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Updated: Jan 11, 2026
A Flow Cytometry-Based Cell Surface Protein Binding Assay for Assessing Selectivity and Specificity of an Anticancer Aptamer
Published on: September 13, 2022
Selection and validation of a cell-internalizing DNA aptamer targeting esophageal squamous cell carcinoma
Kunrong Yang1, Zhenzhou Xiao1, Ran Huo1
1Laboratory of Biochemistry and Molecular Biology Research, Department of Clinical Laboratory, Clinical Oncology School of Fujian Medical University, Fujian Cancer Hospital, Fuzhou, 350014, China.
Abstract:
Esophageal squamous cell carcinoma (ESCC) is the main histological subtype of esophageal cancer and one of the major causes of cancer-related death worldwide. Currently, an effective targeted therapy for ESCC is still lacking. Aptamers have been widely used as an effective tool to identify cell surface targets because of their high affinity and specificity. Accordingly, screening internalized aptamers targeting ESCC can promote the development of targeted drug delivery for this disease. Taking KYSE450 cells as the targets, we used the cell-based Systematic Evolution of Ligands by EXponential enrichment (cell-SELEX) protocol combined with a cell internalization strategy to screen aptamers. After 17 rounds of positive and negative strict screening, we confirmed that the best candidate aptamer was Ap1 and obtained its derived aptamer Ap1-1 through sequence optimization. In vitro experiments showed that Ap1-1 could bind many ESCC cell lines, and its dissociation constant was as low as 22.54 nmol/L, showing excellent cell-internalization ability. In an ESCC xenograft tumor model, Ap1-1 showed significant tumor targeting, and its accumulation in tumor tissue was significantly higher than that in the liver, kidney, and other organs 24 h after administration, indicating that it may have a long half-life in vivo and favorable pharmacokinetic characteristics. Based on the excellent tumor-targeting and internalization properties of aptamer Ap1-1, it is expected to be developed as a new molecular tool for targeted therapy and provide a new strategy for precise ESCC treatment.
Insights
Researchers developed a novel aptamer, Ap1-1, for esophageal squamous cell carcinoma (ESCC) targeted therapy. This aptamer effectively targets and internalizes into ESCC cells, showing promise for precise cancer treatment.
Area of Science:
- Biotechnology
- Molecular Biology
- Oncology
Background:
- Esophageal squamous cell carcinoma (ESCC) is a leading cause of cancer death globally.
- Effective targeted therapies for ESCC remain limited.
- Aptamers offer high affinity and specificity for targeting cell surface markers.
Purpose of the Study:
- To screen and develop internalized aptamers for targeted drug delivery in ESCC.
- To identify novel aptamers with high affinity and cell-internalization capabilities for ESCC treatment.
Main Methods:
- Employed cell-based Systematic Evolution of Ligands by EXponential enrichment (cell-SELEX) with a cell internalization strategy.
- Screened aptamers against KYSE450 cells over 17 rounds.
- Optimized aptamer sequence to derive Ap1-1.
Main Results:
- Identified Ap1-1 as a high-affinity aptamer (dissociation constant of 22.54 nmol/L) with excellent cell-internalization ability.
- Ap1-1 demonstrated significant tumor targeting in an ESCC xenograft model.
- Ap1-1 showed higher accumulation in tumor tissue compared to other organs, suggesting favorable in vivo pharmacokinetics.
Conclusions:
- Aptamer Ap1-1 exhibits potent tumor-targeting and cell-internalization properties for ESCC.
- Ap1-1 is a promising molecular tool for developing targeted therapies in ESCC.
- This aptamer provides a new strategy for precise ESCC treatment.
