3D Telomeric Profiles of MGUS, MMN and Relapsed MM

Abstract 2899

Multiple myeloma (MM) is recognized as the second most common cancer of the blood. It is a malignant disorder of plasma cells and commonly affects adults past the age of 50. Although risk factors have been established, it is currently not possible to assess the individual risk to cancer progression. Moreover, the causes of disease progression from its precursor condition, monoclonal gammopathy of undetermined significance (MGUS), to full-blown MM and its progression to relapsed MM remain elusive. We have performed previous studies on the three-dimensional (3D) nuclear organization of telomeres and found that normal and tumor cells display significant differences in their nuclear organization. These differences were objectively quantified with two software programs, TeloView and TeloScan developed by our group.

We now report on a new double blinded preliminary study with 36 patients, including 20 MM, 12 MGUS and 4 relapsed MM. Using blood- and bone marrow-derived plasma cells from the respective patient groups, we have examined 3D nuclear telomeric profiles of the above patients. Plasma cells from MM, MGUS and relapsed MM exhibit specific 3D telomeric signatures. MM have the highest telomere numbers, followed by MGUS, while relapsed MM presents with the lowest numbers of telomeres and the shortest telomeres. Additional telomere parameters, such as cell cycle distribution profiles (a/c ratio), telomere aggregate numbers, distances from nuclear centre and also exhibited significance (p< 0.001).

Within the MGUS and MM patient groups we studied are patients whose 3D telomeric profiles indicate the beginning of a new signature that resembles signatures of MM and relapsed MM respectively. Blood and bone marrow gave us comparable results opening the future opportunity to base diagnostics and monitoring on blood samples, sparing the patient form invasive bone marrow sampling with potentially adverse effects. Based on our current preliminary data, we propose the following 3D telomeric criteria that define individual signatures of MGUS and MM and progression within each of the groups: telomere numbers, telomere sizes, presence of telomeric aggregates, telomeres per nuclear volume, and a/c ratios. The clinical significance of these findings is the early identification of individuals with high risk of progression. This opens the possibility for better monitoring and early intervention with newer treatments with an acceptable efficacy and low toxicity ratio.