title: Hyposialylation of differentiation-inducer-resistant HL-60 cells.
abstract: The total sialic acid concent of retinoic acid (RA)-resistant or 6-thioguanine (6TG)-resistant HL-60 cells was more than tenfold lower and of dimethylsulfoxide (DMSO)-resistant HL-60 cells was approximately twofold lower than that of parental, wild-type (wt) HL-60 cells. Neuraminidase-inaccessible, ie residual cell-associated sialic acid after neuraminidase treatment, was four- to twelvefold lower in the three differentiation-inducer-resistant sublines than in the parent line. Neuraminidase treatment of 125I-labeled surface membrane glycoproteins (SMGs) from wt HL-60 cells converted the two-dimensional gel electrophoretic pattern to one having features in common with RA- and 6TG-resistant cells. However, neuraminidase treatment did not alter the sensitivity of wt HL-60 cells to differentiation induction by RA, hypoxanthine (purine base), or DMSO. These results indicate that differences in peripheral, neuraminidase-accessible sialic acids are important determinants of the gel electrophoretic mobility of the SMGs of the HL-60 line and sublines but are not likely related to the differentiation-resistance mechanism. Further studies are required to determine if hyposialylation of cryptic, neuraminidase-inaccessible sites has functional significance.
mesh_terms: D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D004351:Drug Resistance; D006098:Granulocytes / Q000166:cytology*; D006801:Humans; D009439:Neuraminidase / Q000378:metabolism; D012794:Sialic Acids / Q000502:physiology*; D012795:Sialoglycoproteins / Q000502:physiology*; D013866:Thioguanine / Q000494:pharmacology; D014212:Tretinoin / Q000494:pharmacology
chemical_list: D012794:Sialic Acids; D012795:Sialoglycoproteins; D014212:Tretinoin; D009439:Neuraminidase; D013866:Thioguanine; D004121:Dimethyl Sulfoxide