Browsing by keyword "CML"

Now showing items 1-3 of 3

    • High-Throughput Screening of Tyrosine Kinase Inhibitor Resistant Genes in CML
      Ma, Leyuan; Roderick, Justine E.; Kelliher, Michelle A.; Green, Michael R. (2016-09-01)
      Genome-wide RNA interference (RNAi) screening in mammalian cells has proven to be a powerful tool for identifying new genes and molecular pathways relevant to many cellular processes and diseases. For example, screening for genes that, when inactivated, lead to resistance to cancer therapeutic drugs can reveal new mechanisms for how resistance develops and identify potential targetable strategies to overcome drug resistance. Here, we describe a detailed procedure for performing a high-throughput RNAi screen using a genome-wide human short hairpin RNA (shRNA) library for identifying tyrosine kinase inhibitor (TKI)-resistance genes in a human CML cell line model.

    • Inhibitory effects of omacetaxine on leukemic stem cells and BCR-ABL-induced chronic myeloid leukemia and acute lymphoblastic leukemia in mice.
      Chen, Yaoyu; Hu, Yiguo; Michaels, S.; Segal, D.; Brown, D.; Li, Shaoguang (2009-03-26)
      Omacetaxine mepesuccinate (formerly homoharringtonine) is a molecule with a mechanism of action that is different from tyrosine kinase inhibitors, and its activity in chronic myeloid leukemia (CML) seems to be independent of the BCR-ABL mutation status. Using BCR-ABL-expressing myelogenous and lymphoid cell lines and mouse models of CML and B-cell acute lymphoblastic leukemia (B-ALL) induced by wild-type BCR-ABL or T315I mutant-BCR-ABL, we evaluated the inhibitory effects of omacetaxine on CML and B-ALL. We showed that more than 90% of the leukemic stem cells were killed after treatment with omacetaxine in vitro. In contrast, less than 9 or 25% of the leukemic stem cells were killed after treating with imatinib or dasatinib, respectively. After 4 days of treatment of CML mice with omacetaxine, Gr-1(+)myeloid leukemia cells decreased in the peripheral blood of the treated CML mice. In the omacetaxine-treated B-ALL mice, only 0.8% of the B220(+)leukemia cells were found in peripheral blood, compared with 34% of the B220(+)leukemia cells in the placebo group. Treatment with omacetaxine decreased the number of leukemia stem cells and prolonged the survival of mice with BCR-ABL-induced CML or B-ALL.

    • Molecular signatures of chronic myeloid leukemia stem cells
      Chen, Yaoyu; Li, Shaoguang (2013-06-06)
      BCR-ABL tyrosine kinase inhibitors (TKIs) are effective in controlling Philadelphia-positive (Ph+) chronic myeloid leukemia (CML) are unlikely to cure the disease because TKIs are unable to eradicate leukemia stem cells (LSCs) responsible for the disease relapse even after tyrosine kinase inhibition. In addition, the TKI resistance of LSCs is not associated with the BCR-ABL kinase domain mutations. These observations indicate that TKI-insensitive LSCs and TKI-sensitive leukemic progenitor cells are biologically different, which leads us to believe that LSCs and more differentiated leukemic cells have different genetic mechanisms. Further study of LSCs to identify the novel gene signatures and mechanisms that control the function and molecular phenotype of LSCs is critical. In this mini-review, we will discuss our current understanding of the biology of LSCs and novel genes that could serve as a molecular signature of LSCs in CML. These novel genes could also serve as potential targets for eradicating LSCs in CML.