Regulation of the O-glycan-type Sialyl-Lewis X (sLex) Bio-synthesis Pathway during Cell Transformation Programs: Epithelial-Mesenchymal Transition (EMT) and Molecular Subtypes in Breast Carcinoma and Human T Cell Activation

Handle URI:
http://hdl.handle.net/10754/626306
Title:
Regulation of the O-glycan-type Sialyl-Lewis X (sLex) Bio-synthesis Pathway during Cell Transformation Programs: Epithelial-Mesenchymal Transition (EMT) and Molecular Subtypes in Breast Carcinoma and Human T Cell Activation
Authors:
AbuElela, Ayman ( 0000-0002-4529-3156 )
Abstract:
During tumor progression and development of distant metastases, a subset of cancer cells undergoes transformation programs, such as epithelial-mesenchymal transition (EMT), to acquire enhanced migratory attributes to commence the metastatic cascade with the intension of achieving an active cell adhesion molecule-mediated organ-specific homing. Similarly, naive T cells reform the assemblage of their surface adhesion molecules during differentiation to activated T cells in order to successfully home to sites of inflammation and other extra-lymphoid organs for surveillance purposes. Sialyl-Lewis X (sLex) is well-known for mediating the homing of epithelial circulating tumor cellss (CTCs) and activated T cells to target sites through the interaction with endothelial selectins. Since glycan structures are not directly encoded by the genome, their expression is dependent on the glycosyltransferase (GT) expression and activity. Yet, the modulation of GTs during breast cancer transformation and in different molecular subtypes is still unknown. In addition, although the regulation of GTs during T cell activation is well-understood, the regulation at the epigenetic level is lacking. O-glycan-type sLex expression and E-selectin binding under static and flow conditions varies among molecular subtypes of breast cancer and upon the induction of EMT which is linked to the expression patterns of GTs. GTs displayed a significant prognostic value of in the association with the patients' survival profiles and in the ability to predict the breast cancer molecular subtypes from the expression data of a random patient sample. Also, GTs were able to differentiate between tumor and their normal counterparts as well as cancer types and glioblastoma subtypes. On the other hand, we studied the regulation of GTs in human CD4+ memory T cells compared to the naive cells at the epigenetic level. Memory T cell subsets demonstrated differential chromatin accessibility and histone marks within the promoters of the GTs genes. Moreover, they showed differential binding of pioneer and nonpioneer transcription factors (TFs). We proposed a model for the regulation of FUT7 during T cell activation that relies on the interplay between chromatin-remodeling and cell-fate-specifying TFs. Furthermore, we developed a fluorescent multiplex cell rolling (FMCR) assay to study the cell adhesion properties under physiological conditions. Compared to the conventional parallel plate flow chamber (PPFC) assay, the novel technique posses a high-throughput capacity which helps eliminate the inter-experimental variation problem by running multiple samples simultaneously and under competitive settings. We also developed a real-time analysis pipeline that enhanced the statistical power of the assay. Overall these modifications to the traditional parallel plate assay improves the reliability and results along with saving time and effort.
Advisors:
Merzaban, Jasmeen S. ( 0000-0002-7276-2907 )
Committee Member:
Magistretti, Pierre J. ( 0000-0002-6678-320X ) ; Gao, Xin ( 0000-0002-7108-3574 ) ; Kubes, Paul; Cummings, Richard
KAUST Department:
Biological and Environmental Sciences and Engineering (BESE) Division
Program:
Bioscience
Issue Date:
Dec-2017
Type:
Dissertation
Appears in Collections:
Dissertations

Full metadata record

DC FieldValue Language
dc.contributor.advisorMerzaban, Jasmeen S.en
dc.contributor.authorAbuElela, Aymanen
dc.date.accessioned2017-12-07T07:57:57Z-
dc.date.available2017-12-07T07:57:57Z-
dc.date.issued2017-12-
dc.identifier.urihttp://hdl.handle.net/10754/626306-
dc.description.abstractDuring tumor progression and development of distant metastases, a subset of cancer cells undergoes transformation programs, such as epithelial-mesenchymal transition (EMT), to acquire enhanced migratory attributes to commence the metastatic cascade with the intension of achieving an active cell adhesion molecule-mediated organ-specific homing. Similarly, naive T cells reform the assemblage of their surface adhesion molecules during differentiation to activated T cells in order to successfully home to sites of inflammation and other extra-lymphoid organs for surveillance purposes. Sialyl-Lewis X (sLex) is well-known for mediating the homing of epithelial circulating tumor cellss (CTCs) and activated T cells to target sites through the interaction with endothelial selectins. Since glycan structures are not directly encoded by the genome, their expression is dependent on the glycosyltransferase (GT) expression and activity. Yet, the modulation of GTs during breast cancer transformation and in different molecular subtypes is still unknown. In addition, although the regulation of GTs during T cell activation is well-understood, the regulation at the epigenetic level is lacking. O-glycan-type sLex expression and E-selectin binding under static and flow conditions varies among molecular subtypes of breast cancer and upon the induction of EMT which is linked to the expression patterns of GTs. GTs displayed a significant prognostic value of in the association with the patients' survival profiles and in the ability to predict the breast cancer molecular subtypes from the expression data of a random patient sample. Also, GTs were able to differentiate between tumor and their normal counterparts as well as cancer types and glioblastoma subtypes. On the other hand, we studied the regulation of GTs in human CD4+ memory T cells compared to the naive cells at the epigenetic level. Memory T cell subsets demonstrated differential chromatin accessibility and histone marks within the promoters of the GTs genes. Moreover, they showed differential binding of pioneer and nonpioneer transcription factors (TFs). We proposed a model for the regulation of FUT7 during T cell activation that relies on the interplay between chromatin-remodeling and cell-fate-specifying TFs. Furthermore, we developed a fluorescent multiplex cell rolling (FMCR) assay to study the cell adhesion properties under physiological conditions. Compared to the conventional parallel plate flow chamber (PPFC) assay, the novel technique posses a high-throughput capacity which helps eliminate the inter-experimental variation problem by running multiple samples simultaneously and under competitive settings. We also developed a real-time analysis pipeline that enhanced the statistical power of the assay. Overall these modifications to the traditional parallel plate assay improves the reliability and results along with saving time and effort.en
dc.language.isoenen
dc.subjectGlycosyltransferasesen
dc.subjectEMTen
dc.subjectMetastasisen
dc.subjectE-Selectinen
dc.titleRegulation of the O-glycan-type Sialyl-Lewis X (sLex) Bio-synthesis Pathway during Cell Transformation Programs: Epithelial-Mesenchymal Transition (EMT) and Molecular Subtypes in Breast Carcinoma and Human T Cell Activationen
dc.typeDissertationen
dc.contributor.departmentBiological and Environmental Sciences and Engineering (BESE) Divisionen
thesis.degree.grantorKing Abdullah University of Science and Technologyen
dc.contributor.committeememberMagistretti, Pierre J.en
dc.contributor.committeememberGao, Xinen
dc.contributor.committeememberKubes, Paulen
dc.contributor.committeememberCummings, Richarden
thesis.degree.disciplineBioscienceen
thesis.degree.nameDoctor of Philosophyen
dc.person.id101991en
All Items in KAUST are protected by copyright, with all rights reserved, unless otherwise indicated.