Tracking of STAT3 signaling for anticancer drug-discovery based on localized surface plasmon resonance

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Cancer Research

Background:

• Signal transducer and activator of transcription 3 (STAT3) protein signaling is vital for cancer cell survival, invasion, and growth.
• STAT3 protein represents an ideal target for novel anticancer drug discovery and development.
• Existing drug screening methods may lack the sensitivity or specificity required for complex signaling pathway analysis.

Purpose of the Study:

• To develop a label-free sensor system for the ultrasensitive monitoring of STAT3 signaling pathways.
• To enable real-time tracking of STAT3 phosphorylation and dimerization for anticancer drug screening.
• To demonstrate the potential of localized surface plasmon resonance (LSPR) for label-free biosensing in drug discovery.

Main Methods:

• Development of a label-free sensor utilizing localized surface plasmon resonance (LSPR) on gold nanoparticles.
• Monitoring of STAT3 protein phosphorylation and dimerization through LSPR wavelength shifts (λmax).
• Validation of the sensor system using STA-21, a known STAT3 dimerization inhibitor, and MCF-7 cancer cell lines.

Main Results:

• The LSPR sensor detected STAT3 phosphorylation and dimerization with distinct red shifts of 3.46 nm and 9.00 nm, respectively.
• The sensor demonstrated a three-fold reduction in LSPR shift in the presence of the STAT3 inhibitor STA-21, confirming specificity.
• The system exhibited high specificity, reproducibility, and compatibility with real biological samples, such as the MCF-7 cell line.

Conclusions:

• The developed label-free LSPR sensor system is effective for tracking STAT3 signaling pathways.
• This sensor shows significant potential as an accurate and sensitive tool for anticancer drug screening.
• The system offers a promising platform for advancing anticancer therapy development through precise molecular interaction monitoring.