A single kinase modulates the diverse extracellular phosphoproteome of glioblastoma multiforme

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'The best work on the pathology of cancer is now done by those who are studying the nature of the seed......but his observation of the properties of the soil may also be useful'. Dr. Stephen Paget, The Lancet, 1889. Dr. Paget's 'seed and soil hypothesis' of 1889 remains a central concept for the last 130+ years. We have come to know that an intricate cross-talk between cancer cells or 'seed' and surrounding tissue or stroma or 'soil' plays a vital role in promoting cancer. In that context, my proposal plans to establish a major player modulating both the 'seed' and the 'soil' of glioblastoma multiforme (GBM). Stage IV brain cancer or glioblastoma multiforme (GBM) poses a major challenge with only 4 FDA approved chemotherapeutic drugs available for treatment. Since initial diagnosis, only 1 out of 10 patients will survive beyond 5 years. When a low- grade brain tumour progresses to grade IV GBM, multiple changes take place including multiplication of its chromosome7. In fact, patients with GBM tumours that exhibit chromosome7 multiplication have the poorest outcome of all patients. Efforts are underway across many laboratories worldwide to understand how chromosome 7 specific genes could be used as markers for grade progression of brain cancer, however, all such studies require risky neurosurgery for removal of the tumour first. Various groups studying the excised GBM tumour or blood of GBM patients have reported various secreted proteins, enzymes, growth factors to be elevated in higher grade brain tumour patients. These secreted proteins either directly promote the GBM tumour growth or provide support externally for tumour growth from the surrounding tissue or 'soil' also referred to as 'stromal support'. Although many laboratories study these secreted proteins, very few realize that all of these secreted proteins are modified by phosphate molecules (called phosphorylation) by a single secreted enzyme. Interestingly, the enzyme is present on chromosome7 and remarkably elevated in stage IV GBM. Upon elevation, the enzyme activity is increased by >20-fold and it puts multiple phosphates on the secreted proteins and then the 'phosphorylated' proteins carry out their functions within the tumour and then often travel from the tumour to blood. Hence if we can study the mechanism of how the enzyme catalysed phosphorylation of the secreted protein affect the function of the proteins either in the context of direct tumour growth or stromal support, we would be able to develop novel therapies to intervene in those mechanisms. Furthermore, capturing the phosphorylated form of the secreted proteins in patients' blood will allow us to predict the following: Is the enzyme more active in the tumour? If so, chromosome7 is probably multiplied, so the tumour might be grade IV. To establish this, I propose the following steps:1. Study how does phosphorylated secreted proteins promote GBM tumour or 'seed' growth. We will utilise primary patient derived GBM cells and Crispr/cas9 genome editing to study GBM growth and invasion properties of cells in mouse brains. 2. Identify how the extracellular phosphorylated proteins could modulate the intracellular growth signals and promote GBM tumours. Various biochemical, biophysical and mass-spectrometry approaches will be carried out to address this aim.3. Establish the first ever phospho-protein detection blood-test to predict brain cancer.4. Elucidate how the enzyme could provide extracellular support or 'soil' for GBM tumour growth. We will utilise various brain cancer mouse models to study how the enzyme in the brain could provide support to tumour growth.Successful completion of these aims will establish multiple predictive, prognostic and therapeutic biomarkers of GBM. Establishing a blood-test to detect progression of low to high-grade brain tumour could be a major breakthrough of the decade.