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Harrison, H.

Publications and source records attributed to Harrison, H..

4 recordsLinked to original sources

An in vitro model of breast cancer metastatic niche priming

Metastatic breast cancer is responsible for around 11,500 deaths a year in the UK. The primary tumour likely plays a major role in priming the distant site for metastasis and crosstalk between primary and metastatic sites may be essential for secondary tumour growth. We have developed a novel in vitro model in which we can further study these interactions; evaluating niche priming and cancer cell conditioning as well as assessing their influence on cell homing and colonisation. In this paper we describe a model that we believe adds to the array of in vitro tools available to study various stages of the metastatic cascade, offering a unique opportunity to assess bidirectional, primary to niche interactions in vitro. We show that proliferation, migration and chemotaxis, and stem cell activity are altered in both cancer cell lines and in lung epithelial cells following linked, fluidic culture. Changes in cell homing and colonisation can be modelled in cell lines and within viable lung tissue explants taken from mice, with breast cancer cells settling and growing within the lung epithelial cells and tissue explants over 7 days. The colonisation/growth of cells injected into the system closely represents that seen following tail vein injection and cancer cells can be seen to settle and grow within the lung epithelial cells.

cancer biology↗

Proteomics of Patient-derived Breast Tumours Identifies a Pro-migratory Osteomodulin-Cyclin Dependent Kinase 1 Axis which Drives Bone Metastasis

Metastasis to different organs remains the main cause of mortality in breast cancer. Molecular predictors of metastasis are limited as well as therapeutic options. Here, we conducted quantitative proteomics and phosphoproteomics analysis of patient-derived tumours, identifying osteomodulin (OMD) as a dysregulated protein and associated with bone metastases. Cancer-associated fibroblasts secrete OMD which increases breast cancer migration in vitro and promotes the formation of bone metastases in vivo. Downstream of OMD, phosphoproteomics identified the activation of cyclin-dependent kinase 1 (CDK1). The OMD-CDK1 signalling axis drives a pro-migratory and pro-survival phenotype in vitro and bone metastasis in vivo. Our findings highlight the importance of OMD and CDK1 in breast cancer bone metastasis and proposes an alternative therapeutic avenue for the treatment and the prevention of organ-specific metastases.

cancer biology↗

RUNX/CBFβ transcription factor complexes promote the phenotypic plasticity of metastatic breast cancer cells

Epithelial to mesenchymal transition (EMT) is a dynamic process that drives cancer cell plasticity and is thought to play a major role in metastasis. Here we show that the plasticity of metastatic breast cancer cells can be promoted by the activity of the RUNX transcription factors. We demonstrate that the RUNX co-regulator CBF{beta} is essential to maintain the mesenchymal phenotype of triple-negative breast cancer cells and that CBF{beta}-depleted cells undergo a mesenchymal to epithelial transition (MET) and re-organise into acini-like structures, reminiscent of those formed by epithelial breast cells. We subsequently show, using an inducible CBF{beta} system, that the MET can be reversed, thus demonstrating the plasticity of RUNX/CBF{beta}-mediated EMT. Moreover, the MET can be reversed by expression of the EMT transcription factor Slug whose expression is dependent on CBF{beta}, RUNX1 and RUNX2. Finally, we demonstrate that loss of CBF{beta} inhibits the ability of metastatic breast cancer cells to invade bone cell cultures and suppresses their ability to form bone metastases in vivo. Together our findings demonstrate that the RUNX/CBF{beta} complexes can determine the plasticity of the metastatic cancer cell phenotypes, suggesting that their regulation in different micro-environments may play a key role in the establishment of metastatic tumours.

cancer biology↗

HIF1-alpha expressing cells induce a hypoxic-like response in neighbouring cancer cells

Hypoxia stimulates metastasis in cancer and is linked to poor patient prognosis. In tumours, oxygen levels vary and hypoxic regions exist within a generally well-oxygenated tumour. However, whilst the heterogeneous environment is known to contribute to metastatic progression, little is known about the mechanism by which heterogeneic hypoxia contributes to cancer progression. This is largely because existing experimental models do not recapitulate the heterogeneous nature of hypoxia. The primary effector of the hypoxic response is the transcription factor Hypoxia inducible factor 1-alpha (HIF1-alpha). HIF1-alpha is stabilised in response to low oxygen levels in the cellular environment and its expression is seen in hypoxic regions throughout the tumour.\n\nWe have developed a model system in which HIF1-alpha can be induced within a sub-population of cancer cells, thus enabling us to mimic the effects of heterogeneic HIF1-alpha expression.\n\nWe show that induction of HIF1-alpha not only recapitulates elements of the hypoxic response in the induced cells but also results in significant changes in proliferation, gene expression and mammosphere formation within the HIF1-alpha negative population.\n\nThese findings suggest that the HIF1-alpha expressing cells found within hypoxic regions are likely to contribute to the subsequent progression of a tumour by modifying the behaviour of cells in the non-hypoxic regions of the local micro-environment.

cancer biology↗