title: The use of spectroscopic imaging and mapping techniques in the characterisation and study of DLD-1 cell spheroid tumour models.
abstract: Determining the chemical and biological compositions of the tumour models used in pharmacological studies is crucial for understanding the interactions between the drug molecules and the tumour micro-environment. Conventional techniques for spheroid characterisation require intensive chemical pre-treatments that result in the removal of unbound metabolites. In this study, the spectroscopic techniques, scanning transmission ion microscopy (STIM), proton-induced X-ray emission (PIXE) mapping, scanning X-ray fluorescence microscopy (SXFM), and Fourier transform infrared (FT-IR) imaging were employed to gain complementary information on the compositions of untreated DLD-l cancer cell spheroids. When used together, these techniques exhibited great potential for providing a comprehensive over-view of the density, biochemistry and elemental compositions within the different regions of the spheroids. STIM density and elemental maps correlated well with cellular density across the spheroid, and showed the accumulation of S, Cu and various lighter elements in the necrotic region. High levels of oxidative stress were evident in the hypoxic region, and different degrees of cellular necrosis as well as high levels of lactate and collagen within the necrotic region were suggested by FT-IR markers. FT-IR imaging was further employed to study the pharmacodynamics of known the cytotoxins, cisplatin and Pt1C3. Cisplatin was observed to induce minimal biochemical changes to the spheroids following 24 hour incubations, whereas Pt1C3 caused severe cellular damage to the spheroid periphery; consistent with their different modes of action.
authors.affiliation: School of Chemistry, The University of Sydney, NSW, 2006, Australia.
authors.forename: Jenny Z
authors.initials: JZ
authors.lastname: Zhang
authors.forename: Nicole S
authors.initials: NS
authors.lastname: Bryce
authors.forename: Rainer
authors.initials: R
authors.lastname: Siegele
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Carter
authors.forename: David
authors.initials: D
authors.lastname: Paterson
authors.forename: Martin D
authors.initials: MD
authors.lastname: de Jonge
authors.forename: Daryl L
authors.initials: DL
authors.lastname: Howard
authors.forename: Chris G
authors.initials: CG
authors.lastname: Ryan
authors.forename: Trevor W
authors.initials: TW
authors.lastname: Hambley
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology; D045744:Cell Line, Tumor; D002945:Cisplatin / Q000494:pharmacology; D003110:Colonic Neoplasms / Q000737:chemistry / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D019344:Lactic Acid / Q000378:metabolism; D046529:Microscopy, Electron, Transmission; D008856:Microscopy, Fluorescence; D018384:Oxidative Stress / Q000502:physiology; D013052:Spectrometry, X-Ray Emission; D017550:Spectroscopy, Fourier Transform Infrared; D018874:Spheroids, Cellular / Q000737:chemistry / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D013455:Sulfur / Q000378:metabolism
chemical_list: D000970:Antineoplastic Agents; D019344:Lactic Acid; D013455:Sulfur; D002945:Cisplatin