Although taxol and many anti-cancer agents are highly lipophilic, they typically do not cross the blood-brain barrier (BBB), due to active efflux by P-glycoprotein. The BBB of patients with malignant brain tumors is often not totally intact and allows chemotherapeutic agents to enter the tumor tissue. However, the amount of drug that reaches the tumor depends on the extent of disruption of the BBB, which varies considerably. Drug concentrations in the brain tissue usually drop with increasing distance from the tumor, and thus the drug concentration is fairly low in the peripheral pars of the tumor, where tumor cells infiltrate the brain. In these areas, where tumor proliferation is most rapid, the BBB is relatively intact. Relapse of patients after surgery is believed to occur from residual tumor cells that have escaped surgery and have infiltrated the """"""""normal"""""""" brain tissue, protected by the BBB. Novel approaches for effective delivery of anti-cancer agents, that are substrates of P-glycoprotein through the BBB would be high desirable and would provide clinicians with additional anti-cancer agents for the treatment of brain tumors in their efforts to increase survival rates of brain tumor patients. Taxol is a representative example of an anti-tumor agent that is a substrate for P-glycoprotein mediated efflux from the BBB. Preliminary results suggest that it is possible to develop taxon analogues that retain cytotoxicity and have the ability to cross the BBB. Based on this observation, the design, synthesis, and biological evaluation of taxon analogues is under study. It is the hypothesis that taxol analogues an be prepared that elude the MDR transporter by altering and/or deleting functional groups that are recognition elements for the transporter. In another approach to overcome P-glycoprotein efflux, it is hypothesized. that analogues in which taxol is covalently linked to known vectors with carriers in the endothelial cells of the BBB will be delivered to the brain with the aid of these transport systems. The designed taxol analogues will be tested for their tubulin assembly properties and their cytotoxic properties against several brain tumor cell lines. They will also be evaluate din vitro for their affinity for the P-glycoprotein in bovine brain micro-vessel endothelial cells (BMEC),a nd for their transcellular permeability properties in diffusion experiments across BMEC monolayers. In vivo studies with an in situ rat perfusion model will be used to assess their in vivo protein to cross the BBB.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA082801-03
Application #
6377426
Study Section
Special Emphasis Panel (ZRG1-BDCN-4 (01))
Program Officer
Jacobs, Tom P
Project Start
1999-07-01
Project End
2004-04-30
Budget Start
2001-05-01
Budget End
2002-04-30
Support Year
3
Fiscal Year
2001
Total Cost
$243,915
Indirect Cost
Name
University of Kansas Lawrence
Department
Pharmacology
Type
Schools of Pharmacy
DUNS #
072933393
City
Lawrence
State
KS
Country
United States
Zip Code
66045
Desino, Kelly E; Ansar, Sabah; Georg, Gunda I et al. (2009) (3R,5S,7as)-(3,5-Bis(4-fluorophenyl)tetrahydro-1H-oxazolo[3,4-c]oxazol-7a-yl)methanol, a novel neuroprotective agent. J Med Chem 52:7537-43
Ge, Haibo; Wang, Jianmei; Kayser, Margaret M et al. (2008) Synthesis, tubulin assembly, and antiproliferative activity against MCF7 and NCI/ADR-RES cancer cells of 10-O-acetyl-5'-hydroxybutitaxel. Bioorg Med Chem Lett 18:6165-7
Turunen, Brandon J; Ge, Haibo; Oyetunji, Jariat et al. (2008) Paclitaxel succinate analogs: Anionic and amide introduction as a strategy to impart blood-brain barrier permeability. Bioorg Med Chem Lett 18:5971-4
Ge, Haibo; Spletstoser, Jared T; Yang, Yan et al. (2007) Synthesis of docetaxel and butitaxel analogues through kinetic resolution of racemic beta-lactams with 7-O-triethylsilylbaccatin III. J Org Chem 72:756-9
Spletstoser, Jared T; Turunen, Brandon J; Desino, Kelly et al. (2006) Single-site chemical modification at C10 of the baccatin III core of paclitaxel and Taxol C reduces P-glycoprotein interactions in bovine brain microvessel endothelial cells. Bioorg Med Chem Lett 16:495-8
Ge, Haibo; Vasandani, Veena; Huff, Jacquelyn K et al. (2006) Synthesis and interactions of 7-deoxy-, 10-deacetoxy, and 10-deacetoxy-7-deoxypaclitaxel with NCI/ADR-RES cancer cells and bovine brain microvessel endothelial cells. Bioorg Med Chem Lett 16:433-6
Rice, Antonie; Liu, Yanbin; Michaelis, Mary Lou et al. (2005) Chemical modification of paclitaxel (Taxol) reduces P-glycoprotein interactions and increases permeation across the blood-brain barrier in vitro and in situ. J Med Chem 48:832-8
Michaelis, M L; Ansar, S; Chen, Y et al. (2005) {beta}-Amyloid-induced neurodegeneration and protection by structurally diverse microtubule-stabilizing agents. J Pharmacol Exp Ther 312:659-68
Michaelis, M L; Seyb, K I; Ansar, S (2005) Cytoskeletal integrity as a drug target. Curr Alzheimer Res 2:227-9
Barboni, Luciano; Giarlo, Guido; Ricciutelli, Massimo et al. (2004) Synthesis, modeling, and anti-tubulin activity of a D-seco paclitaxel analogue. Org Lett 6:461-4

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