Research On Breast Cancer By Multi-technical Infrared Spectroscopy

The number of patients suffering from breast cancer continues to increase worldwide.Its survival rate is closely related to the degree of cancer at the time of diagnosis.Therefore,it is of great significance to research on breast cancer in molecular-level and find a fast and accurate diagnosis method to improve the accurate diagnosis,prognosis and survival rate of patients.Because of the good repeatability and high sensitivity,Fourier transform infrared spectroscopy(FTIRS)technology has been widely used in biological tissue detection,which can be used to qualitatively or quantitatively analyze the components of biological tissues.The combination of spectral data and chemometric methods can be used for the classification and identification of normal biological tissues and diseased samples.In this thesis,FTIRS imaging and hollow fiber attenuated total reflection Fourier transform infrared spectroscopy(HOF-ATR-FTIRS)technology were used for breast tissue research.The main contents were listed as below.(1)FTIRS images were obtained through FTIRS imaging technology,the distribution of main component contents was obtained based on the characteristic band absorbance ratio(area ratio)image combined with FTIR spectral analysis.At the same time,it was found that nucleic acid and protein contents increased,and fat and carbohydrate content decreased during the cancerous process.(2)The HOF-ATR-FTIRS technology was used to collect and analyze multi-point FTIR spectra of breast tissues.It was observed that some characteristic bands shifted and absorbances changed,suggesting that the contents of lipid and carbohydrate in breast tissue decreased and the contents of protein and nucleic acid increased during the cancerization.Additionally,the conformation of the methylene chain was disordered and the hydrogen bond strength increased in cancer breast tissue.(3)Based on HOF-ATR-FTIRS technology,principal component analysis-Fisher discrimination analysis(PCA-FDA)model was constructed,and the total discrimination accuracy of the prediction group,95%,was achieved.(4)Compared to healthy breast tissue,breast cancer tissues had lower content in β-sheet,random coil and atypical helix,while the contents of α-helix and turn became higher by calculating the secondary structure content of the protein(amide Ⅰ)band.In addtion,the ratios of α-helix/β-sheet and turn/α-helix were higher in breast cancer tissue,as well as the ratio of atypical helix/α-helix was lower than that in healthy tissue,which indicate that the secondary structure of the protein changes during the cancerous process.This research shows firstly that healthy and cancerous tissues can be distinguished by FTIRS imaging technology intuitively and accurately,which is expected to become an effective tool for basic research and clinical diagnosis.Then,HOF-ATR-FTIRS technology combined with frequency shift and absorbance ratio analysis is helpful for understanding the canceration mechanism of tissue and component change,and it can also realize in situ diagnosis,monitoring and discrimination of breast cancer.Finally,the study on protein secondary structure content further reveals the internal mechnism of breast cancerization.Multi-technical infrared spectroscopy provides new methods and ideas for the research and diagnosis of breast cancer,and is very helpful to better diagnose and monitor breast cancer and other diseases in laboratory and clinic,and to explore corresponding pathogenesis.