FT-IR microspectroscopy as a tool to assess lung cancer cells response to chemotherapy J. Sule ´-Suso a,b, * , D. Skingsley c , G.D. Sockalingum d , A. Kohler e , G. Kegelaer d , M. Manfait d , A.J. El Haj b a Staffordshire Oncology Centre, University Hospital of North Staffordshire, Princes Road, Stoke on Trent ST4 7LN, UK b Institute for Science and Technology in Medicine, Keele University, Thornburrow Drive, Stoke on Trent ST4 7QB, UK c Department of Biological Sciences, Staffordshire University, College Road, Stoke on Trent ST4 2DE, UK d Unite ´ Me ´DIAN, CNRS UMR 6142, UFR de Pharmacie, University of Reims, 51 Rue Cognacq-Jay, 51096 Reims Cedex, France e Norwegian Food Research Institute, MATFORSK, Oslovien 1, N-1430 A ˚ s, Norway Accepted 14 February 2005 Available online 28 March 2005 Abstract Lung cancer is a disease associated with a poor prognosis. One of the reasons for this is the lack of effective treatment. Chemotherapy, together with surgery and radiotherapy, is one of the main treatments for this disease. However, it is not possible at present to determine which tumours would be more sensitive to a given drug or combination of drugs. In this study, FT-IR microspectroscopy was used to assess lung cancer cells response to the chemotherapeutic agent gemcitabine. Studies on two lung cancer cell lines showed that treatment of in vitro growing lung cancer cells with gemcitabine caused changes in their FT-IR spectral pattern in the 950–1150 cm 1 region. An increase in the 1080 cm 1 peak was observed and the 1080 cm 1 /1050 cm 1 ratio, corresponding to symmetric vibrations of PO 2 groups, and C–O stretches of carbohydrates moieties and glycogen, respectively, was found to increase with the dose of gemcitabine added. Furthermore, the 1080 cm 1 / 1050 cm 1 ratio reached a plateau phase when the lethal dose 75 (LD 75 ) was reached in the case of A549 lung cancer cell line and between the LD 50 and LD 75 in the case of CALU-1 lung cancer cell line. The data here presented shows that it is possible not only to detect changes in the spectra of in vitro growing cancer cells following the addition of gemcitabine but also, to correlate these changes with cell survival. # 2005 Elsevier B.V. All rights reserved. Keywords: Lung cancer; Gemcitabine; FT-IR microspectroscopy; Chemotherapy 1. Introduction In the last years, chemotherapy has become one of the main treatments for several types of cancer. However, due to the many mechanisms involved in the interaction of cancer cells with chemotherapeutic agents, some of them still not well characterised, it is always difficult to choose the best chemotherapy drugs for each individual patient. In the case of non-small cell lung cancer, chemotherapy, together with surgery and radiotherapy, is one of the main treatments for this disease. In the UK, the National Institute for Clinical Excellence recommended that cisplatin is the chemother- apeutic drug of choice in combination with vinorelbine, gemcitabine or paclitaxel [1]. However, it is not possible at present to ascertain the correct combination of drug therapies prior to treating each patient. The ideal would be to have a rapid and effective method that could predict tumour cell sensitivity to chemotherapy. This method could be utilised to help clinicians to choose the best drug or combinations of drugs for each patient. One methodology that might play a role in assessing appropriate chemotherapy treatment is Fourier transform infrared (FT-IR) microspectroscopy. This technique uses infrared light that interacts with a sample and measures the vibrational modes of the functional groups of biomolecules present in cells and tissues. The frequency of light that is absorbed depends upon the nature of the bond between the www.elsevier.com/locate/vibspec Vibrational Spectroscopy 38 (2005) 179–184 * Corresponding author. Fax: +44 1782 554649. E-mail address: jsule@dial.pipex.com (J. Sule ´-Suso). 0924-2031/$ – see front matter # 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.vibspec.2005.02.010