Objective
Plasma cells are responsible for secretion of immunoglobulins (Ig) into the bloodstream, which constitute the humoral immune response. XBP-1 is a transcription factor necessary for the terminal differentiation of B cells into plasma cells. XBP-1 is required for the synthesis and the maintenance of high levels of Ig, and plays a critical role in setting the conditions for their assembly and secretion. Multiple myeloma (MM) is the cancer of plasma cells, and in most cases this cancer retains the capacity to secrete high levels of Ig. MM is impervious to conventional chemotherapies, and constitutes 2% of total deaths from cancer. Recent evidence shows that XBP-1 promotes survival of MM cells. Since XBP-1 is destroyed with a half-life of minutes, we shall explore the mechanisms responsible for its degradation, as factors that may promote MM survival. We shall express recombinant XBP-1, and study its degradation by the proteasome in a cell free assay. In addition, we will use an RNA interference screening to identify genes required for the degradation of XBP-1. Bortezomib is a newly approved drug for MM, which blocks the proteasome.
The reasons why MM shows remarkable sensitivity to bortezomib are unknown. Utilizing cells resistance to proteasome inhibition, we will strive to identify genes and biochemical pathways that confer resistance of MM to treatment with bortezomib. This study may identify novel targets and pathways for the therapy of MM, and provide better understanding of the regulation of XBP-1 levels.
The overall aim is to combat cancer by broadening the knowledge base on molecular mechanisms underlying chemotherapy resistance. In accordance with the IRG objectives, my proposal will implement and transfer to Europe the technology developed at the Whitehead Institute in Cambridge, Mass. USA, where I spent the last 5 years (postdoctoral training), and will strengthen the existing collaboration with Whitehead researchers.
Fields of science
Call for proposal
FP6-2004-MOBILITY-12
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Funding Scheme
EIF - Marie Curie actions-Intra-European FellowshipsCoordinator
JERUSALEM
Israel