Investigation Of Primary Liver Cancer Tissue And Serum Globulin By Surface-enhanced Raman Spectroscopy

In this study, we give a brief overview about recent status and diagnosis methods of the primary liver cancer (PLC). Both the basic principle of Raman scattering (RS) and application in biomedicine for cancer diagnosis by RS were presented in this thesis. We carried out series of experiment based on surface enhanced Raman spectroscopy (SERS) for detecting PLC.Histopathologically, liver tissue (including 48 liver cancerous tissues,48 paracancerous tissues and 23 normal tissue) samples were surgically resected from PLC patients. All of samples were frozen in liquid nitrogen then sliced into microsections. The SERS enhanced basement, silver nanoparticles, was added onto the microsections dried natural under 4℃. Near infrared Raman spectrometer was used to detect the SERS spectra of liver tissues. Averaged SERS spectra of three groups liver tissues were very similar, but the difference spectra between each two groups indicated that there still existed large differences among them.Based on principal component analysis (PCA) coupled with linear discriminant analysis (LDA) and receiver operating characteristic (ROC) analysis for tissues SERS spectra, the sensitivity and specificity for distinguishing PLC cancerous tissue from normal liver tissues group were 93.8% and 100%, respectively. The area under corresponding ROC curve was 1. The sensitivity for distinguishing PLC cancerous tissue from liver paracancerous tissues group was 79.2%, specificity was 93.8%. The area under corresponding ROC curve was 0.945. In addition, the sensitivity and specificity for distinguishing paracancerous tissue from normal liver tissues group were 70.8% and 100%, respectively, and the area under corresponding ROC curve was 1. The above research results indicated that it was great potential for PLC detection by tissue SERS spectra, and it also has certain guiding significance to determine the boundary of tumor resection when operating for PLC patients.Pathological examination is the gold standard in clinical diagnosis for PLC. However, it’s not suitable for survey of PLC owing to its invasive examination. In order to explore a rapid and convenient method for screening liver cancer, human serum collected from 30 PLC patients and 30 normal people were studied. The silver nanoparticles were synthetized as SERS enhanced basement. The near-infrared confocal micro Raman spectrometer was used for collecting the normal Raman spectra and SERS spectra of human serum. The averaged spectra of normal Raman spectra and SERS spectra of serum showed that there was certain difference between PLC group and normal people group, so was the difference spectra between them. PCA and LDA were performed on the spectra. The analyzed results showed that it was not perfect to differentiate PLC from normal people by normal Raman spectroscopy and SERS spectroscopy. The diagnosis of sensitivity and specificity by normal Raman spectroscopy was 67.9% and 65.5%, respectively. And that by SERS spectroscopy were 63.3% (sensitivity) and 60.0%(specificity), respectively.To further explore the early detection for PLC, we separated the serum globulins from PLC patients, hepatitis patients and normal people by cellulose acetate membrane electrophoresis(CAME); Then the separated globulins were incubated with silver nanoparticles for SERS spectra detecting. The research results indicted that the SERS spectra of globulins PLC patients, hepatitis patients and normal people were different among them. Compared to the serum spectra for detecting PLC by SERS, our new method can enormously enhance the effectiveness of differentiating PLC from normal people based on SERS coupled with CAME, and the corresponding sensitivity and specificity based on PCA-LDA analysis were 80.5% and 93.3%, respectively, and the area under the ROC curve was 0.931. Meanwhile, this method for separating hepatitis patient from normal people was also very effective, and the corresponding sensitivity and specificity were 79.4% and 90.0%, respectively, and the area under ROC curve was 0.912. Besides, using SERS spectra for differentiating PLC patient from hepatitis patients was effective too, and the corresponding sensitivity was 78.0%, specificity was 73.5% and the area under ROC curve was 0.849.The results of this research showed that surface-enhanced Raman spectroscopy has great potential in clinical application for primary liver cancer detection. However, a lot of research work is needed before clinical application.