Tumor-Related Gene Changes in Immunosuppressive Syrian Hamster Cholangiocarcinoma

Molecular detection of tick-borne pathogens in infected dogs associated with Rhipicephalus sanguineus tick infestation in Thailand

Background and Aim:

Tick-borne pathogens (TBPs) are of great concern having the potential to threaten canine health. Dogs infected with Ehrlichia canis, Anaplasma platys, Babesia canis, and Hepatozoon canis are commonly found in Thailand; Rhipicephalus sanguineus tick is the most common vector of diseases. This study aimed to determine the prevalence of common TBPs in dogs and their ticks in Thailand using polymerase chain reaction (PCR) and DNA sequencing methods.

Materials and Methods:

Forty-four blood samples were positively diagnosed with TBPs infection by microscopy. Samples were from animal hospitals in Maha Sarakham, Amnat Charoen, Nakhon Ratchasima, and Bangkok, Thailand, during January-June 2020. Five to six ticks were also taken from infected dogs, and then, both blood and tick were analyzed using PCR and DNA sequencing.

Results:

PCR results showed that R. sanguineus was the only tick species detected in this study. The appearance of single infection with E. canis was the most common infection found in dogs and ticks (64% and 82%, respectively). Correlation of pathogen infection in hosts and their vector was performed by similarity detection of pathogens between blood and tick samples based on PCR analysis in 29 samples (66%) but there was no significant differentiation.

Conclusion:

E. canis appears as the most common canine tick-borne pathogen in Thailand, which was detected in both healthy and sick dogs as well as in R. sanguineus. The findings show the relationships among host dogs, pathogens, and ticks. Veterinarians should be proactive in educating pet owners about the risks associated with ticks and their important pathogens and plan effective control strategies.

Monitoring the Progression of Liver Fluke-Induced Cholangiocarcinoma in a Hamster Model Using Synchrotron FTIR Microspectroscopy and Focal Plane Array Infrared Imaging

Cholangiocarcinoma (CCA) is a bile duct cancer that originates in the bile duct epithelium. Northeastern Thailand has the highest incidence of CCA, and there is a direct correlation with liver fluke (Opisthorchis viverrini) infection. The high mortality rate of CCA is a consequence of delayed diagnosis. Fourier transform infrared (FTIR) spectroscopy is a powerful technique that detects the absorbance of molecular vibrations and is perfectly suited for the interrogation of biological samples. In this study, we applied synchrotron radiation-FTIR (SR-FTIR) microspectroscopy and focal plane array (FPA-FTIR) microspectroscopy to characterize periductal fibrosis and bile duct cells progressing to CCA induced by inoculating O. viverrini metacercariae into hamsters. SR-FTIR and FPA-FTIR measurements were performed in liver sections harvested from 1-, 2-, 3-, and 6-month post-infected hamsters compared to uninfected liver tissues. Principal component analysis (PCA) of the tissue samples showed a clear discrimination among uninfected and early-stage (1 and 2 months) and cancerous-stage (3 and 6 months) tissues. The discrimination is based on intensity changes in the phosphodiester band (1081 cm^-1), amino acid residue (∼1396 cm^-1), and C═O stretching carboxylic esters (1745 cm^-1). Infected tissues also show definitive bands at ∼1280, 1234, and 1201 cm^-1 characteristic of the collagen triplet and indicative of fibrosis. Hierarchical cluster analysis (HCA) was performed on the FPA data and showed a classification into specific cell types. Hepatocyte, fibrotic lesion, and bile duct (cancer) were classified and HCA mapping showed similar cellular distribution pattern compared to Sirius red staining. This study was also extended to less invasive sample analysis using attenuated total reflectance-FTIR (ATR-FTIR) spectroscopy. Sera from O. viverrini-infected and uninfected hamsters were analyzed using multivariate analysis, including principal component analysis (PCA), and partial least squares-discriminant analysis (PLS-DA). PCA was able to classify spectra of normal, early-stage CCA, and CCA, while the PLS-DA gave 100% accuracy for the validation. The model was established from 17 samples (11 normal, 6 cancer) in the calibration set and 9 samples in the validation set (4 normal, 2 cancer, 3 precancerous). These results indicate that FTIR-based technology is a potential tool to detect the progression of CCA, especially in the early stages of the disease.

Suppression of IL-6 Gene by shRNA Augments Gemcitabine Chemosensitization in Pancreatic Adenocarcinoma Cells

Pancreatic adenocarcinoma has an exceedingly poor prognosis, accounting for five-year survival of less than 5%. Presently, improving the efficacy of pancreatic adenocarcinoma treatment has been the focus of medical researchers worldwide. Recently, it has been suggested that deregulation of interleukin- (IL-) 6 is caused by a key gene involved in the beginning and development of pancreatic adenocarcinoma. Herein, we investigated whether suppression of IL-6 could augment gemcitabine sensitivity in the PANC-1 cells. We found considerably higher expression of IL-6 in pancreatic adenocarcinoma tissues than that in the adjacent nontumorous tissues. Suppression of IL-6 by shRNA resulted in apoptosis as well as inhibition of cell proliferation and tumorigenicity. In addition, suppression of IL-6 remarkably promoted antitumor effect of gemcitabine, indicating that the combination of shRNA targeting IL-6 with gemcitabine may provide a potential clinical approach for pancreatic cancer therapy.

