Secreted antibody/granzyme B fusion protein stimulates selective killing of HER2-overexpressing tumor cells.

Abstract

Targeted cell killing is required for effective treatment of cancers. We previously described the generation of a chimeric immunocasp-3 protein and its potent selective antitumor activity (Jia, L. T., Zhang, L. H., Yu, C. J., Zhao, J., Xu, Y. M., Gui, J. H., Jin, M., Ji, Z. L., Wen, W. H., Wang, C. J., Chen, S. Y., and Yang, A. G. (2003) Cancer Res. 63, 3257-3262). Here we extend the repertoire of another chimeric pro-apoptotic protein immunoGrB, which comprises an anti-HER2 single-chain antibody, a Pseudomonas exotoxin A translocation domain and active granzyme B. Human lymphoma Jurkat cells transfected with the immunoGrB gene expression vector were able to produce and secrete the chimeric protein. The immunoGrB molecule selectively recognized and destroyed HER2-overexpressing tumor cells both in vitro and in nude mouse after intramuscular injection of the immunoGrB expression plasmid. Further in vivo study showed that intravenous administration of immunoGrB gene-modified lymphocytes led to suppression of HER2-overexpressing tumor growth and prolonged animal survival because of continuous secretion of immunoGrB molecules into blood and lymph fluid. These results demonstrate that the chimeric immunoGrB molecule, which is capable of antibody-directed targeting and granzyme B-mediated killing, has therapeutic potential against HER2 tumors, especially in cases in which caspase-dependent apoptosis is inhibited.

• Authors: Jing Zhao, Li-Hong Zhang, Lin-Tao Jia, Li Zhang, Yan-Ming Xu, Zhi Wang, Cui-Juan Yu, Wei-Dan Peng, Wei-Hong Wen, Cheng-Ji Wang, Si-Yi Chen, An-Gang Yang
• Journal: The Journal of biological chemistry (J Biol Chem) Vol. 279 Issue 20 Pg. 21343-8 (May 14 2004) ISSN: 0021-9258 [Print] United States
• PMID: 15004021 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antibodies
• Recombinant Fusion Proteins
• Receptor, ErbB-2
• GZMB protein, human
• Granzymes
• Gzmb protein, mouse
• Serine Endopeptidases

Topics

• Animals
• Antibodies (toxicity)
• Apoptosis (drug effects)
• Breast Neoplasms (genetics, pathology)
• Cell Death (drug effects)
• Cell Line, Tumor
• Female
• Granzymes
• Humans
• Mice
• Mice, Nude
• Receptor, ErbB-2 (genetics)
• Recombinant Fusion Proteins (toxicity)
• Serine Endopeptidases (toxicity)
• Transfection
• Transplantation, Heterologous