Year: 2017
Type: dissertation
Abstract: Osteosarcoma (OS) is a mesenchymal tumor that is the most common malignant bone tumor in children and young adults. Our objective was to identify novel pathways in OS that may be related to the expression of an immunosuppressive protein ‘programmed cell death ligand 1 (PD-L1)’. Using RT-qPCR, varying levels of relative PD-L1 gene expression was shown in 69 primary OS tumors. Ingenuity pathway analysis was utilized to analyze 400 significantly differentially expressed genes between the high and low PD-L1 expressing OS tumors and the elongation initiation factor 2 (EIF2) pathway was illustrated to be significantly down-regulated (p=3E-07; z-score=-2.5) and the ‘cell death of OS cells’ was predicted to be significantly activated in OS tumors with high PD-L1 expression (p=1E-04; z-score=2.53). Both IFN- and thapsigargin were utilized to observe the effects of attenuating the EIF2 pathway on PD-L1 expression. Overall, the down-regulation of the EIF2 pathway did not influence PD-L1 expression.
Source: TSpace (University of Toronto)
Author: Jung-Hyun Nam
Language: English
Subfield: Oncology
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W2783362276