WP3 – Identification and profiling of malignant, migratory cells
Rationale
Due to diffuse brain infiltration, gliomas and many other brain tumours always recur after surgery, radiation and chemotherapy. The cellular origin of recurrence is migrating tumour cells in the tumour periphery. These migrating tumour cells have infiltrated the brain parenchyma and in intimate contact with astrocytes, neurons and microglia.
Since these cells cannot be removed by surgery, they are critical to eliminate by novel therapies in order to improve patient survival. With detailed knowledge about the phenotype of migrating tumour cells and cells in the surrounding microenvironment, we will identify potential novel therapeutic targets and mechanisms of resistance in this critical cell population.
Objectives
- Molecular characterisation by regular and spatial single cell sequencing
- Validation of targets at protein level in patient tissue cohorts from tumour periphery
- Pre-clinical studies in orthotopic patient-like animal models
Approach
A major obstacle to investigate the tumour periphery has been lack of methodological possibilities to identify the migrating tumour cells. Taking advantage of regular and spatial single cell RNA-seq of human glioblastoma biopsies from the tumour periphery, resolution of the transcriptome for migrating tumour and cells in the surrounding tumour microenvironment will be obtained.
Biopsies from tumour core and periphery will be obtained by surgery and validation of localization of the samples will be histologically confirmed up front by neuropathological evaluation, when the samples are received. Using bioinformatics, potential treatment targets in the periphery will be identified.
Presence and cellular localization of target genes will be validated histologically at the protein level by high-end multiplexing using Imaging Mass Cytometry with metal-tagged antibodies (collaboration with core facility at King’s College, London, UK).
We have established a cohort of >100 samples from the tumour periphery with IDH wildtype and p53 mutated and immunohistochemically positive gliomas (primarily glioblastomas) [18], where immunohistochemistry can be used to detect migrating tumour cells in the tumour periphery.
This cohort will be expanded by samples from other Danish hospitals and from our guest professor Guido Reifenberger. Candidate targets will be functionally investigated in patient-derived GBM cells using both in vitro migration assays and mouse experiments. Based on the validated targets, both approved and new drugs will be tested in the models to go forward with a clinical trial.
Endpoints
Successful testing of new drugs with improved overall survival using orthotopic patient-derived xenograft models.
Expected impact
Elimination of migrating tumour cells left in the brain after surgery. Successful clinical trials with elimination of these cells could prolong GBM patient survival significantly.
The Kristensen Group is located at the Bartholin Institute, which is part of Department of Pathology at Rigshospitalet, Copenhagen University Hospital.