Aptamer Targets Triple-Negative Breast Cancer through Specific Binding to Surface CD49c

Area of Science:

• Biochemistry
• Oncology
• Molecular Biology

Background:

• Targeted cancer therapies offer improved efficacy and reduced side effects.
• Triple-negative breast cancer (TNBC) lacks specific biomarkers, hindering antibody-based targeted therapy development.

Purpose of the Study:

• To identify the molecular target of the PDGC21T aptamer on TNBC cells.
• To validate CD49c as a potential biomarker for TNBC-targeted therapy.

Main Methods:

• Aptamer-mediated immunoprecipitation followed by LC-MS/MS to identify the aptamer's binding target.
• Cell staining assays using aptamer probes and CD49c antibodies for target validation.
• Competition cell-binding assays to confirm aptamer-CD49c interaction.

Main Results:

• The PDGC21T aptamer selectively binds to cultured TNBC cells and in vivo xenografts.
• LC-MS/MS analysis identified CD49c (integrin α3) as the target protein.
• Aptamer and anti-CD49c antibody staining showed similar patterns on TNBC cells.
• Competition assays confirmed CD49c as the specific target of the PDGC21T aptamer.

Conclusions:

• CD49c is identified as the molecular biomarker targeted by the PDGC21T aptamer on TNBC cells.
• This finding provides a basis for developing PDGC21T aptamer-based targeted therapies for TNBC.
• The study highlights the potential of aptamers in overcoming biomarker limitations in cancer therapy.