Abstract
Background: We previously reported that a novel fusion protein (consisting of an amino-terminal fragment of urokinase which binds to the urokinase receptor, and L-methioninase which depletes methionine and arrests the growth of methionine-dependent tumors) inhibited MCF-7 breast cancer cells in vitro. Materials and Methods: We produced this fusion protein, L-methioninase, and a mutated fusion protein without L-methioninase activity by recombinant methods. MCF-7 cell proliferation and mobility were measured in vitro in a culture wounding assay. Protein binding to MCF-7 cells was measured by immunocytochemical localization. MCF-7 tumor xenograft growth was measured in nude mice. Results: The fusion protein was significantly more effective than L-methioninase in either the in vitro or in vivo assays. The binding assay showed that the unmutated and mutated fusion protein bound to the cells, but L-methioninase did not. Conclusion: Our results suggest that this fusion protein has potential as a therapeutic agent for cancer treatment.
Footnotes
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Abbreviations: ATF, amino-terminal fragment of urokinase (amino acids 1-49); IPTG, isopropyl-β-D-thiogalactoside; LB, Luria broth; PMSF, phenylmethylsulfonyl fluoride; SDS-PAGE, sodium dodecyl sulfate-polyacrylamide gel electrophoresis; TPCK, N-p-tosyl-L-phenylalanine chloromethyl ketone.
- Received March 7, 2006.
- Accepted March 15, 2006.
- Copyright© 2006 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved