Granulin Expression in Hamsters during Opisthorchis viverrini Infection-Induced Cholangiocarcinogenesis

Document Type: Research Articles

Authors

1 Graduate School, Faculty of Veterinary Medicine, Khon Kaen University, Khon Kaen, Thailand.

2 WHO Collaborating Centre for Research and Control of Opisthorchiasis (Southeast Asian Liver Fluke Disease)/Tropical Disease Research Center (TDRC), Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.

3 Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.

4 Department of Pathology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.

5 Department of Veterinary Anatomy, Faculty of Veterinary Medicine, Khon Kaen University, Khon Kaen, Thailand.

6 Department of Microbiology, Immunology and Tropical Medicine, and Research Center for Neglected Diseases of Poverty, School of Medicine and Health Sciences, George Washington University, Washington DC 20037, USA.

7 Department of Veterinary Pathobiology, Faculty of Veterinary Medicine, Khon Kaen University, Khon Kaen, Thailand.

Abstract

The secreted growth factor granulin (GRN) is upregulated during diverse epithelial cancers. GRN stimulates
cell growth and development while inhibiting apoptosis. Orthologues of vertebrate granulins evolved in other
animals including the liver fluke Opisthorchis viverrini. Curiously, liver fluke granulin, termed Ov-GRN-1 promotes
cholangiocarcinogenesis during chronic opisthorchiasis but, by contrast, limited information is available concerning
mammalian GRN during liver fluke infection-induced cholangiocarcinoma (CCA). Here we investigated the expression
of mammalian granulin in the O. viverrini-associated a hamster model of opisthorchiasis and liver fluke infection-induced
CCA. Male Syrian golden hamsters were assigned to one of four treatment groups, each group included 30 hamsters: 1)
normal (control), 2) infected with O. viverrini (OV); 3) exposed to N-dimethylnitrosamine in drinking water (DMN);
and 4) infected with O. viverrini and exposed to DMN (OVDMN). Immunohistochemistry using an anti-granulin
specific probe for mammalian granulin was undertaken to monitor expression and location in hepatobiliary tissues of
the hamsters. In parallel, cognate studies of transcription of mRNA and protein. Histopathological examination revealed
development of proliferative lesions from the onset and eruption of CCA onwards, an outcome that was most prominent
in the OVDMN hamsters. Proliferating cell nuclear antigen (PCNA) index rose continuously from initiation of infection
and increased with lesion progression in OV, DMN and markedly in OVDMN hamsters. Expression of GRN in biliary
was elevated in biliary epithelial cells in CCA lesions in hamsters in the DMN and OVDMN groups. Expression of GRN
as assayed by western blot and RT-PCR reflected the same trend as seen with PCNA. Together the histopathogical and
molecular assay based findings revealed marked expression of granulin during cholangiocarcinoma in these hamsters,
and highlighted the prospect that granulin represents a potential prognostic marker for cholangiocarcinoma.

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