Christophe DUBESSY, Associate Professor

Contact information

Inserm U1239 - DC2N (Laboratory of Neuronal and Neuroendocrine Communication and Differentiation)

CURIB building, 2nd floor, room 242

Place Emile Blondel

76821 Mont-Saint-Aignan

Tel: +33(0)235 14 6752

E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

 

Education and Training

·         M.Sc. in Biochemistry, Molecular and Cell Biology, University of Bourgogne / Franche-Comté

·         Ph.D. in Biological Engineering - Oncology, University of Nancy I – H. Poincaré

·         Temporary research and teaching assistants (ATER, Attaché Temporaire d’Enseignement et de Recherche)

·         Post-doctoral fellow, Inserm U413 (H. Vaudry’s lab), University of Rouen

·         HDR (Habilitation à Diriger les Recherches)

·         Holder of a Level I training in animal experimentation

 

Educational Role

Co-responsible for the Licence 1 SVT degree (2006-2012)

Co-responsible for the Licence 3 SV – B2MCP degree (2012-2018)

 

Research area

Involvement of microRNAs and their targets in secretion pathologies: application to the study of secretion dysfunctions in the pheochromocytoma, a tumor of the adrenal medulla gland.

 

Current research

Regulated secretion releases neurohormones that are stored in dense core secretion vesicles (DCSV). These organelles are produced by budding from the membrane of the trans-Golgi network and transported to the plasma membrane where they will fuse in a controlled manner to release their contents into the extracellular space. Many metabolic, neuropsychiatric and neurodegenerative pathologies are associated with a deregulation of this exocytosis and the molecular mechanisms are poorly understood. We hypothesized that microRNAs (miRNAs) would be key actors. These small non-coding RNAs are regulators of gene expression that maintain homeostasis of signaling pathways; their deregulation therefore often leads to alterations in cellular and physiological functions. However, to date, very few miRNAs have been associated with exocytosis processes and without taking into account the totality of this biological process.

Our objective is therefore to study, using bioinformatics and functional approaches, the control of exocytosis by miRNAs in pheochromocytoma (PCC), a rare neuroendocrine tumor of the medullo-adrenal gland. PCC is characterized by hypersecretion of neurohormones such as catecholamines (dopamine, (nor)adrenaline), which causes harmful side effects in patients such as hypertension, which is often fatal to them.

Our studies have revealed that seven miRNAs are differentially expressed in a particular form of pheochromocytomas that secrete physiological levels of catecholamines (collaboration with A. Tabarin (CHU Bordeaux) and C. Bérard (LITIS, Rouen)). These miRNAs are also a molecular signature of these tumours.

 In order to identify the target mRNAs of these seven miRNAs, we developed miRabel (http://bioinfo.univ-rouen.fr/mirabel/), a software for predicting target mRNAs in collaboration with the LITIS laboratory (T. Lecroq, Rouen). We have shown that miRabel outperform the other prediction tools currently available.