Contact versus contactless signatures in leukemia

Gene expression profile (GEP) was analyzed in bone marrow (BM) samples from patients with leukemia or leukemic phase of lymphoma at different time points following aspiration. Among numerous changes in GEP evolved over time a discrete subset of > 60 genes exhibited prompt and sustained switch in expression consistently. Similar results were discovered recently in BM samples from patients with multiple myeloma (GSE36036). GEP was also examined in peripheral blood as well as in BM samples depleted of red blood cells (=WBC) and in cultured cells from some of the patients. Comparative gene expression profiling of whole bone marrow samples from patients with leukemia fixed either immediately following aspiration or after delayed RNA fixation. Comparison was also made between cultured bone marrow cells fixed immediately following spread from the bottom well versus after maintenance in suspension (for 120 minutes).