茶氨酸作为茶叶中的功效成分，具有防治肿瘤的活性。茶氨酸与抗肿瘤药物联合作用，能有效地抑制肿瘤生长，阻止肿瘤迁移，降低抗肿瘤药物毒副作用;茶氨酸单独使用可抑制肿瘤细胞浸润和转移。谷氨酸盐载体在茶氨酸生物活性中扮演了重要的角色，茶氨酸通过作用于谷氨酸盐载体，竞争性抑制了肿瘤细胞对谷氨酸盐的吸收，降低了细胞内谷胱甘肽的生物合成，使GS-X生成减少，抗肿瘤药物不能被泵出细胞，在胞内积累，从而增强了抗肿瘤药物的抗癌效果;茶氨酸还可通过调节人体免疫功能单独发挥抗癌作用。
化疗是治疗恶性肿瘤的重要手段，因其毒性强，副作用大，使患者的生活质量降低，另外还易产生耐药性，影响治疗效果。人们期望茶氨酸可以作为一种天然药物，应用于临床治疗，减轻癌症患者经济负担，缓解治疗痛苦，提高患者的生活质量。茶氨酸作为一种天然活性物质，其具有广阔的应用前景，值得继续研究与开发。
【参考文献】
[1] GRAHAM H N. Green tea composition,consumption,and polyphenol chemistry[J].Prev Med,1992,21(3):334-350.
[2] KITAOKA S,HAYASHI H,YOKOGOSHI H,et al. Transmural potential changes associated with the in vitro absorption of theanine in the guinea pig intestine[J]. Biosci Biotechnol Biochem,1996,60(11):1768-1771.
[3] TERASHIMA T,TAKIDO J,YOKOGOSHI H. Time-dependent changes of amino acids in the serum,liver,brain and urine of rats administered with theanine[J].Biosci Biotechnol Biochem,1999,63(4):615-618.
[4] UNNO T,SUZUKI Y,KAKUDA T,et al. Metabolism of theanine,γ-glutamylethylamide,in rats[J].J Agric Food Chem,1999,47(4):1593-1596.
[5] SADZUKA Y,SUGIYAMA T,MIYAGISHIMA A,et al. The effects of theanine,as a novel biochemical modulator,on the antitumor activity of adriamycin[J].Cancer Letters,1996,105(2):203-209.
[6] SUGIYAMA T,SADZUKA Y. Enhancing effects of green tea components on the antitumor activity of adriamycin against M5076 ovarian sarcoma[J].Cancer Lett,1998,133(1):19-26.
[7] SUGIYAMA T,SADZUKA Y. Combination of theanine with doxorubicin inhibits hepatic metastasis of M5076 ovarian sarcoma[J]. Clin Cancer Res,1999,5(2):413-416.
[8] SADZUKA Y,SUGIYAMA T,SONOBE T. Improvement of idarubicin induced antitumor activity and bone marrow suppression by theanine,a component of tea[J]. Cancer Lett,2000,158(2):119-124.
[9] ZHANG Guo-ying,MIURA Y,YAGASAKI K. Inhibitory effects of theanine and sera from theanine-fed rats on receptor-mediated cancer cell invasion beneath mesothelial-cell monolayers[J].Cytotechnology,2001,36(1-3):195-200.
[10] FRIEDMAN M,MACKEY B E,KIM H J,et al. Structure-activity relationships of tea compounds against human cancer cells[J].J Agric Food Chem,2007,55(2):243-253.
[11] LIU Qian,DUAN Hui-ying,LUAN Jin-ling,et al. Effects of theanine on growth of human lung cancer and leukemia cells as well as migration and invasion of human lung cancer cells[J].Cytotechnology,2009,59(3):211-217.