Transfection of 2,6 and 2,3-sialyltransferase genes and GlcNAc-transferase genes into human glioma cell line U-373 MG affects glycoconjugate expression and enhances cell death.

Abstract

Human glioma cell line U-373 MG expresses CMP-NeuAc : Galbeta1,3GlcNAc alpha2,3-sialyltransferase [EC No. 2.4.99.6] (alpha2,3ST), UDP-GlcNAc : beta-d-mannoside beta1,6-N-acetylglucosaminyltransferase V [EC 2.4.1.155] (GnT-V) and UDP-GlcNAc3: beta-d-mannoside beta1,4-N-acetylglucosaminyltransferase III [EC 2.4.1.144] (GnT-III) but not CMP-NeuAc : Galbeta1,4GlcNAc alpha2,6-sialyltransferase [EC 2.4.99.1] (alpha2,6ST) under normal culture conditions. We have previously shown that transfection of the alpha2,6ST gene into U-373 cells replaced alpha2,3-linked sialic acids with alpha2,6 sialic acids, resulting in a marked inhibition of glioma cell invasivity and a significant reduction in adhesivity. We now show that U-373 cells, which are typically highly resistant to cell death induced by chemotherapeutic agents (< 10% death in 18 h), become more sensitive to apoptosis following overexpression of these four glycoprotein glycosyltransferases. U-373 cell viability showed a three-fold decrease (from 20 to 60% cell death) following treatment with staurosporine, C2-ceramide or etoposide, when either alpha2,6ST and GnT-V genes were stably overexpressed. Even glycosyltransferases typically raised in cancer cells, such as alpha2,3ST and GnT-III, were able to decrease viability two-fold (from 20 to 40% cell death) following stable overexpression. The increased susceptibility of glycosyltransferase-transfected U-373 cells to pro-apoptotic drugs was associated with increased ceramide levels in Rafts, increased caspase-3 activity and increased DNA fragmentation. In contrast, the same glycosyltransferase overexpression protected U-373 cells against a different class of apoptotic drugs, namely the phosphatidylinositol 3-kinase inhibitor LY294002. Thus altered surface protein glycosylation of a human glioblastoma cell line can lead to lowered resistance to chemotherapeutic agents.

• Authors: G Dawson, J R Moskal, S A Dawson
• Journal: Journal of neurochemistry (J Neurochem) Vol. 89 Issue 6 Pg. 1436-44 (Jun 2004) ISSN: 0022-3042 [Print] England
• PMID: 15189346 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Antineoplastic Agents
• Chromones
• Enzyme Inhibitors
• Glycoconjugates
• Morpholines
• N-acetylsphingosine
• Oligosaccharides
• 2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one
• Etoposide
• N-Acetylglucosaminyltransferases
• beta-1,4-mannosyl-glycoprotein beta-1,4-N-acetylglucosaminyltransferase
• alpha-1,6-mannosylglycoprotein beta 1,6-N-acetylglucosaminyltransferase
• Sialyltransferases
• N-acetyllactosaminide alpha-2,3-sialyltransferase
• CASP3 protein, human
• Caspase 3
• Caspases
• Staurosporine
• Sphingosine
• beta-D-Galactoside alpha 2-6-Sialyltransferase

Topics

• Antineoplastic Agents (pharmacology)
• Caspase 3
• Caspases (metabolism)
• Cell Death (genetics)
• Cell Line, Tumor
• Cell Membrane (metabolism)
• Cell Survival (drug effects, genetics)
• Chromones (pharmacology)
• Dose-Response Relationship, Drug
• Drug Resistance, Neoplasm (genetics)
• Enzyme Inhibitors (pharmacology)
• Etoposide (pharmacology)
• Glioma (enzymology, genetics)
• Glycoconjugates (biosynthesis)
• Glycosylation
• Humans
• Morpholines (pharmacology)
• N-Acetylglucosaminyltransferases (genetics, metabolism)
• Oligosaccharides (metabolism)
• Sialyltransferases (genetics, metabolism)
• Sphingosine (analogs & derivatives, pharmacology)
• Staurosporine (pharmacology)
• Transfection
• beta-D-Galactoside alpha 2-6-Sialyltransferase