Determination of the Relative Amount of Nucleic Acids and Proteins in Leukemic and Normal Lymphocytes by Means of Fourier Transform Infrared Microspectroscopy

Abstract

Previous Fourier transform infrared (FT-IR) spectroscopic studies on neoplastic and normal cells have shown different band profiles and intensity associated with absorptions of proteins and nucleic acids. In the present study, an interpretation of such differences has been attempted by comparing the spectra of DNA/RNA/protein mixtures with the spectra, particularly, obtained for lymphocytes from B-chronic lymphatic leukemia (B-CLL) patients and normal donors. FT-IR microspectroscopy analysis showed a good agreement between the intensity and the band profile of the spectra of leukemic lymphocytes and those of the binary mixture made up of 75% human serum albumin and 25% DNA. The addition of small amounts of RNA (1–5%) modified the band shape, making it more similar to the spectrum of normal lymphocytes. An attempt was also made to estimate the relative amounts of DNA and RNA. The results demonstrated an increase in the DNA/RNA ratio value in neoplastic lymphocytes with respect to that reported in literature for normal ones.

Infrared spectroscopy as a tool for discrimination between sensitive and multiresistant K562 cells

“…The absorption bands at 1245 and 1087 cm )1 are characteristic of asymmetric and symmetric phosphodiester vibration of nucleic acids [15]. In glycogen-poor cells such as lymphocytes, Benedetti et al assigned the shoulders present at 1117 and 1020 cm )1 to RNA and DNA, respectively [18].…”

Molecular and chemical characterization by Fourier transform infrared spectroscopy of human breast cancer cells with estrogen receptor expressed and not expressed

“…The ratio between proteins (in this case, the amide I absorption band area) and DNA can be related to malignant transformations; that is, this ratio increases as the tumor malignancy level rises [4]. The MCF-7 cell line had an index of around 0.35 ± 0.03, whereas SKBr3 had a higher value, 0.55 ± 0.04, which could indicate that SKBr3 cell line is derived from a more aggressive tumor compared with MCF-7.…”

Estudo da fotocitotoxicidade dos corantes ciânicos com dois cromóforos em culturas de células neoplásicas

“…The most intense is the amide I band, centered near 1640 cm −1 , which corresponds to the C=O stretching coupled with the N-H bending and the C-N stretching modes of peptidic bonds (26,27). The second band, centered around 1540 cm −1 , corresponds to the stretching of amide II (26)(27)(28)(29). Based on the literature, the positions of the amide I and II bands are indicative of protein structure (18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30), as shown in Figure 1.…”

“…The second band, centered around 1540 cm −1 , corresponds to the stretching of amide II (26)(27)(28)(29). Based on the literature, the positions of the amide I and II bands are indicative of protein structure (18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30), as shown in Figure 1.…”

“…As características de um fotossensibilizador ideal para utilização em TFD são [8, 13, 19, 24, 27,28 Outra característica dos CC que favorece essa interação é a presença em sua estrutura da cadeia de conjugação-π, que possui afinidade com as partes hidrofóbicas das estruturas biológicas.…”