Expression, purification, and characterization of active recombinant prostate-specific antigen in Pichia pastoris (yeast).

Background: Prostate-specific antigen (PSA), a member of the kallikrein family of serine proteases, is a chymotrypsin-like glycoprotein produced by the prostate epithelium. Elevated serum PSA (> 4 ng/ml) is a tumor marker for prostatic cancer and benign prostatic hypertrophy; increasing serum PSA over time is indicative of metastatic disease. It has been suggested that PSA may contribute to tumor metastasis through degradation of extracellular matrix glycoproteins, as well as cleavage of IGF binding protein-3, a modulator of IGF-1.

Enzyme inhibition, polyglutamation, and the effect of LY231514 (MTA) on purine biosynthesis.

The pyrrolopyrimidine-based antifolate, N-¿4-[2-(2-amino-3,4-dihydro-4-oxo-7H-pyrrolo[2,3-d]pyrimidin-5-yl)ethyl ]benzoyl¿glutamic acid, LY231514 (MTA) has demonstrated antitumor activity in a broad array of human tumors, including breast cancer, colon cancer, non-small cell lung cancer, head and neck cancer, pancreatic cancer, and other solid tumors. The biochemical basis of this activity was explored by measuring activation of MTA by polyglutamation and the activity of MTA to inhibit several folate-dependent enzymes: thymidylate synthase, dihydrofolate reductase, and glycinamide ribonucleotide formyltransferase (GARFT). The enzyme folylpolyglutamate synthase (FPGS) activated MTA very efficiently.

The synthesis and biological activity of a series of 2,4-diaminopyrido[2,3-d]pyrimidine based antifolates as antineoplastic and antiarthritic agents.

A new series of 2,4-diaminopyrido[2,3-d]pyrimidine based antifolates 1-3 were synthesized through an efficient conversion of 2-pivaloyl-4-oxo-6-ethynylpyrido[2,3-d]pyrimidine 5 to the corresponding 4-amino analog 7 via the activated 1,2,4-triazole intermediate 6. Compound 7 was used as the key intermediate for the preparation of the final products. The detailed biological evaluation of these compounds both as antineoplastic and antiarthritic agents will be discussed.

The antiproliferative and cell cycle effects of 5,6,7, 8-tetrahydro-N5,N10-carbonylfolic acid, an inhibitor of methylenetetrahydrofolate dehydrogenase, are potentiated by hypoxanthine.

5,6,7,8-Tetrahydro-N5,N10-carbonylfolic acid (LY354899) has been demonstrated to inhibit the dehydrogenase activity of C1-tetrahydrofolate synthase. This compound was only moderately antiproliferative toward CCRF-CEM lymphocytic leukemia cells in culture, but induced apoptosis after long incubation times. Slightly greater potency was observed in CEM cells adapted to grow in low folate media.

Multiple folate enzyme inhibition: mechanism of a novel pyrrolopyrimidine-based antifolate LY231514 (MTA).

Extensive biochemical and pharmacological evidence indicates that LY231514 is a novel antifolate antimetabolite. LY231514 is transported into cells mainly through the reduced folate carrier system and extensively metabolized to polyglutamated forms. The polyglutamates of LY231514 inhibit at least three key folate enzymes: TS, DHFR, and GARFT, and to a lesser extent AICARFT and C1-tetrahydrofolate synthase.