Selection and Optimization of a High-Affinity FGFR4 Aptamer that Blocks FGF19-FGFR4 Signaling

Area of Science:

• Biochemistry
• Molecular Biology
• Oncology

Background:

• Fibroblast growth factor receptor 4 (FGFR4) is a critical target in cancers such as hepatocellular carcinoma, driving tumor growth and resistance.
• The FGF19-FGFR4 signaling axis is implicated in various malignancies.

Purpose of the Study:

• To develop and validate high-affinity aptamers targeting FGFR4 for potential therapeutic and diagnostic applications.
• To investigate the functional impact of aptamer-mediated FGFR4 inhibition on cancer cell behavior.

Main Methods:

• Systematic evolution of ligands by exponential enrichment (SELEX) technique was employed to isolate FGFR4-specific aptamers.
• High-throughput sequencing, structural analysis, flow cytometry, surface plasmon resonance (SPR), and pull-down assays were used for aptamer optimization and validation.
• Functional assays assessed the aptamer's ability to block FGF19-FGFR4 interaction and inhibit downstream signaling and cell migration.

Main Results:

• Multiple high-affinity and specific aptamers targeting FGFR4 were successfully generated and optimized.
• The optimized aptamer, FGFR4zxh-11bm, demonstrated high binding affinity and specificity at protein and cellular levels.
• FGFR4zxh-11bm effectively inhibited FGF19-FGFR4 interaction, downstream FRS2 phosphorylation, and migration of hepatocellular carcinoma cells.

Conclusions:

• This study presents the first systematic development of high-affinity aptamers against FGFR4.
• These aptamers serve as valuable tools for studying the FGF19-FGFR4 pathway and offer potential for targeted cancer therapy, particularly for hepatocellular carcinoma.