Biomaterial Database

Effects of iron, copper and zinc on the activity of ribonucleotide reductase in normal and leukemic human lymphocytes. 1990

M Oblender, and U Carpentieri

Pediatric Department, University of Texas Medical Branch, Galveston 77550.

The activity of ribonucleotide reductase (RR) extracted from normal and leukemic human lymphocytes was assessed. The activity of the enzyme was five times higher in leukemic cells than in normal lymphocytes. Fe and Cu stimulated and Zn inhibited RR activity in both types of cells. Zn also partially reduced the stimulatory effects of Fe and Cu. Deferoxamine (DFX) alone inhibited the activity of the enzyme and enhanced a similar inhibitory action of hydroxyurea (HU). In both cases the inhibitory effects were reversed by Fe and Cu, but not Zn. These findings suggest that: 1) Fe, Cu and Zn may modulate RR activity in vitro and their action is related and interdependent. 2) DFX alone may inhibit RR activity. 3) DFX enhances HU effect on leukemic cells. 4) The effects of both inhibitors may be modified by trace metals.

UI	MeSH Term	Description	Entries
D007501	Iron	A metallic element with atomic symbol Fe, atomic number 26, and atomic weight 55.85. It is an essential constituent of HEMOGLOBINS; CYTOCHROMES; and IRON-BINDING PROTEINS. It plays a role in cellular redox reactions and in the transport of OXYGEN.	Iron-56,Iron 56
D007938	Leukemia	A progressive, malignant disease of the blood-forming organs, characterized by distorted proliferation and development of leukocytes and their precursors in the blood and bone marrow. Leukemias were originally termed acute or chronic based on life expectancy but now are classified according to cellular maturity. Acute leukemias consist of predominately immature cells; chronic leukemias are composed of more mature cells. (From The Merck Manual, 2006)	Leucocythaemia,Leucocythemia,Leucocythaemias,Leucocythemias,Leukemias
D008214	Lymphocytes	White blood cells formed in the body's lymphoid tissue. The nucleus is round or ovoid with coarse, irregularly clumped chromatin while the cytoplasm is typically pale blue with azurophilic (if any) granules. Most lymphocytes can be classified as either T or B (with subpopulations of each), or NATURAL KILLER CELLS.	Lymphoid Cells,Cell, Lymphoid,Cells, Lymphoid,Lymphocyte,Lymphoid Cell
D003300	Copper	A heavy metal trace element with the atomic symbol Cu, atomic number 29, and atomic weight 63.55.	Copper-63,Copper 63
D003676	Deferoxamine	Natural product isolated from Streptomyces pilosus. It forms iron complexes and is used as a chelating agent, particularly in the mesylate form.	Desferrioxamine,Deferoxamine B,Deferoxamine Mesilate,Deferoxamine Mesylate,Deferoxamine Methanesulfonate,Deferoximine,Deferrioxamine B,Desferal,Desferioximine,Desferrioxamine B,Desferrioxamine B Mesylate,Desferroxamine,Mesilate, Deferoxamine,Mesylate, Deferoxamine,Mesylate, Desferrioxamine B,Methanesulfonate, Deferoxamine
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D006918	Hydroxyurea	An antineoplastic agent that inhibits DNA synthesis through the inhibition of ribonucleoside diphosphate reductase.	Hydroxycarbamid,Hydrea,Oncocarbide
D012264	Ribonucleotide Reductases		Ribonucleotide Reductase,Reductase, Ribonucleotide,Reductases, Ribonucleotide
D015032	Zinc	A metallic element of atomic number 30 and atomic weight 65.38. It is a necessary trace element in the diet, forming an essential part of many enzymes, and playing an important role in protein synthesis and in cell division. Zinc deficiency is associated with ANEMIA, short stature, HYPOGONADISM, impaired WOUND HEALING, and geophagia. It is known by the symbol Zn.