Optical sensor revealed abnormal nuclease spatial activity on cancer cell membrane

Area of Science:

• Biochemistry
• Cell Biology
• Molecular Biology

Background:

• Nucleases are enzymes that cleave nucleic acids, crucial for DNA repair and immune defense.
• Their subcellular spatial dynamics, particularly in cancer invasion, remain understudied.
• Membrane-bound nucleases (MNs) are implicated in cancer cell behavior.

Purpose of the Study:

• To develop a sensitive method for mapping membrane-bound nuclease activity at subcellular resolution.
• To investigate the spatial dynamics and levels of MN activity in cancer cells.
• To assess the utility of the developed sensor for single cancer cell detection.

Main Methods:

• Development of a surface-tethered nuclease sensor (SNS) to convert MN activity into a fluorescent signal.
• High-resolution mapping of MN activity on the ventral membrane of cancer cells.
• Quantification of MN activity across multiple cancer and non-cancer cell lines.
• Testing SNS for the detection of single cancer cells among non-cancerous cells.

Main Results:

• SNS successfully mapped MN activity on cell adhesion sites with high resolution and sensitivity.
• MN activity in cancer cells exhibited punctate and coral-shaped patterns.
• MN activity levels were significantly higher in six tested cancer cell lines compared to non-cancer cells.
• SNS accurately detected single breast cancer cells from large populations of adherent non-cancer cells and non-adherent blood cells.

Conclusions:

• The developed SNS provides a sensitive tool for studying MN spatial dynamics at the subcellular level.
• Elevated MN activity is a characteristic of tested cancer cell lines.
• SNS demonstrates potential as a diagnostic tool for sensitive, single-cell cancer detection.