Distinct expression profiles of MSI2 and NUMB genes in myelodysplastic syndromes and acute myeloid leukemia patients

Recent studies have indicated the Musashi2/NUMB pathway as the key regulator of differentiation in chronic myeloid leukemia; however, a comparison of both gene expressions has not yet been made in myelodysplastic syndrome (MDS) and in acute myeloid leukemia (AML). We herein, demonstrate a statistically significant down-modulation of NUMB expression level in high-risk MDS and AML, compared with control individuals. MSI2 expression was significantly reduced in low and high-risk MDS compared with normal control samples. NUMB expression was significantly lower than that of MSI2 in both MDS and AML patient samples, but no differences in the expression levels for either gene were observed in healthy bone marrow cells. Finally, NUMB expression was significantly up-regulated during differentiation of normal and low-risk MDS CD34+ cells through the erythroid lineage. Taken together, results suggest the involvement of NUMB in MDS erythropoiesis; its down-modulation may have a role in MDS progression.