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Published on: January 5, 2024
Fluorescence Imaging Analysis of PTK7 Clustering in Situ via a Programmable DNA Network for Apoptosis Induction and
Kun Han Nie1, Lin Liu1, Haolong Chen2
1Key Laboratory of Biomedical Analytics (Southwest University), Chongqing Science and Technology Bureau, College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, P. R. China.
Abstract:
Inducing cell surface receptor clustering to mediate downstream signaling and reverse drug resistance has become a core cancer therapeutic strategy. However, controllable in situ formation of receptor superclusters remains a key bottleneck. To address these issues, a programmable DNA self-assembly strategy was established by integrating three units of rolling circle amplification (RCA) vector unit, two long DNA strands loaded with aptamer recognition units and the hairpin assembly unit. Fluorescence imaging analysis demonstrated that targeting binding to protein tyrosine kinase 7 (PTK7) can trigger the release of an initiator strand, which in turn activated CHA-driven DNA network formation on the cell membrane. This network induced in situ, self-driven clustering of PTK7 receptors, leading to decreased intracellular calcium levels, loss of mitochondrial membrane potential, and activation of the mitochondrial-mediated intrinsic apoptosis pathway. Ultimately, this process promoted tumor cell apoptosis and downregulated the expression of the resistance-related protein P-glycoprotein (P-gp). This study provides a novel tool for drug-resistant tumor therapy and lays a foundation for antitumor therapy innovation.
Insights
Researchers developed a DNA self-assembly strategy to cluster protein tyrosine kinase 7 (PTK7) on cancer cells. This approach triggers apoptosis and reduces drug resistance protein P-glycoprotein (P-gp) expression, offering a new tool for cancer therapy.
Area of Science:
- Biochemistry
- Molecular Biology
- Nanotechnology
Background:
- Cell surface receptor clustering is crucial for cancer therapy, particularly for reversing drug resistance.
- Controllable *in situ* formation of receptor superclusters is a significant challenge in cancer treatment.
Purpose of the Study:
- To develop a programmable DNA self-assembly strategy for inducing *in situ* receptor clustering.
- To investigate the therapeutic potential of targeting protein tyrosine kinase 7 (PTK7) for cancer treatment.
Main Methods:
- A DNA self-assembly strategy was designed using rolling circle amplification (RCA) vectors, aptamer-loaded DNA strands, and hairpin units.
- Fluorescence imaging was used to analyze the formation of DNA networks and receptor clustering on cell membranes.
- Cellular responses including calcium levels, mitochondrial membrane potential, and apoptosis pathways were assessed.
Main Results:
- Targeting PTK7 initiated DNA network formation and self-driven clustering of PTK7 receptors *in situ*.
- Receptor clustering led to decreased intracellular calcium, loss of mitochondrial membrane potential, and activation of intrinsic apoptosis.
- The treatment downregulated P-glycoprotein (P-gp) expression, a key drug resistance protein.
Conclusions:
- The developed DNA self-assembly system effectively induces PTK7 receptor clustering, promoting tumor cell apoptosis.
- This strategy offers a novel approach for overcoming drug resistance in cancer therapy.
- The study provides a foundation for innovative antitumor therapies using programmable DNA nanotechnology.
