The VICC.ORG Directory of Doctors, Healthcare Providers & Researchers

Josiane Eid, M.D.

Assistant Professor of Cancer Biology
VICC Member
Researcher

Contact Information:

Vanderbilt-Ingram Cancer Center
740 Preston Building
Nashville, TN 37232
615-936-2923

Research Description

The main focus of our research is to explore nuclear signals that control key cytoplasmic events, such as signal transduction pathways and differentiation. If deregulated, these biological events could contribute to cancer development.

As a model, we are basing our studies on SYT-SSX, the translocation protein of synovial sarcoma, and its normal counterpart, the proto-oncoprotein SYT.

Synovial sarcoma is an aggressive soft tissue tumor that affects young adults. It is characterized by a chromosomal translocation between the SYT gene on chromosome 18 and the SSX gene on the X chromosome. As a result, a fusion protein, SYT-SSX, forms at the breakpoint. Since the X/18 rearrangement occurs in almost all cases of synovial sarcoma and is considered the hallmark of the cancer, SYT-SSX is thought to play a pivotal role in tumor formation

SYT and cell adhesion:

We have shown that during contact inhibition, SYT, when in complex with the nuclear transactivator p300, relays a nucleus-to-cytoplasm signal that allows the cell to undergo tight adhesion and spread on the extracellular matrix. Interfering with the integrity of the complex leads to a change in cell shape and its inability to adhere on fibronectin.

Contact inhibition is a fundamental biological event that prevents uncontrolled cell division. Proper cell adhesion is an important feature of contact inhibition, and tumor cells that lose their ability to contact inhibit become invasive and metastasize.

We are interested in studying the biological function of the proto-oncoprotein SYT in the control of cell adhesion during contact inhibition of growth and in controlling adhesive events and tissue architecture in 3D-cultures.

SYT-SSX and b-catenin/Wnt pathway:

We have recently found that the oncogene SYT-SSX induces translocation of b-catenin, the mediator of the Wnt pathway, into the nucleus, where both proteins appear to co-exist in a transcriptionally active complex.

we are currently investigating b-catenin function control by SYT-SSX and determining the pathway involved in this process. This will elucidate, in part, the mechanism of tumorigenesis by SYT-SSX.

SYT-SSX, SYT and chromatin remodeling:

Both SYT and SYT-SSX bind chromatin. they are thought to be involved in chromatin remodeling. We are applying proteomic as well as molecular biological analysis to determine and compare the contribution of both proteins in the control of gene expression and their effect on cell homeostatsis.

We are currently deciphering the role of SYT-SSX in polycomb repression.

Most recently, we have initiated a new research project that involves the role of NOTCH signaling in

synovial sarcoma development and self-renewal of mesenchymal progenitor/stem cells.

Publications


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