Background/Aim: Recently, we reported that coiled-coil domain containing 25 (CCDC25) protein is elevated in the sera of patients with cholangiocarcinoma (CCA) and is suggested to be a diagnostic biomarker for CCA. This study aimed to examine whether serum CCDC25 level can be a unique biomarker for CCA. Bioinformatic analyses using Human Protein Atlas (HPA) database and Gene Expression Profiling Interactive Analysis 2 (GEPIA2) indicated that CCDC25 protein and mRNA are expressed not only in CCA but also in other cancers, such as colorectal cancer (CRC), breast cancer (BC), and hepatocellular carcinoma (HCC), all of which are the top 5 cancers highly prevalent in Thailand. Materials and Methods: Using a quantitative dot blot assay, serum CCDC25 levels were measured for 30 healthy controls (HC), 34 CRC, 42 BC, 43 HCC, and 83 CCA. Results: The serum CCDC25 levels of CCA patients (0.193±0.039 ng/μl) were significantly higher than those of CRC (0.019±0.006 ng/μl), BC (0.036±0.015 ng/μl), HCC (0.035±0.016 ng/μl), and higher than those of HC (0.012±0.003 ng/μl). The serum CCDC25 level can discriminate CCA from the HC, CRC, BC, and HCC with a sensitivity of 100, 99, 94, and 94%, respectively, and specificity of 100, 100, 98, and 95%, respectively. Conclusion: CCDC25 is a candidate diagnostic biomarker for CCA.Cholangiocarcinoma (CCA) is a malignancy of cholangiocytes in the intrahepatic and extrahepatic bile ducts. CCA is highly endemic in the Greater Mekong Subregion, particularly Thailand (1). Currently, there is no screening or diagnostic test that can reliably detect CCA at the early stage. The clinicopathological examination is the most reliable method for the diagnosis of CCA. For routine CCA diagnosis, blood biomarkers including alkaline phosphatase (ALP), carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) are currently considered as markers, but they have limited sensitivity and specificity, and CA19-9 is not considered a CCA specific biomarker (2, 3).CCDC25 is a 25 kDa coiled protein present in various mammalian cells. Its encoding gene is located on human 294

Cholangiocarcinoma (CCA) is a tumor arising from cholangiocytes lining the bile ducts. Vascular invasion and lymph node metastasis are important prognostic factors for disease staging as well as clinical therapeutic decisions for CCA patients. In the present study, we applied CCA sera proteomic analysis to identify a potential biomarker for prognosis of CCA patients. Then, using bioinformatics tools, we identified angiopoietin-like protein 4 (ANGPTL4) which expressed highest signal intensity among candidate proteins in proteomic analysis of CCA sera. Expression of ANGPTL4 in CCA tissues was determined using immunohistochemistry. The results showed that ANGPTL4 was stained at higher level in CCA cells when compared with normal cholangiocytes. The high expression of ANGPTL4 was associated with lymph node metastasis and advanced tumor stage (p = 0.013 and p = 0.031, respectively). Furthermore, serum ANGPTL4 levels in CCA and healthy control (HC) were analyzed using a dot blot assay. And it was found that ANGPTL4 level was significantly higher in CCA than HC group (p < 0.0001). ROC curve analysis revealed that serum ANGPTL4 level was effectively distinguished CCA from healthy patients (cutoff = 0.2697 arbitrary unit (AU), 80.0% sensitivity, 72.7% specificity, AUC = 0.825, p < 0.0001). Serum ANGPTL4 level was associated with vascular invasion and lymph node metastasis (p = 0.0004 and p = 0.006), so that it differentiated CCA with vascular invasion from CCA without vascular invasion (cutoff = 0.5526 AU, 64.9% sensitivity, 92.9% specificity, AUC = 0.751, p = 0.006) and it corresponded to CCA with/without lymph node metastasis (cutoff = 0.5399 AU, 71.4% sensitivity, 70.8% specificity, AUC = 0.691, p = 0.01) by ROC analysis. Serum ANGPTL4 levels showed superior predictive efficiency compared with CA 19-9 and CEA for vascular invasion and lymph node metastasis. In addition, serum ANGPTL4 level was an independent predictive indicator by multivariate regression analysis. In conclusion, serum ANGPTL4 could be a novel prognostic biomarker for prediction of vascular invasion and lymph node metastasis of CCA patients.

