Raman spectroscopy of single human tumour cells exposed to ionizing radiation in vitro.
This work investigates the capability of Raman spectroscopy (RS) to study the effects of ionizing radiation on single human tumour cells. Prostate tumour cells (cell line DU145) are cultured in vitro and irradiated to doses between 15 and 50 Gy with single fractions of 6 MV photons. Single-cell Raman spectra are acquired from irradiated and unirradiated cultures up to 5 days post-irradiation. Principal component analysis is used to distinguish the uniquely radiation-induced spectral changes from inherent sources of spectral variability arising from cell cycle differences and other known factors. We observe uniquely radiation-induced spectral changes which are correlated with both the irradiated dose and the incubation time post-irradiation. The spectral changes induced by radiation arise from biochemical differences in lipids, nucleic acids, amino acids and conformational protein structures between irradiated and unirradiated cells. To our knowledge, this study is the first use of RS to observe radiation-induced biochemical differences in single cells, and is the first use of vibrational spectroscopy to observe uniquely radiation-induced biochemical differences in single cells independent of concurrent cell-cycle- or cell-death-related processes.
Department of Physics and Astronomy, University of Victoria, Victoria BC V8W 3P6, Canada. qmatthew@uvic.ca
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Matthews
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Brolo
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Lum
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Duan
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Jirasek
D000596:Amino Acids / Q000528:radiation effects; D002453:Cell Cycle / Q000528:radiation effects; D016923:Cell Death / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D006801:Humans; D008055:Lipids / Q000528:radiation effects; D008297:Male; D009696:Nucleic Acids / Q000528:radiation effects; D017785:Photons; D025341:Principal Component Analysis; D011471:Prostatic Neoplasms / Q000473:pathology / Q000532:radiotherapy; D011487:Protein Conformation / Q000528:radiation effects; D011839:Radiation, Ionizing; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013997:Time Factors; D014407:Tumor Cells, Cultured
D000596:Amino Acids; D008055:Lipids; D009696:Nucleic Acids