Mouse Myeloid Leukemic M1 Cells Research Articles

Changes in phospholipid and ganglioside during differentiation of mouse myeloid leukemia cells

When mouse myeloid leukemia M1 cells were induced to differentiate into macrophages by bacterial lipopolysaccharide (LPS), phospholipids and gangliosides of the cells changed markedly. The amounts of phosphatidylcholine, phosphatidylethanolamine and phosphatidylinositol per mg protein increased 30%, 20% and 30%, respectively, during differentiation, but the others, phosphatidylserine and sphingomyelin, did not increase significantly. Three species of gangliosides constituted of major portions of gangliosides in M1 cells. Several-fold increase in monosialoganglioside GM1 was observed in the LPS-treated cells with a concomitant decrease in disialogangliosides. Based upon the treatment with sialidase, this GM1 was identified to be GM1b, which was recently found in rat ascites hepatoma cells and human erythrocyte membranes.

Induction by synthetic polyribonucleotide poly(I) of differentiation of cultured mouse myeloid leukemic cells

The effects of some synthetic polyribonucleotides on induction of differentiation of mouse myeloid leukemic M1 cells were examined. Poly(I) was found to be a potent inducer; on treatment with 100–200 μg/ml of poly(I) for 2–4 days, M1 cells differentiated into cells resembling macrophages and granulocytes and developed phagocytosis and locomotive activities, Fc receptors and lysozyme activity. Poly(C) was less effective than poly(I) for induction of phagocytic activity, while the other single-stranded RNAs, poly(U) and poly(A), had no effect. Double-stranded RNAs, such as poly(I) · poly(C) and poly(A) · poly(U), were cytotoxic to M1 cells, and differentiation of the cells could not be detected even at the highest tolerable concentrations of these double-stranded RNAs.