FTIR spectroscopic assessment of water structure in human breast benign and malignant tissues

Considerable compositional differences of water, nucleic acids and proteins were observed between benign and malignant breast tissues based on the curve-fitting analysis of the infrared absorption band in the frequency region 3100–3600 cm–1. Compared to normal tissue, the tendency of an increase in the proportions of strongly H-bonded water (ASBW) with biomolecules and a decrease in that of weakly H-bonded water (AWBW) was observed in abnormal tissues. Subsequently, ASBW/AWBW ratios dramatically increased. The proportions of nucleic acid–NH2 groups (ANA) and the proportions of protein N–H groups (APR) in abnormal tissues increased from those of normal tissue. The ratios ANA/APR in fibroadenoma and carcinoma tissues are higher than those in normal and hyperplasia tissues whose ANA/APR ratios are located in the same region. The ANA and ANA/APR in carcinoma tissue are the highest. These differences may be related to the cell proliferation in abnormal tissues and the unregulated growth and dedifferentiation of carcinoma cells.