HOXA9 gene expression in acute myeloid leukemia.

Homeobox genes encode the class of transcription factors in vertebrates and are found in clusters called A, B, C, and D on four separate chromosomes. HOXA9 gene is part of the cluster A on chromosome 7 and encodes a DNA-binding transcription factor which may regulate gene expression, morphogenesis, and differentiation. The objective of this study was to determine the HOXA9 gene expression in acute myeloid leukemia (AML). For this purpose, semi-quantitative reverse transcriptase-polymerase chain reaction was used to measure HOXA9 gene expression in human erythroleukemia (HEL) cell line and bone marrow mononuclear cells from 54 AML patients and 20 healthy individuals. The data show that HOXA9 mRNA expression was negative in 20 healthy individuals but was positive in HEL cells and in 22 out of 54 (40.74%) AML patients. The complete remission rate (45.45%) of the patients who expressed the gene was significantly lower than that (71.86%) in patients who did not express the gene after chemotherapy. Therefore, it was concluded that HOXA9 gene might be involved in the pathogenesis of AML and played as a worse prognostic factor in AML.