Generally, cancer is linked to the occurrence of successive mutations occurring in a given cell and on specific genes responsible for the proliferation of the cells that make up the tumour. These mutations are present only in cancer cells and not in the whole organism. They are therefore not hereditary.
Biological Mechanisms of Brain Tumours
Thus, in the case of gliomas, a mutation of a gene in a particular cell, an oligodendrocyte for example, and only in that cell type and not in all cells of the body, causes it to multiply.
The team of Prof. Marc SANSON and Dr. Emmanuelle HUILLARD is trying to characterize the mutations of each cell type that cause brain tumours. The search for these mutations takes place in the cancer cells themselves after biopsy or surgery of the tumour.
This research involves sequencing, or reading, the whole DNA of a cell and comparing it with that of a normal cell of the same individual. Differences in DNA sequences are then distinguished that correspond to mutations in the tumor: some of them alter normal cell function, including cell proliferation.
Thanks to Paris Brain Institute’s genotyping/sequencing platform, it is now possible to read the whole DNA of a very small number of cells very reliably and in just a few hours, compared to several weeks earlier.
On the other hand, a faster molecular diagnostic technology has been developed at the CIM, nanopore sequencing. This technique allows, among other things, the study of structural variants, single mutations, and the epigenetic methylation pattern over a day, using a single tool and at a lower cost.
By identifying these mutations that cause brain tumours, it is possible to:
- Accurate diagnosis of the tumour
- Understanding the Mechanisms Behind Tumours
- Identification of new therapeutic pathways.
At Paris Brain Institute
Researchers from Prof. Marc SANSON’s team and Dr. Emmanuelle HUILLARD focused on different specific subtypes of gliomas: gliomas of the middle line of the adult brain and spinal cord. They found a mutation present in 20% of the cases in the FGFR1 gene. Now there are specific treatments that target this gene, chordoid gliomas characterized by a very specific mutation (Rosenberg), gliomas with genetic instability that would make them vulnerable to specific treatments including immunotherapy (Touat, nature), gliomas characterized by a large inflammatory response
The team also generated important results in two other types of tumors: primary brain lymphomas with a prognostic and predictive molecular classification of response to treatment (Hernandez, Ann Oncol), and meningitis…