Kinase experiment:

Stock solution of Cytarabine is prepared in absolute ethanol, and serial dilutions of Cytarabine are prepared. CCRF-CEM cells are suspended in RPMI medium supplemented with 10% FBS, 0.1% gentamicin, and 1% sodium pyruvate. The cells are suspended in their respective media to give 10 mL volumes of cell suspension at a final density of 3-6×104 cells/mL. Appropriate volumes of Cytarabine solution are transferred to the cell suspensions, and incubation is continued for 72 hours. The cells are spun down and resuspended in fresh Cytarabine -free medium, and final cell counts are determined. The data are analyzed by sigmoidal curve fitting of the cell count versus Cytarabine concentration, and the results are expressed as the IC50 (Cytarabine concentration that inhibits cell growth to 50% of the control value).

Animal experiment:

Pregnant rats are injected intraperitoneally (i.p.) with 250 mg/kg of Cytarabine on Day 13 of gestation (GD13). Under the conditions of this experiment, congenital anomalies and growth retardation are detected at a high rate in perinatal fetuses, although the incidence of fetal death is not markedly increased. At 1, 3, 6, 9, 12, 24, and 48 h after the treatment, six dams each are killed by heart puncture under ether anesthesia, and the placentas are collected. As controls, six pregnant rats are injected i.p. with an equivalent volume of PBS on GD13 and killed at the same time point as Cytarabine-treated groups. Of the six dams obtained at each time point, three are used for histopathological analyses and three for reverse transcription-polymerase chain reaction (RT-PCR) analysis.

Cytarabine hydrochloride is an effective drug in the treatment of cancers of white blood cells [1].

Cytarabine hydrochloride is a dxoxycytidine (dC) analogue. Cytarabine hydrochloride has been found to be phosphorylated into a triphophate form, and thus compete with dCTP for incorporation into DNA. Cytarabine hydrochloride has reported to incorporate into DNA and block DNA synthesis by inhibiting the function of DNA and RNA polymerases. In addition, incorporated has shown a growth inhibition dose-dependent curve using acute myelogenous leukemia (AML) in a growth inhibition assay with IC50 values of 16nM,103μM and 223μM for CCRF-CEM, CEM/AraC8C and CEM/dCK-cell lines, respectively. Moreover, Cytarabine hydrochloride has been exhibited to retrovirally transducer rat leukemic KA cells by WST-1 assay with IC50 values of 0.69μM,1.73μM and 0.037μM for KA, kA/GFP and KA/wt, respectively [1,2].

References:
[1] Tobias SC1, Borch RF.Synthesis and biological evaluation of a cytarabine phosphoramidate prodrug. Mol Pharm. 2004 Mar-Apr; 1(2):112-6.
[2] Veuger MJ1, Heemskerk MH, Honders MW, Willemze R, Barge RM.Functional role of alternatively spliced deoxycytidine kinase in sensitivity to cytarabine of acute myeloid leukemic cells. Blood. 2002 Feb 15; 99(4):1373-80.