A comparative proteomic analysis of bile for biomarkers of cholangiocarcinoma

Abstract

Cholangiocarcinoma is a primary malignant tumor of the bile duct epithelium. Cholangiocarcinoma is usually detected at an advanced stage when successful treatment is no longer possible. As the tumor originates from the bile duct epithelium, bile is an ideal source of tumor biomarkers for cholangiocarcinoma. In this study, we used a quantitative proteomics approach to identify potential tumor-associated proteins in the bile fluid of six cholangiocarcinoma patients. Three different gross-appearance tumor types were used in the analysis: mass-forming type (n = 2), periductal infiltrating type (n = 2), and intraductal growth type (n = 2). Two bile samples from non-cancerous patients were used as controls. Isobaric labeling, coupled with Tandem mass spectrometry, was used to quantify protein levels in the bile of cholangiocarcinoma and control patients. In all, 63 proteins were significantly increased in cholangiocarcinoma bile compared to normal bile. Alpha-1-antitrypsin was one of the overexpressed proteins that increased in cholangiocarcinoma bile samples. Immunohistochemical analysis revealed that alpha-1-antitrypsin was detected in 177 (50%) of 354 cholangiocarcinoma tissues from our Tissue Bank. Immunoblotting of 54 cholangiocarcinoma bile samples showed that alpha-1-antitrypsin was positive in 38 (70%) samples. Fecal enzyme-linked immunosorbent assay showed that alpha-1-antitrypsin level was able to distinguish cholangiocarcinoma patients from normal individuals. In conclusion, alpha-1-antitrypsin is a potential marker for early diagnosis of cholangiocarcinoma.

Constitutive release of CPS1 in bile and its role as a protective cytokine during acute liver injury

“…While nonprotein bile components are well characterized, only a limited number of bile proteins have been identified due to technical challenges (29). Proteomic analysis has identified several proteins in bile (30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40). Notably, CPS1 has not been reported previously as a human bile component, although another urea cycle enzyme, ornithine transcarbamylase, was reported nearly 60 y ago as a bile component, and was studied as a potential marker of liver disease (41)(42)(43)(44)(45).…”

Quantitative proteomic analysis of bile in extrahepatic cholangiocarcinoma patients

“…studies have investigated the possibilities of liquid biopsy using blood, bile juice, sweat, urine, and feces as a novel and noninvasive diagnostic method [2][3][4][5]. Cancer-derived protein can be released into bile by necrosis and apoptosis of tumor cells, and bile includes tumor-specific molecules and provides useful information during malignant transformation in real time [5,6].…”

Proteomic Landscape of Cholangiocarcinomas Reveals Three Different Subgroups According to Their Localization and the Aspect of Non‐Tumor Liver

“…[11] At last, several quantitative proteomic analyses identified biomarkers of CC directly from bile samples. [12][13][14] Using MALDI imaging, an in situ proteomic approach, we confirmed the tumor heterogeneity, at the cellular level, of CC H and iCC and reported an overexpression of human neutrophil peptides 1-3 and S100 proteins (A6 and A11) in the tumor and stromal parts of CC H , respectively. [15] In addition, comparative protein expression performed by a proteinarray approach identified MUC5A, AKT2, keratin 8, and annexin II overexpression in CC H , while VEGFA and filamin A were upregulated in iCC.…”

“…In addition, differential proteomic analysis between normal and malignant cholangiocytes identified a set of deregulated proteins, mostly involved in metabolic pathways and cell structure . At last, several quantitative proteomic analyses identified biomarkers of CC directly from bile samples . Using MALDI imaging, an in situ proteomic approach, we confirmed the tumor heterogeneity, at the cellular level, of CC H and iCC and reported an overexpression of human neutrophil peptides 1–3 and S100 proteins (A6 and A11) in the tumor and stromal parts of CC H , respectively .…”