) The goal of this research program is the development of new drugs for the treatment of resistant diseases. Although adriamycin (doxorubicin) and other anthracycline drugs are valuable chemotherapeutic agents, a major problem associated with their use is specific and multi-drug resistance. This study will explore the mechanism of drug cytotoxicity in both sensitive and resistant human breast cancer cells, with and without treatment by doxorubicin, daunorubicin, and epidoxorubicin. Preliminary studies indicate that formaldehyde plays a critical role in this mechanism, and that newly synthesized anthracycline-formaldehyde conjugates exhibit greatly enhanced cytotoxicity toward resistant cells. In addition, serious side effects associated with anthracycline drugs, including cardiotoxicity and myelosuppression, may be reduced since the intracellular redox chemistry which produces formaldehyde is now unnecessary. The chemistry, differential cytotoxicity and delivery of these new drugs, Doxoform, Daunoform, and Epidoxoform, will be fully characterized. The studies will be extended to both sensitive and resistant human prostate cancer cells to explore the generality of the drug applicability and mechanism. The aminoglycoside antibiotics such as gentamycin, tobramycin, neomycin, and amikacin will also be examined in conjunction with resistant and sensitive strains of E. coli to determine whether similar mechanisms of cytotoxicity are operative. This research will employ chemical ionization mass spectrometry in a tandem flowing afterglow-selected ion flow tube for the quantitative characterization of formaldehyde and catalytically related species in sensitive and resistant cells, with or without treatment of both conventional drugs and drug-formaldehyde conjugates. These studies will be complemented by confocal microscopy, HPLC, flow cytometry, UV/Visible spectroscopy, NMR, and electrospray mass spectrometry for a full characterization of these systems. The drug effectiveness (IC50) will be interpreted in terms of the intracellular chemistry, drug delivery, and the nature of the drug-DNA adducts as revealed by all these techniques, with the aim of developing even more effective drugs against resistant diseases.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA078756-02
Application #
2896637
Study Section
Special Emphasis Panel (ZRG3-SSS-6 (01))
Program Officer
Forry-Schaudies, Suzanne L
Project Start
1998-07-01
Project End
2001-06-30
Budget Start
1999-07-01
Budget End
2000-06-30
Support Year
2
Fiscal Year
1999
Total Cost
Indirect Cost
Name
University of Colorado at Boulder
Department
Chemistry
Type
Schools of Arts and Sciences
DUNS #
City
Boulder
State
CO
Country
United States
Zip Code
80309
Dernell, William S; Powers, Barbara E; Taatjes, Dylan J et al. (2002) Evaluation of the epidoxorubicin--formaldehyde conjugate, epidoxoform, in a mouse mammary carcinoma model. Cancer Invest 20:713-24
Taatjes, D J; Koch, T H (2001) Nuclear targeting and retention of anthracycline antitumor drugs in sensitive and resistant tumor cells. Curr Med Chem 8:15-29
Kato, S; Burke, P J; Koch, T H et al. (2001) Formaldehyde in human cancer cells: detection by preconcentration-chemical ionization mass spectrometry. Anal Chem 73:2992-7
Burke, P J; Koch, T H (2001) Doxorubicin-formaldehyde conjugate, doxoform: induction of apoptosis relative to doxorubicin. Anticancer Res 21:2753-60
Kato, S; Burke, P J; Fenick, D J et al. (2000) Mass spectrometric measurement of formaldehyde generated in breast cancer cells upon treatment with anthracycline antitumor drugs. Chem Res Toxicol 13:509-16
Gaudiano, G; Koch, T H; Lo Bello, M et al. (2000) Lack of glutathione conjugation to adriamycin in human breast cancer MCF-7/DOX cells. Inhibition of glutathione S-transferase p1-1 by glutathione conjugates from anthracyclines. Biochem Pharmacol 60:1915-23
Taatjes, D J; Fenick, D J; Koch, T H (1999) Nuclear targeting and nuclear retention of anthracycline-formaldehyde conjugates implicates DNA covalent bonding in the cytotoxic mechanism of anthracyclines. Chem Res Toxicol 12:588-96
Taatjes, D J; Koch, T H (1999) Growth inhibition, nuclear uptake, and retention of anthracycline-formaldehyde conjugates in prostate cancer cells relative to clinical anthracyclines. Anticancer Res 19:1201-8
Podell, E R; Harrington, D J; Taatjes, D J et al. (1999) Crystal structure of epidoxorubicin-formaldehyde virtual crosslink of DNA and evidence for its formation in human breast-cancer cells. Acta Crystallogr D Biol Crystallogr 55:1516-23