title: Label-free identification and characterization of living human primary and secondary tumour cells.
abstract: We used three label-free minimally invasive methods to characterize individual cells derived from primary and secondary tumours from the same patient, and of the same type – colorectal. Raman spectroscopy distinguished cells by their biochemical 'fingerprint' in a vibrational spectrum with 100% accuracy, and revealed that the primary cell line contains more lipids and alpha-helix proteins, whereas the secondary cell line contains more porphyrins and beta-sheet proteins. Stimulated Raman scattering (SRS) microscopy distinguished cells in chemically-specific images of CH2 bonds which revealed lipid droplets in secondary tumour cells. Atomic force microscopy (AFM) was used to distinguish cells with 80% accuracy by measuring their elasticity – secondary tumour cells (SW620) are around 3 times softer than primary ones (SW480). As well as characterizing the physical and biochemical differences between cell lines in vitro, these techniques offer three novel methods which could potentially be used for diagnosis – to assign a tumour as primary or secondary.
authors.affiliation: Institute for BioEngineering, University of Edinburgh, UK.
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Tsikritsis
authors.forename: Susanna
authors.initials: S
authors.lastname: Richmond
authors.forename: Patrick
authors.initials: P
authors.lastname: Stewart
authors.forename: Alistair
authors.initials: A
authors.lastname: Elfick
authors.forename: Andrew
authors.initials: A
authors.lastname: Downes
mesh_terms: D045744:Cell Line, Tumor; D006801:Humans; D066292:Lipid Droplets / Q000737:chemistry / Q000473:pathology*; D008055:Lipids / Q000032:analysis*; D008853:Microscopy / Q000379:methods; D018625:Microscopy, Atomic Force; D009369:Neoplasms / Q000737:chemistry / Q000473:pathology*; D011166:Porphyrins / Q000032:analysis*; D017433:Protein Structure, Secondary; D011506:Proteins / Q000032:analysis*; D013059:Spectrum Analysis, Raman / Q000379:methods*; D014407:Tumor Cells, Cultured
chemical_list: D008055:Lipids; D011166:Porphyrins; D011506:Proteins