Página 1 a partir de 1305 resultados
Impressive antitumor activity has been observed with fludarabine phosphate against tumors that express Escherichia coli purine nucleoside phosphorylase (PNP) due to the liberation of 2-fluoroadenine in the tumor tissue. 6-Methylpurine (MeP) is another cytotoxic adenine analog that does not exhibit
BACKGROUND
Pancreatic cancer is one of the most common tumors and has a 5-year survival for all stages of less than 5%. Most patients with pancreatic cancer are diagnosed at an advanced stage and therefore are not candidates for surgical resection. In recent years, investigation into alternative
As leads we took several benzo-fused seven- and six-membered scaffolds linked to the pyrimidine or purine moieties with notable anti-proliferative activity against human breast, colon and melanoma cancerous cell lines. We then decided to maintain the double-ringed nitrogenous bases and change the
To explore anti-gastric cancer agents with high efficacy and selectivity, we report the design, synthesis and optimization of a novel series of 3-(2,6,9-trisubstituted-9H-purine)-8-chalcone derivatives starting from the compound PCA-15 reported by us previously. Most of the target compounds
Gene-directed enzyme prodrug therapy based on the E. coli purine nucleoside phosphorylase (PNP) gene produces efficient tumour cell killing. PNP converts adenosine analogs into toxic metabolites that diffuse across cell membranes to kill neighbouring untransduced cells (PNP-GDEPT). Interference with
This report details the effects of methotrexate on the intracellular folate pools of the MCF-7 human breast cancer cell line. To achieve this goal, we designed a high-pressure liquid chromatography system capable of separating the physiologic folates. The folate pools were quantitated following
We measured serial urine levels of hypoxanthine, xanthine, and uric acid in 19 children with acute lymphocytic leukemia (ALL) receiving allopurinol therapy during tumor lysis; four of these children developed acute renal failure. The urinary excretion of uric acid rose moderately from 447 +/- 251
BACKGROUND
The use of Escherichia coli purine nucleoside phosphorylase (PNP) to activate fludarabine has demonstrated safety and antitumor activity during preclinical analysis and has been approved for clinical investigation.
METHODS
A first-in-human phase I clinical trial (NCT 01310179; IND 14271)
Metalation of 6-methyl-9-(tetrahydro-2H-pyran-2-yl)purine (10) with lithiating agents of varying basicities such as n-BuLi and LiHMDS in THF at -78 degrees C resulted in metalation at both of the 6-CH(3) moiety and the 8-CH position, irrespective of the molar equivalence of the base. On the other
Effect of utilization of purine and pyrimidine in the culture medium by human gastric cancer cells (KATO III) was evaluated. Nucleosides mixture solution (OG-VI), consisting of inosine, guanosine 5' monophosphate (5'GMP), cytidine, uridine and thymidine (4: 4: 4: 3: 1 in molar ratio) was used and
The recruitment into the cycling state of resting Yoshida AH 130 hepatoma cells was studied with respect to its dependence on respiration in an experimental system wherein the overall energy requirement for this recruitment can be supplied by the glycolytic ATP. The G1-S transition of these cells,
The changes in the biochemical parameters of peritoneal macrophages and their coupling to the secretory and phagocytic functions in CH3A mice during the growth of the reinoculated solid hepatoma 22a were studied. The DNA and RNA synthesis during the active tumour growth was more intense than that in
The purine de novo biosynthetic pathway has become a target for chemotherapeutic agents and because of the possible contribution of the salvage of extracellular purines to cellular purine pools an examination of the ability of mouse tumors in vivo to exploit the salvage pathways was undertaken. Our
Studies on purine de novo-synthesis and cyclic AMP in normal and pathologic leukocytes. The destruction of neoplastic cells by cytostatic agents depends on the existence of metabolic reactions within the cells which can be specifically blocked by these agents. Concerning the action of purine
We previously showed that classical 6-substituted pyrrolo[2,3-d]pyrimidine antifolates bind to folate receptor (FR) α and the target purine biosynthetic enzyme glycinamide ribonucleotide formyltransferase (GARFTase) with different cis and trans conformations. In this study, we designed novel analogs