Defining the invasive cell components in glioblastoma: identification of new therapeutic targets.

Malignant brain tumours (glioblastomas) grow rapidly, recruit new blood vessels, in order to achieve a nutrient supply, and show extensive tumour cell invasion into the surrounding brain. They also display an extensive cellular variation (heterogeneity) characterized by cells displaying different mutations. Even after radical surgery and chemotherapy, the tumours eventually recur. It has for long been recognized that a major problem in the clinical management of the disease is based on the invasive cells that migrate from the main tumour mass into the surrounding brain. At present it is not known if these cells represent a specific cell population within the tumours and how they differ from the tumour cells present in the main tumour mass. By combining state-of-the-art animal models that reflect human disease, and new technologies where single cells can be separated and analysed individually, the INVATARGET project will analyse and characterize in detail the invasive cells within brain tumours. The information generated from the project will identify new therapeutic targets towards the invasive cells. This information will be further used to design and validate new therapeutic principles towards the invasive cells in brain tumours. In the project, we have now shown, by sequencing analyses that the brain itself reprogram the glioma cells towards invasion. Based on these results, we have identified a set of compounds that will target the invasive cells, and preclinical therapy experiments are ongoing. We have, among-others, identified a tricyclic compound, that have been used to treat Schizophrenia that can be re-purposed for glioma treatment. Moreover based on its chemical structure, we have made two new compounds that exhibit strong therapeutic effects in vitro and in vivo. These compounds are currently evaluated for patenting. The following results should be highlighted: -We have shown thar the normal brain changes the gene expression in the tumor cells towards invasion. This is characterized, among others, by changes in their metabolism towards anaerobic respiration. -We have shown that multiple cellular clones within the tumors have invasive capacities. -We have identified Thioridazine, a drug that was used to treat Schizofrenia, to have a therapeutic effect on brain tumors in vivo. -Since Thioridazine was withdrawn from the market based on cardiotoxic effects, we have synthesized >30 new tricyclic structures. Following therapeutic screening, we have identified two that show better therapeutic effects compared to Thioridazine. These two compounds are now under patenting.

INTERNASJONALT SAMARBEID: Prosjektet har ledet til økt internasjonalt samarbeid. Dette reflekteres gjennom en rekke publikasjoner sammen med flere utenlandske institusjoner. Prosjektet har også ledet til en utvikling av to nye potensielle legemidler for behandling av hjernekreft. Vi er i ferd med å patentere disse gjennom VIS som er UiB sitt technology transfer office. Vi vil i vår videre forskning studere mekanismene bak deres anti-tumor effekt og deres farmakokinetikk.

Patients with malignant brain tumors (glioblastomas) have a poor prognosis with a two year survival rate as low as 3.3%. In particular, extensive local invasion into the brain parenchyma is a primary characteristic of gliomas. Through results from The Cancer Genome Atlas (TCGA), considerable progress has been made on the genomic characterization of gliomas where resected specimens were taken from the bulk tumor mass. Yet, and at present it is not clear if the single invasive cells, present deep within the brain parenchyma, show the same genomic profiles as those in the tumor core. Central questions in this context are: 1) Do the infiltrative cells reflect the same cellular heterogeneity as the tumour cells in the bulk tumor mass, or do they represent a clonal sub-population within the tumors? -and 2) Is there a genomic and/or transcriptomic signature associated with the invasive cells that characterizes them? -and 3) can this signature be targeted by specific drugs that interfere with the signature? (infiltrative or invasive capacity). The main aim of this application is to characterize in detail the single invasive cells, at the genomic and transcriptomic level, and to determine if these cells can be targeted based on their transcriptomic profiles. For this purpose we will combine our state-of-the art human glioblastoma animal models with state-of-the art single cell analysis technology (Fuidigm Technology) in order to characterize at the single cell level the genomic and transcriptomic profiles of the invasive cells in GBMs. Based on the transcriptomic profiles generated we will use connectivity map (cMap), as well as validation studies, to screen for drugs that target the invasive cells.