Fluorescence spectra from cancerous and normal human breast and lung tissues

Abstract

Laser spectroscopy provides a unique and sensitive approach to reveal changes in the physical and chemical properties that occur in healthy and abnormal cells in tissues. There are well-known intrinsic fluorophors, flavins, and porphyrins bound to proteins within cells that fluoresce in the visible spectral region. These native fluorophors display well-defined spectral features that characterize the local environment and state of the cells. Recently, Alfano and co-workers1,2 established that the fluorescence spectroscopy and relaxation times from malignant and normal rat tissues were different. The differences were attributed to the transformation of the local environment surrounding the fluorophors assigned to be flavins and porphyrins in the normal and cancerous rat tissues. We extended our past fluorescence work1-3 to human breast and lung tissues. We show that there exist differences in the spectral profiles measured for normal and malignant tissues. The assignments of the fluorescence peaks at ~520 and 600 nm are consistent with our past assignments in rat kidney tissues.1-3 The fluorescence profile for the cancer tissues exhibit smoother spectral profiles than the normal tissues. The 600-nm peaks in the cancer tissue are reduced compared to normal tissues.