Team science approach to solve how centrosome-amplification is maintained in cancer cells

This will be a multidisciplinary PhD project, combing four areas of research expertise, from four group leaders in the department of Biomedical Sciences at The Univertsity of Lancaster. The overaching aim is to combine these areas of cancer cell biology and advanced imaging to enable the dynamics of centrosome amplification to be examined at a population level.

Centrosomes are small, intracellular organelles that nucleate microtubules. During cell division normal cells contain 2 centrosomes, which organise each half of the bipolar mitotic spindle, allowing for successful cell division and proliferation.

Centrosome amplification (CA) is a common feature of cancers and there is currently much attention on the possibility of using CA as a cancer specific therapeutic target (1).

However, a fundamental aspect of centrosome amplification, how amplification occurs and is maintained in a population of cells, has not yet been examined, perhaps because of the technical challenge of tracking centrosome number in cell populations.

Intriguingly, in humans, both tumours and cancer cell lines are heterogeneous for CA, yet in cancer cell lines the degree of CA remains stable over many cell generations (AF lab, unpublished data). These seemingly stable proportions of cells could be maintained in the population via two mechanisms:
1. There are “static”, discrete populations of cells e.g. 65% normal and 35% with amplification, which only give rise to cells of the same level of amplification.
Or
2. CA is “progressive” i.e. new cells with centrosome amplification are being formed continuously in a population, whilst cells with very high levels of centrosome amplification are being lost.
The answer as to which one of these is the case will have profound implications for treatments targeting CA. For example, if only 35% of cells contain CA and this is a discrete, stable population, then treatments targeting CA will only ever be able to target these 35% of cells. If, on the other hand CA is gained progressively, then extended treatments with drugs targeting CA could eliminate a large proportion of the growing tumour cells.

The first main aim of the project will be to address this question. This part of the project will use centrosome and cell cycle “biosensors” in uveal melanoma cells to allow centrosome number to be tracked by live-cell imaging (2). This will be coupled with centrifugal, counter-flow elutriation to allow cell cycle synchronisation (3) and microfluidic plating in microwells (4), to allow us to track individual cells and determine how centrosomes have been inherited.

Once this key question has been answered, the project will turn to the mechanisms behind CA population control. Firstly, RNA-Seq data that the AF lab has recently generated comparing patient matched metastatic cancer cell lines with CA and primary tumour cells without CA will be interrogated to identify key transcriptomic data that could explain how some cells are able to gain and maintain a high degree of CA compared to others. Once a shortlist of likely candidate genes/proteins have been identified, siRNA knockdown or protein overexpression will be used to test if their centrosomal populations can be manipulated using the identified targets. Finally, it will be tested if modifying CA populations can make cancer cells more sensitive to centrosome-declustering therapeutic agents.

To summarise, the main aims are:
1. Test hypothesis that CA occurs “progressively” in populations of cells.
2. To use RNA-Seq data to identify key changes that can account for the occurrence and maintenance of a high degree of centrosome amplification in metatstaic, compared to primary cancer cells.
3. To prove how CA occurs and is maintained in cell populations by testing function of key genes/proteins (using siRNA knockdowns and/or protein overexpression) identified in RNA-Seq data.
We are looking for a highly motivated individual with excellent communication skills, the capacity to work well in a team and the ability to solve problems creatively. Candidates with (or expecting to graduate with) a degree in any related disciple are invited to apply.

Our labs in the Division of Biomedical and Life Sciences are a friendly research environment that strongly supports the individual needs of each postgraduate student. We welcome applications from people in all diversity groups.