Clonorchis sinensis excretory-secretory products increase malignant characteristics of cholangiocarcinoma cells in three-dimensional co-culture with biliary ductal plates

Clonorchis sinensis and Cholangiocarcinoma

Clonorchiasis is a parasitic disease caused by Clonorchis sinensis, a trematode that inhabits the intrahepatic bile ducts of humans and mammals. C. sinensis is one of common food-borne trematodes, prevalent in East Asia including Korea. The International Agency for Research on Cancer reclassified C. sinensis as the Group 1 biological carcinogen of human cholangiocarcinoma (CCA). Evidence supporting the carcinogenicity of C. sinensis includes epidemiological studies showing increased prevalence and odds ratio (OR) of CCA in clonorchiasis patients, the development of CCA in experimental animals, and molecular studies. Approximately 10% of CCA in Korea are believed to be solely caused by clonorchiasis, with an OR of 4.7 for CCA risk among clonorchiasis patients. All hamsters exposed to both of C. sinensis and N-nitrosodimethylamine (NDMA) developed CCA while those exposed to either C. sinensis or NDMA alone did not. In vitro studies using cell models investigated carcinogenetic changes of the intracellular molecules and genes following stimulation with a soluble extract of C. sinensis. The in vitro stimulated cells showed a significant shift to G2/M phage, produced oncogenic molecules, changed expression of oncogenes, increased cell proliferation and suppressed apoptosis. Additionally, the gap-junction proteins between cells, such as connexin (Cx) 43, Cx 26, and Cx 32, were changed significantly, disrupting intercellular homeostasis. These findings suggest that C. sinensis and nitrogen compounds synergistically stimulate the cholangiocytes to become neoplastic. C. sinensis is a biological carcinogen of human CCA, and the World Health Organization guidelines enlist food-borne trematodes as one of target neglected tropical diseases to be eliminated by 2030. The present article reviews and updates perspectives on clonorchiasis, focusing on carcinogenesis.

Correlation analysis of the impact of Clonorchis sinensis juvenile on gut microbiota and transcriptome in mice

Clonorchiasis remains a non-negligible global zoonosis, imposing serious socio-economic burdens in endemic regions. The interplay between gut microbiota and the host transcriptome is crucial for maintaining health; however, the impact of Clonorchiasis sinensis juvenile infection on these factors is still poorly understood. This study aimed to investigate their relationship and potential pathogenic mechanisms. The BALB/c mouse model of early infection with C. sinensis juvenile was constructed. Pathological analyses revealed that C. sinensis juvenile triggered liver inflammation, promoted intestinal villi growth, and augmented goblet cell numbers in the ileum. Additionally, the infection altered the diversity and structure of gut microbiota, particularly affecting beneficial bacteria that produce short-chain fatty acids, such as Lactobacillus and Muribaculaceae, and disrupted the Firmicutes/Bacteroidetes ratio. Gut transcriptome analysis demonstrated an increase in the number of differentially expressed genes (DEGs) as infection progressed. Enriched Gene Ontology items highlighted immune and detoxification-related processes, including immunoglobulin production and xenobiotic metabolic processes. Kyoto Encyclopedia of Genes and Genomes pathway analysis further indicated involvement in circadian rhythm, as well as various detoxification and metabolic-related pathways (e.g., glutathione metabolism and glycolysis/gluconeogenesis). Prominent DEGs associated with these pathways included Igkv12-41, Mcpt2, Arntl, Npas2, Cry1, and Gsta1. Correlation analysis additionally identified Bacteroides_sartorii as a potential key regulator in the interaction between gut microbiota and transcriptome. This study sheds light on the alterations in gut microbiota and transcriptome in mice following C. sinensis juvenile infection, as well as their correlation, laying a foundation for a better understanding of their interaction during infection.

IMPORTANCE

This study highlighted the impact of C. sinensis juvenile infection on the gut microbiota and transcriptome of BALB/c mice. It induced liver inflammation, promoted intestinal villi growth, and altered goblet cell numbers. The infection also disrupted the diversity and structure of gut microbiota, particularly affecting beneficial bacteria. Transcriptome analysis revealed increased expression of genes related to immune response and detoxification processes. Important pathways affected included circadian rhythm, glutathione metabolism, and glycolysis/gluconeogenesis. Notable genes implicated included Igkv12-41, Mcpt2, Arntl, Npas2, Cry1, and Gsta1. Bacteroides_sartorii emerged as a potential key regulator in this interaction.

