Monitoring The Effect Of TK Gene Therapy On Tumors Using Optical Imaging

Along with the development of optical imaging technologies and widely used in the field of oncology, it doesn't only realize the visualization of the therapy process at the whole-body level, but also be used to research on the molecular mechanism of tumor therapy and metastasis in vivo. In recent years, suicide gene system becomes hope for anti-tumor therapy, because of its own advantages, such as high target-specific and less side-effect than chemotherapeutics.In this dissertation, the anti-tumor effect of Thymidine Kinase (TK) suicide gene was studied with optical imaging technique, and the molecular mechanism of TK gene therapy was explored. The main contents and conclusions are as following.First, TK suicide gene system combined with tumor necrosis factor was used to study the synergetic inhibiting effect on human adenoid cystic carcinoma (ACC-M) cells with optical imaging technique. In vivo results indicated that tumor necrosis factor improved the therapy effect of TK suicide gene system on ACC-M cells, which was also approved by the in vivo results. Furthermore, tumor necrosis factor was found to inhibit tumor growth by destroying the tumor-angiogenesis.Fluorescence Resonance Energy Transfer (FRET) technique was used to study the mechanism of TK gene therapy, by screening the stable CD3-expressing ACC-M cells (ACC-M-CD3), and TK-GFP/CD3 co-expressing ACC-M cells (ACC-M-TK-GFP-CD3). CD3 was the FRET probe for examining the activation of caspase-3 protease. The results indicated that"bystander effect"of TK gene was unrelated with the activation of caspase-3. Moreover, feasible protocol was given to solve the model problem in the process of anti-metastasis therapy, by discussing and dealing with the degradation of metastasis capability and"gene disappearance"of ACC-M-TK-GFP cells.For in vivo monitoring the therapy effect of TK-gene and studying its mechanism, this study provided the tumor models of optical labeled cells and small animal, and the novel optical imaging method. It will be very useful for the study on the anti-tumor effect of TK gene.