ABSTRACT
Objective To reveal the impact of anti-lung cancer A549 by theanine, which may regulate T lymphocytes through dendritic cells (DCs), and to observe the immune protection of theanine on SCID mice transplanted tumors. Methods SCID mice were reconstructed after immunization, then A549 cells were inoculated. The immune protection and immune treatment of theanine stimulated DCs were observed. Results In the theanine-stimulated DC group, as well as DC group, the time needed to form tumor were significantly prolonged (F = 29. 5, P ＜ 0. 01). And the transplanted tumors were smallest (F =69. 51, P ＜0. 01) and lightest (F = 190. 9, P ＜0. 01) in the theanine-stimulated DC group. 50 days after tumor-bearing, the transplanted tumors in the theanine-stimulated DC group were smaller than in the control group, and the surface were smoother with no adhesions. Under light microscope, a large thin slice necrosis was showed in the theanine-stimulated DC group, and the VEGF expression was also reduced (F = 31.4, P ＜ 0. 01). Conclusions The anti-tumor immune protection and treatment mechanism of theanine-stimulated DCs were possibly through regulation of T cells, as well as the VEGF expression reducing,thereby inhibited tumor blood vessel formation.
ABSTRACT
Objective To observe the effect of theanine in vitro and in vivo, including suppression of lung tumor growth, tumor an-giogenesis and promotion of apoptosis. Methods The inhibitory effects of theanie on lung cancer A549 cells were analyzed by MTT assays. The cell cycle and the apeptotic percentage of A549 cells were detected by FCM. The angiogenesis effect of theanine was observed with CAM model. The inhibitory effects of theanine were observed with lung carcinoma nude mice model, and the immunohistochemic technique was used to investigate the expression of CD34 and VEGF (vascular endothelial growth factor). Results Treatment of A549 cells with VEGF re-sulted in significant dose-dependent and time-dependent inhibition. FCM detection indicated that administration of EGCG resulted in an in-crease in cells in the S phase of the cell cycle and a typical apoptosis peak before the GI phase with an apoptosis rate of 15.9%. There was a significant difference in tumor volume and weight in theanine group compared with control group after two-week treatment, and the tumor in-hibition rate was 43.6%. There was no significant difference in expression of VEGF in tumor tissue according to tumor MVD marked by CD34 between the theanie group and control group. Thus, theanine could obviously inhibit tumor angiogenesis. Conclusion VEGF can ar-rest lung tumor growth via the promotion of tumor cell apoptosis and the inhibition of tumor angiogenesis.