A dual biomarker detection platform for quantitating circulating tumor DNA (ctDNA)

Area of Science:

• Biomedical Engineering
• Molecular Diagnostics
• Cancer Biomarkers

Background:

• Circulating tumor DNA (ctDNA) is a valuable noninvasive biomarker for real-time cancer assessment.
• ctDNA provides critical diagnostic and prognostic information throughout cancer treatment.
• Accurate quantification of ctDNA is essential for personalized cancer therapy.

Purpose of the Study:

• To develop a novel dual biomarker detection platform for sensitive ctDNA quantification.
• To detect tumor-specific mutations and methylation in the PIK3CA gene using ctDNA.
• To establish a DNA biosensor for real-time monitoring of cancer progression.

Main Methods:

• A DNA biosensor was constructed using peptide nucleic acids probe-gold nanoparticles (PNA-AuNPs) and lead phosphate apoferritin (LPA).
• The biosensor utilized a sandwich-structure on a screen-printed electrode (SPE) with PNA probes and anti-5-Methylcytosine antibodies.
• Square-wave voltammetry (SWV) was employed to detect electrochemical signals for ctDNA quantification.

Main Results:

• The DNA biosensor demonstrated a linear current response to ctDNA concentrations from 50-10000 fM.
• A low detection limit of 10 fM was achieved for ctDNA.
• The biosensor successfully detected ctDNA in serum samples from cancer patients.

Conclusions:

• The PNA-AuNPs and LPA-based dual biomarker detection platform offers a sensitive method for ctDNA quantification.
• This biosensor provides a promising approach for noninvasive cancer detection and monitoring.
• The platform facilitates personalized cancer therapy by enabling real-time assessment of malignancies.