IDENTIFICATION OF A MOLECULAR SIGNATURE PREDICTIVE OF REFRACTORINESS IN ACUTE MYELOID LEUKEMIA

Acute Myeloid Leukemia (AML) blast cells are immature committed myeloid cells unable to spontaneously undergo terminal maturation, characterized by heterogeneous sensitivity to natural differentiation inducers. No data are available so far by which infer the AML’s response to differentiating therapy. Thus, we have initially profiled by GeneChip arrays the gene expression of several AML cell lines: they derived by the original blast cell populations and are still characterized by the same immunophenotype, retain a different sensitivity or resistance to All-Trans Retinoic-Acid (ATRA) and Vitamin-D3 (VD) and never undergo spontaneously terminal maturation. Here we show that differences exist by which predict the cell line differentiation fate. Next we constructed a signature able to predict resistance or sensitivity to the differentiation induction and tested it, using a TaqMan platform, for its capability to predict the in-vitro response of 28 VD or ATRA treated AML blast cell populations. Finally, by a meta-analysis of public available microarray data we demonstrated that our signature of 11 genes, among them is particularly intriguing the presence of Meis1 and ID3, that was formerly designed to identify differentiation therapy resistant populations, turned out to be a good classifier for clusters of patients known to have poor prognostic significance.