TY - JOUR
T1 - Modulation of arabinosylcytosine metabolism by arabinosyl-2-fluoroadenine in lymphocytes from patients with chronic lymphocytic leukemia
T2 - Implications for combination therapy
AU - Gandhi, V.
AU - Nowak, B.
AU - Keating, M. J.
AU - Plunkett, W.
PY - 1989
Y1 - 1989
N2 - 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 μmol/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 μmol/L F-ara-A and 20 to 24 hours after the first dose (25 to 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.
AB - 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 μmol/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 μmol/L F-ara-A and 20 to 24 hours after the first dose (25 to 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.
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U2 - 10.1182/blood.v74.6.2070.2070
DO - 10.1182/blood.v74.6.2070.2070
M3 - Article
C2 - 2478221
AN - SCOPUS:0024436221
SN - 0006-4971
VL - 74
SP - 2070
EP - 2075
JO - Blood
JF - Blood
IS - 6
ER -