chondroitin and Leukemia

We have previously shown that heparin and heparan sulfate stimulate the growth of human erythroleukemia cells in vitro in the presence of serum or plasma. To determine whether heparin and other glycosaminoglycans (GAGs) are involved in the growth of leukemia cells, effects of GAGs on the growth of three leukemia cell lines expressing different phenotypes, the HEL, HL60 and U937 cell lines were studied using both plasma clot and serum-free agar systems. The cells were cultured with different doses of six GAGs: hyaluronic acid, chondroitin sulfate, dermatan sulfate, keratan sulfate, heparin and heparan sulfate. It was found that, in serum-free agar system, no GAG was able to stimulate (HEL) cell growth. In contrast, when serum-containing culture systems were used, all six GAGs promoted colony formation of HL60 and U937 cells. In addition, all GAGs, except keratan sulfate, stimulated the growth of HEL cells. The findings suggest that the GAGs may play an indirect role in enhancing leukemia cell proliferation by different mechanisms.

Topics: Cell Division; Chondroitin; Culture Media; Dermatan Sulfate; Glycosaminoglycans; Heparin; Heparitin Sulfate; Humans; Hyaluronic Acid; Keratan Sulfate; Leukemia; Leukemia, Monocytic, Acute; Leukemia, Promyelocytic, Acute; Tumor Cells, Cultured

Proteoglycans of 300 000 mol.wt. were isolated from dispersed rat basophil tumour cells after labelling of the sulphated mucopolysaccharides with 35S in vitro:90% of the 35S-labelled mucopolysaccharides were extracted at high salt concentration. Alkali degradation of the 35S-labelled proteoglycans yielded glycosaminoglycan chains of 40 000 mol.wt. The composition of the salt-extracted 35S-labelled mucopolysaccharides, as defined by parallel or sequential degradation with chondroitinase AC, chondroitinase ABC and heparinase and resolution of the disaccharide-digestion products obtained with chondroitinase AC, was 48--61% chondroitin 4-sulphate, 20--30% dermatan sulphate, 10--15% heparin and 7--9% chondroitin 6-sulphate. Most of the salt-extracted 35S-labelled mucopolysaccharides were highly charged, with heparin and chondroitin 6-sulphate being relatively uniform in this regard, whereas chondroitin 4-sulphate and dematan sulphate exhibited a range of charge characteristics. The diversity of sulphated mucopolysaccharides present in the rat leukaemic basophil is in contrast with the predominance of heparin in the rat mast cell.

Topics: Animals; Basophils; Chondroitin; Chondroitinases and Chondroitin Lyases; Chromatography, Gel; Glycosaminoglycans; Heparin; Leukemia; Rats; Sulfur Radioisotopes

Topics: Acids; Acute Disease; Chondroitin; Chromatography, DEAE-Cellulose; Glycosaminoglycans; Humans; Leukemia; Leukemia, Lymphoid; Leukemia, Myeloid; Leukocytes; Sodium; Sulfates; Sulfur Isotopes