title: Differentiating responses of lung cancer cell lines to Doxorubicin exposure: in vitro Raman micro spectroscopy, oxidative stress and bcl-2 protein expression.
abstract: The potential of Raman micro spectroscopy as an in vitro, non-invasive tool for clinical applications has been demonstrated in recent years, specifically for cancer research. To further illustrate its potential as a high content and label free technique, it is important to show its capability to elucidate drug mechanisms of action and cellular resistances. In this study, cytotoxicity assays were employed to establish the toxicity profiles for 24 hr exposure of lung cancer cell lines, A549 and Calu-1, to the commercially available drug, doxorubicin (DOX). Raman spectroscopy, coupled with Confocal Laser Scanning Microscopy and Flow Cytometry, was used to track the DOX mechanism of action, at a subcellular level, and to study the mechanisms of cellular resistance to DOX. Biomarkers related to the drug mechanism of action and cellular resistance to apoptosis, namely reactive oxygen species (ROS) and bcl-2 protein expression, respectively, were also measured and correlated to Raman spectral profiles. Calu-1 cells are shown to exhibit spectroscopic signatures of both direct DNA damage due to intercalation in the nucleus and indirect damage due to oxidative stress in the cytoplasm, whereas the A549 cell line only exhibits signatures of the former mechanism of action. PCA of nucleolar, nuclear and cytoplasmic regions of A549 and Calu-1 with corresponding loadings of PC1 and PC2.
authors.affiliation: FOCAS Research Institute, Dublin Institute of Technology, Kevin Street, Dublin, 8, Ireland.|School of Physics, Dublin Institute of Technology, Kevin Street, Dublin, 8, Ireland.
authors.forename: Zeineb
authors.initials: Z
authors.lastname: Farhane
authors.affiliation: Université François-Rabelais de Tours, Faculty of Pharmacy, EA 6295 Nanomédicaments et Nanosondes, 31 avenue Monge, 37200, Tours, France.
authors.forename: Franck
authors.initials: F
authors.lastname: Bonnier
authors.affiliation: FOCAS Research Institute, Dublin Institute of Technology, Kevin Street, Dublin, 8, Ireland.|School of Physics, Dublin Institute of Technology, Kevin Street, Dublin, 8, Ireland.
authors.forename: Marcus Alexander
authors.initials: MA
authors.lastname: Maher
authors.affiliation: FOCAS Research Institute, Dublin Institute of Technology, Kevin Street, Dublin, 8, Ireland.
authors.forename: Jane
authors.initials: J
authors.lastname: Bryant
authors.affiliation: FOCAS Research Institute, Dublin Institute of Technology, Kevin Street, Dublin, 8, Ireland.
authors.forename: Alan
authors.initials: A
authors.lastname: Casey
authors.affiliation: FOCAS Research Institute, Dublin Institute of Technology, Kevin Street, Dublin, 8, Ireland.
authors.forename: Hugh James
authors.initials: HJ
authors.lastname: Byrne
mesh_terms: D045744:Cell Line, Tumor / Q000187:drug effects; D004317:Doxorubicin / Q000494:pharmacology*; D006801:Humans; D008175:Lung Neoplasms; D018384:Oxidative Stress; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D013059:Spectrum Analysis, Raman
chemical_list: C000595707:BCL2 protein, human; D019253:Proto-Oncogene Proteins c-bcl-2; D004317:Doxorubicin
keywords: Confocal Laser Scanning Microscopy; Cytotoxicity; Doxorubicin; Flow Cytometry; ROS; Raman micro spectroscopy; bcl-2 protein; drug resistance