Genus Bithynia: morphological classification to molecular identification

Snails of the genus Bithynia, whose primary habitat is slow-flowing ponds and ditches, serve as the first intermediate hosts of liver fluke. Currently, approximately 200 million individuals worldwide are at risk of liver fluke infection, yet questions still persist regarding the taxonomic identification of Bithynia genus, a crucial player in the transmission of this disease. Accurate taxonomic classification of the Bithynia genus could significantly enhance current understanding of the disease's transmission mechanisms. In this article we comprehensively review the extensive research conducted on Bithynia genus, spanning past inquiries up to the latest findings. The primary emphasis is placed on exploring the taxonomic identification of this genus within various technological settings. We then present a consolidated analysis of the morphological taxonomic identification methods, highlighting their strengths and limitations. We also introduce a novel perspective on the future direction of identification and classification efforts for the members of this genus, emphasizing the crucial role Bithynia plays in the epidemiological cycle of liver fluke transmission. We conclude by urging researchers to prioritize the significance of the members of this genus in the epidemiological cycle of liver fluke transmission and in control measures for disease dissemination, within the context of the vector organisms.

The role of helminths and their antigens in cancer therapy: insights from cell line models

BACKGROUND

Recent articles have explored the effect of worms on cancer cells. This review focused on various cell cultures employed to understand which cells are more commonly and less utilized.

METHODS

The present review analyzed studies published between 2013 and 2023 to obtain information about different cell cultures used in cancer studies involving helminths. Databases such as PubMed, Google Scholar, HINARI, and the Cochrane Library were searched.

RESULTS

This search yielded 130 records, but 97 papers were excluded because they were either irrelevant to the research topic (n = 72) or contradicted the research idea (n = 25).The remaining twenty-one articles focused on different types of worms, such as Echinococcus granulosus, Clonorchis sinensis, Opisthorchis felineus, Opisthorchis viverrini, Trichinella spiralis, Toxocara canis, and Heligmosomoides polygyrus.

CONCLUSION

Due to the presence of numerous antigens, parasites at different growth stages can impact various cells through unknown mechanisms. Given the high diversity of antigens and their effects, artificial intelligence can assist in predicting initial outcomes for future studies.

Prevalence and species identification of trematode metacercariae in Qiqihar, Northeast China

Fishborne trematode (FBT) is an important group of parasites that are endemic worldwide to a certain extent. However, despite the epidemiological significance, the species and phylogenetic evolution characteristics of FBT metacercariae have not been well studied. In this study, a total of 600 Pseudorasbora parva (P. parva) specimens were collected from Qiqihar, 61.8% (371/600) were found to be infected with trematode metacercariae. A total of three kinds of trematodes metacercariae were obtained, and they were identified as Clonorchis sinensis (C. sinensis), Metorchis orientalis (M. orientalis), and Metorchis taiwanensis (M. taiwanensis) by morphological and phylogenetic analysis with infection rates of 47.7% (286/600), 15.5% (93/600), and 23.7% (142/600), respectively. Meanwhile, a survey of the three trematodes metacercariae showed that the infection rate of C. sinensis metacercariae was the highest in September, up to 66% (66/100), and the lowest in June at 26% (26/100). The infection rate of M. orientalis metacercariae was the highest in October at 26% (26/100) and the lowest in June at 5% (5/100). The infection rate of M. taiwanensis metacercariae was at its peak in November at 36% (36/100) and the lowest in July at 15% (15/100). The co-infection of metacercariae of C. sinensis and M. taiwanensis was the most common and reached a peak in October, and their infection rate was higher in autumn than in summer. The peak of infection intensity of metacercariae for C. sinensis, M. orientalis, and M. taiwanensis were different: C. sinensis was 24/g in September, M. orientalis was 7/g in October, and M. taiwanensis was 10/g in November. From the above results, it was confirmed that three species of trematodes metacercaria played an important role in infection of second intermediate hosts in Qiqihar region. Studying the morphological characteristics and sequencing the ITS2 gene for a phylogenetic tree of them will be useful for future molecular evolution, biology, and ecology of trematode metacercariae.

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.

Clonorchis sinensis infection amplifies hepatocellular carcinoma stemness, predicting unfavorable prognosis

BACKGROUND

Extensive evidence links Clonorchis sinensis (C. sinensis) to cholangiocarcinoma; however, its association with hepatocellular carcinoma (HCC) is less acknowledged, and the underlying mechanism remains unclear. This study was designed to investigate the association between C. sinensis infection and HCC and reveal the relationship between C. sinensis infection and cancer stemness.

