Clonorchis sinensis infestation promotes three-dimensional aggregation and invasion of cholangiocarcinoma cells

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.

An integrated microfluidic system for automatic detection of cholangiocarcinoma cells from bile

Cholangiocarcinoma (CCA) is an aggressive cancer that originates from the epithelial cells lining the bile ducts. Due to its location deep within the body and nonspecific symptoms in the early stages, it is often diagnosed at the advanced stage, thus leading to worse prognosis. Circulating tumor cells within liquid biopsies (i.e. blood) have been considered as promising biomarkers for CCA diagnosis, though current methods for profiling them are not satisfactory in terms of sensitivity and specificity. Herein we developed a new cancer cell probing and immuno-tracking assay known as "CAPTURE", which was performed on an integrated microfluidic system (IMS) to automate CCA diagnosis from bile with a sample amount of only 1 mL. The assay utilized magnetic beads surface-coated with two affinity reagents, a nucleic acid aptamer (HN16) and a glycosaminoglycan (SCH 45-mix), for capturing cancer cells in bile; the "gold standard" anti-epithelial cell adhesion molecule was used as a comparison. In a single-blind test of 54 CCA-positive (+) and 102 CCA-negative (-) clinical samples, sensitivities and specificities of 96 and 80%, respectively, were documented with the CAPTURE assay on-bench. An IMS composed of a centrifugal module for sample pretreatment and a CAPTURE module for cell capture and staining was integrated with a new "vertical integration module" for detecting cancer cells from bile without human intervention. Furthermore, a novel micro-tier structure within the centrifugal module was designed to block passage of gallbladder stones with diameters >1 mm, thereby preventing their interference during the subsequent CAPTURE assay. Improved sensitivity and specificity (100 & 83%, respectively) by using three affinity reagents were achieved on the IMS when using 26 clinical bile samples, confirming its clinical bio-applicability for CCA diagnosis. This approach could be therefore used for early-stage CCA diagnostics, ideally enabling effective treatment, as well as reducing potential for relapse.

Babesia microti Infection Inhibits Melanoma Growth by Activating Macrophages in Mice

Babesia microti is an obligate intraerythrocytic protozoan transmitted by an Ixodes tick. Infections caused by protozoa, including Plasmodium yoelii and Toxoplasma gondii, are shown to inhibit tumor development by activating immune responses. Th1 immune response and macrophages not only are essential key factors in Babesia infection control but also play an important role in regulating tumor development. In this study, we investigated the effects of B. microti infection on melanoma in tumor-bearing mice. The results showed that B. microti infection could inhibit the growth of melanoma, significantly enlarge the spleen size (p ≤ 0.0001), and increase the survival period (over 7 days) of tumor-bearing mice. Mouse spleen immune cell analysis revealed that B. microti-infected tumor-bearing mice could increase the number of macrophages and CD4+ T cells, as well as the proportion of CD4+ T cells and M1 macrophages in the tumor. Immunohistochemical assays showed that B. microti infection could inhibit tumor angiogenesis (p ≤ 0.0032). Meanwhile, both B. microti-infected erythrocytes and culture supernatant were observed to significantly (p ≤ 0.0021) induce the mRNA expression of iNOS, IL-6, and TNF-α in macrophages. Moreover, B. microti culture supernatant could also repolarize IL-4-induced M2 macrophages to the M1 type. Overall, B. microti exerted antitumor effects by stimulating the immune system of tumor-bearing mice and inducing the polarization of immunosuppressive M2 macrophages to pro-inflammatory M1 macrophages.

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.

Pathogens and Carcinogenesis: A Review

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

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.

Expanded complement of Niemann-Pick type C2-like protein genes in Clonorchis sinensis suggests functions beyond sterol binding and transport

Background

The parasitic flatworm Clonorchis sinensis inhabits the biliary tree of humans and other piscivorous mammals. This parasite can survive and thrive in the bile duct, despite exposure to bile constituents and host immune attack. Although the precise biological mechanisms underlying this adaptation are unknown, previous work indicated that Niemann-pick type C2 (NPC2)-like sterol-binding proteins might be integral in the host-parasite interplay. Expansions of this family in some invertebrates, such as arthropods, have shown functional diversification, including novel forms of chemoreception. Thus, here we curated the NPC2-like protein gene complement in C. sinensis, and predicted their conserved and/or divergent functional roles.

Methods

We used an established comparative genomic-bioinformatic approach to curate NPC2-like proteins encoded in published genomes of Korean and Chinese isolates of C. sinensis. Protein sequence and structural homology, presence of conserved domains and phylogeny were used to group and functionally classify NPC2-like proteins. Furthermore, transcription levels of NPC2-like protein-encoding genes were explored in different developmental stages and tissues.

Results

Totals of 35 and 32 C. sinensis NPC2-like proteins were predicted to be encoded in the genomes of the Korean and Chinese isolates, respectively. Overall, these proteins had low sequence homology and high variability of sequence alignment coverage when compared with curated NPC2s. Most C. sinensis proteins were predicted to retain a conserved ML domain and a conserved fold conformation, with a large cavity within the protein. Only one protein sequence retained the conserved amino acid residues required in bovine NPC2 to bind cholesterol. Non-canonical C. sinensis NPC2-like protein-coding domains clustered into four distinct phylogenetic groups with members of a group frequently encoded on the same genome scaffolds. Interestingly, NPC2-like protein-encoding genes were predicted to be variably transcribed in different developmental stages and adult tissues, with most being transcribed in the metacercarial stage.

