We have studied the potential contribution of ABCG2 (breast cancer resistance protein) to resistance to nucleoside analogues. In cells transfected with DNA constructs resulting in overexpression of human or mouse ABCG2, we found resistance against cladribine, clofarabine, fludarabine, 6-mercaptopurine, and 6-mercaptopurine riboside in both MDCKII and HEK293 cells and against gemcitabine only in...

L-Asparaginase, in the dose of greater than or equal to 6000 IU/sq m three times weekly, was demonstrated to be an effective agent in reinduction of remissions in childhood leukemia. Four hundred thirteen children with acute lymphocytic leukemia were treated with L-asparaginase. Doses i.m. ranged from 300 to 12,000 IU/sq m. None of the patients had received prior asparaginase therapy. 6-Mercapt...

Resistance to purine analogs by loss of nucleotide-forming capacity was observed in a number of experimental tumor systems. Such resistance frequently was accom panied by loss of specific purine ribonucleotide pyrophosphorylase activities. How ever, it is evident that other mechanisms of resistance to purine analogs also exist both in mouse leukemia and in human leukemia. Attention was focused ...

The concentrations of homogenate-nitrogen, of DNA, and the activities of various nucleotidases, adenosine deaminase, cathepsin and lactic dehydrogenase have been studied in homogenates of Sarcoma 180 from non treated mice, from mice given injec tions of 6-carboxymethylcellulose in saline, and from mice treated with 6-mercaptopurine suspended in saline containing 6-carboxymethylcellulose. Statis...

Epidemiology From data collected by the Surveillance, Epidemiology, and End Results (SEER) program of the National Cancer Institute, it is estimated that there were 5330 cases of newly diagnosed ALL (3150 in males and 2180 in females) in 2010 in the United States, approximately 60% of which were diagnosed in patients younger than 20 years of age.[1] Hence, while the total number of cases of leu...

By reaction of 6-mercaptopurine (Ia), with acetoxyhydrargyriobenzol resp. mercuric acetate the 6-(phenylhydrargyriothio)-purine (IIa) resp. bis-(6-purinylthio)hydrargyrium (IIIa) was obtained. Analogically were prepared from starting compound Ib-Id the 2-amino-6-(phenylhydrargyriothio)-purine (IIb), its 9-(1-ß-Dribofuranosyl)-derivative (IIc), 4-(phenyl-hydrargyriothio)-pyrazolo[3,4-d]pyrimidin...