Intracellular dynamics of topoisomerase I inhibitor, CPT-11, by slit-scanning confocal Raman microscopy
- 546 Downloads
Most molecular imaging technologies require exogenous probes and may have some influence on the intracellular dynamics of target molecules. In contrast, Raman scattering light measurement can identify biomolecules in their innate state without application of staining methods. Our aim was to analyze intracellular dynamics of topoisomerase I inhibitor, CPT-11, by using slit-scanning confocal Raman microscopy, which can take Raman images with high temporal and spatial resolution. We could acquire images of the intracellular distribution of CPT-11 and its metabolite SN-38 within several minutes without use of any exogenous tags. Change of subcellular drug localization after treatment could be assessed by Raman imaging. We also showed intracellular conversion from CPT-11 to SN-38 using Raman spectra. The study shows the feasibility of using slit-scanning confocal Raman microscopy for the non-labeling evaluation of the intracellular dynamics of CPT-11 with high temporal and spatial resolution. We conclude that Raman spectromicroscopic imaging is useful for pharmacokinetic studies of anticancer drugs in living cells.
KeywordsSlit-scanning Raman microscopy Molecular imaging Non-labeling method Anticancer-drug
We thank Dr. Katsumasa Fujita and Dr. Keisaku Hamada of Osaka University for their helpful discussion, and Dr. Taisuke Ota and Dr. Minoru Kobayashi of Nanophoton Corporation for their useful advice. Grant-in-Aid (C-20500396) from the Ministry of Education, Culture, Sports, Science, and Technology of Japan.
Conflict of interest statement
- Belhoussinea R, Morjania H, Millota JM, Sharonova S, Manfaita M (1998) Confocal scanning microspectrofluorometry reveals specific anthracyline accumulation in cytoplasmic organelles of multidrug-resistant cancer cells. J Histochem Cytochem 46:1369–1376Google Scholar
- Carey PR (1982) Protein conformation from Raman and Resonance Raman spectra. In: Carey PR (ed) Biochemical applications of Raman and resonance Raman spectroscopies. Academic Press, New York, pp 71–98Google Scholar
- Harada Y, Ota T, Dai P, Yamaoka Y, Hamada K, Fujita K, Takamatsu T (2008) Imaging of anticancer agent distribution by a slit-scanning Raman microscope. Proc SPIE 6853:685308–685308-5Google Scholar
- Hu ZP, Yang XX, Chen X, Chan E, Duan W, Zhou SF (2007) Simultaneous determination of irinotecan (CPT-11) and SN-38 in tissue culture media and cancer cells by high performance liquid chromatography: application to cellular metabolism and accumulation studies. J Chromatogr B Analyt Technol Biomed Life Sci 850:575–580PubMedCrossRefGoogle Scholar
- Jolliffe T (2002) Principal component analysis. Springer Series in statistics, 2nd edn. Springer Verlag, New York, pp 1–228Google Scholar
- Nanophoton Co (2008) http://www.nanophoton.jp/eng/index.html
- Oshima Y, Furihata C, Sato H (2008) Development of a direct Raman imaging system for rapid diagnosis of malignant tumor. Proc SPIE 6859:685905–685905-5Google Scholar