Cytarabine hydrochloride

Cytarabine hydrochloride is an antimetabolic agent and DNA synthesis inhibitor with IC50 of 16 nM.

Signaling Pathways >> Autophagy >> Autophagy

Signaling Pathways >> Cell Cycle/DNA Damage >> Nucleoside Antimetabolite/Analog

Research Areas >> Cancer

IC50: 16 nM (DNA synthesis)

Cytarabine is phosphorylated into a triphosphate form (Ara-CTP) involving deoxycytidine kinase (dCK), which competes with dCTP for incorporation into DNA, and then blocks DNA synthesis by inhibiting the function of DNA and RNA polymerases. Cytarabine displays a higher growth inhibitory activity towards wild-type CCRF-CEM cells compared to other acute myelogenous leukemia (AML) cells with IC50 of 16 nM[1]. Cytarabine apparently induces apoptosis of rat sympathetic neurons at 10 μM, of which 100 μM shows the highest toxicity and kills over 80% of the neurons by 84 hours, involving the release of mitochondrial cytochrome-c and the activation of caspase-3, and the toxicity can be attenuated by p53 knockdown and delayed by bax deletion[2].

Cytarabine (250 mg/kg) also causes placental growth retardation and increases placental trophoblastic cells apoptosis in the placental labyrinth zone of the pregnant Slc:Wistar rats, which increases from 3 hour after the treatment and peaks at 6 hour before returning to control levels at 48 hour, with remarkably enhanced p53 protein, p53 trancriptional target genes such as p21, cyclinG1 and fas and caspase-3 activity[3]. Cytarabine is highly effective against acute leukaemias, which causes the chCytarabineteristic G1/S blockage and synchronization, and increases the survival time for leukaemic Brown Norway rats in a weak dose-related fashion indicating that the use of higher dosages of Cytarabine does not contribute to its antileukaemic effectiveness in man[4].

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).

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.

[1]. Tobias, S.C. and R.F. Borch, Synthesis and biological evaluation of a cytarabine phosphoramidate prodrug. Mol Pharm, 2004. 1(2): p. 112-6.

[2]. Besirli, C.G., et al. Cytosine arabinoside rapidly activates Bax-dependent apoptosis and a delayed Bax-independent death pathway in sympathetic neurons. Cell Death Differ, 2003. 10(9): p. 1045-58.

[3]. Yamauchi, H., et al., Involvement of p53 in 1-beta-D-arabinofuranosylcytosine-induced trophoblastic cell apoptosis and impaired proliferation in rat placenta. Biol Reprod, 2004. 70(6): p. 1762-7.

[4]. Richel, D.J., et al., Comparison of the antileukaemic activity of 5 aza-2-deoxycytidine and arabinofuranosyl-cytosine in rats with myelocytic leukaemia. Br J Cancer, 1988. 58(6): p. 730-3.

Azacitidine (5-Azacytidine) | Broxuridine | Forodesine (hydrochloride) | Floxuridine | Raltitrexed | Trifluorothymidine | Vidarabine | Tipiracil hydrochloride | Clofarabine | Doxifluridine | Nelarabine | 8-Azaguanine | RX-3117 | Tegafur | LY2334737

MOLECULAR FORMULA :

C9-H13-N3-O5.Cl-H

MOLECULAR WEIGHT :

279.71

HEALTH HAZARD DATA

ACUTE TOXICITY DATA

TYPE OF TEST :

Standard Draize test

ROUTE OF EXPOSURE :

Administration into the eye

SPECIES OBSERVED :

Human

TYPE OF TEST :

Standard Draize test

ROUTE OF EXPOSURE :

Administration into the eye

SPECIES OBSERVED :

Primate - monkey

TYPE OF TEST :

Standard Draize test

ROUTE OF EXPOSURE :

Administration into the eye

SPECIES OBSERVED :

Rodent - rabbit

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Oral

SPECIES OBSERVED :

Rodent - rat

DOSE/DURATION :

>3200 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Intraperitoneal

SPECIES OBSERVED :

Rodent - rat

DOSE/DURATION :

5500 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Oral

SPECIES OBSERVED :

Rodent - mouse

DOSE/DURATION :

826 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Intraperitoneal

SPECIES OBSERVED :

Rodent - mouse

DOSE/DURATION :

825 mg/kg

TOXIC EFFECTS :

Behavioral - food intake (animal) Behavioral - changes in motor activity (specific assay) Nutritional and Gross Metabolic - weight loss or decreased weight gain

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Subcutaneous

SPECIES OBSERVED :

Rodent - mouse

DOSE/DURATION :

2262 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Intravenous

SPECIES OBSERVED :

Mammal - dog

DOSE/DURATION :

172 mg/kg

TOXIC EFFECTS :

Gastrointestinal - nausea or vomiting

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Intravenous

SPECIES OBSERVED :

Primate - monkey

DOSE/DURATION :

396 mg/kg

TOXIC EFFECTS :

Behavioral - changes in motor activity (specific assay) Gastrointestinal - changes in structure or function of salivary glands Gastrointestinal - nausea or vomiting

TYPE OF TEST :

TDLo - Lowest published toxic dose

ROUTE OF EXPOSURE :

Intraperitoneal

DOSE :

280 mg/kg

SEX/DURATION :

female 15 day(s) after conception

TOXIC EFFECTS :

Reproductive - Effects on Newborn - biochemical and metabolic

TYPE OF TEST :

Specific locus test

TYPE OF TEST :

Cytogenetic analysis

MUTATION DATA

TYPE OF TEST :

Mutation in mammalian somatic cells

TEST SYSTEM :

Rodent - mouse Lymphocyte

DOSE/DURATION :

5 mg/L

REFERENCE :

EMMUEG Environmental and Molecular Mutagenesis. (Alan R. Liss, Inc., 41 E. 11th St., New York, NY 10003) V.10- 1987- Volume(issue)/page/year: 12,85,1988