A small molecule significantly inhibits the bcr/abl fusion gene at the mRNA level in human chronic myelogenous leukemia.

Bcr/abl fusion gene is the marker gene in chronic myelogenous leukemia (CML) and becomes the target for CML therapy. Although Imatinib opened a new way to treat CML, the resistance to the drug caused by bcr/abl fusion protein mutation stimulated search for new molecules to inhibit bcr/abl expression. In our research, it was found that a novel 2-aminosteroid (H89465) possessed special mechanism in treating CML. H89465 inhibits the proliferation of both non-resistant and resistant CML cells such as K562, Meg-01 and clinical primary CML cells. It prolongs the survival time of NOD/SCID mice inoculated with K562 leukemia cells. The mechanism underlying the effects is concerned with down-regulation of bcr/abl mRNA expression followed by decreasing the BCR/ABL protein expression and tyrosine kinase activity in CML cells. Our results demonstrate that H89465 possesses the therapeutic potential in treating human CML.