Stimulated Raman scattering microscopy with spectral phasor analysis: applications in assessing drug-cell...

Area of Science:

• Biophysics
• Cancer Biology
• Pharmacology

Background:

• Statins, primarily for cardiovascular health, exhibit anti-tumour activity in breast cancer.
• Assessing statin efficacy and mechanisms in live cancer cells remains a challenge.

Purpose of the Study:

• To characterize breast cancer cell responses to statins using Stimulated Raman Scattering (SRS) microscopy.
• To investigate potential statin resistance mechanisms in breast cancer cells.

Main Methods:

• Multi-wavelength SRS imaging and spectral phasor analysis were used on MCF-7, SK-BR-3, and MDA-MB-231 cells treated with atorvastatin and rosuvastatin.
• Label-free SRS imaging focused on the high wavenumber Raman spectrum (2800-3050 cm⁻¹) to visualize lipid droplets.
• Spectral phasor analysis differentiated cellular compartments based on intrinsic SRS signals.

Main Results:

• SRS imaging revealed lipid droplet distribution in live breast cancer cells under biocompatible conditions.
• Spectral phasor analysis identified a lipid-accumulating phenotype in statin-resistant cells.
• A weaker lipid accumulation phenotype correlated with reduced cell viability in response to statins.

Conclusions:

• Lipid accumulation may indicate a resistance mechanism in breast cancer cells treated with statins.
• Label-free SRS microscopy offers a novel method for assessing drug-induced phenotypic changes and drug-cell interactions at the subcellular level.