Caracterização bioquímica de células sadias e neoplásicas através de espectroscopia vibracional / Biochemical characterization of healthy and neoplastic cells by vibrational spectroscopy

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

The molecular mechanisms and changes leading to the development and progression of cancers are extremely complex. FTIR spectroscopy can detect biochemical features of biological materials, enabling the important characterization and differentiation of cells. By looking at the individual absorption bands, it is possible to spot similarities and differences between the cells, which help to understand the changes observed in the same disease cell line group or between healthy and diseases cells. In this work we characterized four sets of neoplastic cells with FTIR spectroscopy. Each cell set was composed of two cell lines: the first one was a set composed by murine melanoma (B16F10) and human melanoma (C8161), the second one was colorectal adenocarcinoma (HT-29), and adenocarcinoma of the cervix (HeLa), the third one two human breast cancers cell lines (SKBr3 cells and MCF-7), and the last one was human leukemia cell line (JURKAT) and peripheral blood mononuclear cell (PBMC). Comparing all cell lines, differences in the following absorption bands were identified: 1084cm-1 (DNA sugar and PO2), 1236cm-1 (phosphodiester bonds), 1540cm-1 (amide II stretching), 2851cm-1, and 2921cm-1 (CH2 stretching). Some groups revealed differences in the absorption bands related to C C and C O stretching (967cm-1), amide I beta sheet and alpha helix structure (1650cm-1 and 1742cm-1, respectively), allowing the characterization of these diseases, differentiating them efficiently through the area and peaks displacement of the absorption bands. Through this work it was possible to verify the FTIR spectroscopy potential for application on basic studies, aiming cells characterization from the biochemical point of view, trying to understand which biological factors are related to each spectral differences observed, and provide qualitative information concerning the chemical bonds associated with certain biomarkers in each biological sample. The ratio analysis between the areas of different absorption bands was another point discussed. By this analysis it was possible to define biomarkers key bands in cell differentiation. The ratios commonly used in the literature were compared and new combinations were evaluated, aiming more efficient differentiation. The new ratios defined were (i) 1053cm-1 and 1084cm-1; (ii) 1540cm-1 and 10840cm-1; (iii) 1650cm-1 and 1084cm-1; (iv) 1395cm-1 and 1053cm-1; (v) 1453cm-1 and 1053cm-1; (vi) 1084cm-1 and 1646cm-1; (vii) 1084cm-1 and 2851cm-1 and, finally, (viii) 1053cm-1 and 3060cm-1. Through these ratios, related to proteins, lipids, DNA and RNA it was possible to differentiate the cell lines not only belonging to the same pathology, but from every each other cell line. Advances related to the detection of biochemical alterations in cells and tissues will occur with the employment of new mathematical procedures for data analysis and the development of new technologies that will enable detection of weak and broad absorption bands with better accuracy. Peak displacement, alterations related to band width, and variations in the relative ratios of the main biological compounds, may carry important information with respect to biomarkers involved with different disease types. These biomarkers, detected by FTIR spectroscopy, will be used to differentiate and classify neoplastic and healthy cells as well as to lead to advances related to the development of clinical protocols.

ASSUNTO(S)

vibracional cell células spectroscopy neoplastic ftir ftir cancer infravermelho câncer espectroscopia

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