Dissecting the role of centrosome amplification on nuclear deformability during cancer invasion

Primary supervisor: Susana Godinho, Queen Mary University of London

Secondary supervisor: Jeremy Carlton, King’s College London

Project

Centrosome amplification is a widespread feature of human tumours and is associated with malignancy and metastasis by promoting genomic instability and invasion (1-3). It has been established that centrosome amplification can promote invasion, leading to extreme nuclear deformation to allow nuclear migration through thin cellular protrusions (2). However, the mechanisms leading to nuclear deformation are still unknown.

When centrosomes are amplified, microtubules become acetylated to promote kinesin-1 transport. This drives a global intracellular re-organisation of multiple organelles and compartments, including vimentin (Monteiro et al, in preparation). Vimentin, an understudied component of the intracellular cytoskeleton, confers rigidity to the nucleus and protects against nuclear rupture during migration in confined spaces (4). We found that in cells with amplified centrosomes, vimentin is displaced towards the leading edge of the cell, suggesting that regulation of vimentin transport could play a role in cell invasion by decreasing nuclear rigidity.

Here, we propose to investigate how amplified centrosomes contribute to alterations of nuclear envelope properties to promote invasion. We hypothesise that vimentin displacement, instead of loss, could facilitate nuclear deformability without deleterious nuclear rupture and DNA damage.

Aim 1. Characterisation of nuclear envelope properties in cells with amplified centrosomes

Using non transformed and cancer cells where centrosome amplification can be efficiently induced, we will determine the physical properties of the nucleus (e.g. AFM) and nuclear envelope composition (e.g. immunofluorescence, proteomics) in response to centrosome amplification and vimentin displacement (by depleting aTAT1 or kinesin-1 to prevent vimentin displacement).

Aim 2. Dissect the role of vimentin displacement in migration through confined spaces

Using different systems to study cell migration through confined spaces (3D cultures, microchannels), we will assess the role of centrosome amplification and vimentin displacement during migration through confined spaces (e.g. using FRB/FKBP system to re-localise vimentin). Our preliminary data suggests that cells with extra centrosomes migrate faster through small pores. Nuclear rupture, nuclear envelope repair and DNA damage will also be investigated in collaboration with the Carlton lab (5). DNA methylation patterns in response to compression will be determined to explore the long-term effects of vimentin displacement.

Aim 3. Investigate the role of vimentin displacement in vivo

Established syngeneic mouse models of breast cancer will be used to assess invasion in response to centrosome amplification and the role of vimentin displacement and tubulin acetylation in this process. This will determine the therapeutic potential of blocking nuclear deformation in preventing invasion and metastasis. Levels of tubulin acetylation and vimentin localisation will be assessed in primary tumours, invasive front and metastasis of breast cancer patients that we have access through the Breast Cancer Tissue Bank at the BCI.

Outcomes: This studentship will 1) identify novel mechanisms associated with nuclear deformation and 2) define the contribution of vimentin to nuclear envelope deformability, rigidity and repair. Our preliminary data suggest that tubulin acetylation plays a role in this process. Because tubulin acetylation can occur in response to several stimuli, we anticipate this mechanism could be more prevalent in cancer cells than anticipated. Furthermore, this work could define novel pathways to target cancer invasion by blocking efficient nuclear deformation and migration.

Candidate background

This project would suit candidates with a background in biology and an interest in cell biology, cytoskeleton and cancer cell invasion.

Potential Research Placements

1. Jeremy Carlton, King’s College London/ Francis Crick Institute
2. Making Lab, Francis Crick Institute
3. TBC, Aim: Learn how to do Atomic Force microscopy (AFM) will be very beneficial for this project.

References

1. Ganem N. et al., (2009). “A mechanism linking extra centrosomes to chromosomal instability”. Nature, 460(7252):278:82
2. Godinho S.A. et al., (2014). “Oncogene-like induction of cellular invasion from centrosome amplification”, Nature, 510(7503):167-71.
3. Arnandis, T. et al., (2018). “Oxidative stress in cells with extra centrosomes drives non-cell autonomous invasion”. Developmental Cell, 47(4):409-424
4. Petteson et al., (2019). “Vimentin protects cells against nuclear rupture and DNA damage during migration”, Journal Cell Biology, 218(12):4079-4092.
5. Jung-Garcia et al., (2021). “LAP1 regulates nuclear plascicity to enable constrained migration”, BioRxiv, 449503.