Postdoctoral Research Fellowship

Endocytic control of EGFR signaling and biological response, and its subversion in cancer

Description

Applications are invited for postdoctoral research scientists in the area of quantitative molecular and cellular biology, cellular biochemistry and cancer cell biology. The successful candidate will work in close collaboration with a systems biologist to develop and validate a quantitative ODE model of epidermal growth factor receptor (EGFR) activation and trafficking in physiology and cancer. The project is a collaborative effort between the Istituto Europeo di Oncologia (IEO) in Milan, Italy and The Microsoft Research - University of Trento Centre for Computational and Systems Biology (COSBI) in Rovereto (TN), Italy.

Background: Endocytosis is a critical regulator of EGFR signaling and downstream biological responses, such as proliferation, migration, stem cell homeostasis, and differentiation. The EGFR can be internalized by different endocytic pathways that direct the receptor to different fates (e.g., recycling or degradation), influencing the strength, duration and spatiotemporal resolution of signaling (Sigismund et al., Dev Cell 2008; Sigismund et al., EMBO J 2013; Caldieri et al., Science 2017).

We previously built a semi-quantitative model of EGFR early activation that exclusively considers events occurring at the plasma membrane and is capable of: i) making non-obvious predictions about EGFR activation and degradation, ii) identifying a fragility point in the system exploited by cancer cells, iii) pinpointing the molecular determinant responsible for the fragility (Capuani et al., Nat Comm, 2015). By integrating mathematical modeling with wet-lab experiments, we are now generating a fully quantitative and time-resolved advanced model of EGFR endocytosis and signaling with the aim of identifying additional fragility points in endocytic circuitries that could be exploited by cancer cells to gain proliferative/migratory advantages.

Project aims: The successful candidate will be involved in:

1) Construction and validation of the advanced model in a back and forth approach with the systems biologist, by: i) measuring the endocytic rate constants (Ke) of the different endocytic pathways at different concentrations of ligand and receptors; ii) measuring the same parameters under conditions of perturbation of the different endocytic pathways; iii) measuring the rate of EGFR recycling, degradation, and downstream signaling in the above conditions.

2) Experimental validation of model predictions, in particular those related to the time-resolved evolution of EGFR degradation and signaling, and the correlation between EGFR/EGF levels and EGF-dependent biological readouts (e.g., proliferation, migration, invasion, morphogenesis and stem cell regulation) in non-tumorigenic contexts and in cancer.

A series of assays and model systems have already been developed in the lab to tackle these aims:

1. Endocytic assays. We have genetic and pharmacological tools to interfere with the major endocytic routes and optimized quantitative EGFR internalization and trafficking assays.

2. Migration and invasion assays. Migration/invasion experiments are set up in the lab (e.g., wound healing, transwell Matrigel assay, chemotaxis assays, 3D organoid growth/invasion in Matrigel).

3. CSC and EMT analysis. We have established a series of assays to analyze cancer stem cell (CSC) properties and epithelial-to-mesenchymal transition (EMT) phenotypes.

4. Organoid culture systems. Procedures for culturing primary mouse and human breast mammary organoids in 3D morphogenetic Matrigel assays are well established in our lab. Patient-derived organoids from breast cancers are also available and will be used to investigate relevance of model predictions in a clinically relevant cancer model system. 

The work will be performed at the IEO in Milan, Italy, under the supervision of Prof. Pier Paolo Di Fiore, Head of the Novel Diagnostic Programs, and Dr. Sara Sigismund. As part of the research team, the successful candidate will join a highly motivated research group and will have the opportunity to access all the facilities, expertise, knowledge and tools available in Pier Paolo Di Fiore’s group and at the IEO.

Required skills and experience:

• PhD in Biology, Biotechnology or related fields;

• excellent English communication skills, both written and verbal.

Desirable skills and experience:

• experience with cell culture, molecular biology and biochemistry techniques;

• experience with primary cell and organoid cultures;

• experience with mouse handling and in vivo techniques (e.g., organ explant, orthotopic injections).

Salary will be commensurate to CV, previous experience and skills.

Location:

The work location is the IEO, Department of Experimental Oncology, Via Adamello 16, 20141 Milan.