Identification of genes that may predict response to azacitidine treatment.

Azacitidine (AZA) is a hypomethylating drug used to treat disorders associated with myelodysplasia and related neoplasms. Approximately 50% of patients do not respond to AZA and have very poor outcomes. It is of great interest to identify predictive biomarkers for AZA responsiveness. Therefore, we searched for specific genes whose expression level was associated with response status.Using microarrays, we analyzed gene expression patterns in bone marrow CD34+ cells from 32 patients with myelodysplastic syndromes, chronic myelomonocytic leukemia, and acute myeloid leukemia with myelodysplasia-related changes before AZA therapy. Total RNA was isolated from bone marrow CD34+ cells obtained from myelodysplasia and related neoplasms patients who underwent treatment with 5-azacytidine (AZA, Vidaza). Using Illumina Human HT-12 v. 4 microarrays, we assayed gene expression profiles in patient CD34+ cells before AZA treatment in order to collect basic data for search for markers of the prediction of therapy response.