In Vitro and In Vivo Inhibitory Effects of α-Mangostin on Cholangiocarcinoma Cells and Allografts

We investigated the anti-cholangiocarcinoma effect of α-mangostin from Garcinia mangostana pericarp extract (GM) in a human cholangiocarcinoma (CCA) cell line and a hamster CCA allograft model. In vitro, human CCA cells were treated with GM at various concentrations and for different time periods; then cell-cycle arrest and apoptosis were evaluated using flow cytometry, and metastatic potential with wound healing assays. In vivo, hamster allografts were treated with GM, gemcitabine (positive control) and a placebo (negative control) for 1 month; tumor weight and volume were then determined. Histopathological features and immunostaining (CK19 and PCNA) characteristics were examined by microscopy. The present study found that α-mangostin could: inhibit CCA cell proliferation by inducing apoptosis through the mitochondrial pathway; induce G1 cell-cycle arrest; and inhibit metastasis. Moreover, α-mangostin could inhibit CCA growth, i.e. reduce tumor mass (weight and size) and alter CCA pathology, as evidenced by reduced positive staining for CK19 and PCNA. The present study thus suggested that α-mangostin is a promising anti-CCA compound whose ready availability in tropical countries might indicate use for prevention and treatment of CCA.

A Promising Serum Autoantibody Marker, Anti-Heat Shock Protein 90α, for Cholangiocarcinoma

The present study was designed to investigate cholangiocarcinoma (CCA) antibodies in hamster serum. Hamster CCA cell lines were processed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. A candidate biomarker was confirmed by immunoprecipitation and western blot, and was further analyzed using ELISA and sera from normal control hamsters, hamsters with opisthorchiasis and hamsters with various stages of CCA, as well as from CCA patients and healthy individuals. One candidate marker was identified as HSP90α, as indicated by a high level of anti-HSP90α in hamster CCA sera. It was found that the levels of anti-HSP90α were specifically elevated in the sera of hamsters with CCA compared with other groups and progressively increased with the clinical stage. At the cut-off point of 0.4850 on the receiver operating characteristic curve, anti-HSP90α could discriminate CCA from healthy control groups with a sensitivity of 76.2%, specificity of 71.4% and total accuracy 75.5%. In the present study, we have shown that anti-HSP90α may be a potential useful serum biomarker to discriminate CCA cases from healthy persons.

A combination of liver fluke infection and traditional northeastern Thai foods associated with cholangiocarcinoma development

Opisthorchis viverrini infection is one of the risk factors for cholangiocarcinoma (CCA) in northeast Thailand, a region with one of the highest reported incidence rates of CCA. The traditional practice of eating raw fish, repeated exposure to liver flukes, and consumption of nitrosamine-contaminated food are major risk factors for CCA. So far, there have been no reports about which northeastern traditional dishes may be involved in CCA development. The present study, thus, investigated the effects of traditional foods. It focused specifically on the consumption of fermented foods in combination with O. viverrini infection in hamsters. Syrian hamsters were divided into six groups: (i) normal hamsters, (ii) O. viverrini infection only and (iii)-(vi) O. viverrini infection plus fermented foods (pla som-fish fermented for 1 day), som wua-fermented beef, som phag-fermented vegetables, and pla ra-fish fermented for 6 months. Syrian hamster livers were used for analysis of histopathological changes through hematoxylin and eosin; Sirius Red; and immunohistostaining for cytokeratin-19, proliferating cell nuclear antigen, and CA19-9. Hamster sera were used for liver and kidney function tests. Results of all O. viverrini-infected groups and fermented food groups showed that histopathological changes consisted primarily of aggregations of inflammatory cells surrounding the hepatic bile duct, especially at the hilar region. However, there was a difference in virulence. Interestingly, aggregations of inflammatory cells, new bile duct formation, and fibrosis were observed in subcapsular hepatic tissue, which correlated to positive immunohistochemical staining and increased liver function test. The present study suggests that fermented food consumption can exacerbate cholangitis and cholangiofibrosis, which are risk factors for cholangiocarcinoma-associated opisthorchiasis.

Potential targeted therapy for liver fluke associated cholangiocarcinoma

Biliary tree cancer or cholangiocarcinoma (CCA) is an unusual subtype of liver cancer with exceptionally poor prognosis. Lack of specific symptoms and availability of early diagnostic markers account for late diagnosis of CCA. Surgical treatment is a gold standard choice but few patients are candidates and local recurrence after surgery is high. Benefit of systemic chemotherapy is limited; hence, better treatment options are required. The differences in etiology, anatomical positions and pathology make it difficult to generalize all CCA subtypes for a single treatment regimen. Herein, we review the uniqueness of molecular profiling identified by multiple approaches, for example, serial analysis of gene expression, exome sequencing, transcriptomics/proteomics profiles, protein kinase profile, etc., that provide the opportunity for treatment of liver fluke-associated CCA. Anti-inflammatory, immunomodulator/immunosuppressor, epidermal growth factor receptor or platelet-derived growth factor receptor inhibitors, multi-targeted tyrosine kinase inhibitor, IL6 antagonist, nuclear factor-κB inhibitor, histone modulator, proteasome inhibitor as well as specific inhibitors suggested from various study approaches, such as MetAP2 inhibitor, 1,25(OH)2 D3 and cyclosporine A are suggested in this review for the treatments of this specific CCA subtype. This might provide an alternative treatment option for CCA patients; however, clinical trials in this specific CCA group are required.