METHODS

A comprehensive analysis of 839 HCC patients categorized into C. sinensis (-) HCC and C. sinensis (+) HCC groups was conducted. Chi-square and Mann-Whitney U tests were used to assess the association between C. sinensis infection and clinical factors. Kaplan-Meier and Cox regression analyses were used to evaluate survival outcomes. Immunohistochemistry was used to determine CK19 and EpCAM expression in HCC specimens.

RESULTS

Compared to C. sinensis (-) HCC patients, C. sinensis (+) HCC patients exhibited advanced Barcelona Clinic Liver Cancer (BCLC) stage, higher male prevalence and more liver cirrhosis as well as elevated alpha-fetoprotein (AFP), carbohydrate antigen 19-9 (CA19-9), eosinophil, complement 3 (C3), and complement 4 (C4) values. C. sinensis infection correlated with shorter overall survival (OS) (p < 0.05) and recurrence-free survival (RFS) (p < 0.05). Furthermore, Cox multivariate analysis revealed that C. sinensis infection was an independent prognostic factor for OS in HCC patients. Importantly, C. sinensis infection upregulated the expression of HCC cancer stem cell markers CK19 and EpCAM.

CONCLUSION

HCC patients with C. sinensis infection exhibit a poor prognosis following hepatectomy. Moreover, C. sinensis infection promotes the acquisition of cancer stem cell-like characteristics, consequently accelerating the malignant progression of HCC.

AUTHOR SUMMARY

Clonorchis sinensis (C. sinensis) is a prominent food-borne parasite prevalent in regions such as China, particularly in Guangxi. C. sinensis has been associated with various hepatobiliary system injuries, encompassing inflammation, periductal fibrosis, cholangiocarcinoma and even hepatocellular carcinoma (HCC). A substantial body of evidence links C. sinensis to cholangiocarcinoma, However, the connection between C. sinensis and HCC and the intricate mechanisms underlying its contribution to HCC development remain incompletely elucidated. Our study demonstrates clear clinicopathological associations between C. sinensis and HCC, such as gender, BCLC stage, liver cirrhosis, MVI, AFP, CA19-9, circulating eosinophils and complements. Furthermore, we found that the co-occurrence of C. sinensis exhibited a significant association with shorter OS and RFS in patients diagnosed with HCC. A major finding was that C. sinensis infection promotes the acquisition of cancer stem cell-like characteristics, consequently accelerating the malignant progression of HCC. Our results provide a more comprehensive comprehension of the interplay between C. sinensis and HCC, shedding fresh light on the carcinogenic potential of C. sinensis.

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.

A comparative study of clinicopathological and imaging features of HBV-negative and HBV-positive intrahepatic cholangiocarcinoma patients with different pathologic differentiation degrees

Hepatitis B is a risk factor for the development of intrahepatic cholangiocarcinoma. The prognosis of HBV-related ICC remains to be further investigated. To investigate the clinical, pathological and imaging features of intrahepatic cholangiocarcinoma of hepatitis B virus-positive and -negative patients. Data from January 31, 2012 to December 31, 2019 of 138 patients were retrospectively analyzed. The patients were divided into hepatitis B virus-positive group (group A[n = 66]) and virus-negative group (group B[n = 72]), and the patients were divided into groups according to pathological differentiation degree and tumor size. The differences in clinical, imaging characteristics and the progression-free survival between groups were analyzed. There were significant differences in gender, age, HBc antibody, CA125 and AFP, tumor distribution site, maximum diameter, plain scan density, inferior hepatic angle, peritumoral bile duct dilatation, vascular encasement invasion, intrahepatic bile duct dilatation and lymphadenopathy between the two groups (P < 0.05); There were statistical differences in signs of vascular encasement invasion between the two groups with well-to-moderately differentiated tumors (P < 0.05); there were statistical differences in tumor density uniformity, signs of vascular encasement invasion and lymphadenopathy between the two groups with poorly differentiated tumors (P < 0.05). Large groups A and B showed differences in tumor density uniformity, vascular encasement invasion, arterial phase, overall reinforcement pattern, peritumoral bile duct stones and biliary dilatation (P < 0.05). There was no statistical difference in postoperative PFS between the two groups (P > 0.05). The clinical and imaging features of ICC of hepatitis B virus-positive and -negative patients are different, and there is little difference in postoperative disease-free survival time.

