LAUSR

Abstract 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.