阿扎胞苷, Azacitidine

5-Azacytidine

Potent DNA methyltransferase 1 (DNMT1) inhibitor (IC50 = 0.2 μM). Incorporated into DNA, inhibits DNMT1 activity to induce DNA hypomethylation. Interferes with protein synthesis. Shows anti-metabolic and anti-cancer activities in vitro. Active in vivo. At high doses the compound can have effects on other DNA methyltransferases.

5-Azacytidine, a chemical analogue of the DNA and RNA nucleoside cytidine, is an inhibitor of DNA methyltransferases, potentially serving to reverse epigenetic changes. It reduces hypermethylation associated with certain diseases, including myelodysplastic syndromes (IC50s = 2.4 and 2.6 μM for in vitro anti-myeloma activity) and cancer (IC50s ~ 0.4 μM for inhibiting proliferation of various cancer cell lines). 5-Azacytidine has a reported half-life of 17 hours and is considerably cytotoxic; it must be incorporated into DNA to covalently trap DNA methyltransferases.

A potent growth inhibitor and cytotoxic agent. It acts as a demethylating agent by inhibiting DNA methyltransferase.

Pharmaceutical secondary standards for application in quality control provide pharma laboratories and manufacturers with a convenient and cost-effective alternative to the preparation of in-house working standards

Azacitidine is a pyrimidine nucleoside analogue of cytidine with antineoplastic activity. Azacitidine is incorporated into DNA, where it reversibly inhibits DNA methyltransferase, thereby blocking DNA methylation. Hypomethylation of DNA by azacitidine may activate tumor suppressor genes silenced by hypermethylation, resulting in an antitumor effect. This agent is also incorporated into RNA, thereby disrupting normal RNA function and impairing tRNA cytosine-5-methyltransferase activity. (NCI04)

Azacitidine is a cytosine analogue and antineoplastic agent used in the therapy of myelodysplastic syndromes. Azacitidine is associated with a low rate of transient serum enzyme elevations during therapy and has only rarely been implicated in cases of clinically apparent acute liver injury with jaundice.

Azacitidine, also known as vidaza or ladakamycin, belongs to the class of organic compounds known as glycosylamines. Glycosylamines are compounds consisting of an amine with a beta-N-glycosidic bond to a carbohydrate, thus forming a cyclic hemiaminal ether bond (alpha-amino ether). Azacitidine is a drug which is used for treatment of patients with the following french-american-british myelodysplastic syndrome subtypes: refractory anemia or refractory anemia with ringed sideroblasts (if accompanied by neutropenia or thrombocytopenia or requiring transfusions), refractory anemia with excess blasts, refractory anemia with excess blasts in transformation (now classified as acute myelogenous leukemia with multilineage dysplasia), and chronic myelomonocytic leukemia. Azacitidine exists as a solid, soluble (in water), and a very weakly acidic compound (based on its pKa). Azacitidine has been detected in multiple biofluids, such as urine and blood. Within the cell, azacitidine is primarily located in the cytoplasm. Azacitidine can be biosynthesized from beta-D-ribose. Azacitidine is formally rated as a probable carcinogen (by IARC 2A) and is also a potentially toxic compound.

An azanucleoside and epigenetic modulator that interferes with nucleic acid metabolism. The compound gets incorporated into RNA and inhibits ribonucleotide reductase subunit RRM2 in leukemia cell lines. Intracellularly, 5-azacytidine can get converted into 2′-deoxy-5-azacytidine (decitabine) and subsequently incorporated in DNA, where it irreversibly inhibits DNMT1 methyltransferase. In human epithelial cell lines, this compound decreases Src-activated expression of a histone chaperone CAF1 and inhibits cell motility and invasiveness.

Title: Azacitidine

CAS Registry Number: 320-67-2

CAS Name: 4-Amino-1-b-D-ribofuranosyl-1,3,5-triazin-2(1H)-one

Additional Names: 5-azacytidine; 5-AzaC; ladakamycin

Manufacturers' Codes: U-18496; NSC-102816

Trademarks: Mylosar (formerly); Vidaza (Pharmion)

Molecular Formula: C8H12N4O5

Molecular Weight: 244.20

Percent Composition: C 39.35%, H 4.95%, N 22.94%, O 32.76%

Literature References: DNA methylation inhibitor; analog of the pyrimidine nucleoside, cytidine, q.v. Chemical synthesis: A. Piskala, F. Sorm, Collect. Czech. Chem. Commun. 29, 2060 (1964); M. W. Winkley, R. K. Robins, J. Org. Chem. 35, 491 (1970). Production by fermentation of Streptoverticillium ladakanus and activity: L. J. Hanka et al., Antimicrob. Agents Chemother. 1966, 619; M. E. Bergy, R. R. Herr, ibid. 625. HPLC determn in pharmaceutical prepns: L. D. Kissinger, N. L. Stemm, J. Chromatogr. 353, 309 (1986). Toxicology study: P. E. Palm, C. J. Kensler, U.S. Clearinghouse Fed. Sci. Tech. Inform. (PB-194791, 1970) 191 pp., C.A. 75, 33704j (1971). Review of clinical experience in acute nonlymphocytic leukemia: A. B. Glover et al., Cancer Treat. Rep. 71, 737-746 (1987); of mechanism of action: A. B. Glover, B. Leyland-Jones, ibid. 959-964. Review of carcinogenic risk: IARC Monographs 50, 47-63 (1990). Clinical efficacy in b-thalassemia: C. H. Lowrey, A. W. Nienhuis, N. Engl. J. Med. 329, 845 (1993); in myelodysplastic syndrome: L. R. Silverman et al., J. Clin. Oncol. 20, 2429 (2002); A. B. Kornblith et al., ibid. 2441.

Properties: Crystals from aq ethanol, mp 235-237° (dec). [a]D26 +22.4° (c = 1 in water). uv max (water): 241 nm (e 8767); (0.01N HCl): 249 nm (e 3077); (0.01N KOH): 223 nm (e 24200). Soly (mg/ml): 40 warm water, 14 cold water, 28 0.1N HCl, 43 0.1N NaOH, 52.7 DMSO, 1 acetone, 1 chloroform, 1 hexane. LD50 in mice (mg/kg): 115.9 i.p.; 572.3 orally (Palm, Kensler).

Melting point: mp 235-237° (dec)

Optical Rotation: [a]D26 +22.4° (c = 1 in water)

Absorption maximum: uv max (water): 241 nm (e 8767); (0.01N HCl): 249 nm (e 3077); (0.01N KOH): 223 nm (e 24200)

Toxicity data: LD50 in mice (mg/kg): 115.9 i.p.; 572.3 orally (Palm, Kensler)

CAUTION: This substance is reasonably anticipated to be a human carcinogen: Report on Carcinogens, Eleventh Edition (PB2005-104914, 2004) p III-24.

Therap-Cat: Antineoplastic.

Keywords: Antineoplastic; Antimetabolites; Pyrimidine Analogs.