Ultrastructural and immunohistochemical analysis of cholangiocarcinoma in immunized Syrian golden hamsters infected with Opisthorchis viverrini and administered with dimethylnitrosamine

Preclinical activity of fluvastatin-loaded self-nanoemulsifying delivery system against breast cancer models: Emphasis on apoptosis

Statins trigger apoptotic cell death in some types of growing tumor cells in a cholesterol-lowering-independent manner. Self-nanoemulsifying delivery systems (SNEDs) are potentially effective for the suppression of breast cancer development. This study aims to investigate the potential anticancer activity of fluvastatin (FLV)-SNEDs in breast cancer while comparing it with FLV in vitro as well as in vivo exploiting/using MDA-MB-231 and Erhlich ascites carcinoma (EAC)-bearing mice, respectively. Biochemical analysis of liver and kidney functions, oxidative stress markers, and histopathological examinations of such tumor tissues were performed showing the potentiality of SNEDs as a nanocarrier for antitumor agents. FLV-SNEDs demonstrated more potent anticancer activity compared to FLV on MDA-MB-231 and hepatocellular carcinoma (HepG2) cells. In vivo experiments on the EAC-bearing mice model indicated that FLV and-to a greater extent-FLV-SNEDs ameliorated EAC-induced hepatotoxicity and nephrotoxicity. FLV or FLV-SNEDs evidently reduced the percent of Ki-67 +ve EAC cells by 57.5% and 86.5% in comparison to the vehicle-treated EAC group. In addition, FLV or FLV-SNEDs decreased Bcl-2 levels in serum and liver specimens. In contrast, FLV or FLV-SNEDs significantly activated the executioner caspase-3. Simultaneously, both FLV and FLV-SNEDs stimulated p53 signaling and modulated Bcl-2 protein levels in treated cells. Collectively, these results support the contribution of apoptotic cell death in mediating the anticancer activities of FLV and FLV-SNEDs against murine EAC model in vivo. This study provides new understandings of how FLV and FLV-SNEDs regulate EAC cell viability via upregulation of p53 signaling, and through modulation of cleaved caspase-3 as well as antiapoptotic Bcl-2 marker.

Cancer vaccines and immunotherapeutic approaches in hepatobiliary and pancreatic cancers

Hepatobiliary and pancreatic cancers along with other gastrointestinal malignancies remain the leading cause of cancer-related deaths worldwide. Strategies developed in the recent years on immunotherapy and cancer vaccines in the setting of primary liver cancer as well as in pancreatic cancer are the scope of this review. Significance of orthotopic and autochthonous animal models which mimic and/or closely reflect human malignancies allowing for a prompt and trustworthy analysis of new therapeutics is underlined. Combinational approaches that on one hand, specifically target a defined cancer-driving pathway, and on the other hand, restore the functions of immune cells, which effector functions are often suppressed by a tumor milieu, are shown to have the strongest perspectives and future directions. Among combinational immunotherapeutic approaches a personalized- and individual cancer case-based therapy is of special importance.

Effect of Opisthorchis felineus infection and dimethylnitrosamine administration on the induction of cholangiocarcinoma in Syrian hamsters

The food-borne liver trematode Opisthorchis felineus is an emerging source of biliary tract diseases on the territory of the former Soviet Union and Eastern Europe. This parasite along with trematodes Opisthorchis viverrini and Clonorchis sinensis belong to the triad of epidemiologically important liver flukes of the Opisthorchiidae family. It is known that O. viverrini and C. sinensis are the main risk factors of cholangiocarcinoma (CCA) in the endemic regions. The carcinogenic potential of O. felineus has not been well researched because of the absence of systematic pathomorphological, clinical, and epidemiological studies on O. felineus opisthorchiasis.

In the present study, we show the results of detailed histopathological analysis and comprehensive evaluation of inflammation, bile duct dysplasia, periductal fibrosis, bile duct hyperplasia, bile duct proliferation, egg granuloma, cysts, cholangiofibrosis, and CCA from 10 to 30 weeks following infection of Syrian hamsters with O. felineus accompanied by oral administration of dimethylnitrosamine (DMN). The results revealed that O. felineus contributes to bile duct cancer development in the hamster model. During the combined action of O. felineus and DMN, morphological features of the liver underwent dramatic changes at the cellular and organ levels. Already in the early stages of the experiment, we observed extensive periductal fibrosis, active inflammation, proliferation of the bile duct, bile duct dysplasia and egg granulomas. Later, against the background of all these changes, cholangiofibrosis and CCA were found.

Our work is the first step in the study of carcinogenic potential of O. felineus . Obtained data indicate the risk of CCA of patients having chronic O. felineus opisthorchiasis, and underscore the need for the development of programs for control of this helminthiasis.

