lithium-chloride and Leukemia--Erythroblastic--Acute

Traditional RNA isolation methods use chaotropic agents and anionic detergents to lyse cells and solubilize nucleic acids. In contrast, the cationic surfactant, Catrimox-14, lyses cells and simultaneously precipitates RNA, thereby protecting it from RNases. We describe and compare four methods for extracting RNA from cultured cells that differ in the technique used to extract the RNA from the precipitate. The first uses a high-salt solution (guanidinium isothiocyanate). In the second, the RNA is extracted with a polar solvent (formamide). The third involves conversion of the RNA to the sodium salt by treatment of the precipitate in situ with sodium acetate in ethanol. The fourth uses 2 M lithium chloride to convert the RNA in the pellet to the lithium salt in situ. We applied these methods to human leukemia cells growing in culture and each method resulted in excellent yields of RNA (typically 23 micrograms/million K562 cells, 13 micrograms/million HL-60 cells) over a wide range of cell concentrations (1 x 10(5) - 3 x 10(7)/ml) and of good to excellent quality as judged by agarose electrophoresis and UV absorbance data (OD260/280 1.90-2.05). The advantages and limitations of each method are discussed.

Topics: Acetates; Acetic Acid; Cations; Detergents; Electrophoresis, Agar Gel; Formamides; Guanidines; Humans; Isothiocyanates; Leukemia, Erythroblastic, Acute; Leukemia, Promyelocytic, Acute; Lithium Chloride; Quaternary Ammonium Compounds; RNA, Neoplasm; Trimethyl Ammonium Compounds; Tumor Cells, Cultured

Lithium has been found to be a novel inhibitor of the terminal differentiation of Friend murine erythroleukemia cells. A general method for the quantitative analysis of differentiation inhibitors has been developed and used to compare the site of inhibition by lithium with that by vanadate. Lithium inhibits the commitment to differentiation (K 1/2 approximately 10 mM) induced by DMSO (dimethylsulfoxide) at non-toxic concentrations that have only a small effect on the rate of proliferation. Inhibition is reversible and probably requires entry of Li+ into the cell, since it is blocked by high KCl in the medium. LiCl is most effective when present during the first 10 h of DMSO treatment, before commitment is initiated. Computer-assisted analysis of the kinetics of commitment demonstrate that inhibition by lithium is best described by including a lithium-sensitive 'priming' event, which occurs with high probability prior to commitment.

Topics: Animals; Cell Differentiation; Cell Division; Chlorides; Dimethyl Sulfoxide; Hemoglobins; Kinetics; Leukemia, Erythroblastic, Acute; Leukemia, Experimental; Lithium; Lithium Chloride; Mice; Models, Biological; Stochastic Processes

This report describes the ability of ultra-pure lithium chloride (LiCl) to influence the growth kinetics and differentiation of Friend erythroleukemia cells in vitro. LiCl (0.2-50 mEq/l) was effective in reducing the ability of Friend cells to grow in liquid suspension culture (p less than or equal to 0.001). In addition, the capacity of these erythroleukemic cells to respond to the inducing agent dimethyl sulfoxide (DMSO) was also significantly reduced (p less than or equal to 0.001). These results demonstrate that LiCl can influence not only the proliferation of erythroleukemia cells but also their subsequent differentiation after exposure to such chemical inducers.

Topics: Animals; Cell Differentiation; Cell Division; Cell Line; Chlorides; Clone Cells; Dimethyl Sulfoxide; Erythropoiesis; Friend murine leukemia virus; Kinetics; Leukemia, Erythroblastic, Acute; Leukemia, Experimental; Lithium; Lithium Chloride; Time Factors

Lithium is known to cause leucocytosis in normal humans, and lithium salts have been used therapeutically in attenuating leucopenia in patients undergoing chemotherapy. Recent reports also described leukaemia development during lithium treatment. We have investigated the effect of lithium chloride on the proliferation of human myeloid, erythroblastic, and T- and B-lymphoblast leukaemia cells in vitro. Colony formation by cells of the myeloid leukaemia lines HL-60 and KG-1 was enhanced by lithium chloride, and maximal stimulation was seen at 5 X 10(-4) M. Lithium also increased the proliferation of KG-1a cells, a subline of KG-1 cells that does not respond to colony-stimulating factor, indicating a direct growth-promoting effect on myeloid leukaemia cells. Lithium was found to enhance colony formation by the T-lymphoblast cell line MOLT 4 and the B-lymphoblast line IM-9 at concentrations between 10(-6) and 10(-3) M. The addition of lithium chloride to murine Friend or human K-562 erythroleukaemia cells also caused an augmentation in colony formation. These observations may have relevance to the therapeutic use of lithium in patients with haematological malignancies.

Topics: Animals; Cell Division; Cell Line; Chlorides; Dose-Response Relationship, Drug; Hematopoietic Stem Cells; Humans; Leukemia, Erythroblastic, Acute; Leukemia, Experimental; Leukemia, Lymphoid; Leukemia, Myeloid, Acute; Lithium; Lithium Chloride; Mice