Investigation of the molecular mechanisms and microenvironmental cues driving adaptive resistance to FLT3 targeted therapy in acute myeloid leukaemia.

Primary Supervisor: Dr Paolo Gallipoli, Barts Cancer Institute, Queen Mary University of London

Secondary Supervisor: Prof Cristina Lo Celso The Francis Crick Institute and Imperial College London

Acute myeloid leukaemia (AML) is a cancer of unmet need with a 30% survival rate at 5 years[1]. Improved understanding of AML biology has driven the development of targeted therapies but these have not translated into significant improvement in patient outcome mostly as a result of disease relapse. FLT3 tyrosine kinase receptor activating mutations are the most frequent recurrent mutations in AML and associate with poor prognosis, despite recently introduced specific inhibitors. We previously showed that FLT3-mutant AML displays specific metabolic adaptations in response to targeted therapy[2]. Our preliminary data suggest that chemoresistant cells rely particularly on fatty acid metabolism. Interestingly high body mass indexes are associated with both increased risk of developing FLT3-mutant AML and relapse risk following therapy[3]. This clinical observation suggests that excess adipose tissue in the microenvironment might play a role in both the establishment and chemoresistance of FLT3 mutant AML. We previously used intravital microscopy and advanced microscopy protocols to study the role of the microenvironment in leukaemia initiation, therapy resistance and relapse[4].

In this project, the candidate will combine the expertise and technology of the host labs to test the main hypothesis that an adipose tissue niche is preferentially co-opted by FLT3 mutant AML to support its establishment and resistance to therapy. An already characterised FLT3 mutant murine leukaemia[5], and wild-type counterpart, will be transplanted in recipient mice expressing reporters for different components of bone marrow and other visceral niches including adipocytes throughout the body. Disease establishment and response to FLT3 inhibitors will be monitored in vivo to study dynamic changes in the leukaemia cell molecular profiles, behaviour and microenvironmental interactions from early stages to response to therapy. The effects of perturbations of fatty acid metabolism or other niche interactions using either pharmacological or genetic inhibition on leukaemia establishment, maintenance and microenvironmental interactions in FLT3 leukaemia before and after therapy will be assessed in vivo. Molecular and biochemical/metabolic analysis of the effects that targeting the leukaemia/microenvironment interactions has at cellular level will be performed by in vivo and ex vivo analyses. Beyond this initial aim, we will test whether chemotherapy-driven increased adipose niche recruitment is a widely-occurring mechanism supporting chemoresistant cells in non FLT3-mutated leukaemia models. Finally, using recently developed HSC reporter mice, we will define if in our models the interactions of normal and leukaemic stem cells within the niche are different during disease establishment and following therapy. This will identify any specific leukaemia/niche interactions which can be targeted therapeutically with reduced toxicity. Throughout the study, the main findings will be validated using primary samples and xenografts.

The ideal candidate will have a degree in biomedical sciences, a strong drive to answer fundamental research questions and desire to pursue a scientific career. Previous laboratory experience, i.e. MSc, and experience with murine models will be advantageous. The candidate will develop several specific and transferrable skills and will be encouraged to develop his independent thinking from the early stages of the project. He/she will be expected to work flexible hours and as a part of a team.

Potential research placements

1. Training in relevant skills for the project including in vitro models of leukaemia, viability assays and molecular techniques (protein and gene expression, flow cytometry, microscopy). Dr Gallipoli, QMUL

2. Familiarisation with in vivo models of leukaemia, work with immunocompromised mice, analysis of metabolic pathways and advanced microscopy approaches. Prof. Lo Celso, The Francis Crick Institute.

3. Intravital microscopy and image analysis approaches. Prof. Lo Celso and Dr. Andreas Bruckbauer (Facility for Imaging by Light Microscopy), Imperial College London

The funding for this studentship covers students with home tuition fee status only. For more information on home tuition fee status please visit the UKCISA website. Please note that we will only be able to offer studentships to candidates that have home tuition fee status or provide evidence that they can fund the international portion of the tuition fee from external sources (i.e. not self-funded).

References

1. Döhner, H. et al., Acute Myeloid Leukemia. N. Engl. J. Med. 373, 1136–1152 doi: 10.1056/NEJMra1406184 (2015)

2. Gallipoli, P. et al., Glutaminolysis is a metabolic dependency in FLT3 ITD acute myeloid leukemia unmasked by FLT3 tyrosine kinase inhibition. Blood. 131,1639-1653; doi: 10.1182/blood-2017-12-820035 (2018)

3. Mazzarella, L. et al., Obesity is a risk factor for acute promyelocytic leukemia: evidence from population and cross-sectional studies and correlation with FLT3 mutations and polyunsaturated fatty acid metabolism. Haematologica. 105, 1559-1566; doi: 10.3324/haematol.2019.223925 (2020)

4. Hawkins, E.D. et al., T-cell acute leukaemia exhibits dynamic interactions with bone marrow microenvironments. Nature. 538, 518–522 doi: 10.1038/nature19801 (2016)

5. Mupo, A. et al., A powerful molecular synergy between mutant Nucleophosmin and Flt3-ITD drives acute myeloid leukemia in mice. Leukemia. 27, 1917–1920, doi: 10.1038/leu.2013.77. (2013)