Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1406338 | Journal of Molecular Structure | 2011 | 5 Pages |
Abstract
The interaction of cultured colon cancer cells with alpha-difluoromethylornithine (DFMO), an irreversible inhibitor of ornithine decarboxylase, has been investigated, using Raman micro-spectroscopy, in order to investigate DFMO induced effects. Raman spectra of the cultured HCT116 colon cancer cells treated with DFMO at different concentrations (0, 1, 2.5, 5, and 7.5Â mM) were recorded in the range 550-2300Â cmâ1. It has been shown that second derivative profile of the raw Raman spectrum of the colon cancer cells (i.e., the original experimental spectrum without any computational corrections) discriminates the weak but sharp bands from the strong, broad fluorescence background, and gives information about the position of the peaks and their band widths. The relative integrated intensities of the 781Â cmâ1 and 788Â cmâ1 DNA/RNA marker bands to that of 1451Â cmâ1 band are found to decrease by addition of DFMO. Up to 65% reduction in the magnitude of the 1003Â cmâ1 band, the characteristic phenylalanine ring breathing mode, in comparison to that of 1451 band, is observed. The results indicate DFMO induced apoptosis. On the other hand the intensity ratio of the tyrosine Fermi doubled around 830Â cmâ1 and 850Â cmâ1, which is a marker of hydrogen-bonding state of phenolic OH, is changed. The addition of DFMO may alter the tyrosine environment in cells, and parts of tyrosine residues are exposed. We also observed some modifications in amide I band, pointing out the alterations of the secondary structure of cell proteins by the presence of DFMO.
Keywords
Related Topics
Physical Sciences and Engineering
Chemistry
Organic Chemistry
Authors
S. Akyuz, A.E. Ozel, K. Balci, T. Akyuz, A. Coker, E.D. Arisan, N. Palavan-Unsal, A. Ozalpan,