Organoid: Bridging the gap between basic research and clinical practice

Nowadays, the diagnosis and treatment system of malignant tumors has increasingly tended to be more precise and personalized while the existing tumor models are still unable to fully meet the needs of clinical practice. Notably, the emerging organoid platform has been proven to have huge potential in the field of basic-translational medicine, which is expected to promote a paradigm shift in personalized medicine. Here, given the unique advantages of organoid platform, we mainly explore the prominent role of organoid models in basic research and clinical practice from perspectives of tumor biology, tumorigenic microbes-host interaction, clinical decision-making, and regenerative strategy. In addition, we also put forward some practical suggestions on how to construct a new generation of organoid platform, which is destined to vigorously promote the reform of basic-translational medicine.

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.

The Truman Show for Human Helminthic Parasites: A Review of Recent Advances in In Vitro Cultivation Platforms

Throughout history, parasites and parasitic diseases have been humankind's constant companions, as evidenced by the findings of tapeworm eggs in ancient, mummified remains. Helminths are responsible for causing severe, long-term, and debilitating infectious diseases worldwide, especially affecting economically challenged nations due to prevailing deficits in access to sanitation, proper hygiene practices, and healthcare infrastructure. Socio-ecological drivers, such as poverty, migration, and climate change, continue to contribute to parasites and their disease vectors being spread beyond known endemic zones. The study of parasitic diseases has had a fair amount of success leading to the development of new chemotherapeutic agents and the implementation of parasite eradication programs. However, further progress in this direction has been hampered by the challenges of culturing some of these parasites in in vitro systems for efficient availability, basic life cycle, infection studies, and effectiveness of novel treatment strategies. The complexity of the existing models varies widely, depending on the parasite and its life cycle, ranging from basic culture methods to advanced 3D systems. This review aims to highlight the research conducted so far in culturing and maintaining parasites in an in vitro setting, thereby contributing to a better understanding of pathogenicity and generating new insights into their lifecycles in the hopes of leading to effective treatments and prevention strategies. This work is the first comprehensive outline of existing in vitro models for highly transmissible helminth diseases causing severe morbidity and mortality in humans globally.

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.

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.

Clonorchis sinensis aggravates biliary fibrosis through promoting IL-6 production via toll-like receptor 2-mediated AKT and p38 signal pathways

Clonorchis sinensis is an important food-borne zoonotic parasite which has been linked to biliary fibrosis and cholangiocarcinoma. However, the details of the pathogenesis of C. sinensis were unclear. To explore the role and regulatory mechanism of toll-like receptor 2 (TLR2) in C. sinensis-induced biliary fibrosis, we established the C. sinensis-infected C57BL/6 mouse model with TLR2-/- and wild type (WT) mice. The mortality rate, liver lesions, TLR2 and TGF-β1 expression, phosphorylation of Smad2/3, AKT, p38, ERK and p65, and cytokine productions were analyzed. Furthermore, similar parameters were examined in mouse biliary epithelial cells (BECs) co-cultured with C. sinensis excretory/secretory proteins (ESPs). The results showed that TLR2 expression was enhanced significantly in C. sinensis-infected WT mice and mouse BECs. C. sinensis-infected TLR2-/- mice exhibited an increased weight and a decreased mortality rate; significantly alleviated liver lesions and biliary fibrosis, reduced numbers of myofibroblasts; decreased expression of TGF-β1 and phosphorylation level of AKT, p38 and Smad2/3; significantly decreased production of IL-6, TNF-α and IL-4, while increased production of IFN-γ compared with C. sinensis-infected WT mice. Furthermore, C. sinensis ESPs could activate TLR2-mediated AKT and p38 pathways to increase the production of IL-6 in mouse BECs. In conclusion, these data indicate that C. sinensis infection activated TGF-β1-Smad2/3 through TLR2-mediated AKT and p38 pathways to promote IL-6 production, which resulted in myofibroblast activation and aggravating biliary fibrosis in mice.

Clonorchis sinensis infection induces hepatobiliary injury via disturbing sphingolipid metabolism and activating sphingosine 1-phosphate receptor 2

Clonorchis sinensis (C. sinensis) infection induces severe hepatobiliary injuries, which can cause inflammation, periductal fibrosis, and even cholangiocarcinoma. Sphingolipid metabolic pathways responsible for the generation of sphingosine-1-phosphate (S1P) and its receptor S1P receptors (S1PRs) have been implicated in many liver-related diseases. However, the role of S1PRs in C. sinensis-mediated biliary epithelial cells (BECs) proliferation and hepatobiliary injury has not been elucidated. In the present study, we found that C. sinensis infection resulted in alteration of bioactive lipids and sphingolipid metabolic pathways in mice liver. Furthermore, S1PR2 was predominantly activated among these S1PRs in BECs both in vivo and in vitro. Using JTE-013, a specific antagonist of S1PR2, we found that the hepatobiliary pathological injuries, inflammation, bile duct hyperplasia, and periductal fibrosis can be significantly inhibited in C. sinensis-infected mice. In addition, both C. sinensis excretory-secretory products (CsESPs)- and S1P-induced activation of AKT and ERK1/2 were inhibited by JTE-013 in BECs. Therefore, the sphingolipid metabolism pathway and S1PR2 play an important role, and may serve as potential therapeutic targets in hepatobiliary injury caused by C. sinensis-infection.

