[Fourier transform infrared spectra analysis of nucleic acid in human breast tissue]

DNA molecular constitution is damaged to result in the inductive variation of base structure in female breast tissue under the influence of physical factors and chemical factors. The present research indicated that the FTIR spectra can reflect sensitively the change in the constitution. Our findings indicated that normal, benign and cancerous breast tissues are different in constitution and content of protein, nucleic acid and sugar, comparing the FTIR spectra, deconvolution spectra and date analysis. The result indicated that the content of collagen protein and nucleic acid increased obviously in cancerous tissue, while the content of glycoprotein increased gradually except mucinous carcinoma. After extracting nucleic acid of breast tissue, we further investigated the difference of constitution and content of base and phosphate by comparing normal, benign and cancerous breast tissues. The spectra and spectral data showed that the degree of hydrogen-bonding of base ring guanine (Gue) increased in cancerous tissue, base ring adenine (Ade) presented mostly in oxydic 8-OH-Ade via the attack of the *OH in cancerous breast, the peak position shifted to higher wave number with enhancing of C=N vibration, and the content of phosphate increased. After deconvolution, the ratio A1080/A1050 showed that the amount of PO2- relative to C-O increased from normal to cancerous breast tissues. It provided a important basis to study the mechanism of cancerization from molecular biology and molecular medicine.