In vivo effects of localization and/or CXCR4 inhibition on gene expression profiles of OCI-AML3 cells

OCI-AML3, a human acute myeloid leukemia cell line, was inoculated into NOD/SCID/IL-2rγnull (NSG) mice. After engraftment and leukemic expansion were documented, mice were divided into 3 groups: control, or treatment for 24 or 72 hours with daily injections of LY2510294, a CXCR4-inhibitory peptide. OCI-AML3 cells were isolated from peripheral blood (PB), bone marrow (BM), or spleen (SP) for gene expression profiling (GEP). The OCI-AML3 cells used had been engineered to express luciferase and GFP, to facilitate imaging of tumor burden and cell sorting, respectively. 1×10e6 cells/mouse were used for inoculation. Adequate tumor burden and involvement of PB were established on Day 40 after inoculation by bioluminescence and flow cytometry (FACS), respectively, and LY2510924 was started in the treated groups. Three 24-hr mice were sacrificed on Day 41 for collection of PB, femoral BM, and SP, from which OCI-AML3 cells were isolated by FACS, on the basis of GEP and human CD45 expression, and fixed in RNAlater. Similar harvests were performed on 3 control mice on Day 42, and 2 72-hr mice on Day 43. Total RNA was isolated and underwent 2 rounds of amplification and biotin-labeling for hybridization to Illumina HT12v4.0 human gene expression arrays.