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.

STYK1 promotes epithelial-mesenchymal transition and tumor metastasis in human hepatocellular carcinoma through MEK/ERK and PI3K/AKT signaling

“…Although surgical techniques and adjuvant therapy have improved, long-term survival remains low due to metastasis 3 . Aberrant activation and dysfunction of crucial genes result in progression of HCC 4 5 6 . Therefore, it is critical to identify specific molecular markers and elucidate the molecular mechanisms involved in HCC that could serve as clinical/prognostic factors.…”

An Electrochemical Sensor Based on Structure Switching of Dithiol-modified Aptamer for Simple Detection of Ochratoxin A

“…In this study, the proposed sensor was regenerated, as shown in the Experimental section. Briefly, the sensor was incubated with 50 mM NaOH, which is an efficient denaturant reagent for the aptamer 34 and disturbs the interaction between the aptamer and OTA by shifting the pH. Denaturation promoted OTA release without affecting the affinity of the surface-bound aptamer.…”

Gold Nanoparticles for Diagnostics: Advances towards Points of Care

“…These interactions are ruled by a combination of pi bond stacking, London dispersion forces and hydrogen bonding [67,68]. Some aptamers have been developed to bind to wide range of analytes such as metal ions [69]], proteins [70,71] and whole cells [72]. Aptamers are generated through a process denominated systematic evolution of ligands by exponential enrichment (SELEX) [73].…”