Conclusions

The results of the present investigation confirms an expansion of NPC2-like proteins in C. sinensis, suggesting a diverse array of functions beyond sterol binding and transport. Functional explorations of this protein family should elucidate the mechanisms enabling the establishment and survival of C. sinensis and related flukes in the biliary systems of mammalian hosts.

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

Clonorchis sinensis is a carcinogenic human liver fluke, prolonged infection which provokes chronic inflammation, epithelial hyperplasia, periductal fibrosis, and even cholangiocarcinoma (CCA). These effects are driven by direct physical damage caused by the worms, as well as chemical irritation from their excretory-secretory products (ESPs) in the bile duct and surrounding liver tissues. We investigated the C. sinensis ESP-mediated malignant features of CCA cells (HuCCT1) in a three-dimensional microfluidic culture model that mimics an in vitro tumor microenvironment. This system consisted of a type I collagen extracellular matrix, applied ESPs, GFP-labeled HuCCT1 cells and quiescent biliary ductal plates formed by normal cholangiocytes (H69 cells). HuCCT1 cells were attracted by a gradient of ESPs in a concentration-dependent manner and migrated in the direction of the ESPs. Meanwhile, single cell invasion by HuCCT1 cells increased independently of the direction of the ESP gradient. ESP treatment resulted in elevated secretion of interleukin-6 (IL-6) and transforming growth factor-beta1 (TGF-β1) by H69 cells and a cadherin switch (decrease in E-cadherin/increase in N-cadherin expression) in HuCCT1 cells, indicating an increase in epithelial-mesenchymal transition-like changes by HuCCT1 cells. Our findings suggest that C. sinensis ESPs promote the progression of CCA in a tumor microenvironment via the interaction between normal cholangiocytes and CCA cells. These observations broaden our understanding of the progression of CCA caused by liver fluke infection and suggest a new approach for the development of chemotherapeutic for this infectious cancer.

The oriental liver fluke, Clonorchis sinensis, is a biological carcinogen of humans and is the cause of death of infectious cancer patients in China and Korea. Its chronic infection promotes cholangiocarcinogenesis due to direct contact of host tissues with the worms and their excretory-secretory products (ESPs); however, the specific mechanisms underlying this pathology remain unclear. To assess its contribution to the progression of cholangiocarcinoma (CCA), we developed a 3-dimensional (3D) in vitro culture model that consists of CCA cells (HuCCT1) in direct contact with normal cholangiocytes (H69), which are subsequently exposed to C. sinensis ESPs; therefore, this model represents a C. sinensis-associated CCA microenvironment. Co-cultured HuCCT1 cells exhibited increased motility in response to C. sinensis ESPs, suggesting that this model may recapitulate some aspects of tumor microenvironment complexity. Proinflammatory cytokines such as IL-6 and TGF-β1 secreted by H69 cells exhibited a crosstalk effect regarding the epithelial-mesenchymal transition of HuCCT1 cells, thus, promoting an increase in the metastatic characteristics of CCA cells. Our findings enable an understanding of the mechanisms underlying the etiology of C. sinensis-associated CCA, and, therefore, this approach will contribute to the development of new strategies for the reduction of its high mortality rate.

Development of Microplatforms to Mimic the In Vivo Architecture of CNS and PNS Physiology and Their Diseases

Understanding the mechanisms that govern nervous tissues function remains a challenge. In vitro two-dimensional (2D) cell culture systems provide a simplistic platform to evaluate systematic investigations but often result in unreliable responses that cannot be translated to pathophysiological settings. Recently, microplatforms have emerged to provide a better approximation of the in vivo scenario with better control over the microenvironment, stimuli and structure. Advances in biomaterials enable the construction of three-dimensional (3D) scaffolds, which combined with microfabrication, allow enhanced biomimicry through precise control of the architecture, cell positioning, fluid flows and electrochemical stimuli. This manuscript reviews, compares and contrasts advances in nervous tissues-on-a-chip models and their applications in neural physiology and disease. Microplatforms used for neuro-glia interactions, neuromuscular junctions (NMJs), blood-brain barrier (BBB) and studies on brain cancer, metastasis and neurodegenerative diseases are addressed. Finally, we highlight challenges that can be addressed with interdisciplinary efforts to achieve a higher degree of biomimicry. Nervous tissue microplatforms provide a powerful tool that is destined to provide a better understanding of neural health and disease.

