Biochemical differentiation between cancerous and normal human colorectal tissues by micro-Raman spectroscopy

M Karnachoriti; I Stathopoulos; M Kouri; E Spyratou; S Orfanoudakis; D Lykidis; Μ Lambropoulou; N Danias; N Arkadopoulos; E P Efstathopoulos; Y S Raptis; I Seimenis; A G Kontos

doi:10.1016/j.saa.2023.122852

Biochemical differentiation between cancerous and normal human colorectal tissues by micro-Raman spectroscopy

Spectrochim Acta A Mol Biomol Spectrosc. 2023 Oct 15:299:122852. doi: 10.1016/j.saa.2023.122852. Epub 2023 May 14.

Authors

M Karnachoriti¹, I Stathopoulos², M Kouri³, E Spyratou⁴, S Orfanoudakis⁵, D Lykidis⁶, Μ Lambropoulou⁶, N Danias⁷, N Arkadopoulos⁷, E P Efstathopoulos², Y S Raptis⁸, I Seimenis⁹, A G Kontos¹⁰

Affiliations

¹ School of Applied Mathematical and Physical Sciences, National Technical University Athens, 15780 Zografou, Athens, Greece; Department of Medicine, Democritus University of Thrace, 68100 Alexandroupolis, Greece.
² 2(nd) Department of Radiology, Medical School, National & Kapodistrian University of Athens, 15772 Athens, Greece.
³ Department of Medicine, Democritus University of Thrace, 68100 Alexandroupolis, Greece; 2(nd) Department of Radiology, Medical School, National & Kapodistrian University of Athens, 15772 Athens, Greece; Medical Physics Program, University of Massachusetts Lowell, MA 01854, United States.
⁴ Department of Medicine, Democritus University of Thrace, 68100 Alexandroupolis, Greece; 2(nd) Department of Radiology, Medical School, National & Kapodistrian University of Athens, 15772 Athens, Greece.
⁵ School of Applied Mathematical and Physical Sciences, National Technical University Athens, 15780 Zografou, Athens, Greece; Alpha Information Technology S.A., Software & System Development, 68131 Alexandroupolis, Greece.
⁶ Laboratory of Histology-Embryology, Medical Department, Democritus University of Thrace, Alexandroupolis, Greece.
⁷ 4(th) Department of Surgery, School of Medicine, Attikon University Hospital, Univ. of Athens, 12462 Athens, Greece.
⁸ School of Applied Mathematical and Physical Sciences, National Technical University Athens, 15780 Zografou, Athens, Greece.
⁹ Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece.
¹⁰ School of Applied Mathematical and Physical Sciences, National Technical University Athens, 15780 Zografou, Athens, Greece. Electronic address: [email protected].

PMID: 37216817
DOI: 10.1016/j.saa.2023.122852

Abstract

Human colorectal tissues obtained by ten cancer patients have been examined by multiple micro-Raman spectroscopic measurements in the 500-3200 cm^-1 range under 785 nm excitation. Distinct spectral profiles are recorded from different spots on the samples: a predominant 'typical' profile of colorectal tissue, as well as those from tissue topologies with high lipid, blood or collagen content. Principal component analysis identified several Raman bands of amino acids, proteins and lipids which allow the efficient discrimination of normal from cancer tissues, the first presenting plurality of Raman spectral profiles while the last showing off quite uniform spectroscopic characteristics. Tree-based machine learning experiment was further applied on all data as well as on filtered data keeping only those spectra which characterize the largely inseparable data clusters of 'typical' and 'collagen-rich' spectra. This purposive sampling evidences statistically the most significant spectroscopic features regarding the correct identification of cancer tissues and allows matching spectroscopic results with the biochemical changes induced in the malignant tissues.

Keywords: Colorectal cancer; Human colon tissues; K-means clustering; Machine learning; Principal component analysis; Raman spectroscopy.

MeSH terms

Amino Acids
Collagen
Colorectal Neoplasms* / diagnosis
Humans
Principal Component Analysis
Spectrum Analysis, Raman* / methods

Substances

Collagen
Amino Acids