Mechanosensing Using GaInP Nanowires
Author
Summary, in English
Mechanical forces exists in many cellular processes, including cell proliferation, migration, rearrangement and differentiation. The transformation of cancer cells from normal cells, cancer metastasis and cell rearrangement during morphogenesis all involve changes in cellular mechanical forces.
Although there are some studies about normal cell and cancer cell force measurements, a direct comparison of the forces exerted by normal and cancer cells has not been performed. Furthermore, monitoring mechanical forces to evaluate the effect of anticancer drugs has not been explored yet. To fill this research gap, we developed a force measurement method with inherently fluorescent nanowires and measured the traction forces exerted by breast cancer cells and breast epithelial normal-like cells. This measurement was further used to evaluate the effects of an anticancer drug effect on cell traction forces.
Mechanical forces play an important role in the rearrangement of cells during morphogenesis. However, the link between mechanical forces and cell rearrangement in tissues is poorly understood. Therefore, we measured the traction forces exerted by cells in the Drosophila melanogaster eye imaginal disc during morphogenesis.
In this thesis work, we first studied the effects of nanowire array geometry on cell morphology, in order to find the proper geometry for performing force measurements. We found that high nanowire densities are needed for the cells to sit on top of nanowires, which is a requirement for a proper calculation of cell forces. We further studied cell migration and proliferation on nanowires and flat samples with and without an anti-cancer drug treatment, at the individual cell level. We found that anticancer drug DFMO reduced cell division but that a small population of cell was unaffected by the drug. We then performed force measurements on cells and tissue. We measured traction forces of breast cancer cells and breast epithelial normal-like cells using nanowires. Breast cancer cells are found to exert higher forces than normal cells on nanowires. With anticancer drug treatment (DFMO), the forces exerted by cancer cells decrease substantially. We finally measured forces in the drosophila eye imaginal disc. Higher forces were measured before the progression of the morphogenetic furrow, revealing the importance of traction forces in tissue reshaping.
Although there are some studies about normal cell and cancer cell force measurements, a direct comparison of the forces exerted by normal and cancer cells has not been performed. Furthermore, monitoring mechanical forces to evaluate the effect of anticancer drugs has not been explored yet. To fill this research gap, we developed a force measurement method with inherently fluorescent nanowires and measured the traction forces exerted by breast cancer cells and breast epithelial normal-like cells. This measurement was further used to evaluate the effects of an anticancer drug effect on cell traction forces.
Mechanical forces play an important role in the rearrangement of cells during morphogenesis. However, the link between mechanical forces and cell rearrangement in tissues is poorly understood. Therefore, we measured the traction forces exerted by cells in the Drosophila melanogaster eye imaginal disc during morphogenesis.
In this thesis work, we first studied the effects of nanowire array geometry on cell morphology, in order to find the proper geometry for performing force measurements. We found that high nanowire densities are needed for the cells to sit on top of nanowires, which is a requirement for a proper calculation of cell forces. We further studied cell migration and proliferation on nanowires and flat samples with and without an anti-cancer drug treatment, at the individual cell level. We found that anticancer drug DFMO reduced cell division but that a small population of cell was unaffected by the drug. We then performed force measurements on cells and tissue. We measured traction forces of breast cancer cells and breast epithelial normal-like cells using nanowires. Breast cancer cells are found to exert higher forces than normal cells on nanowires. With anticancer drug treatment (DFMO), the forces exerted by cancer cells decrease substantially. We finally measured forces in the drosophila eye imaginal disc. Higher forces were measured before the progression of the morphogenetic furrow, revealing the importance of traction forces in tissue reshaping.
Publishing year
2018-01-05
Language
English
Full text
Document type
Dissertation
Publisher
Solid State Physics, Lund University
Topic
- Nano Technology
- Cell Biology
Keywords
- Traction force, fluorescent nanowires, morphology, migration
- Fysicumarkivet A:2018:Li
Status
Published
Supervisor
ISBN/ISSN/Other
- ISBN: 978-91-7753-560-7
- ISBN: 978-91-7753-559-1
Defence date
9 February 2018
Defence time
09:30
Defence place
Rydbergsalen, Fysicum, Professorsgatan 1, Lund University, Faculty of Engineering.
Opponent
- Monica Cotta (Professor)