Hemoglobin Synthesis in Murine Virus-Induced Leukemic Cells In Vitro: Stimulation of Erythroid Differentiation by Dimethyl Sulfoxide

Abstract

Cells of a cloned line of murine virusinduced erythroleukemia were stimulated to differentiate along the erythroid pathway by dimethyl sulfoxide at concentrations that did not inhibit growth. A rise in the number of benzidine-positive normoblasts was accompanied by increased synthesis of heme and hemoglobin and a decrease in the malignancy of the cells. This action of dimethyl sulfoxide, which was reversible, may represent the derepression of leukemic cells to permit their maturation.The opportunity to explore the possibility that leukemia is a disease resulting from a block in the process of maturation of hematopoietic cells has been provided by established tissue culture lines of murine virus-induced erythroleukemic cells (1-3). These cells, which grow in suspension, have continued to exhibit a limited degree of differentiation along the erythroid line throughout their 4-year serial passage history. Although they synthesize hemoglobin (4, 5), they are malignant as tested by bioassay in syngeneic hosts. They produce virus which, although low in leukemogenic activity, is a highly effective immunizing agent (6).During the course of studies to determine the effect of superinfecting these cells with Friend leukemia virus, dimethyl sulfoxide (DMS0) was added to the medium. DMS0 had been demonstrated to enhance infectivity of both poliovirus RNA (7) and mengovirus RNA (8), as well as transformation by polyoma virus (9). It is also known to stabilize enveloped viruses (10). The wide range of biological activities of DMSO has been described (11). The present report de-scribes an effect of DMSO on the differentiation of established lines of murine virus-induced leukemic cells and illustrates still another property of this compound.In the dose-response experiments initially set up to determine the toxicity of DMSO on the leukemic cell lines, a striking effect on the differentiation of these cells was noted. Of the cells allowed to grow in medium containing 2% DMS0 for 4 days, a majority of the erythroblasts had matured to normoblasts which stained benzidine-positive (B+). The increase in the number of cells maturing along the erythroid series in DMS0-containing medium was accompanied by an increase in the amount of hemoglobin synthesized. MATERIALS AND METHODSThe origin of the cell lines of murine Friend leukemia virusinduced leukemic cells and their clonal derivatives has been described previously (1,2). Methods for maintaining the cell culture, cloning on semisoft agar, and the medium were also detailed in these earlier reports.The present experiments were done on a clone designated 707, in which 1-2% of the cells are B+ (5). Cells were generally seeded at a concentration of 105 per ml (except where otherwise indicated) either in 32-oz. (900 ml) prescription bottles containing 60 ml of medium or in Falcon plastic Petri dishes (60 X 15 mm) containing 10 ml of medium. Dehydrated Eagle's basal medium diluted with Earle's balanced salt solution and supplemented with 15% fetal calf serum was used. The cultures were ...

The carbonic anhydrase I locus contains a c-Myb target promoter and modulates differentiation of murine erythroleukemia cells

“…Friend virus-infected mouse erythroleukemia (MEL) cell lines provide an early erythroid precursor model system that can be induced to terminally differentiate with chemical agents such as HMBA in cell culture (Friend et al, 1971;Marks and Rifkind, 1978). Expression of c-Myb is downregulated during MEL cell differentiation, and forced expression of c-Myb blocks chemically induced MEL cell differentiation (McClinton et al, 1990).…”

Direct association of YY-1 with c-Myc and the E-box binding protein in regulation of glycophorin gene expression

“…Expression of a variety of erythroid-speci®c genes including globin and glycophorin genes is induced in MEL cells in response to treatment with DMSO (Friend et al, 1971;Marks and Rifkind, 1978;Matsui et al, 1989). We previously identi®ed a locus control region (LCR)-like region (Gp-LCR) located far upstream of the mouse glycophorin gene (Terajima et al, 1994(Terajima et al, , 1995Nemoto et al, 1996).…”

c-Jun inhibits NF-E2 transcriptional activity in association with p18/maf in Friend erythroleukemia cells

“…When exposed to DMSO or other inducers, F-MEL cells undergo phenotypic changes that resemble the ®nal stages of normal erythropoiesis (Friend et al, 1971;Chen et al, 1982). The most striking feature is the increased synthesis of globin chains which results primarily from the activation of globin gene transcription (Charnay et al, 1984;Profous-Juchelka et al, 1983).…”