Project description:Using Gfi1b conditional mice, deletion of gfi1b in the hematopietic system was induced by injecting MxCre tg Gfi1bfl/fl mice with pIpC. 30 days after injection, Cd150 pos, Cd 48 neg, Lin neg Sca and c-kit pos stem cells were sortrted from Gfi1bfl/fl and Mxcre tg Gfi1bfl/fl mice and analysed. We used the mouse Affymetrix Gene ST Array. The study should determine whether loss of Gfi1 alters the gene expression pattern in the hematopietic stem cells.
Project description:Using Gfi1b conditional mice, deletion of gfi1b in the hematopietic system was induced by injecting MxCre tg Gfi1bfl/fl mice with pIpC. 30 days after injection, Cd150 pos, Cd 48 neg, Lin neg Sca and c-kit pos stem cells were sortrted from Gfi1bfl/fl and Mxcre tg Gfi1bfl/fl mice and analysed. We used the mouse Affymetrix Gene ST Array.
Project description:A transcriptome study in mouse hematopoietic stem cells was performed using a sensitive SAGE method, in an attempt to detect medium and low abundant transcripts expressed in these cells. Among a total of 31,380 unique transcript, 17,326 (55%) known genes were detected, 14,054 (45%) low-copy transcripts that have no matches to currently known genes. 3,899 (23%) were alternatively spliced transcripts of the known genes and 3,754 (22%) represent anti-sense transcripts from known genes.
Project description:Differentiation of hematopoietic stem cells (HSCs) is regulated by a concert of different transcription factors (TFs). A disturbed function of TFs can be the basis of (pre)malignancies such as myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML). Growth Factor Independence 1b (Gfi1b) is a repressing TF with a key role in quiescence of HSCs and emergence and maturation of erythrocytes and platelets. Here, we show that low expression of GFI1B in blast cells is associated with inferior prognosis of MDS and AML patients. Using mouse models with either reduced expression or conditional deletion of Gfi1b, crossed with a mouse model reflecting human MDS or AML, we demonstrate that AML development was accelerated with heterozygous loss of Gfi1b, and latency was further decreased when Gfi1b was conditionally deleted. Loss of Gfi1b significantly enhanced stemness of leukemic cells with upregulation of genes fundamentally involved in leukemia development. On a molecular level, we found that loss of Gfi1b not only increased the levels of reactive oxygen species (ROS) but also induced gene expression changes of key AML pathways such as the p38/AKT pathway. These results demonstrate that Gfi1b functions as an oncosuppressor in MDS/AML development. We used microarrays to detail the effect of loss of Gfi1b expression on key AML-pathways in a mouse model system