Clonorchis sinensis infection modulates key cytokines for essential immune response impacted by sex

Infection with helminths can modulate the host immune response, which ultimately shape morbidity and mortality of the associated diseases. We studied key cytokines for essential immune response in sera from 229 southeastern China individuals infected with Clonorchis sinensis and 60 individuals without C. sinensis infection, and measured serum specific IgG and IgE against worms in these people. Individuals infected with C. sinensis had significantly higher antigen-specific IgG and IgE levels, which were positively correlated with egg counts in feces. However, less enhancement of IgE antibody was observed in females when compared to males with similar infection levels. C. sinensis infection caused diminished Th1 cytokines (IL-1β, IL-2, IL-12p70, IFN-γ and TNF-α), Th2 cytokine (IL-4), as well as Th17 cytokine (IL-17A) in sera, which showed decreasing trend by infection intensity. Notably, these phenotypes were more significant in females than those in males. Although C. sinensis infection is associated with the development of hepatobiliary diseases, there was no significant correlation between the dampened cytokine profiles and the hepatobiliary morbidities. Our study indicates C. sinensis infection is strongly related to the immune suppression in human. Sex differences shape the immune milieus of clonorchiasis. This study provides a better understanding of how worms affect immune responses and cause a long-term immune alternation in humans with C. sinensis infection.

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.

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.

Marked elevation of serum alpha-fetoprotein following Clonorchis sinensis infection: A rare case report

Clonorchiasis, also known as the liver fluke disease, is caused by eating raw freshwater fish or shrimps that contain Clonorchis sinensis cyst larvae, which mainly involves the hepatobiliary system. Chronic abdominal pain and distention, loss of appetite, and hepatomegaly are the most common clinical manifestation. Persistent infection with Clonorchis sinensis would result in chronic inflammation, epithelial hyperplasia, and periductal fibrosis and even progress to cholangiocarcinoma. Nevertheless, the majority of the infected people are asymptomatic or mildly symptomatic, contributing to its high misdiagnosis rate. Alpha-fetoprotein (AFP) is a well-known biomarker for hepatocellular carcinoma (HCC). A high level of AFP can also be caused by several benign diseases, causing confusion and influencing treatment decisions. So far, clonorchiasis with a markedly elevated level of AFP has been rarely reported. We present a case of clonorchiasis with a high level of AFP in a 52-year-old man. We hope to raise clinical awareness of this food-borne disease. Clonorchiasis should be considered in patients with extremely high levels of AFP, excluding HCC and germ cell tumors, especially if the patient has a history of ingesting raw freshwater fish or shrimps.

Autophagy of hepatic stellate cell induced by Clonorchis sinensis

BACKGROUND

Clonorchis sinensis was a food-borne zoonotic parasite in the worldwide and also an important risk factor of hepatic fibrosis. Excretory/secretion products of C. sinensis (CsESPs) are involved in parasite-host interactions and contribute to the development of hepatic damage. The aim of the present study was to investigate whether CsESPs and CsTP (adult protein) could induce autophagy of hepatic stellate cells (HSCs) and further activate HSCs so as to participate in the pathogenesis of hepatic fibrosis.

METHODS AND RESULTS

The human hepatic stellate cell line LX-2 was stimulated by CsESPs and CsTP. CsESPs showed the effect on cell proliferation in methyl thiazolyl tetrazolium (MTT) assay while CsTP failed. Autophagosomes and autolysosomes were observed after the transmission mRFP-EGFP-LC3 plasmid into the LX-2 cells. CsESPs had more powerful to induce the accumulation of autophagosomes and autolysosomes to enhance autophagic flux compared with CsTP. Western-blotting analysis confirmed that the ratio of LC3-II/I in LX-2 cells was up-regulated after CsESPs treatment for 6 h, which further proved that CsESPs could induce autophagy in LX-2 cells. Meanwhile, q-PCR results showed that the mRNA levels of collagen I, collagen III and α-SMA decreased in LX-2 cells after treatment with autophagy inhibitor chloroquine, whereas they increased when combination with CsESPs.

