title: Effect of suppression of TGF-beta1 expression on cell-cycle and gene expression of beta-1,4-galactosyltransferase 1 in human hepatocarcinoma cells.
abstract: beta-1,4-galactosyltransferase 1 (beta1,4-GT 1) is localized both in the Golgi complex where it catalyzes the transfer of galactose from UDP-galactose to terminal N-acetylglucosamine forming Galbeta1 --> 4GlcNAc structure, and on the cell surface where it serves as an adhesion molecule. It has previously been reported that the expression of beta1,4-GT 1 was cell-cycle-specific, regulated by cell growth. Transforming growth factor-beta1 (TGF-beta1) could regulate cell G1/S phase transition and modulate cell growth in many types of cells. In this study, we introduced the antisense-TGF-beta1 into SMMC-7721 cell, a human hepatocarcinoma cell line, for blocking its intrinsic TGF-beta1 expression, and changing its cell-cycle, and then analyzed the gene expression of beta1,4-GT 1 together with the beta1,4-GT activity. The result showed that the antisense-TGF-beta1 transfected SMMC-7721 cells (AST/7721) were growth enhanced, with more cells in S phase and less cells in G2/M phase compared with the mock transfected cells (pcDNA3/7721). At the same time, it was found that the gene expression of beta1,4-GT 1 in AST/7721 was decreased to one fifth that of pcDNA3/7721, and the cell surface beta1,4-GT activity was reduced to one fifth of the control, while the total activity of beta1,4-GT was decreased to one half that of the control. The results indicate that suppression of TGF-beta1 expression resulted in change of cell-cycle together with the decreased gene expression of beta1,4-GT 1 and beta1,4-GT activity in human hepatocarcinoma cells.
authors.affiliation: Key Laboratory of Glycoconjugate, Ministry of Public Health, People's Republic of China.
authors.forename: S W
authors.initials: SW
authors.lastname: Zhang
authors.forename: W S
authors.initials: WS
authors.lastname: Lin
authors.forename: X L
authors.initials: XL
authors.lastname: Ying
authors.forename: D
authors.initials: D
authors.lastname: Zhu
authors.forename: M Y
authors.initials: MY
authors.lastname: Guo
authors.forename: J X
authors.initials: JX
authors.lastname: Gu
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000201:enzymology* / Q000473:pathology; D002453:Cell Cycle / Q000502:physiology*; D005700:Galactosyltransferases / Q000235:genetics* / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D006801:Humans; D006868:Hydrolysis; D008113:Liver Neoplasms / Q000201:enzymology* / Q000473:pathology; D014162:Transfection; D016212:Transforming Growth Factor beta / Q000235:genetics / Q000502:physiology*; D014407:Tumor Cells, Cultured
chemical_list: D016212:Transforming Growth Factor beta; D005700:Galactosyltransferases; C119701:beta-1,4-galactosyltransferase I