Modulation of arabinosylcytosine metabolism by arabinosyl-2- fluoroadenine in lymphocytes from patients with chronic lymphocytic leukemia: implications for combination therapy
Year: 1989
Type: article
Abstract: Our previous studies indicated that K562 cells loaded with arabinosyl-2-fluoroadenine 5'-triphosphate (F-ara-ATP) accumulated arabinosylcytosine 5'-triphosphate (ara-CTP) at a threefold higher rate compared to the control cells. In the present study lymphocytes were obtained from patients with chronic lymphocytic leukemia before and after F-ara-A monophosphate therapy. The rate of ara-CTP accumulation after in vitro ara-C incubation was compared in lymphocytes obtained prior to therapy without any other manipulation, after ex vivo F-ara-ATP (100 mumol/L) treatment, and after in vivo F-ara-A monophosphate therapy. Lymphocytes showed a 2.2-fold (n = 23) and 1.7-fold (n = 23) median increase in the cellular concentration of ara-CTP after an ex vivo incubation with 100 mumol/L F-ara-A and 20 to 24 hours after the first dose (25 or 30 mg/m2) of F-ara-A monophosphate in vivo treatment, respectively. Although the rates of F-ara-ATP and ara-CTP accumulation varied among patients, a relationship was observed in individuals between the cellular concentration of F-ara-ATP at the beginning of the ara-C incubation and ara-CTP accumulation. These studies strongly suggest that a protocol designed to administer F-ara-A monophosphate prior to ara-C infusion will augment ara-CTP accumulation by leukemia cells.
Source: Blood
Authors: V Gandhi, B Nowak, MJ Keating, W Plunkett
Institution: The University of Texas MD Anderson Cancer Center
Language: English
Subfield: Genetics
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
Funder: National Cancer Institute
Award: G1042671589
OpenAlex ID: W2416330504