The contribution of cell mechanical properties to cancer metastasis

Spennati, Giulia (2019) The contribution of cell mechanical properties to cancer metastasis. PhD thesis, University of Glasgow.

Due to Embargo and/or Third Party Copyright restrictions, this thesis is not available in this service.

Abstract

The ability of tumour cells to propagate inside the body, generating metastasis, is the cause of 90 % of cancer-associated deaths. During metastasis, cancer cells modify their migratory strategy by interacting with the surrounding environment and modulating their mechanical properties. Therefore, studying the contribution of cell biomechanics to cancer invasion could help gain a broader knowledge of the metastatic process. This work aims to develop and validate methods, techniques and platforms to study cell mechanical properties and their roles in cancer invasion. Considering that cancer cells are a heterogeneous population, we divided MDA MB 231 breast cancer cells and MDA MB 435 melanoma cancer cells into subpopulations based on their ability to move through narrow membrane pores (3um), aiming to identify the correlation between cell mechanical properties and cancer cell invasiveness.
At first, we established a method to study cell elasticity and adhesion forces using atomic force microscopy. Using this technique, we found lower values of Young’s modulus and adhesion forces in the more invasive subpopulation. Transcriptome analysis, performed by our collaborators at the Beatson Cancer Institute, revealed an overexpression of the MAPK/ERK signalling pathway in these cells, causing a lower organisation of the actin filaments in the cytoskeleton and a reduction of cell stiffness and adhesion forces. We demonstrated that inhibition of the MAPK/ERK pathway, using MEK inhibitors (Trametinib and U0126), causes an increase in stiffness and adhesion forces in these cells. We also developed a high-throughput microfluidic device to investigate the link between these findings and the dynamics of cancer cell invasion in confined environments under the effect of a chemotactic gradient.
Considering the influence of the tumour microenvironment in regulating the cell migratory strategy by modulating cell mechanics, we used organotypic tissue slices to develop a new platform to study cancer cell metastasis in an in vivo like model. As the first step, we developed a reliable protocol for the culture of precision cut liver slices (PCLS) to maintain their viability and morphological parameters in vitro for up to 3 days. We then established a new method to study cancer cell invasion in organotypic tissue slices. Using the MDA MB 231 cells as the model system to validate the platform, we observed that more invasive subpopulation of cells showed higher invasiveness than the original population in liver tissue, which is in agreement with previous results using the other methods or platforms (i.e. Boyden chambers, wound healing assay, collagen matrix, and in vivo model). Similar results were found in the following experiment investigating MDA MB 231 migration in organotypic brain slices.
To explore the potential of this in vivo like platform for preclinical oncological drug testing, throughput had to be considered. To this end, we combined this platform with a microfluidic device previously developed for high-throughput drug testing on tissue slices and further improved the culturing technique, which resulted in increased viability and higher maintenance of morphological features for up to 7 days. The combination of this new platform with the microfluidic device could, in future, allow the simultaneous study of the effects of several drugs on cell metastasis in an in vivo like environment replicating the metastatic site.

Item Type: Thesis (PhD)
Qualification Level: Doctoral
Keywords: Cell mechanics, cell migration, cancer, cancer metastasis, atomic force microscopy, microfluidic, organotypic tissue slices'.
Subjects: Q Science > Q Science (General)
Q Science > QC Physics
Q Science > QH Natural history > QH301 Biology
T Technology > T Technology (General)
Colleges/Schools: College of Science and Engineering > School of Engineering > Biomedical Engineering
Funder's Name: Engineering & Physical Sciences Research Council (EPSRC)
Supervisor's Name: Yin, Prof. Huabing and Olson, Prof. Michael
Date of Award: 2019
Embargo Date: 15 June 2023
Depositing User: Giulia Spennati
Unique ID: glathesis:2019-81453
Copyright: Copyright of this thesis is held by the author.
Date Deposited: 15 Jun 2020 15:12
Last Modified: 15 Jun 2020 15:12
URI: http://theses.gla.ac.uk/id/eprint/81453
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