Clonorchis sinensis and Clonorchiasis: The Relevance of Exploring Genetic Variation

Parasitic trematodes (flukes) cause substantial mortality and morbidity in humans. The Chinese liver fluke, Clonorchis sinensis, is one of the most destructive parasitic worms in humans in China, Vietnam, Korea and the Russian Far East. Although C. sinensis infection can be controlled relatively well using anthelmintics, the worm is carcinogenic, inducing cholangiocarcinoma and causing major suffering in ~15 million people in Asia. This chapter provides an account of C. sinensis and clonorchiasis research-covering aspects of biology, epidemiology, pathogenesis and immunity, diagnosis, treatment and control, genetics and genomics. It also describes progress in the area of molecular biology (genetics, genomics, transcriptomics and proteomics) and highlights challenges associated with comparative genomics and population genetics. It then reviews recent advances in the sequencing and characterisation of the mitochondrial and nuclear genomes for a Korean isolate of C. sinensis and summarises salient comparative genomic work and the implications thereof. The chapter concludes by considering how advances in genomic and informatics will enable research on the genetics of C. sinensis and related parasites, as well as the discovery of new fluke-specific intervention targets.

Clonorchis sinensis excretory-secretory products promote the migration and invasion of cholangiocarcinoma cells by activating the integrin β4-FAK/Src signaling pathway

Cholangiocarcinoma (CCA) is a slow-growing but highly metastatic cancer. Its metastatic potential largely explains its high mortality rate. A recognized risk factor for CCA development is infection with the liver flukes Opisthorchis viverrini and Clonorchis sinensis. We previously reported that the excretory-secretory products (ESPs) of C. sinensis promoted the three-dimensional aggregation and invasion of CCA cells. In the present study, a quantitative real-time PCR array of extracellular matrix (ECM) and adhesion molecules was used to examine the regulatory mechanism of ESP-mediated CCA cell migration and invasion. In particular, the expression levels of integrin α isoforms and β4 were upregulated in response to ESPs. Increased expression of integrin β4 was probably correlated with activation of focal adhesion kinase (FAK) and the steroid receptor coactivator (Src) family kinase and the subsequent activation of two downstream focal adhesion molecules, paxillin and vinculin. Moreover, inhibition of FAK/Src activation reduced paxillin and vinculin phosphorylation and attenuated ESP-induced CCA cell migration and invasion. These findings suggest that the integrin β4-FAK/Src signaling axis may play a crucial role in clonorchiasis-associated CCA metastasis during tumor progression.

Parasite Infection, Carcinogenesis and Human Malignancy

Cancer may be induced by many environmental and physiological conditions. Infections with viruses, bacteria and parasites have been recognized for years to be associated with human carcinogenicity. Here we review current concepts of carcinogenicity and its associations with parasitic infections. The helminth diseases schistosomiasis, opisthorchiasis, and clonorchiasis are highly carcinogenic while the protozoan Trypanosoma cruzi, the causing agent of Chagas disease, has a dual role in the development of cancer, including both carcinogenic and anticancer properties. Although malaria per se does not appear to be causative in carcinogenesis, it is strongly associated with the occurrence of endemic Burkitt lymphoma in areas holoendemic for malaria. The initiation of Plasmodium falciparum related endemic Burkitt lymphoma requires additional transforming events induced by the Epstein-Barr virus. Observations suggest that Strongyloides stercoralis may be a relevant co-factor in HTLV-1-related T cell lymphomas. This review provides an overview of the mechanisms of parasitic infection-induced carcinogenicity.

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The helminth diseases schistosomiasis, opisthorchiasis, and clonorchiasis are highly carcinogenic.

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Trypanosoma cruzi has a dual role in cancer development including both carcinogenic and anticancer properties.

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Initiation of Plasmodium falciparum related endemic Burkitt lymphoma requires additional transforming events induced by EBV.

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Strongyloides stercoralis may be a relevant co-factor in HTLV-1-related T cell lymphomas.

We searched MEDLINE database and PubMed for articles from 1970 through June 30, 2016. Search terms used in various combinations were “parasite infection”, “carcinogenesis”, “cancer”, “human malignancy”, “parasite and cancer”, “infection-associated cancer”, “parasite-associated cancer” “schistosomiasis”, “opisthorchiasis”, “malaria”, “Chagas disease”, and “strongyloidiasis”. Articles resulting from these searches and relevant references cited in those articles were selected based on their related topics and were reviewed. Abstracts and reports from meetings were also included. Articles published in English were included.

Current status and perspectives of Clonorchis sinensis and clonorchiasis: epidemiology, pathogenesis, omics, prevention and control

Clonorchiasis, caused by Clonorchis sinensis (C. sinensis), is an important food-borne parasitic disease and one of the most common zoonoses. Currently, it is estimated that more than 200 million people are at risk of C. sinensis infection, and over 15 million are infected worldwide. C. sinensis infection is closely related to cholangiocarcinoma (CCA), fibrosis and other human hepatobiliary diseases; thus, clonorchiasis is a serious public health problem in endemic areas. This article reviews the current knowledge regarding the epidemiology, disease burden and treatment of clonorchiasis as well as summarizes the techniques for detecting C. sinensis infection in humans and intermediate hosts and vaccine development against clonorchiasis. Newer data regarding the pathogenesis of clonorchiasis and the genome, transcriptome and secretome of C. sinensis are collected, thus providing perspectives for future studies. These advances in research will aid the development of innovative strategies for the prevention and control of clonorchiasis.