title: Aptamer-based Sandwich Assay and its Clinical Outlooks for Detecting Lipocalin-2 in Hepatocellular Carcinoma (HCC).
abstract: We validated a single-stranded, DNA aptamer-based, diagnostic method capable of detecting Lipocalin-2 (LCN2), a biomarker from clinically relevant hepatocellular carcinoma (HCC) patient serum, in the sandwich assay format. Nine aptamers (LCN2_apta1 to LCN2_apta9) for LCN2 were screened with SELEX processes, and a sandwich pair (LCN2_apta2 and LCN2_apta4) was finally chosen using surface plasmon resonance (SPR) and dot blotting analysis. The result of the proposed aptamer sandwich construction shows that LCN2 was sensitively detected in the concentration range of 2.5-500 ng mL(-1) with a limit of detection of 0.6 ng mL(-1). Quantitative measurement tests in HCC patients were run on straight serum and were compared with the performance of the conventional antibody-based ELISA kit. The aptamer sandwich assay demonstrated an excellent dynamic range for LCN2 at clinically relevant serum levels, covering sub-nanogram per mL concentrations. The new approach offers a simple and robust method for detecting serum biomarkers that have low and moderate abundance. It consists of functionalization, hybridization and signal read-out, and no dilution is required. The results of the study demonstrate the capability of the aptamer sandwich assay platform for diagnosing HCC and its potential applicability to the point-of-care testing (POCT) system.
authors.affiliation: Department of Microbiology, Chungbuk National University, 1 Chungdae-Ro, Seowon-Gu, Cheongju 362-763, South Korea.
authors.forename: Kyeong-Ah
authors.initials: KA
authors.lastname: Lee
authors.affiliation: Department of Microbiology, Chungbuk National University, 1 Chungdae-Ro, Seowon-Gu, Cheongju 362-763, South Korea.
authors.forename: Ji-Young
authors.initials: JY
authors.lastname: Ahn
authors.affiliation: Department of Microbiology, Chungbuk National University, 1 Chungdae-Ro, Seowon-Gu, Cheongju 362-763, South Korea.
authors.forename: Sang-Hee
authors.initials: SH
authors.lastname: Lee
authors.affiliation: Department of Microbiology, Chungbuk National University, 1 Chungdae-Ro, Seowon-Gu, Cheongju 362-763, South Korea.
authors.forename: Simranjeet
authors.initials: S
authors.lastname: Singh Sekhon
authors.affiliation: Division of Gastroenterology and Hepatology, Research Institute of Clinical Medicine, Department of Internal Medicine, Chonbuk National University, Medical School and Hospital, Jeonju, 561-756, South Korea.
authors.forename: Dae-Ghon
authors.initials: DG
authors.lastname: Kim
authors.affiliation: Graduate School of Semiconductor and Chemical Engineering, Chonbuk National University, 567 Baekje-daero, Deokjin-Gu, Jeonju, 561-756, South Korea.
authors.forename: Jiho
authors.initials: J
authors.lastname: Min
authors.affiliation: Department of Microbiology, Chungbuk National University, 1 Chungdae-Ro, Seowon-Gu, Cheongju 362-763, South Korea.
authors.forename: Yang-Hoon
authors.initials: YH
authors.lastname: Kim
mesh_terms: D000209:Acute-Phase Proteins; D000328:Adult; D000368:Aged; D052157:Aptamers, Nucleotide; D006528:Carcinoma, Hepatocellular / Q000097:blood* / Q000175:diagnosis; D005260:Female; D006801:Humans; D000071068:Lipocalin-2; D054834:Lipocalins / Q000097:blood*; D008113:Liver Neoplasms / Q000097:blood* / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D025202:Molecular Diagnostic Techniques; D011518:Proto-Oncogene Proteins / Q000097:blood*; D015203:Reproducibility of Results; D052156:SELEX Aptamer Technique; D012680:Sensitivity and Specificity; D020349:Surface Plasmon Resonance / Q000379:methods
chemical_list: D000209:Acute-Phase Proteins; D052157:Aptamers, Nucleotide; C489506:LCN2 protein, human; D000071068:Lipocalin-2; D054834:Lipocalins; D011518:Proto-Oncogene Proteins