CONCLUSIONS

These results suggested that CsESPs-induced autophagy might be involved in the activation of HSCs, and consequently participate in the pathogenesis of hepatic fibrosis caused by C. sinensis infection.

Hematological, immunological, and polyamines alterations in the concomitant occurrence of Fasciola gigantica and hepatic leiomyoma in cattle

No previous studies have investigated the polyamines alterations during fascioliasis due to F. gigantica in ruminants. This study was therefore carried out to find out the possible relationship between the extent of liver destruction and leiomyoma and some hematological and immunological parameters and polyamines alterations in F. gigantica infection. Fifty cattle with liver fascioliasis and fifteen healthy cattle were selected for the study. For the histopathological study, liver tissue samples were stained with hematoxylin and eosin (H&E) and Masson's Trichrome methods. The leiomyoma suspected specimens were immunohistochemically stained for smooth muscle actin and desmin. Different hematological parameters were investigated in infected and non-infected animals. Furthermore, levels of putrescine, spermidine, and spermine were measured in homogenized liver samples. Serum IL-4 and TNF-α levels were also evaluated. By histological examination, the lesions were noted in all the infected specimens. These lesions were varied from leiomyoma, chronic catarrhal cholangitis, arteriosclerosis, telangiectasia, and fresh migratory tunnels filled with RBC and eosinophils. Comparison of hemogram results between infected and non-infected groups revealed a significant decrease in red blood cell counts (RBC), mean corpuscular hemoglobin concentration (MCHC), and platelet count (PLT) in infected animals. Also, a significant elevation in mean corpuscular volume (MCV) concentration was detected in infected animals. The putrescine and spermine levels of the infected animals were significantly higher than the non-infected animals. Although spermidine was increased in infected livers, its elevation was not significant. Based on the results, the level of IL-4 and TNF-α was not significantly changed in infected animals. In conclusion, the concurrent occurrence of leiomyoma and fascioliasis due to F. gigantica and polyamines elevation (putrescine and spermine) is reported for the first time. The role of polyamines in the concurrent occurrence of leiomyoma and fascioliasis is an area for future research.

Biliary Migration, Colonization, and Pathogenesis of O. viverrini Co-Infected with CagA+ Helicobacter pylori

Co-infection with the cagA strain of Helicobacter pylori exacerbates the pathology of human liver fluke Opisthorchis viverrini (OV) infection leading to cholangiocarcinoma. However, underlying mechanisms remain unclear. We report a significant increase in cagA-positive and cagA-negative H. pylori in the stomach, blood, bile, and in the OV worms of co-infected Syrian golden hamsters at one hour, three hours, and one month, post-infection, compared to hamsters infected with either OV or H. pylori alone. Except in the worms, H. pylori numbers declined at three months post-infection, particularly in the bile fluid of co-infected animals. Both strains of H. pylori were immunohistochemically detected in the tegument of the worm, as well as in the bile duct epithelium when co-infected with O. viverrine, but not in H. pylori infection alone. Interestingly, only the cagA-positive strain was detected in the gut of the worm. Co-infection between cagA-positive H. pylori and O. viverrini resulted in a more severe biliary pathology and decreased E-cadherin expression in vivo and in vitro than those of the cagA-negative strain. These data suggest that O. viverrini acts as a carrier of cagA-positive H. pylori and co-migrates to the bile ducts, whereas O. viverrini facilitates H. pylori colonization and enhances the biliary pathogenesis and carcinogenesis.

The m6A writers regulated by the IL-6/STAT3 inflammatory pathway facilitate cancer cell stemness in cholangiocarcinoma

OBJECTIVE

Investigation of the regulatory mechanisms of cell stemness in cholangiocarcinoma (CCA) is essential for developing effective therapies to improve patient outcomes. The purpose of this study was to investigate the function and regulatory mechanism of m6A modifications in CCA cell stemness.

METHODS

Interleukin 6 (IL-6) treatment was used to induce an inflammatory response, and loss-of-function studies were conducted using mammosphere culture assays. Chromatin immunoprecipitation, polysome profiling, and methylated RNA immunoprecipitation analyses were used to identify signaling pathways. The in vitro findings were verified in a mice model.

