The goal of this proposal is to advance the treatment of human colon cancer by the development of Fura+AZT-based drug combinations. Studies indicate that AZT-induced cytotoxicity and incorporation into DNA are related to intracellular a) pools of dttp, b) capacity to generate AZTTP and c) DTTP:AZTTP ratios. Proposed experiments will correlate the effect of Fura on these 3 parameters with its ability to increase AZT cytotoxicity in 2 human colon tumor cell lines (HCT-8 and GC3) with different sensitivities to AZT(+/-Fura) (Specific Aim 1, SA1). These studies will be extended in vivo to evaluate the effect(s) that Fura exerts on AZTTP synthesis and utilization in normal and human colon tumor tissue obtained from mice. An important aspect will be to correlate Fura-induced depletion of DTTP pools with its effect on [3H]- AZT incorporation into tissue nucleic acids (SA2). Methods to increase DTTP pools, reduce AZT(+/-Fura) cytotoxicity and increase its therapeutic index will also be developed. In vitro experiments will identify the relationship between cellular pools of dThd and Dthd nucleotides or the cytotoxicity of Fura+AZT, by their quantitation in cells incubated in varying concentrations of exogenous Dthd. The ability of the nucleoside transport inhibitor dipyridamole (DP), alone or combined with exogenous Dthd, to effect these parameters will also be assessed (SA3). In vivo, alterations in tissue Dthd pools, Dthd nucleotide pools and AZT(+/-Fura) incorporation into tissue nucleic acids produced by administration of exogenous Dthd, DP, or their combination, will be investigated (SA4). All of the above studies will serve as the basis for the development (in nude mice bearing human colon tumors) of various preclinical therapeutic regimens of Fura+AZT(SA5). Finally, through multi-center collaborations, these studies will a) serve to identify relevant parameters to be monitored in clinical trials and b) have immediate utility in the design of future clinical trials of Fura+AZT (SA6). In summary, it is anticipated that completion of these studies will have an immediate impact on the therapeutic options for the treatment of human colon cancer.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA055358-02
Application #
3199897
Study Section
Experimental Therapeutics Subcommittee 1 (ET)
Project Start
1992-06-15
Project End
1995-05-31
Budget Start
1993-06-01
Budget End
1994-05-31
Support Year
2
Fiscal Year
1993
Total Cost
Indirect Cost
Name
Roger Williams Hospital
Department
Type
DUNS #
City
Providence
State
RI
Country
United States
Zip Code
02908
Darnowski, J W; Davol, P A; Goulette, F A (1997) Human recombinant interferon alpha-2a plus 3'-azido-3'-deoxythymidine. Synergistic growth inhibition with evidence of impaired DNA repair in human colon adenocarcinoma cells. Biochem Pharmacol 53:571-80
Clark, J; Sikov, W; Cummings, F et al. (1996) Phase II study of 5-fluoruracil leucovorin and azidothymidine in patients with metastatic colorectal cancer. J Cancer Res Clin Oncol 122:554-8
Davol, P A; Goulette, F A; Frackelton Jr, A R et al. (1996) Modulation of p53 expression by human recombinant interferon-alpha2a correlates with abrogation of cisplatin resistance in a human melanoma cell line. Cancer Res 56:2522-6
Beitz, J G; Damowski, J W; Cummings, F J et al. (1995) Phase I trial of high-dose infused zidovudine combined with leucovorin plus fluorouracil. Cancer Invest 13:464-9
Sharma, M; Jain, R; Ionescu, E et al. (1995) Quantitative analysis of 3'-azido-3'-deoxythymidine incorporation into DNA in human colon tumor cells. Bioconjug Chem 6:536-40
Tosi, P; Visani, G; Ottaviani, E et al. (1994) Hydroxyurea enhances 3'-azido-3'-deoxythymidine (AZT) cytotoxicity in human chronic myeloid leukemia models. Eur J Haematol 52:291-5
Darnowski, J W; Goulette, F A (1994) 3'-Azido-3'-deoxythymidine cytotoxicity and metabolism in the human colon tumor cell line HCT-8. Biochem Pharmacol 48:1797-805
Turk, P S; Belliveau, J F; Darnowski, J W et al. (1993) Isolated pelvic perfusion for unresectable cancer using a balloon occlusion technique. Arch Surg 128:533-8;discussion 538-9
Posner, M R; Darnowski, J W; Weitberg, A B et al. (1992) High-dose intravenous zidovudine with 5-fluorouracil and leucovorin. A phase I trial. Cancer 70:2929-34
Tosi, P; Calabresi, P; Goulette, F A et al. (1992) Azidothymidine-induced cytotoxicity and incorporation into DNA in the human colon tumor cell line HCT-8 is enhanced by methotrexate in vitro and in vivo. Cancer Res 52:4069-73