Project description:Gene expression analysis of twenty patient-derived T-ALL xenografts was performed to determine if a GLI activation signature was enriched in GANT-61 sensitive cells.
Project description:Introduction. Glucocorticoids are critical drugs used to treat acute lymphoblastic leukemia, and response to glucocorticoids is highly predictive of outcome. Here we report a study evaluating the NOD/SCID xenograft mouse model to investigate glucocorticoid-induced gene expression. Methods. NOD/SCID mice were inoculated with ALL-3, a glucocorticoid-sensitive xenograft, and when highly engrafted were randomised to either dexamethasone 15mg/kg or vehicle control IP. Cells were harvested at 0, 8, 24 or 48 hours thereafter, RNA was extracted and hybridised onto Illumina WG-6_V3 chips. Results. The 8 hour dexamethasone-treated timepoint had the highest number of significantly differentially expressed genes with minimal changes seen across the time-matched controls. Replicate analysis revealed that using data from 3 replicates instead of 4 resulted in excellent recovery scores of >0.9 at timepoints with high signal. When assessed at the level of pathways, gene expression changes in the 8 hour xenograft samples were similar to patients treated with glucocorticoids. Conclusions. The NOD/SCID xenograft mouse model provides a reproducible experimental model system in which to investigate clinically-relevant mechanisms of in vivo glucocorticoid-induced gene regulation in ALL; the 8 hour timepoint provides the highest number of significantly differentially expressed genes; time-matched controls are redundant and excellent recovery scores can be obtained with 3 replicates. At 0, 8, 24 or 48 hours, NOD/SCID xenograft mice were treated with vehicle control, or dexamethasone. We used 4 biological replicates per time point (3 at the 48hour time point), each of which went onto an Illumina HumanWG-6_V3_0_R1_11282955_A microarray. Samples from each of the 7 groups were divided across a total of 5 microarray slides
Project description:Introduction. Glucocorticoids are critical drugs used to treat acute lymphoblastic leukemia, and response to glucocorticoids is highly predictive of outcome. Here we report a study evaluating the NOD/SCID xenograft mouse model to investigate glucocorticoid-induced gene expression. Methods. NOD/SCID mice were inoculated with ALL-3, a glucocorticoid-sensitive xenograft, and when highly engrafted were randomised to either dexamethasone 15mg/kg or vehicle control IP. Cells were harvested at 0, 8, 24 or 48 hours thereafter, RNA was extracted and hybridised onto Illumina WG-6_V3 chips. Results. The 8 hour dexamethasone-treated timepoint had the highest number of significantly differentially expressed genes with minimal changes seen across the time-matched controls. Replicate analysis revealed that using data from 3 replicates instead of 4 resulted in excellent recovery scores of >0.9 at timepoints with high signal. When assessed at the level of pathways, gene expression changes in the 8 hour xenograft samples were similar to patients treated with glucocorticoids. Conclusions. The NOD/SCID xenograft mouse model provides a reproducible experimental model system in which to investigate clinically-relevant mechanisms of in vivo glucocorticoid-induced gene regulation in ALL; the 8 hour timepoint provides the highest number of significantly differentially expressed genes; time-matched controls are redundant and excellent recovery scores can be obtained with 3 replicates.
Project description:Leukemic cells from either peripheral blood or bone marrow were obtained from 6 patients with acute lymphocytic leukemia. These cells were used to generate mouse xenografts and a comparison was made between those two sample sources. Six pairs of human leukemia and associated xenografts are compared.
Project description:Prior to the onset of autoimmune destruction, type 1 diabetic patients and an animal model thereof, the nonobese diabetic (NOD) mouse, show morphological and functional abnormalities in target organs, which may act as inciting events for leukocyte infiltration. To better understand these abnormalities, but without the complications associated with inflammatory infiltrates, we examined genes expressed in autoimmune target tissues (pancreas, submandibular glands, and lacrimal glands) of NOD/scid mice and of autoimmune-resistant C57BL6/scid mice. Keywords: tissue expression, disease prone versus resistant strain comparison
Project description:Leukemic cells from either peripheral blood or bone marrow were obtained from 6 patients with acute lymphocytic leukemia. These cells were used to generate mouse xenografts and a comparison was made between those two sample sources.
Project description:Pre-clinical models that effectively recapitulate human disease are critical for expanding our knowledge of cancer biology and drug resistance mechanisms. For haematological malignancies, the non-obese diabetic/severe combined immunodeficient (NOD/SCID) mouse is one of the most successful models to study paediatric acute lymphoblastic leukaemia (ALL). However, for this model to be effective for studying engraftment and therapy responses at the whole genome level, careful molecular characterisation is essential.Here, we sought to validate species-specific gene expression profiling in the high engraftment continuous ALL NOD/SCID xenograft. Using the human Affymetrix whole transcript platform we analysed transcriptional profiles from engrafted tissues without prior cell separation of mouse cells and found it to return highly reproducible profiles in xenografts from individual mice. The model was further tested with experimental mixtures of human and mouse cells, demonstrating that the presence of mouse cells does not significantly skew expression profiles when xenografts contain 90% or more human cells. In addition, we present a novel in silico and experimental masking approach to identify probes and transcript clusters susceptible to cross-species hybridisation.We demonstrate species-specific transcriptional profiles can be obtained from xenografts when high levels of engraftment are achieved or with the application of transcript cluster masks. Importantly, this masking approach can be applied and adapted to other xenograft models where human tissue infiltration is lower. This model provides a powerful platform for identifying genes and pathways associated with ALL disease progression and response to therapy in vivo.
Project description:Relapse and acquired drug resistance in T-cell acute lymphoblastic leukemia (T-ALL) remains a significant clinical problem. The current study used a pre-clinical model of induction therapy for pediatric ALL in NOD/SCID mice (Samuels et al Blood Cancer Journal (2014) 4, e232; doi:10.1038/bcj.2014.52) to study the development of drug resistance. We performed transcription profiling by array of human CD45-positive lymphocytes from patients with acute pediatric lymphoblastic leukemia, xenografted in NOD/SCID mice treated with vincristine, daunorubicin, dexamethasone and L-asparagine. Both the primary-patient-derived and xenograft cells were analysed. The VLXD2 treatment regime is described in full in the protocols associated with this submission and in Samuels et al (Blood Cancer Journal (2014) 4, e232; doi:10.1038/bcj.2014.52). This study is an extension of E-MEXP-3916.