Exploring breast cancer-related biochemical changes in circulating extracellular vesicles using Raman spectroscopy

Area of Science:

• Biochemistry
• Biomedical Engineering
• Analytical Chemistry

Background:

• Extracellular vesicles (EVs) are circulating biomarkers with potential for breast cancer (BC) detection.
• Analyzing EV biochemical profiles is challenging due to low abundance, complex composition, and biomolecular corona formation.
• Current methods for EV analysis are often time-consuming and complex.

Purpose of the Study:

• To establish Raman spectroscopy (RS) as a rapid tool for profiling circulating EVs in breast cancer (BC).
• To differentiate EVs from other extracellular particles (EPs) like lipoproteins (LPs) using RS.
• To assess RS's accuracy in quantifying biomolecules and compare it with traditional assays.
• To investigate compositional differences in large EVs (lEVs) and small EVs (sEVs) between BC patients and healthy controls (HC).

Main Methods:

• Raman spectroscopy (RS) was utilized to analyze extracellular particles (EPs) in blood samples.
• RS was employed to differentiate and characterize lipoproteins (LPs) and extracellular vesicles (EVs).
• The study quantified major biomolecule classes using RS and compared results with conventional biochemical assays.
• Compositional analysis of large EVs (lEVs) and small EVs (sEVs) was performed for both healthy controls (HC) and breast cancer (BC) patients.

Main Results:

• Raman spectroscopy successfully differentiated various extracellular particles (EPs), including lipoproteins (LPs) and extracellular vesicles (EVs).
• RS demonstrated capability in quantifying major biomolecule classes, with results comparable to traditional biochemical assays.
• Distinct biochemical signatures were identified in EVs from breast cancer (BC) patients compared to healthy controls (HC).
• Increased levels of nucleic acids and lipids were observed in the EVs of the BC group.

Conclusions:

• Raman spectroscopy is a viable and rapid technique for analyzing the biochemical profile of circulating extracellular vesicles (EVs).
• RS can differentiate EVs from other particles and quantify biomolecules, offering a potential advancement in breast cancer (BC) biomarker research.
• The identified biochemical differences in EVs, specifically elevated nucleic acids and lipids in BC patients, warrant further investigation as potential diagnostic markers.