RESULTS

We first identified that m6A writers were highly expressed in CCAs and further showed that STAT3 directly bound to the gene loci of m6A writers, showing that IL-6/STAT3 signaling regulated expressions of m6A writers. Downregulating m6A writers prevented cell proliferation and migration in vitro and suppressed CCA tumorigenesis in vivo. Notably, the knockdown of m6A writers inhibited CCA cell stemness that was triggered by IL-6 treatment. Mechanistically, IGF2BP2 was bound to CTNNB1 transcripts, significantly enhancing their stability and translation, and conferring stem-like properties. Finally, we confirmed that the combination of m6A writers, IGF2BP2, and CTNNB1 distinguished CCA tissues from normal tissues.

CONCLUSIONS

Overall, this study showed that the IL-6-triggered inflammatory response facilitated the expressions of m6A writers and cell stemness in an m6A-IGF2BP2-dependent manner. Furthermore, the study showed that m6A modification was a targetable mediator of the response to inflammation factor exposure, was a potential diagnostic biomarker for CCA, and was critical to the progression of CCA.

Omega-Class Glutathione Transferases of Carcinogenic Liver Fluke, Clonorchis sinensis, Modulate Apoptosis and Differentiation of Host Cholangiocytes

The small liver fluke Clonorchis sinensis causes hepatobiliary ductal infections in humans. Clonorchiasis is characterized histopathologically by ductal dysplasia, hyperplasia and metaplasia, which closely resembles cholangiocarcinoma (CCA). The disruption of programmed cell death is critical for malignant transformation, while molecular events underlying these phenomena have poorly been understood in clonorchiasis-related CCA tumorigenesis. We incorporated recombinant C. sinensis omega-class glutathione transferase (rCsGSTo) 1 or 2 into human intrahepatic biliary epithelial cells (HIBECs) and analyzed pathophysiological alterations of HIBECs upon the application of oxidative stress. rCsGSTos partially but significantly rescued HIBECs from cell death by inhibiting oxidative stress-induced apoptosis (p < 0.01). rCsGSTos modulated transcriptional levels of numerous genes. We analyzed 13 genes involved in programmed cell death (the upregulation of five antiapoptotic and two apoptotic genes, and the downregulation of one antiapoptotic and five apoptotic genes) and 11 genes associated with cell differentiation (the increase in seven and decrease in four genes) that showed significant modifications (p < 0.05). The induction profiles of the mRNA and proteins of these differentially regulated genes correlated well with each other, and mostly favored apoptotic suppression and/or cell differentiation. We detected increased active, phosphorylated forms of Src, PI3K/Akt, NF-κB p65, MKK3/6 and p38 MAPK, but not JNK and ERK1/2. CsGSTos were localized in the C. sinensis-infected rat cholangiocytes, where cytokeratin 19 was distributed. Our results demonstrated that CsGSTos excreted to the biliary lumen are internalized and accumulated in the host cholangiocytes. When cholangiocytes underwent oxidative stressful condition, CsGSTos appeared to be critically involved in both antiapoptotic process and the differentiation of host cholangiocytes through the regulation of target genes following the activation of responsible signal molecules.

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.

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.

Microbiome dysbiosis in cancer: Exploring therapeutic strategies to counter the disease

Cancer being a multiplex disease which involves many genomic and physiological alterations that occur consistently in the cancerous tissue, making the treatment and management of the disease even more complicated. The human gut microbiota (GM) harbors collective genomes of microbes comprising of trillions of bacteria along with fungi, archaea, and viruses that have the tendency to affect the development and progression of cancer. Moreover, inter-microbial interactions, diversity and distinct differences among the GM populations could influence the course of disease, making the microbiome an ideal target or to be modulated in such a way so as to improve cancer therapeutics with better efficacy and reduced toxicity. Current review focuses upon exploring the association of gut microbiota with the progression of cancer for which a structured search of bibliographic databases for peer-reviewed research literature has been carried out using focused review questions and inclusion/exclusion criteria. Through this review one could envisage a wide-spectrum role of microbiota in maintaining host metabolism, immune homeostasis paving the way for an anticancer diagnostic and therapeutic solution that has the potential to counter the menace of anti-cancer drug resistance as well.

