Descriptif du sujet
This proposal is included in an INCA grant (PLBIO 2018-2020) funded collaborating project between INSERM U1030 at Gustave Roussy (Dr Nazanine Modjtahedi coordinator of the project), INSERM UMR-S1180 at Pharmacy Faculty in Chatenay-Malabry and IRSN. The present project will be performed at IRSN in Fontenay-aux Roses (30 minutes from Paris Center, and 20 minutes from Gustave Roussy) under the supervision of Dr Fabien Milliat (Head of the Radiobiology medical Exposure laboratory at IRSN) in close collaboration with Nazanine Modjtahedi.
Through the reprogramming of their metabolism and the secretion of signaling factors and metabolites, cancer cells establish a symbiotic interaction with the tumor microenvironment effectors, including vascular cells. The aim of the proposed postdoctoral program is to study the impact of cancer cell metabolism on the distal communication with endothelial cell, particularly in conditions of exposure to ionizing radiation. As mitochondria are key players in the metabolic reprogramming of cancer cells and in the propagation of stress signals generated in response to microenvironmental factors (hypoxia, vascular perfusion …) or to the effects of anticancer treatments (chemo- and radiotherapy), the program will be dedicated to the characterization of the role of a selected group of mitochondrial proteins that regulate the mitochondrial bioenergetics.
The project will be divided into two mains tasks developed in parallel. The general aim of the first task is to study in vitro the impact of tumor cell bioenergetics and tumor-derived metabolites on the cross-talk (through the secretion of signaling factors) with endothelial cells. This intercellular signaling could favor tumor-derived angiogenesis by influencing endothelial cells’ proliferation, differentiation and migration. For the realization of this task, isogenic cell lines knocked-down for a selected panel of mitochondrial proteins will be established at Gustave Roussy and studied at IRSN. Endothelial cells’ phenotype exposed to the conditioned culture medium of selected isogenic cancer cells will be monitored by analyzing the comparative transcriptomic profile of the exposed ECs, using a “home-made” TaqMan Low Density Array as well as their proliferative and metabolic status. The biological readouts to objectify ECs’ capacity to proliferate, invade or to form capillary tubes will be assessed using various techniques including IHC, flow cytometry and videomicroscopy using an Incucyte systems. In a second set of experiments, ECs will be cocultured with cancer cells (using transwell chamber systems) and the follow up will be realized for the same biological readouts as for the first set of experiments.
The second task will be developed using an innovative preclinical mouse model (subcutaneous xenograft in immune-incompetent “nude” mice). The aim will be to evaluate the impact of tumor cell reprogramming (using small molecules or knocked-down isogenic cancer cell lines) on tumor growth, tumor-derived vascularization and normal tissue (lung) tolerance to injury after radiotherapy. In vivo irradiation will be performed using a Small Animal Radiation Research Platform, which is a unique precision radiation platform available at IRSN. Tumor growth, tumoral vascularization and normal tissues injury (lung injury) will be monitored using a panel of methods including, tumor size measurement, μCt imaging of lung, Fluorescent BS1-lectin IV injection to image microvasculature and vascular integrity (both for lung and tumors), anatomo-pathology et IHC analyses.
Funding: INCA-funded contract available for 18 month, start in January 2019
- Strong experience with mouse preclinical models and in vivo tumorigenesis
- Standard molecular and cell biology techniques for the in vitro characterization of normal and cancer cells
- Highly motivated, with excellent communication skills
- Capacity for autonomous work and collaborative efforts
Highly qualified and talented applicants should send an application to Dr Fabien Milliat (email@example.com) The application will include a motivation letter and a short synopsis of doctoral work, a CV, a list of publications and communications. Contact information for two referees