Whole genome transcriptional analysis of leukemic CLL cells purified from bone marrow of xeno-transplanted mice

The development and progression of CLL are dependent upon a complex microenvironmental network of cellular and molecular signals. As an example the in vitro survival of CLL cells is supported by nurse-like cells, which have been identified as a CLL-specific tumor-associated macrophage (TAM) population. However little is known regarding the role of TAMs in CLL development and progression. In the CLL xenograft model based on the engraftment of MEC1 human CLL cell line into Rag2-/-γc-/-, we analyzed the whole-genome transcriptome of leukemic B cells, exposed in vivo to TAMs, isolated from the bone marrow. We found an enrichment of genes involved in inflammation and interaction between TAMs and leukemic cells. Rag2-/-γc-/- were injected intravenously with MEC1 cells and sacrificed at early stage of leukemia (n=3). RNA was isolated from: i) in vitro pre-injected human CD19+ MEC1 cells and ii) human CD19+ MEC1 cells purified from murine bone marrow by magnetic separation and processed for illumina whole-genome gene expression direct-hybridization assay