Comparison of FTIR spectra of different breast cell lines to detect spectral biomarkers of pathology

Many efforts have been made for several years to make Fourier Transform Infrared (FTIR) micro-spectroscopy usable in the cytological diagnostic. In fact, some events arising when cells undergo a disease, as alterations in the relative content of biochemical cellular components and variations of the proteins secondary structure, lead to modifications of the FTIR spectra, as changes of relative intensity and/or spectral shifts of specific peaks. In this study, we compare FTIR spectra measured for three different breast cell lines: the non-malignant MCF10A cell line, the malignant non-metastatic MCF7 cell line and the metastatic MDA cell line. The major differences of average absorption spectra involve a blue-shift of amide I and II bands and a larger relative intensity of nucleic acid bands in MCF7 spectra with respect to the other ones. Curve fitting also provided important information about spectral markers able to discriminate the three cell lines. In fact, the ratio of sum of the areas of peaks at 2852 and 2922 cm 1 with respect to the sum of the areas of peaks at 2873 and 2958 cm 1 is able to differentiate the non-malignant, malignant and metastatic cells among them. These results suggest that FTIR microspectroscopy may be a potentially useful tool for breast cancer diagnosis at cytological level.