Investigating the role of Ajuba LIM domain protein in Pancreatic Ductal Adenocarcinoma

Rolo, Sonia (2025) Investigating the role of Ajuba LIM domain protein in Pancreatic Ductal Adenocarcinoma. PhD thesis, University of Glasgow.

Abstract

The relationship between a cell and its microenvironment is complex, dynamic and bidirectional. In cancer, an altered extracellular matrix (ECM) composition promotes tumour development through the modification of activities such as cellular proliferation, metabolism, mobility and survival. In pancreatic ductal adenocarcinoma (PDAC), the high matrix rigidity results in large tumours and leads to increased invasiveness. The ECM stiffness is sensed by cells through mechanosensing proteins and transduced by mechanotransduction actors into a cellular response. YAP/TAZ, several LIM domain proteins and a plethora of other proteins are involved in mechanotransduction pathways. Using polyacrylamide hydrogels of tuneable stiffnesses, I showed that cell morphology, proliferation, mRNA expression, transcription factors activities and cellular metabolism are modified by stiffness in a pancreatic KPC-derived mouse cell line (KRasG12D and p53R172H) named PDACA. The combination of polyacrylamide hydrogel stiffness and the use of RNA sequencing technology allowed me to identify Ajuba, a LIM protein, as a mechanosensitive protein. Ajuba was shown to be a versatile scaffold protein involved in many cellular activities such as adhesion, cell migration, invasion, and proliferation in many cancer types. However, in PDAC, the role of Ajuba is mostly unexplored. Our study shows that Ajuba localises at mature focal adhesions in PDACA cells. Interestingly, the downregulation of Ajuba induces a decrease in cellmatrix adhesion and an increase in cell invasion. However, no modification of focal adhesion formation, focal adhesion turnover or cellular migration was found. Finally, using a combination of polyacrylamide hydrogel stiffness and the use of RNA sequencing technology, I also showed that the downregulation of Ajuba modifies both mRNA expression and transcription factor activities. Collectively our results indicate that Ajuba is both a mechanosensitive and a mechanotransducer in PDAC.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Subjects: R Medicine > RC Internal medicine > RC0254 Neoplasms. Tumors. Oncology (including Cancer)
• Colleges/Schools: College of Medical Veterinary and Life Sciences > School of Cancer Sciences
• Supervisor's Name: Machesky, Professor Laura
• Date of Award: 2025
• Depositing User: Theses Team
• Unique ID: glathesis:2025-84843
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 29 Jan 2025 12:09
• Last Modified: 29 Jan 2025 12:19
• Thesis DOI: 10.5525/gla.thesis.84843
• URI: https://theses.gla.ac.uk/id/eprint/84843