Dana Farber Cancer Institute
Medical Oncology Dept.
Boston, MA, USA
by Lynne Lederman, Phd
NOTE: Dr. Carrasco was unavailable, so this research was presented by Dr. Tonon.
X-box Binding Protein-1 (XBP-1) is a differentiation and unfolded protein/ER stress response factor. A transgenic mouse model of myeloma, Eµ-XPB-1s, expressing XBP-1 in mice develop either a severe cutaneous disease or MGUS followed by myeloma after a long latency period, mirroring human disease progression. Those developing myeloma also develop renal complications, a monoclonal antibody spike, plasma cells infiltrating the bone marrow, and bone lytic lesions. However, unlike human disease, the monoclonal gammopathy is primarily IgM, which is rare in human patients, not IgG. Nevertheless, this system may allow testing of the role of genes that are upregulated or amplified in human disease.