The challenge of cholangiocarcinoma: dissecting the molecular mechanisms of an insidious cancer

Cholangiocarcinoma is a fatal cancer of the biliary epithelium and has an incidence that is increasing worldwide. Survival beyond a year of diagnosis is less than 5%, and therapeutic options are few. Known risk factors include biliary diseases such as primary sclerosing cholangitis and parasitic infestation of the biliary tree, but most cases are not associated with any of these underlying diseases. Numerous in vitro and in vivo models, as well as novel analytical techniques for human samples, are helping to delineate the many pathways implicated in this disease, albeit at a frustratingly slow pace. As yet, however, none of these studies has been translated into improved patient outcome and, overall, the pathophysiology of cholangiocarcinoma is still poorly understood. There remains an urgent need for new approaches and models to improve management of this insidious and devastating disease. In this review, we take a bedside-to-bench approach to discussing cholangiocarcinoma and outline research opportunities for the future in this field.

Overexpression of microRNA-21 regulating PDCD4 during tumorigenesis of liver fluke-associated cholangiocarcinoma contributes to tumor growth and metastasis

MicroRNA, an endogenous noncoding RNA modulating gene expression, is a key molecule that by its dysregulation plays roles in inflammatory-driven carcinogenesis. This study aimed to investigate the role of oncomiR miR-21 and its target, the programmed cell death 4 (PDCD4) in tumor growth and metastasis of the liver fluke Opisthorchis viverrini-associated cholangiocarcinoma (CCA). The expression levels of miR-21 and PDCD4 were analyzed using the TaqMan miRNA expression assay and immunohistochemistry in liver tissues of both O. viverrini plus N-nitrosodimethylamine (NDMA)-treated hamsters and human CCA samples (n=23 cases). The functional assay for miR-21 was performed in CCA cell lines by the anti-miR-21 and pre-miR-21 transfection procedures. The peak of miR-21 levels were reached at 2 (hyperplastic lesions) and 6 (CCA) months of the O. viverrini plus NDMA-induced group and had a reverse response with its target PDCD4 proteins. In human CCA, miR-21 was overexpressed in tumor tissues when compared with nontumor tissues (P=0.0034) and had a negative correlation with PDCD4 protein (P=0.026). It was also found that high expression of miR-21 was significantly correlated with shorter survival (P<0.05) and lymph node metastasis (P=0.037) of CCA patients. Transient transfection of pre-miR-21 reduced the PDCD4 level and resulted in an increase of M213 CCA cell growth and wound-induced migration ability. These results indicated that miR-21 plays a role in the carcinogenesis and metastasis of O. viverrini-associated CCA by suppressing the function of PDCD4. Modulation of aberrantly expressed miR-21 may be a useful strategy to inhibit tumor cell phenotypes or improve response to chemotherapy.

Molecular mechanisms of cholangiocarcinoma

Cholangiocarcinoma (CC), the malignant tumor of the epithelial cells lining the biliary ducts, has undergone a worldwide increase in incidence and mortality. The malignant transformation of the biliary cells originates from a multistep process evolving through chronic inflammation of the biliary tract to CC. In the last few years several advances have been towards understanding and clarifying the molecular mechanisms implicated in the cholangiocarcinogenesis process. However, many pathophysiologic aspects governing the growth of CC are still undefined. The poor prognosis of this tumor underlines the urgent need to codify the underlying molecular mechanisms involved in the growth and progression of CC in order to design effective preventive measures and valid treatment regimens. This review reports on progresses made in the last few years in clarifying the molecular pathways involved in the process of cholangiocarcinogenesis.

Cholangiocarcinoma

Cholangiocarcinoma is a primary hepatic malignancy originating from bile duct epithelium. It is the second most common primary hepatic neoplasia, and its incidence has increased within the last 3 decades. Although several risk factors have been identified, especially chronic biliary tract inflammation, most patients with cholangiocarcinoma have no identifiable risk factors. Recent developments in radiologic and molecular diagnostic methods have helped in the diagnosis of this disease. The only curative therapy is surgical resection or liver transplantation. For patients with advanced stage disease, survival remains limited. With growing understanding of the molecular and cellular etiology of this disease, new targeted therapies are being developed.

Establishment of a novel orthotopic xenograft model of human gallbladder carcinoma

OBJECTIVE

Gallbladder cancer is characterized by high morbidity and mortality. An appropriate human xenograft animal model could serve as a research tool to investigate new therapeutic strategies.

SUMMARY BACKGROUND DATA

To date, the few reports describing a xenograft animal model showed significant limitations. We improved a murine orthotopic human xenotransplantation model by implanting human gallbladder carcinoma cells directly into the lumen of the gallbladder.