Background/Aim: Prognosis of cholangiocarcinoma (CCA), especially of intrahepatic CCA (iCCA), is poor primarily due to difficulties in earlier diagnosis. Since the majority of iCCA patients are elders, their prognosis cannot be correctly predicted by pathological features and/or resection status alone. Consideration for comorbidity and/or risks of subclinical diseases at diagnosis is critically necessary for the prediction of prognosis of iCCA patients. This study aimed to develop a simple but reliable scoring system for prognosis of iCCA patients at the time of diagnosis. Patients and Methods: Serum samples from 152 iCCA patients were collected, and four commonly used biochemical markers, serum aspartate aminotransferase, alkaline phosphatase, cystatin C and creatinine-based estimated glomerular filtration rate were measured. Then, the values of individual patients were scored as 0, 1, and 2 (low, medium, and high) by tertiles or clinically relevant cutoff points and summed to construct a prognostic score with a range between 0 to 8. Results: Patients with high scores of 2-4 and 5-8 exhibited significantly shorter survival times compared to those with low scores of 0-1 p<0.001). Cox regression analysis suggested that the score could be an independent predictor for the survival of iCCA patients. The odds of advanced tumor stage in high score iCCA patients (2)(3)(4), respectively. This scoring system allowed further stratification of death rates per 100 person-years of iCCA patients. Conclusion:The ability of such a simple scoring system to discriminate risk might be helpful for iCCA patients to determine therapeutic programs at the time of diagnosis.

Background/Aim: Angiopoietin-like protein 4 (ANGPTL4) is a multifunctional signaling protein implicated in carbohydrate metabolism, inflammation, cancer growth and progression, anoikis resistance, angiogenesis, and metastasis. However, signaling pathways of ANGPTL4 in cholangiocarcinoma (CCA) remain unknown. The aim of this study was to explore ANGPTL4-related signaling proteins and pathways associated with CCA biology. Materials and Methods: ANGPTL4 of CCA cells was silenced by small interfering RNA (siRNA) with scramble control and ANGPTL4-related signaling proteins were investigated using mass spectrometry, bioinformatics tools and molecular docking. Results: Among the 321 differentially expressed proteins, 151 were downregulated. Among them, bioinformatic analyses revealed that ANGPTL4 interacts with DNA-dependent protein kinase catalytic subunit (PRKDC) and 60S ribosomal protein L21 (RPL21) via AKT serine/threonine kinase 1 (AKT1), mechanistic target of rapamycin kinase (MTOR) and ribosomal protein L5 (RPL5). Online database analysis showed that mRNA and protein expression levels of ANGPTL4-related signaling proteins were significantly higher in CCA than in normal tissues. Moreover, a high mRNA expression level was associated with high tumor grade (p<0.0001) and lymph node metastasis (p<0.0001). Conclusion: The signaling pathway of ANGPTL4 in CCA progression might be regulated by PRKDC and RPL21. Furthermore, high expression of ANGPTL4-related signaling proteins has potential to be used in clinical prognosis.Cholangiocarcinoma (CCA) is a type of highly aggressive cancer that can develop anywhere in the biliary tree or within the liver parenchyma (1). It is a rare cancer worldwide, but it is highly prevalent in Thailand, with the highest prevalence of 85/100,000 population being recorded in northeast Thailand and in association with the high prevalence of infection with the oncogenic liver fluke (Opisthorchis viverrini) (2-4). Although complete surgical resection is the only curative treatment for CCA, the postoperative 5-year survival rate of patients remains low (11.2%) due to late presentation of clinical symptoms (5, 6). Carbohydrate antigen 19-9 (CA19-9) and carcinoembryonic antigen (CEA) are currently used tumor markers for clinical diagnosis/prognosis of CCA. However, elevation of these markers has also been found in benign biliary diseases, pancreatic cancer, and colorectal cancer, amongst others (7-9). Hence, developing reliable biomarkers and exploring the mechanisms underlying CCA progression are essential to improve the outcomes of patients with CCA.Angiopoietin-like protein 4 (ANGPTL4) is a secreted protein with a highly hydrophobic signal peptide and has an N-terminal coiled-coil domain and a C-terminal fibrinogen-like fragment (10). It has a variety of biological roles in both normal and 490