth infections on the development of NCDs is likely related to helminth-specific factors, including species, developmental stage and disease burden. Mechanical and chemical damage induced by the helminth in combination with pathologic host immune responses contribute to the long-term inflammation that increases risk for NCD development. Robust studies from animal models and human clinical trials are needed to understand the immunologic mechanisms of helminth-induced NCDs. Understanding the complex connection between helminths and NCDs will aid in targeted public health programs to reduce helminth-induced NCDs and reduce the high rates of morbidity that affects millions of people living in parasite-endemic, LMICs globally.

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.

Comparison of Cholangiocarcinoma and Hepatocellular Carcinoma Incidence Trends from 1993 to 2012 in Lampang, Thailand

Liver cancer is the most common cancer in Northern Thailand, mainly due to the dietary preference for raw fish, which can lead to infection by the parasite, O. viverrini, a causal agent of cholangiocarcinoma. We conducted a temporal trend analysis of cross-sectional incidence rates of liver cancer in Lampang, Northern Thailand. Liver cancer data from 1993–2012 were extracted from Lampang Cancer Registry. The multiple imputation by chained equations method was used to impute missing histology data. Imputed data were analyzed using Joinpoint and age-period-cohort (APC) models to characterize the incidence rates by gender, region, and histology, considering hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA). We observed a significant annual increase in CCA incidence and a considerable decrease in HCC incidence for both genders in Lampang. The APC analysis suggested that CCA incidence rates were higher in older ages, younger cohorts, and later years of diagnosis. In contrast, HCC incidence rates were higher in older generations and earlier years of diagnosis. Further studies of potential risk factors of CCA are needed to better understand and address the increasing burden of CCA in Lampang. Our findings may help to draw public attention to cholangiocarcinoma prevention and control in Northern Thailand.

Persistent advanced periductal fibrosis is associated with cagA-positive Helicobacter pylori infection in post-praziquantel treatment of opisthorchiasis

BACKGROUND

Liver fluke infection caused by Opisthorchis viverrini is associated with several hepatobiliary diseases including advanced periductal fibrosis (APF) and cholangiocarcinoma. Recently, we demonstrated a persistent APF in over one-third of opisthorchiasis patients after worm removal by praziquantel (PZQ) treatment. However, the underlying mechanism(s) of this phenomena is unclear. Given a co-infection with Helicobacter pylori (H. pylori) especially cagA-positive strain enhances APF, we hypothesized that H. pylori with CagA virulent factor contributes to persistent APF.

MATERIALS AND METHODS

Seventy-five opisthorchiasis patients who underwent ultrasonography and treatment with PZQ were recruited in the 2-year follow-up study. Helicobacter and its cagA in the feces were examined by conventional and qPCR. Correlations between prevalence or bacterial loads of Helicobacter spp., H. pylori, and cagA-positive H. pylori before and after PZQ treatment were analyzed among resolved, slowly resolved, relapsed, and persistent APF groups.

RESULTS

Overall, prevalence of Helicobacter spp., H. pylori, and cagA-positive H. pylori declined after PZQ treatment. However, only the prevalence and bacterial loads of cagA-positive H. pylori detected at 2-year post-treatment were significantly lower than those before treatment (p < .05). In addition, both prevalence and bacterial loads of cagA-positive H. pylori were significantly lower in the resolved APF group after PZQ treatment, while there were no significant changes in the slowly resolved, relapsed, and persistent APF groups. Among the APF subgroups, cagA-positive H. pylori prevalence in both relapsed and persistent APF groups were significantly higher than the resolved APF group.

CONCLUSION

The results support our hypothesis that H. pylori, especially cagA-positive strain, contributes to the relapsed and persistent APF. A supplementary antibiotic treatment for H. pylori to reduce persistent APF and eventually CCA is warranted.

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.

Global changes in gene expression related to Opisthorchis felineus liver fluke infection reveal temporal heterogeneity of a mammalian host response

The food-borne trematode Opisthorchis felineus colonizes bile ducts of the liver of fish-eating mammals including humans. Among chronically infected individuals, this opisthorchiasis involves hepatobiliary problems, including chronic inflammation, periductal fibrosis, biliary intraepithelial neoplasia, and even cholangiocarcinoma. Despite numerous studies at the pathomorphological level, the systemic response and cellular pathogenesis of these disorders are not well studied.

To conduct in-depth research and to gain insights into the mechanism by which O. felineus infection causes precancerous liver lesions, we (i) applied a next-generation-sequencing–based technology (high-throughput mRNA sequencing) to identify differentially expressed genes in the liver of golden hamsters infected with O. felineus at 1 and 3 months postinfection and (ii) verified the most pronounced changes in gene expression by western blotting and immunohistochemistry.

A total of 2151 genes were found to be differentially expressed between uninfected and infected hamsters (“infection” factor), whereas 371 genes were differentially expressed when we analyzed “time × infection” interaction. Cluster analysis revealed that sets of activated genes of cellular pathways were different between acute (1 month postinfection) and chronic (3 months postinfection) opisthorchiasis. This enriched KEGG pathways were “Cell adhesion molecules”, “Hippo signaling”, “ECM-receptor interaction”, “Cell cycle”, “TGF-beta”, and “P53 signaling”. Moreover, epithelial–mesenchymal transition was the most enriched (q-value = 2.2E-07) MSigDB hallmark in the set of differentially expressed genes of all O. felineus–infected animals. Transcriptomic data were supported by the results of western blotting and immunohistochemistry revealing the upregulation of vimentin, N-cadherin, and α-smooth muscle actin postinfection.

Our data expand knowledge about global changes in gene expression in the O. felineus–infected host liver and contribute to understanding the biliary neoplasia associated with the liver fluke infection.

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A total of 2151 genes were found to be differentially expressed during the infection.

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Epithelial-Mesenchymal Transition was the most enriched process in the infected animals.

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Different pathways were activated between acute and chronic opisthorchiasis.