Alveolar rhabdomyosarcoma, an aggressive childhood tumor derived from skeletal muscle, exhibits a characteristic 2;13 chromosomal translocation that results in the aberrant expression of a novel fusion protein. The function of the hybrid pax3/ALV protein is unknown but it is thought to act as a transcription factor. To understand the biological significance of this peptide and to determine whether the transcript provides a target for tumor-specific gene modulation, ribozyme-mediated cleavage of the mRNA will be accomplished. Since overexpression of pax3 results in oncogenic transformation in cultured cells, the chimeric pax3/ALV protein may play an important role in both the development of alveolar rhabdomyosarcoma and the inhibition of normal myogenic differentiation. If modulation of the rhabdomyosarcoma phenotype can be achieved, the potential exists for the design of viral vectors that specifically cleave the chimeric mRNA in vivo. Novel adenovirus vectors will be constructed to specifically express ribozymes or suicide inactivation genes in rhabdomyosarcoma. To increase the efficiency of infection of tumor cells in vivo by these recombinant virus, replication-competent adenovirus containing a tumor specific promoter will be produced. The goals of this proposal are therefore to 1) modulate the rhabdomyosarcoma phenotype using ribozymes, 2) design and construct vectors to specifically deliver these agents to the appropriate cells in vivo and 3) develop antibodies raised against the fusion protein to allow rapid diagnosis of alveolar rhabdomyosarcoma in tumor biopsies. Since the use of ribozymes to modulate gene expression is not limited to rhabdomyosarcoma, this proposal may further provide information concerning the applicability of these agents in other tumor model systems.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
First Independent Research Support & Transition (FIRST) Awards (R29)
Project #
5R29CA066124-05
Application #
2871845
Study Section
Experimental Therapeutics Subcommittee 1 (ET)
Program Officer
Forry-Schaudies, Suzanne L
Project Start
1995-02-01
Project End
2000-01-31
Budget Start
1999-02-01
Budget End
2000-01-31
Support Year
5
Fiscal Year
1999
Total Cost
Indirect Cost
Name
St. Jude Children's Research Hospital
Department
Type
DUNS #
067717892
City
Memphis
State
TN
Country
United States
Zip Code
38105
Wierdl, Monika; Wall, Amelia; Morton, Christopher L et al. (2003) Carboxylesterase-mediated sensitization of human tumor cells to CPT-11 cannot override ABCG2-mediated drug resistance. Mol Pharmacol 64:279-88
Wierdl, Monika; Morton, Christopher L; Harris, Linda C et al. (2003) p53-mediated regulation of expression of a rabbit liver carboxylesterase confers sensitivity to 7-ethyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxycamptothecin (CPT-11). J Pharmacol Exp Ther 304:699-705
Morton, C L; Potter, P M (2000) Comparison of Escherichia coli, Saccharomyces cerevisiae, Pichia pastoris, Spodoptera frugiperda, and COS7 cells for recombinant gene expression. Application to a rabbit liver carboxylesterase. Mol Biotechnol 16:193-202
Morton, C L; Wierdl, M; Oliver, L et al. (2000) Activation of CPT-11 in mice: identification and analysis of a highly effective plasma esterase. Cancer Res 60:4206-10
Pawlik, C A; Iyengar, R V; Krull, E J et al. (2000) Use of the ornithine decarboxylase promoter to achieve N-MYC-mediated overexpression of a rabbit carboxylesterase to sensitize neuroblastoma cells to CPT-11. Mol Ther 1:457-63
Potter, P M; McKenzie, P P; Hussain, N et al. (2000) Construction of adenovirus for high level expression of small RNAs in mammalian cells. Application to a Bcl-2 ribozyme. Mol Biotechnol 15:105-14
Wierdl, M; Morton, C L; Danks, M K et al. (2000) Isolation and characterization of a cDNA encoding a horse liver butyrylcholinesterase: evidence for CPT-11 drug activation. Biochem Pharmacol 59:773-81
Morton, C L; Wadkins, R M; Danks, M K et al. (1999) The anticancer prodrug CPT-11 is a potent inhibitor of acetylcholinesterase but is rapidly catalyzed to SN-38 by butyrylcholinesterase. Cancer Res 59:1458-63
Potter, P M; Wolverton, J S; Morton, C L et al. (1998) Cellular localization domains of a rabbit and a human carboxylesterase: influence on irinotecan (CPT-11) metabolism by the rabbit enzyme. Cancer Res 58:3627-32
Danks, M K; Morton, C L; Pawlik, C A et al. (1998) Overexpression of a rabbit liver carboxylesterase sensitizes human tumor cells to CPT-11. Cancer Res 58:20-2

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