The glioma is a primitive tumor of the central nervous system. It involves the interstitial nervous tissue and the cells of that tissue (astrocytes, oligodendrocytes, ependymocytes, choroidal cells, etc.). Depending on the affected cell types, identified by histological analysis, several types of gliomas are described. In addition, several grades from I to IV, identified in humans and to a lesser extend in dogs, allow a classification based on severity.
In dogs, Boxers and other brachycephalic (short-nosed) breeds, such as French Bulldog, English Bulldog, Boston Terrier, Dogue de Bordeaux … show a clear predisposition for this type of tumors.
The clinical neurological signs which indicate the possible presence of a cerebral tumor are due first to the location of the tumor and second, to the pressure the tumorous mass exerts on the rest of the cerebral tissue (intercranial hypertension).
In humans, the prognosis of these tumors is very reserved and treatments are not very effective. New therapeutic tests are underway, but so far little data is available on the genetic origins of these tumors. However, genetic variants common to several cancers including glioma have been recently identified : Shete S., Genome-wide association study identifies five susceptibility loci for glioma. Nat Genet. 2009 Aug;41(8):899-904 ; Panditharatna E, Yaeger K, Kilburn LB, Packer RJ, Nazarian J. Clinicopathology of diffuse intrinsic pontine glioma and its redefined genomic and epigenomic landscape. Cancer Genet. 2015 Jul-Aug;208(7-8):367-73)
Multicentric research projects looking for genes of predisposition are underway, but it remains difficult to illustrate in a heterogeneous population such as humans.
In dogs, there have been very few genetic research projects to date, but the brachyocephalic breed predisposition and the “histological resemblance” between human and canine gliomas makes them a very interesting model to use in order to identify the predisposition genes, as well as the early cascade of events that lead to tumor formation. Thus several studies consider the dog as a particularly interesting spontaneous model on the immunological and genetic scale : (Candolfi M. et al, Intracranial glioblastoma models in preclinical neuro-oncology: neuropathological characterization and tumor progression. J Neurooncol. 2007 Nov;85(2):133-48 ; Truvé K, Dickinson P, Xiong A, York D, Jayashankar K, Pielberg G, Koltookian M, Murén E, Fuxelius HH, Weishaupt H, Swartling FJ, Andersson G, Hedhammar Å, Bongcam-Rudloff E, Forsberg-Nilsson K, Bannasch D, Lindblad-Toh K. Utilizing the Dog Genome in the Search for Novel Candidate Genes Involved in Glioma Development-Genome Wide Association Mapping followed by Targeted Massive Parallel Sequencing Identifies a Strongly Associated Locus. PLoS Genet. 2016 May 12;12(5):e1006000)
The goals of the genetic research project on dog gliomas are :
- To identify the predisposing genes in dogs, which would allow the developement of predictive tests in the long-term
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To transfer the knowledge gained about gliomas which are similar in humans, in order to better understand their genesis and to plan ahead for targeted therapeutics.
This research project calls upon veterinary specialists, dog clubs, breeders and dog owners who want to help in advancing research in this domain, to participate in this project.
To participate in this research, please send us:
- Blood samples in EDTA tubes of brachycephalic breeds (or other breeds) affected by gliomas, as well as elderly dogs with no signs of cancer (which will serve as controls) : CNRS_Gliome_Protocole
- A questionnaire filled out for each affected dog: CNRS_Gliome_Questionnaire
- A photocopy of the pedigree or information on the parents (if possible and if available)
- A photocopy of the clinical results or histological analyses or imagery : CNRS_Gliome_Protocol
In case of a tumor biopsy, surgery or death of the dog, it would be beneficial to receive samples of the tumorous masses (or non tumorous, in the case of an autopsy) done in accordance specifically for complementary analyses (sample tubes furnished by us, by request). To do this, please contact us +33 (0)2 23 23 45 09 rapidly right after the event or ideally beforehand, so that we can inform you or your veterinarian of the procedure to follow and ship specific kit for sampling
We remind you that the data collected at the CNRS are confidential.
For more information, you can contact the team by phone at 02 23 23 45 09 or by email cani-dna@univ-rennes1.fr