In vivo and in vitro studies using Clonorchis sinensis adult-derived total protein (CsTP) on cellular function and inflammatory effect in mouse and cell model

Clonorchis sinensis (C. sinensis) can induce a food-borne parasitic disease (clonorchiasis). Numerous studies have analyzed functional proteins, immunologic factors, pro-inflammatory cytokines, and cell signaling transduction that promote the development of clonorchiasis. In a previous study, it was shown that C. sinensis adult-derived total protein (CsTP) might be involved in the pathogenesis and development of liver fibrosis via bringing about Th2 immune response. In the present study, further investigation of CsTP on cellular function and inflammatory effect in vitro and in vivo has been elicited. CsTP induced inflammation and autophagy as evidenced by upregulation of TNF-α, IFN-γ, and autophagic markers LC3B and P62. Exposed to CsTP upregulated the antiapoptotic gene Bcl-2 expression, diminished the apoptosis induced by H₂O₂, but promoted the proliferation and migration of LX-2 cells in proper concentration range. Additionally, the protein levels of p-AKT and p-mTOR were repressed in response to CsTP, suggesting a correlation of blocking the activation of mTOR/AKT signaling pathway. These results revealed that CsTP might exacerbate hepatic pathological changes by regulating cell proliferation, apoptosis, autophagy, and inflammation in the liver and LX-2 cells. Some effects might be partially involved in the mTOR and AKT pathways.

Liver fluke granulin promotes extracellular vesicle-mediated crosstalk and cellular microenvironment conducive to cholangiocarcinoma

Crosstalk between malignant and neighboring cells contributes to tumor growth. In East Asia, infection with the liver fluke is a major risk factor for cholangiocarcinoma (CCA). The liver fluke Opisthorchis viverrini secretes a growth factor termed liver fluke granulin, a homologue of the human progranulin, which contributes significantly to biliary tract fibrosis and morbidity. Here, extracellular vesicle (EV)-mediated transfer of mRNAs from human cholangiocytes to naïve recipient cells was investigated following exposure to liver fluke granulin. To minimize the influence of endogenous progranulin, its cognate gene was inactivated using CRISPR/Cas9-based gene knock-out. Several progranulin-depleted cell lines, termed ΔhuPGRN-H69, were established. These lines exhibited >80% reductions in levels of specific transcript and progranulin, both in gene-edited cells and within EVs released by these cells. Profiles of extracellular vesicle RNAs (evRNA) from ΔhuPGRN-H69 for CCA-associated characteristics revealed a paucity of transcripts for estrogen- and Wnt-signaling pathways, peptidase inhibitors and tyrosine phosphatase related to cellular processes including oncogenic transformation. Several CCA-specific evRNAs including MAPK/AKT pathway members were induced by exposure to liver fluke granulin. By comparison, estrogen, Wnt/PI3K and TGF signaling and other CCA pathway mRNAs were upregulated in wild type H69 cells exposed to liver fluke granulin. Of these, CCA-associated evRNAs modified the CCA microenvironment in naïve cells co-cultured with EVs from ΔhuPGRN-H69 cells exposed to liver fluke granulin, and induced translation of MAPK phosphorylation related-protein in naïve recipient cells in comparison with control recipient cells. Exosome-mediated crosstalk in response to liver fluke granulin promoted a CCA-specific program through MAPK pathway which, in turn, established a CCA-conducive disposition.

Clonorchis sinensis and clonorchiasis

Clonorchis sinensis is a fish-borne trematode that inhabits the bile duct of mammals including humans. Clonorchiasis is prevalent in China, Korea, and Vietnam, and 15-20 million people are estimated to be infected by this fluke. Freshwater snails act as the first intermediate host for the proliferation of C. sinensis larvae and shed the cercariae into water. The cercariae penetrate the skin of freshwater fish and transform to metacercariae. Humans are infected by eating raw or undercooked freshwater fish as dishes of filet, "sashimi," or congee, which contain C. sinensis metacercariae. In humans, the C. sinensis metacercariae excyst in the duodenum, and juvenile flukes migrate up via bile chemotaxis into bile ducts. Once there, C. sinensis provokes hyperplasia of the bile duct epithelium, obstructive jaundice, ascites, liver enlargement and cirrhosis, and infrequent cholangiocarcinoma (CCA). Although the association between C. sinensis infection and CCA has been firmly established in past decades, the underlying mechanisms are not elucidated in detail. In the context of chronic clonorchiasis-associated hepatobiliary aberrations, the constitutive disruption of redox homeostasis and dysregulation of physiological signaling pathways may promote the malignant transformation of cholangiocytes, thus leading to substantial acquisition of a more aggressive phenotype by these cells: CCA. With advances of genomic and molecular biological approaches, diverse C. sinensis proteins that are essential for parasite physiology and pathogenicity have been identified and characterized. Some of the proteins have been considered as attractive targets for development of vaccines and chemotherapeutics. Candidate antigens for reliable serodiagnosis of clonorchiasis have been studied.