[Micro-Raman spectra for lipids in colorectal tissue]

Area of Science:

• Biophysics
• Molecular Spectroscopy
• Oncology

Background:

• Colorectal cancer (CRC) etiology requires molecular-level understanding.
• Biochemical alterations in cancer cells are key to disease progression.
• Non-invasive diagnostic tools are crucial for early cancer detection.

Purpose of the Study:

• To investigate the molecular basis of colorectal cancer using confocal Raman microscopy.
• To identify spectral biomarkers indicative of cancerous transformation in colorectal tissues.
• To differentiate between normal and cancerous colorectal tissues based on lipid molecular signatures.

Main Methods:

• Confocal Raman microscopy was employed to acquire micro-Raman spectra (900-2100 cm(-1)).
• Spectra were collected from 234 samples across 39 patients, comparing cancerous and adjacent normal colorectal tissues.
• Statistical analysis, including mean comparisons and scatter plots, was used to analyze spectral data.

Main Results:

• Decreased Raman bands at 1064 and 1134 cm(-1) (C-C lipid skeleton) were observed in cancer tissues.
• The ratio of Raman intensities (I1299/I1264) differed significantly between normal (3.17) and cancerous (1.33) tissues.
• A decision line (I1299/I1264 = 1.96) achieved 94% accuracy in distinguishing cancer from normal tissue.

Conclusions:

• Spectral differences indicate decreased lipid longitudinal order and increased lipid unsaturation in colorectal cancer.
• These lipid alterations lead to increased lipid fluidity in cancerous cells compared to normal cells.
• Confocal Raman spectroscopy shows potential as a diagnostic tool for colorectal cancer based on lipid molecular changes.