RAB11 RECYCLING IN OVARIAN CANCER METASTASIS

Ovarian cancer is the 6th most common cancer in women in the UK, and most women are diagnosed with a particularly aggressive and lethal form called high grade serous ovarian cancer (HGSOC). The poor outlook for HGSOC patients has changed very little over recent years, and few targeted therapies have been discovered.
Our study focuses on how the positioning of cell surface proteins is controlled by endocytic trafficking, where cargoes removed from the cell surface are delivered back to perform their function. Rab11 is a major regulator of endocytic trafficking that is linked to ovarian cancers, and we will focus our attention on this family of proteins. We will investigate how HGSOC cells use endocytic trafficking to control their interaction with the surrounding environment, study the machinery involved in delivering cargoes and identify new cargoes that control how HGSOC cells invade into and proliferate at new sites as the cancer spreads.
Because this project is a close collaboration with scientists and clinicians, we have access to HGSOC patient samples and the knowledge to isolate patient cells and tissues in order to study the disease in humans. We will work towards using cells and tissues from the same patient, in order to understand the process of ovarian cancer spread. We will also take cells and tissue from patients before and after chemotherapy, so that we can understand how Rab11 driven endocytic trafficking can also help HGSOC cells to survive and avoid chemotherapy. This will allow us to gain insight into new potential therapies for ovarian cancer patients.

High grade serous ovarian cancer (HGSOC) is the most common and lethal form of ovarian cancer, and the 5 year survival rate is less than 40%. This statistic has changed very little in the decades since the current surgical and chemotherapy treatments were introduced, and few targeted therapies have been identified.
HGSOC preferentially metastasises to the omentum within the peritoneal cavity, and this step is thought to contribute to further dissemination, resistance to therapy and ultimately patient death. We will focus on how HGSOC cells invade into and proliferate within fibronectin-rich islands of stroma within this tissue. We will use surgically resected patient tissues to generate cell lines and explants to understand how HGSOC cells interact with their matrix environment at the metastatic niche.
The Rab11 family controls endocytic trafficking, and has 3 members: Rab11a, Rab11b and Rab25. Whilst their role in endocytic recycling is clear, and several effector pathways have been described, how their GTPase cycle is controlled in mammalian cells is not clear. Rab11s control the trafficking of cargoes including the major fibronectin receptor, alpha-5 beta-1 integrins, and Rab25 expression is associated with poor outcome in HGSOC. We aim to understand which Rab11s contribute to HGSOC dissemination, and identify the machinery that controls Rab11-dependent trafficking in HGSOC cells. We will also investigate which cargoes control HGSOC cell invasion, proliferation and resistance to therapy, using cell biology techniques in autologous models of HGSOC in the omentum. Rab11a and Rab11b are expressed ubiquitously, and hence may not be appropriate targets for cancer therapy. However targeting the proteins that promote cargo delivery, or the cargos themselves, could prove effective. We will identify the molecular machinery that controls delivery of specific cargoes to promote HGSOC progression, and thus provide line of sight to therapeutic targets to tackle this disease

This multidisciplinary proposal spans aspects of cell biology and clinical cancer research, and is relevant to biomedical science and analytical tool and method development. Thus there are wide ranging direct and indirect beneficiaries of this project.

1. Pharmaceutical industry. Understanding how ovarian cancer disseminates will provide insight into a process that underlies this lethal disease. We will develop methods that allow this process to be studied using cells and tissues from the same patient. This impact will be short term and direct. Our ongoing links with industry (PC and RE with Astra Zeneca, RE and EC with Arquer diagnostics, RE with Tesaro and Clovis) will allow us to rapidly fulfil translational potential. We will reveal potential therapeutic targets that will form the basis of ongoing studies by us and others. This impact is direct and medium to long term.

2. Biotechnology: Our study will develop techniques to analyse cell movement in 3D matrix, and PC is in talks with Phasefocus with a view to setting up a CASE studentship. Furthermore, together with Dr Egor Zindy (Imaging analyst within the Welcome Trust Centre for Cell-Matrix Research) we are developing software plugins (ImageJ, Matlab, Python) to support our method development and image analysis. All of these methods will be of great interest across bioscience and biotechnology. We will continue our collaborations with industry to generate methods which can be applied by the wider community. We expect that industry will express interest in commercialising aspects of our methodology, and we will identify partners to share our knowledge. This impact will be direct and mid-term.

3. The public. We will use public engagement events organised by the Wellcome Trust Centre for Cell-Matrix Research as a platform to disseminate our work and its significance to the general public, and our labs will host school pupils to allow them to gain practical knowledge of biosciences. We will also visit schools to help build an understanding of how science is beneficial to all. This impact is indirect and mid to long term.

4. Researchers in the wider community. Understanding how endocytic trafficking coordinates cell-matrix interactions and how trafficking pathways are organised is highly relevant to biology. Revealing how ovarian cancer cells use these pathways to survive and proliferate will be of particular interest to cancer research. Accordingly, scientists working in any of those areas might be highly interested in the outcome of the project. The impact will be direct and immediate.

5. Staff working on the project.
Staff working on the project will also benefit by participating in an interdisciplinary project and receiving training from the labs involved, in addition to attending training courses, workshops. Communication skills will be enhanced by presenting data at national and international conferences. This impact will be direct and immediate.