AML is a cancer that arises in bone marrow hematopoietic stem cells (HSCs) or progenitor cells that are destined to become myeloid cells (cells normally committed to fighting infections). Gene microarray technology uses small chips containing gene "probes" to measure the level of expression of thousands of specific genes simultaneously by using samples of genetic material obtained from normal or diseased cells. HSCs are parent cells in the bone marrow that can potentially give rise to any one of the various types of blood cells. Progenitor cells are those that have arisen from HSC and are committed to producing a specific type of blood cell.
The study of children and adults found that leukemic cells of each major known prognostic subtype of AML had a specific "signature" of gene expression. The exact signature depended on the underlying genetic mutation that contributed to the formation and growth of the leukemic cells; and it corresponded to over- or under-expression of sets of genes from leukemic cells as compared to their expression in normal white blood cells. Prognostic subtypes are categories of different forms of AML that are recognized because they tend to have known, predictable outcomes following treatment.
Importantly, this study also demonstrated that the gene expression signatures identified in the pediatric leukemias could also be used to accurately diagnose the identical form of leukemia when it occurs in adults. Thus, insights gained from pediatric AML, which is a relatively rare disease, should rapidly lead to improved u
Contact: Bonnie Cameron
St. Jude Children's Research Hospital