Proteomic analysis to identify plasma orosomucoid 2 and kinesin 18A as potential biomarkers of cholangiocarcinoma

Article type: Research Article

Authors: Rucksaken, Rucksak^{a; f} | Khoontawad, Jarinya^{a; f} | Roytrakul, Sittiruk^b | Pinlaor, Porntip^{c; f} | Hiraku, Yusuke^g | Wongkham, Chaisiri^{d; f} | Pairojkul, Chawalit^{e; f} | Boonmars, Thidarut^{a; f} | Pinlaor, Somchai^{a; f; *}

Affiliations: [a] Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand | [b] Proteomics Research Laboratory, Genome Institute Biotechnology, Pathumthani, Thailand | [c] Centre for Research and Development in Medical Diagnostic Laboratory, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand | [d] Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand | [e] Department of Pathology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand | [f] Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand | [g] Department of Environmental and Molecular Medicine, Mie University Graduate School of Medicine, Tsu, Mie, Japan

Correspondence: [*] Corresponding author: Somchai Pinlaor, Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand. Tel.: +66 43 348 387; Fax: +66 43 202 475; E-mail: psomec@kku.ac.th.

Abstract: Proteomic analysis was performed to search for the diagnostic biomarkers of the early stage of cholangiocarcinoma (CCA). For this purpose, CCA was experimentally induced in hamsters by the combination of N-nitrosodimethylamine (NDMA) treatment and Opisthorchis viverrini (OV) infection. Pooled plasma of normal control, NDMA-treated, OV-infected and OV + NDMA (ON) treated group was separated by 1-D PAGE, and the trypsin-digested bands were analyzed with LC-MS/MS. Among 82 overexpressed proteins, the study focused on 26 proteins overexpressed in ON group because CCA development was almost exclusively found in this group. A further selection was made based on the protein overexpression on day 21, the precancerous stage. Orosomucoid 2 (Orm2) was overexpressed in OV and ON groups and kinesin 18A (KIF18A) was overexpressed in the ON group. The overexpression levels were verified by real-time RT-PCR and western blotting in the liver and plasma. The transcription and translation levels of these two candidate molecules increased significantly at 21 days post-treatment before tumor development. Immunohistochemistry revealed KIF18A was expressed in the epithelial cells of newly formed small bile ducts, some inflammatory cells and hepatocytes. These results suggest that Orm2 and KIF18A could be the potential biomarkers for early diagnosis of CCA.

Keywords: Opisthorchis viverrini, cholangiocarcinoma, orosomucoid 2, kinesin 18A, plasma proteome

DOI: 10.3233/CBM-130296

Journal: Cancer Biomarkers, vol. 12, no. 2, pp. 81-95, 2013