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UCL Great Ormond Street Institute of Child Health

Great Ormond Street Institute of Child Health

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The HMMR protein as a potential oncogenic driver in neuroblastoma

Supervisors names
Andrew Stoker
 

Project outline
Neuroblastoma remains a difficult oncological challenge in young children, with poor overall survival rates and high morbidity (1). There is a great need to gain both a better understanding of oncogenic signaling mechanisms in this heterogenous tumour and the discovery of novel drug targets. Our recent, unpublished studies have highlighted a specific protein called HMMR, as a promoter of various neuroblastoma tumour cell behaviours. HMMR is unusual in having a cell surface form that acts as a hyaluronic acid receptor, plus a cytoplasmic and nuclear form that controls microtubule dynamics (2,3). HMMR is a tumour-promoter in several cancers, controlling chromosome stability, cell proliferation and tumour cell invasiveness. Our data also now show for the first time that HMMR has similar potential in neuroblastoma.

We have shown that loss of HMMR in neuroblastoma a cell line can reduce proliferation, motility and stemness. From phosphoproteomic analysis, we also know that HMMR regulates ERK signaling and also aspects of DNA integrity. The biochemical mechanisms are currently less clear and this project aims to unravel this complex biochemistry and cell biology. 

In the proposed work we will focus on understanding if the cellular roles of HMMR in neuroblastoma cells requires its surface interaction with hyaluronic acid ligands. We will also aim to characterise how HMMR then influences DNA stability in these cells and if this relates to its pro-cancer function. 

Objectives and timeline
The Objectives and broad timeline of this work are as follows:

  • (months 1-18). Investigate the broader role of HMMR in further neuroblastoma cell lines. Develop a wider range HMMR-deficient neuroblastoma cell lines and also develop an inducible, degradable form of HMMR protein using CRISPR/Cas9 targeting. Deficient lines will be developed using existing guide RNA approaches. The degradable form of HMMR will allow us to understand the rapid signaling changes that occur after acute removal of HMMR function. This approach with use degron insertions fused to the HMMR gene (4).
  • (months 1-24). Understand the signaling effectors of HMMR. Using the degradable HMMR and further drug-treated cells, we will analyse the phosphoproteome of the cells after HMMR loss, to understand what primary targets are used by HMMR. To complement this, we will also examine the direct binding partners of HMMR through pull-down approaches and proteomics analysis.
  • (Months 12-36). Experimentally validate the signaling pathways used by HMMR. For this we will take knowledge from earlier objectives and design cell perturbation with relevant chemical inhibitors of HMMR interactors and effectors. We will assay cell biochemistry as well as proliferation, migration and stem cell characters. This will employ the HMMR-deficient and degradable HMMR systems above, to ultimately define and validate the key mechanism through which HMMR controls the cancerous behaviour of the tumour cells.

References
Brodeur, G. M. Nat Rev Cancer 3, 203-216 (2003). 
Maxwell, C. A., McCarthy, J. & Turley, E. Journal of Cell Science 121, 925 - 932 (2008).
Hall, C. L. & Turley, E. A. J Neurooncol 26, 221-229 (1995). 
Phanindhar, K. & Mishra, R. K. BioTechniques 74, 186-198 (2023).  


Contact
Andrew Stoker; a.stoker@ucl.ac.uk