Engineering glycan-binding proteins for the detection, analysis and treatment of cancer cells
Author(s)
Powlesland, Alex Stephen
Type
Thesis or dissertation
Abstract
Aberrant glycosylation in cancer cells can often lead to an increase in the exposure
of unusual glycan structures. The presence of these structures can be exploited by
engineering glycan-binding proteins as novel tools for the characterisation of
glycoproteins bearing cancer-associated glycan structures. The carbohydraterecognition
domain (CRD) of a rat serum mannose-binding protein (MBP) has been
modified to mimic the glycan-specificity of a galactose-binding C-type lectin. Galactosebinding
MBP (GalMBP) binds selectively to cancer-associated glycan structures on an
array of glycans, including Lewis-type structures and T antigen.
GalMBP binding to breast cancer cell lines has been demonstrated and GalMBP
ligands on these cell lines have been purified on affinity columns of immobilised GalMBP.
Analysis and purification of GalMBP ligands from MCF7 cell membranes led to the
identification of a restricted population of high molecular weight glycoproteins.
Proteomic and glycomic analysis of these glycoproteins by mass spectrometry showed
that they are forms of CD98hc that bear glycans displaying heavily fucosylated termini,
including Lewisx and Lewisy structures. Glycoproteomic analysis of a panel of commonly
studied breast cancer cell lines reveals wide variations in the levels of Lewisx and the T
antigen as well as the proteins that they are carried on. Proteins identified in multiple cell
lines by GalMBP, including the mucin MUC-1 bearing T antigen and CD98hc, may
represent common cancer-cell surface targets for GalMBP.
The use of GalMBP as a proteomic tool for characterisation of glycoproteins bearing
Lewisx has also been demonstrated on a panel of Hodgkin’s Reed-Sternberg cell lines.
Identification of common protein carriers of Lewisx among different cell lines including
CD98hc and ICAM-1 provides information about the likely role of these structures in the
pathology of Hodgkin's Lymphomas and supports the previous finding that CD98hc is a
novel protein carrier of Lewisx structures.
of unusual glycan structures. The presence of these structures can be exploited by
engineering glycan-binding proteins as novel tools for the characterisation of
glycoproteins bearing cancer-associated glycan structures. The carbohydraterecognition
domain (CRD) of a rat serum mannose-binding protein (MBP) has been
modified to mimic the glycan-specificity of a galactose-binding C-type lectin. Galactosebinding
MBP (GalMBP) binds selectively to cancer-associated glycan structures on an
array of glycans, including Lewis-type structures and T antigen.
GalMBP binding to breast cancer cell lines has been demonstrated and GalMBP
ligands on these cell lines have been purified on affinity columns of immobilised GalMBP.
Analysis and purification of GalMBP ligands from MCF7 cell membranes led to the
identification of a restricted population of high molecular weight glycoproteins.
Proteomic and glycomic analysis of these glycoproteins by mass spectrometry showed
that they are forms of CD98hc that bear glycans displaying heavily fucosylated termini,
including Lewisx and Lewisy structures. Glycoproteomic analysis of a panel of commonly
studied breast cancer cell lines reveals wide variations in the levels of Lewisx and the T
antigen as well as the proteins that they are carried on. Proteins identified in multiple cell
lines by GalMBP, including the mucin MUC-1 bearing T antigen and CD98hc, may
represent common cancer-cell surface targets for GalMBP.
The use of GalMBP as a proteomic tool for characterisation of glycoproteins bearing
Lewisx has also been demonstrated on a panel of Hodgkin’s Reed-Sternberg cell lines.
Identification of common protein carriers of Lewisx among different cell lines including
CD98hc and ICAM-1 provides information about the likely role of these structures in the
pathology of Hodgkin's Lymphomas and supports the previous finding that CD98hc is a
novel protein carrier of Lewisx structures.
Date Issued
2010
Date Awarded
2010-02
Advisor
Taylor, Maureen
Drickamer, Kurt
Creator
Powlesland, Alex Stephen
Publisher Department
Molecular Biosciences
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)