Date of Award

Spring 5-1-2023

Document Type



College of Arts and Sciences

Degree Program


Degree Name

Master of Science

Thesis Advisor

Daniel B. Stovall, Ph.D.

Committee Member

Matthew Stern, Ph.D.

Committee Member

Kathryn Kohl, Ph.D.


RING1- and YY1-Binding Protein (RYBP), Tumor Suppressor, Glioblastoma Multiforme, Cancer Cell Invasion, Cancer Cell Migration, Epithelial-to-Mesenchymal Transition

Committee Member

Victoria Frost, Ph.D.


Glioblastoma multiforme (GBM) is an aggressive form of brain cancer that has horrendous survival outcomes with the use of current therapies. Further study into its molecular mechanisms will inform development of new, more effective treatments. The Polycomb protein RING1- and YY1- Binding Protein (RYBP) has emerged as an important gene in multiple cancers. In complex with other Polycomb proteins, RYBP acts to repress regions of chromatin, though it also performs other functions independent of these complexes. RYBP has a tumor suppressive role in various cancers, but may act as an oncogene in others, demonstrating its context-specific effects. The role of RYBP in GBM has not yet been elucidated. In GBM, RYBP expression is frequently downregulated compared to normal brain tissue, suggesting it may act as a tumor suppressor in GBM. Thus, we hypothesized that forced expression of RYBP in GBM cell lines would activate apoptosis while decreasing cell invasion, migration, and proliferation. We transduced U-118 or T98G GBM cell lines with lentivirus expressing RYBP or a GFP control and established stable cell lines. RYBP-expressing U-118 and T98G cells showed decreased migration in wound- healing assays and invasion in Matrigel-coated Boyden chamber assays when compared to control cells. SDS-PAGE and Western blots were performed to measure changes in epithelial-to-mesenchymal transition (EMT) and apoptotic protein markers among transduced cells, and WST-1 assays were conducted to study the changes in proliferation. Overall, our findings suggest RYBP exerts anti-tumor effects in GBM and acts as a tumor suppressor gene. Future work should investigate the mechanism of RYBP’s phenotypic effects in GBM.


: I would like to express my deepest gratitude to Daniel Stovall for being an amazing and insightful mentor. I am extremely grateful to Victoria Frost, Kathryn Kohl, and Matthew Stern for sharing their knowledge and feedback as members of my thesis committee. Special thanks to my fellow lab members Brayden Fults, Lauren Patterson, Alex Lee, and Michelle Aguilar-Gaspar. Lastly, I would like to acknowledge the SC INBRE DRP Grant 5P20GM103499-21 for making my research possible.

Bucher - Copyright agreement for thesis.pdf (83 kB)
Bucher, Ronald W. Signed Copyright Agreement