Ignite Creation Date:
2024-05-05 @ 10:13 PM
Last Modification Date:
2024-10-26 @ 10:15 AM
Study NCT ID:
NCT01058798
Status:
COMPLETED
Last Update Posted:
2010-01-29
First Post:
2010-01-27
Brief Title:
The Role of Glycosyltransferases in the Oncogenesis of Neuroblastoma
Sponsor:
National Taiwan University Hospital
Organization:
National Taiwan University Hospital
Study Overview
Official Title:
The Role of Glycosyltransferases in the Oncogenesis of Neuroblastoma
Status:
COMPLETED
Status Verified Date:
2010-01
Last Known Status:
None
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
False
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
None
Brief Summary:
Neuroblastoma NB is the most common malignant tumor of infancy Approximately 60 of NB patients are clinically diagnosed as the stage IV disease and have a very poor prognosis with a 5-year survival rate of no more than 30 The mechanism underlying the tumorigenesis of NB remains largely unclear It has been suggested that the pathogenesis of NB is due to a failure of differentiation or apoptosis of the embryonic NB cells
Well-regulated glycosylation is essential for the normal development of the nervous system Altered expression of glycosyltransferases with resulting dysregulated glycosylation of neuroblastic cells might lead to the development of NB The β14-N-acetylgalactosaminyltransferase III B4GALNT3 exhibits GalNAc transferase activity to form the GalNAcβ14GlcNAc LacdiNAc or LDN structure The Drosophila B4GALNTA homolog of human B4GALNT3 has been suggested to regulate the neuronal development By immunohistochemical studies we demonstrated that the expression of B4GALNT3 correlated well with histological grade of differentiation in 87 NB tumor samples In addition positive B4GALNT3 expression predicted a favorable patients outcome These evidences suggest that the regulation of glycosyltransferases is critical for the development of NB
To further explore the role of glycosyltransferases in the differentiation and development of NB we propose a 3-year project with the following 3 major aims
Aim Ⅰ Clarifying the effects of B4GALNT3 on NB cell behavior in vitro and in vivo For further understanding the effects of B4GALNT3 on NB cells NB cells with stable overexpression of B4GALNT3 are to be selected Then NB cell phenotype and behavior changes after overexpression of B4GALNT3 are evaluated by in vitro assays as well as by a nude mice xenograft model In addition the expression of B4GALNT3 will be suppressed by siRNA then the response of NB cells to ATRA-induced differentiation is evaluated
Aim Ⅱ Clarifying the target proteins glycosylated by B4GALNT3 as well as their associated downstream pathways in vitro and in vivo The possible proteins glycosylated by B4GALNT3 are evaluated by comparing differential protein expressions between B4GALNT3-transfected and mock-transfected NB cells using proteomics analysis NB tumor samples with low and high B4GALNT3 expression levels are also subjected to proteomics analysis to explore the possible target proteins glycosylated by B4GALNT3 in vivo After identifying the target proteins modified by B4GALNT3 the downstream pathways to affect NB cell differentiation will also be evaluated
Aim Ⅲ Clarifying whether B4GALNT4 a family member of B4GALNT plays a similar role as B4GALNT3 as well as how the expression of these enzymes are controlled epigenetically in human NB cell lines and tumor samples The expression levels of B4GALNT4 in human NB samples are evaluated by RT-PCR and immunohistochemistry The methylation status of the promoter sites of both B4GALNT3 and B4GALNT4 are examined in various NB cell lines as well tumor samples Furthermore NB tumor samples exhibiting high and low B4GALNT levels are subjected to microRNA array
Altogether our studies will not only establish the functional role of the family of glycosyltransferases in the cell behavior of NB but also illustrate how the expression of glycosyltransferases are regulated epigenetically and how the glycosyltransferases affect NB cell behavior Therefore our results might shed light to the oncogenesis of NB as well as target therapy of NB
Well-regulated glycosylation is essential for the normal development of the nervous system Altered expression of glycosyltransferases with resulting dysregulated glycosylation of neuroblastic cells might lead to the development of NB The β14-N-acetylgalactosaminyltransferase III B4GALNT3 exhibits GalNAc transferase activity to form the GalNAcβ14GlcNAc LacdiNAc or LDN structure The Drosophila B4GALNTA homolog of human B4GALNT3 has been suggested to regulate the neuronal development By immunohistochemical studies we demonstrated that the expression of B4GALNT3 correlated well with histological grade of differentiation in 87 NB tumor samples In addition positive B4GALNT3 expression predicted a favorable patients outcome These evidences suggest that the regulation of glycosyltransferases is critical for the development of NB
To further explore the role of glycosyltransferases in the differentiation and development of NB we propose a 3-year project with the following 3 major aims
Aim Ⅰ Clarifying the effects of B4GALNT3 on NB cell behavior in vitro and in vivo For further understanding the effects of B4GALNT3 on NB cells NB cells with stable overexpression of B4GALNT3 are to be selected Then NB cell phenotype and behavior changes after overexpression of B4GALNT3 are evaluated by in vitro assays as well as by a nude mice xenograft model In addition the expression of B4GALNT3 will be suppressed by siRNA then the response of NB cells to ATRA-induced differentiation is evaluated
Aim Ⅱ Clarifying the target proteins glycosylated by B4GALNT3 as well as their associated downstream pathways in vitro and in vivo The possible proteins glycosylated by B4GALNT3 are evaluated by comparing differential protein expressions between B4GALNT3-transfected and mock-transfected NB cells using proteomics analysis NB tumor samples with low and high B4GALNT3 expression levels are also subjected to proteomics analysis to explore the possible target proteins glycosylated by B4GALNT3 in vivo After identifying the target proteins modified by B4GALNT3 the downstream pathways to affect NB cell differentiation will also be evaluated
Aim Ⅲ Clarifying whether B4GALNT4 a family member of B4GALNT plays a similar role as B4GALNT3 as well as how the expression of these enzymes are controlled epigenetically in human NB cell lines and tumor samples The expression levels of B4GALNT4 in human NB samples are evaluated by RT-PCR and immunohistochemistry The methylation status of the promoter sites of both B4GALNT3 and B4GALNT4 are examined in various NB cell lines as well tumor samples Furthermore NB tumor samples exhibiting high and low B4GALNT levels are subjected to microRNA array
Altogether our studies will not only establish the functional role of the family of glycosyltransferases in the cell behavior of NB but also illustrate how the expression of glycosyltransferases are regulated epigenetically and how the glycosyltransferases affect NB cell behavior Therefore our results might shed light to the oncogenesis of NB as well as target therapy of NB
Detailed Description:
None
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
None
Is a FDA Regulated Device?:
None
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?:
None