Pharmacology of Selective Antitumor Action Antifolates

Sirotnak, Francis M.

Abstract

Coordinated in vitro and in vivo studies of biochemical and pharmacokinetic aspects of folate analog pharmacology are proposed in murine tumor models. It continues our earlier studies which provided evidence for a role of membrane transport of folate analogs in their selective antitumor action. Studies initiated with L1210 cells will now consider questions as to differences in the multiplicity and structural specificity of systems transporting folate analogs in normal proliferative tissue and tumors differing in responsiveness. Specificity for diastereoisomers of reduced folates, homologs of 4-amino folates and folic acid and metabolites will be evaluated along with dihydrofolate reductase binding specificity. Quantitative aspects of the dynamics and interrelationship between the pharmacokinetics and membrane transport of folate analogs will be sought in different tissues during therapy. Transport parameters will be assessed by measuring intracellular accumulation in vivo, after removing cells from drug-treated mice and also by probing the kinetic interrelationships with pharmacologic agents such as probenacid. The extent and time-course for perturbations of dihydrofolate reductase level, of tetrahydrofolate synthesis and utilization and of dihydrofolate accumulation in various tissues will be explored in vivo during and after therapy and evaluated in respect to requirements for intracellular exchangeable levels of drug. Studies of polyglutamate formation in vivo from methotrexate will be continued and initiated with aminopterin to fully assess this metabolism in terms of the observed pharmacokinetics in each tissue. More rigorous assessment of the membrane permeability and hydrolysis of intracellular polyglutamates vis a vis unchanged analog will also be made. Biochemical studies will also be initiated in L1210 cells in culture seeking a basis of the schedule-dependent synergism between methotrexate and vincristine. Similar studies of the interaction of 5-FU with the 5-arylpyrimidine antifolate, DDMP, will also be initiated to ascertain synergism similar to that demonstrated to 5-FU with methotrexate.

Funding Agency

• Agency: National Institute of Health (NIH)
• Institute: National Cancer Institute (NCI)
• Type: Research Project (R01)
• Project #: 5R01CA022764-08
• Application #: 3165919
• Study Section: Experimental Therapeutics Subcommittee 2 (ET)
• Project Start: 1978-02-01
• Project End: 1986-01-31
• Budget Start: 1985-02-01
• Budget End: 1986-01-31
• Support Year: 8
• Fiscal Year: 1985

Institution

• Name: Sloan-Kettering Institute for Cancer Research
• DUNS #: 064931884
• City: New York
• State: NY
• Country: United States
• Zip Code: 10065

Publications

Piper, J R; Ramamurthy, B; Johnson, C A et al. (1996) Analogues of 10-deazaaminopterin and 5-alkyl-5,10-dideazaaminopterin with the 4-substituted 1-naphthoyl group in the place of 4-substituted benzoyl. J Med Chem 39:614-8

Egan, M G; Sirlin, S; Rumberger, B G et al. (1995) Rapid decline in folylpolyglutamate synthetase activity and gene expression during maturation of HL-60 cells. Nature of the effect, impact on folate compound polyglutamate pools, and evidence for programmed down-regulation during maturation. J Biol Chem 270:5462-8

Bunni, M A; Sirotnak, F M; Otter, G M et al. (1994) Disposition of leucovorin and its metabolites in the plasma, intestinal epithelium, and intraperitoneal L1210 cells of methotrexate-pretreated mice. Cancer Chemother Pharmacol 34:455-8

Schlemmer, S R; Sirotnak, F M (1993) Retentiveness of methotrexate polyglutamates in cultured L1210 cells. Evidence against a role for mediated plasma membrane transport outward. Biochem Pharmacol 45:1261-6

Piper, J R; Johnson, C A; Otter, G M et al. (1992) Synthesis and antifolate evaluation of 10-ethyl-5-methyl-5,10- dideazaaminopterin and an alternative synthesis of 10-ethyl-10- deazaaminopterin (edatrexate). J Med Chem 35:3002-6

Barrueco, J R; O'Leary, D F; Sirotnak, F M (1992) Metabolic turnover of methotrexate polyglutamates in lysosomes derived from S180 cells. Definition of a two-step process limited by mediated lysosomal permeation of polyglutamates and activating reduced sulfhydryl compounds. J Biol Chem 267:15356-61

Piper, J R; Malik, N D; Rhee, M S et al. (1992) Synthesis and antifolate evaluation of the 10-propargyl derivatives of 5-deazafolic acid, 5-deazaaminopterin, and 5-methyl-5-deazaaminopterin. J Med Chem 35:332-7

Barrueco, J R; Sirotnak, F M (1991) Evidence for the facilitated transport of methotrexate polyglutamates into lysosomes derived from S180 cells. Basic properties and specificity for polyglutamate chain length. J Biol Chem 266:11732-7

Rumberger, B G; Barrueco, J R; Sirotnak, F M (1990) Differing specificities for 4-aminofolate analogues of folylpolyglutamyl synthetase from tumors and proliferative intestinal epithelium of the mouse with significance for selective antitumor action. Cancer Res 50:4639-43

Rumberger, B G; Schmid, F A; Otter, G M et al. (1990) Preferential selection during therapy in vivo by edatrexate compared to methotrexate of resistant L1210 cell variants with decreased folylpolyglutamate synthetase activity. Cancer Commun 2:305-10