Raman Spectroscopic Studies Of Human Stomach Cells And The Interactions Between Malignant Stomach Cells And Drugs

Stomach cancer has the first mortality in all cancers in china. Early diagnosis of cancer, therefore, is crucial to effective treatment of the patients and to higher survival rates. At present, gastrocopy is the primary method for clinic identification of stomach cancer, but unobvious symptom of the early patients often results in an erroneous diagnosis. It is imperative to develop new techniques to diagnose various cancers at early stage. For treatment of the late cancer patients, chemotherapy is the most effective method applied by doctors. The study of the interaction between anticancer drugs and cells can enhance the efficiency of drugs and reduce the side effects. Raman spectroscopy is a powerful research technique to diagnose cancer cells and to study the interaction between drugs and biological molecules, especially in solution and in living system. In this thesis, Raman spectroscopy is used to study the stomach cells and the interaction between stomach cancer cells and 5-fluorouracil (5-Fu). The main results are as follows:1. In malignant stomach cells, biological molecules such as DNA, protein, lipid, undergo a series of changes in content or structure, that is, the content of nucleic acid increases obviously, and the protein secondary structure in part transforms from -sheet or disordered structures to a-helical. In addition, hydrogen bonds in protein are broken, and the content of lipid decreases.2. The study on the interaction between 5-Fu and stomach cancer cells by Raman spectroscopy indicates that 5-Fu interacts with both normal and malignant cells, but the interaction with the later is rather weak. In the reaction between 5-Fu and malignant stomach cell, 5-Fu restrains the duplication of DNA and reduces the DNA content. It also affects the structure of protein as it changes the number of hydrogen bonds in protein and the saturation of the lipid chain. The reaction also leads to an increase of the lipid content. On contrast, the action between 5-Fu and the normal cells only results in change of the DNA content.