Thèse Rôle du Cuivre au Cours de la Tumorigenèse H/F

Université Grenoble Alpes

Établissement : Université Grenoble Alpes
École doctorale : CSV- Chimie et Sciences du Vivant
Laboratoire de recherche : Laboratoire de Chimie et Biologie des Métaux
Direction de la thèse : Aurélien DENIAUD ORCID 0000000198623617
Début de la thèse : 2026-10-01
Date limite de candidature : 2026-04-09T23:59:59

Le cuivre (Cu) est un oligo-élément essentiel pour l'homme, mais de nouveaux rôles dans la différenciation cellulaire et la tumorigenèse ont été décrits au cours de la dernière décennie. En particulier, pour des raisons encore inconnues, le Cu augmente l'activité de kinases telles que MEK1, qui favorisent la croissance tumorale. Le Cu libre étant très nocif, la cellule possède des mécanismes d'homéostasie qui orchestrent avec précision le transport du Cu et son adressage aux protéines cibles. Pour maintenir toutes les fonctions dépendantes du Cu, les cellules cancéreuses ont besoin de plus de Cu que les cellules saines. Ceci est cohérent avec le niveau plus élevé de Cu mesuré dans des tumeurs telles que le glioblastome (GBM), où le(s) rôle(s) du Cu reste(nt) à explorer. De plus, nos données préliminaires ont déjà mis en évidence des différences dans l'homéostasie du Cu entre différentes lignées cellulaires d'adénocarcinome pulmonaire.
Dans le cadre de ce projet de doctorat, nous cherchons à comprendre le rôle du Cu et les optimisations de l'homéostasie du Cu dans les cellules d'adénocarcinome pulmonaire et de GBM. Ces questions seront abordées à l'aide de modèles biologiques pertinents et en suivant l'expression et la localisation des protéines à Cu, qui seront complétées par une cartographie élémentaire du Cu et une analyse de la coordination du Cu en utilisant des approches synchrotrons originales.
Ainsi, les mécanismes d'homéostasie du Cu dans les cellules pulmonaires et cérébrales et les modifications survenant lors de la tumorigenèse seront déchiffrés. Le rôle des différentes fonctions dépendantes du Cu sera également rationalisé dans les cellules cancéreuses. Dans l'ensemble, les résultats obtenus au cours de ce projet fourniront des pistes pour le développement de thérapies appropriées à base de Cu en fonction du type de cancer.

Copper (Cu) is an essential trace element used by enzymes to perform redox reactions. However, free Cu can trigger oxidative stress and protein unfolding. Intracellular Cu concentration is therefore tightly controlled by chelation mechanisms that lead to less than one free Cu ion per cell. General Cu homeostasis mechanisms are known at the cellular level. Cu is transported into the cell as Cu(I) via the transmembrane protein Ctr1, then bound by cytosolic Cu(I) chaperones that delivers Cu to target proteins. An important pathway is the so-called secretory pathway that involves the chaperone Atox1 that brings Cu to the membrane Cu transporters ATP7A and/or ATP7B depending on the cell type. Moreover, growing evidences highlight Cu as a key element in tumorigenesis, notably for mitochondrial bioenergetics or in lysyl oxidases (LOX) implicated in extracellular matrix remodeling or as cofactor of specific kinases (MEK1, ULK1) important for cell proliferation. However, the role of Cu in these novel functions remains unclear and the modifications of Cu homeostasis mechanisms enabling the optimal acquisition and delivery of Cu in cancer cells have not been comprehensively studied yet. Indeed, to sustain these diverse Cu-dependent processes, cancer cells require higher Cu levels compared to healthy cells, as evidenced by elevated Cu measured in neoplastic tissues. We thus make the hypothesis that cancer cells should have developed mechanisms to optimize Cu uptake, storage and availability. Our preliminary data in lung adenocarcinoma cells showed an increase in Cu intracellular level corroborated with the abolished expression of ATP7B in the most aggressive cell line, supporting our hypothesis. Similarly, in brain tumors elevated Cu levels has been described but the role of Cu in glioblastoma (GBM), one of the main brain tumors, has never been explored and only very recently Cu has been shown to favor GBM growth. It is thus fundamental to investigate the importance of the different Cu-related functions upon tumorigenesis and the modifications of Cu homeostasis mechanisms occurring to sustain these Cu-dependent functions.

The project aims at determining Cu homeostasis mechanisms in lung cells and understand its modifications upon tumorigenesis using various lung healthy and adenocarcinoma cell lines. In a second part of the project, Cu homeostasis in glioblastoma cells will be studied and compared with knowledge on Cu homeostasis in healthy brain cells.
To reach these goals, Cu protein localization will be determined, in particular those involved in the secretory pathway (Atox1, ATP7A, ATP7B), and integrated with information on Cu level and subcellular distribution. In parallel, Cu-dependent functions important for cancer cells will be assessed.
Altogether, these data will enable to propose a first model on the regulation of Cu homeostasis in healthy lung cells, and then highlight the key modifications that appeared in lung adenocarcinoma cell lines and show how this impacts their aggressivity. It will also be possible to decipher the role(s) of Cu in glioblastoma cells and the specificity of cancer stem cells regarding Cu.
Overall, this project aims to rationalize the role(s) of Cu in cancer cells which is necessary to later develop appropriate Cu-based therapies depending on the cancer context as well as to identify possible novel targets for therapy.

In the PhD project, the student will study Cu homeostasis mechanisms in lung cells and understand its modifications upon tumorigenesis using various lung adenocarcinoma cell lines. In a second part of the project the student will analyze Cu homeostasis in GBM cells and compare it with knowledge on Cu homeostasis in brain cells.
The project will be split into three main parts dedicated to the study of Cu homeostasis in different biological models, i, in non-tumoral lung cells using notably the bronchial epithelial cell line 16HBE14o-, ii, using different lung adenocarcinoma cell lines including H322 and H358, iii, in GBM cell lines containing stem cells or not, TG1 and U251, respectively.
In these different biological models, several methodologies mastered in the team and with close collaborators will be used. The sensitivity to Cu will be assessed for the different cellular models. In conditions non-toxic for the cells, the global level of Cu will be determined by ICP-MS and the level of expression of proteins involved in Cu homeostasis will be analyzed with a specific focus on Atox1, ATP7A and ATP7B for which subcellular distribution will be followed using confocal microscopy in a first instance, and super resolution microscopy to be able to correlate Atox1 trafficking and ATP7A/B locations in function of Cu intracellular level. In parallel, using synchrotron-based X-ray fluorescence microscopy, Cu intracellular distribution and local redox status will be obtained enabling to determine Atox1-ATP7A/B-dependent Cu trafficking pathways and storage. Finally, Cu-dependent activities linked with tumorigenesis will be assessed in the different biological models: MEK1 and Ulk1 kinase activities and LOX activity.