Date of Completion

2023

Document Type

Honors College Thesis

Department

Biochemistry

Thesis Type

College of Arts and Science Honors, Honors College

First Advisor

Gary Stein

Second Advisor

Matt Liptak

Third Advisor

Jay Silveira

Keywords

RUNX1, Breast Caner, Mesenchymal Transition, tumor supressor

Abstract

Runt related transcription factor 1 (RUNX1) is a tumor suppressor gene well understood for its role in acute myeloid leukemia1. It also is known to have a role in breast cancer, however which is a context in which comparatively less is known about its function2. Currently, one of the key facts known about the relationship between RUNX1 and breast epithelium cells is that the downregulation of RUNX1 is responsible for an epithelial mesenchymal transition (EMT) in these cells3. This is hypothesized to be a crucial first step in tumorigenesis, as it results in cells separating from one another and gaining the ability to move to other parts of the body4. The aim of this study was to degrade RUNX1 using the ubiquitin mediated degradation tag (dTAG) system in MCF10A non-cancerous mammary epithelial cells and observe the epigenetic effects on several genes also implicated in EMT. These genes included epithelial cadherin (E-cadherin), and tight junction protein 1 (ZO-1), genes involved in intercellular adhesion, vimentin, an intermediate filament and marker of EMT, and claudin, a gene known to be lost when breast cells become cancerous5-9. Additionally, the genes SNAI1 (Snail) and SNAI2 (Slug), and ZEB-1 all of which are transcriptional repressors of E-Cadherin, were examined due to their relationship to E-Cadherin10, 11. Two of these proteins, vimentin, and claudin-1, were found to have changes in expression that reflected what would be expected of them when a tumor suppressor gene was degraded. Specifically, vimentin expression increased, and claudin-1 expression decreased. Contrary to what was initially expected however, expression of both ZO-1 and E-Cadherin increased after RUNX1 degradation, while expression of Snail, ZEB-1, and Slug decreased. This suggests that perhaps that while RUNX1 does appear to contribute to EMT, the mechanism may be more complex, and removal of this gene alone may not be enough for a complete transition. Additionally, there are many pathways that induce EMT, and these may not be the critical components driving EMT upon RUNX1 loss.

Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.

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