Cytotoxic genes from traditional Chinese medicine inhibit tumor growth both in vitro and in vivo

• Published in: Journal of integrative medicine 2014-11, Vol.12 (6), p.483-494
• Main Authors: Zhang, Yuan-hui, Wang, Yuan, Yusufali, Ali Hussein, Ashby, Frederick, Zhang, Daniel, Yin, Zi-fei, Aslanidi, George V., Srivastava, Arun, Ling, Chang-quan, Ling, Chen
• Format: Article
• Language: English
• Subjects: Animals; Antineoplastic Agents, Phytogenic - pharmacology; Apoptosis - physiology; cancer gene therapy; Cell Line, Tumor; cytotoxic genes; Dependovirus; DNA, Complementary; Genetic Vectors; Humans; Liver Neoplasms - physiopathology; medicine, Chinese traditional; Medicine, Chinese Traditional - methods; Mice; Neoplasms - physiopathology; recombinant adeno-associated virus vector; trichosanthin; Trichosanthin - genetics; Trichosanthin - pharmacology; 中国; 传统医药; 体内; 体外抑制作用; 基因抑制; 细胞毒性; 肿瘤生长; 重组腺相关病毒
• ISSN: 2095-4964
• DOI: 10.1016/S2095-4964(14)60057-1

OBJECTIVE： Little effort has been made to study the protein-encoding genes isolated from traditional Chinese medicine（TCM） drugs, and the delivery of these genes into malignant cells through recombinant adeno-associated virus（r AAV） vectors has not been attempted. METHODS： We synthesized the c DNAs of five known cytotoxic proteins isolated from TCM drugs and the FLAG epitope-tagged c DNAs were subcloned into a r AAV plasmid vector. The protein expression was confi rmed by Western blot assay. Various cancer cell lines were transfected with the above plasmids and cell growth was monitored both in vitro and in vivo. The best cytotoxic gene was further packaged into r AAV vectors, under the control of a liver cancer-specifi c promoter. The liver tumor growth was then monitored following intratumor administration of the r AAV vectors.RESULTS： The expression plasmids, encoding individual potential cytotoxic genes tagged with FLAG epitope, were successfully generated and sequenced. Among these genes, trichosanthin（TCS） gene yielded the most promising results for the inhibition of cancer cell growth in vitro. The over-expressed TCS functioned as a type I ribosome-inactivating protein, followed by inducing apoptosis that is associated with the Bcl-PARP signaling pathway. Furthermore, intratumor injection of r AAV vectors containing the TCS gene signifi cantly inhibited the growth of human hepatocellular carcinoma tumors in a murine xenograft model.CONCLUSION： Our studies suggest that the use of TCM cytotoxic genes is a useful therapeutic strategy for treating human cancers in general, and liver tumors in particular.