Analysis of neoplastic changes in mouse lung using Fourier-transform infrared microspectroscopy

Methods based on infrared microspectroscopy were explored as a means to distinguish normal from neoplastic lung tissue. Mice were exposed to urethane, a known environmental carcinogen. After 3\u20138 months, lungs were removed, snap-frozen, sectioned and analyzed by standard histological methods and by infrared microspectroscopy. Neoplasms were readily observed in mice treated with urethane. Ultra-structurally, the neoplasms were composed entirely of type II alveolar cells displaying intracellular lamellar bodies. A fusion of two spectral pre-processing techniques, optimal region selection and linear discriminant analysis (LDA), was used to search for infrared spectral signatures distinguishing normal from neoplastic tissue. These techniques showed clear and reproducible differences between the complex spectra of these tissue types, suggesting that infrared microspectroscopy in conjunction with spectral processing technology may be useful to reveal subtle spectral differences occurring following induction of neoplastic changes and to interpret their biochemical origins.Peer reviewed: YesNRC publication: Ye