PMA induces shift from chondroitin to heparan sulphate on proteoglycans correlating with fibronectin adhesion of MDS human leukemia cells.
We have analysed the mechanism of PMA-induced adhesion of the MDS human leukemia cell line. Affinity to various matrix ligands indicated that PMA induced fibronectin adhesion of MDS cells. This interaction could not be inhibited by RGDS-peptide, therefore it was most probably not mediated by integrins. Rather, both the basal and PMA-induced fibronectin adhesion of MDS cells could be inhibited by heparin and much less efficiently by chondroitin sulphate, suggesting that glycosaminoglycans of proteoglycans may be responsible for the change in adhesive phenotype. PMA stimulation of MDS cells induced a significant increase in proteoglycan biosynthesis. Studies on the glycosaminoglycan pattern of the proteoglycans showed that PMA treatment initiated a shift in glycanation of the MDS-proteoglycans from the predominant chondroitin sulphate-proteoglycans in control cells to a predominant heparan sulphateproteoglycans in adherent cells. These data indicate that protein kinase C, the main target of PMA, may have a profound role in the regulation of glycanation pattern of proteoglycans. Furthermore, such alterations in the cellular proteoglycans may significantly affect the matrix adhesion potential of hematopoietic cells.
Tímár
J
J
1st Institute of Pathology and Experimental Cancer Research, Semmelweis University of Medicine, Budapest, Hungary.
Diczházi
C
C
Bartha
Ladányi
A
A
Tarcsafalvi
A
A
Lapis
K
K
D002448:Cell Adhesion; D002809:Chondroitin Sulfates / Q000502:physiology*; D005353:Fibronectins / Q000502:physiology*; D006497:Heparan Sulfate / Q000502:physiology*; D006801:Humans; D007938:Leukemia / Q000473:pathology*; D011509:Proteoglycans / Q000502:physiology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
D002809:Chondroitin Sulfates; D005353:Fibronectins; D006497:Heparan Sulfate; D011509:Proteoglycans; D013755:Tetradecanoylphorbol Acetate