METHODS

Mz-ChA-1 cells were orthotopically injected into the gallbladder of Severe Combined Immune Deficiency (SCID) beige mice inducing the growth of solid tumors. The natural course of the disease, tumor growth, and metastases were analyzed. The cytotoxic drug gemcitabine was tested in vitro and in vitro.

RESULTS

All animals revealed solid tumors in the inoculated area with liver infiltration. The median tumor volume in the untreated group was significantly higher than in the gemcitabine-treated group. Immunohistochemical staining revealed expression of human cytokeratin 7 and cytokeratin 8. To analyze tumor cell proliferation, the tumors were stained for the antigen Ki-67, and labeling indices were calculated for both groups. Animals receiving gemcitabine treatment showed significantly lower mean labeling indices. In vitro investigation revealed a significant reduction of DNA synthesis. DNA fragmentation, as a measure of apoptosis, was elevated by roughly 20% within 24 h of treatment. With this, we successfully established an orthotopic xenotransplant animal model and investigated the in vitro and in vivo effects of gemcitabine in human xenografted Mz-ChA-1 gallbladder adenocarcinoma.

CONCLUSION

This model resembles the clinical situation as closely as possible and offers a relevant option for the preclinical testing of new therapeutic strategies.

Pollutant-induced effects on immunological and physiological interactions in aquatic host–trematode systems: implications for parasite transmission

Under conditions of pollution both host and parasite are susceptible to the pathogenic effects of toxicants, which in turn may result in detrimental changes to their immunological and physiological processes. Digenetic trematodes, which encompass species of both medical and economic importance, possess complex life cycles and are common parasites of both vertebrates and molluscs. The combined stress induced by pollution and parasitism influences the physiology of the host which can have implications not only on host survival but also on the functional biology of resident parasite populations. The present paper reviews the effects of pollutants on the immunology and physiology in both vertebrate and molluscan host–trematode systems and the implications for parasite transmission.

Hepatobiliary changes, antibody response, and alteration of liver enzymes in hamsters re-infected with Opisthorchis viverrini

We investigated pathological changes, antibody response, and liver enzymes in hamsters re-infected with Opisthorchis viverrini. Group 1 received a single dose of 50 metacercariae; Groups 2 and 3 were first dosed with of 30 metacercariae and re-infected with 20 more once or twice at three month intervals. Inflammation and liver cell necrosis were observed on 3D (day 3) for Group 3 and 7D for Group 2 in comparison with 21D for Group 1. Pathological changes included peri-ductal fibrosis, bile duct dilation, and small bile duct formation. Increased O. viverrini-specific IgG levels ranked in the order Group 3>Group 2>Group 1. Liver enzyme activity was related to inflammatory cell infiltration. Re-infection induced faster inflammation and more severe pathological changes in association with parasite-specific antibody during chronic inflammation. This study emphasizes that there is an important relationship between the gradual decreases of inflammation with a concomitant increase in fibrosis after re-infection.

Comparative proteomic analysis of juvenile and adult liver fluke, Opisthorchis viverrini

We used comparative two-dimensional gel electrophoresis to highlight proteins that are differentially expressed in the maturation stage of the parasite Opisthorchis viverrini (OV). The proteins differentially expressed in the juvenile/adult forms of the parasite are thought to be important for survival and pathogenesis. We used a nonlinear gradient pH ranged 3-10 strips for isoelectric focusing to resolve soluble proteins from four different maturation periods of OV from 1 week juvenile to 4 week adult. Approximately 210-240 protein spots were resolved by 2-DE in two ranges of pI (4.5-5.8 and 6.0-8.0). At least 35 protein spots were differentially expressed in 4 week adult compared to 1 week juvenile fluke. These proteins may involve in sex organ development and egg production. Comparative analysis of the OV proteome of different aged parasites during maturation may help to better understand parasite biology, pathogenesis/carcinogenesis related to this parasite and lead to the identification of new targets of vaccines and drugs.

Expression of tenascin in bile duct cancer of hamster liver by combined treatment of dimethylnitrosamine with Opisthorchis viverrini infections

Tenascin is an extracellular matrix glycoprotein known to be an essential factor for the modulation of reciprocal interactions between the epithelium and mesenchyme during embryogenesis and tumourigenesis. The interactions between the expression of tenascin in the liver of Syrian golden hamster and the development of bile duct cancer in an Opisthorchis viverrini-associated cholangiocarcinoma model were investigated. The tenascin was expressed in connective tissues surrounding the dilated ducts, ductal rims and the stroma of cancers, and strongly in the stroma flame of necrotic cancer nodules. The mRNA signal for tenascin was also recognized in the stroma cells. The potential roles of tenascin as prognostic tumour markers are discussed.