Increased expression of AML1-a and acquired chromosomal abnormalities in childhood acute lymphoblastic leukemia

A semi-quantitative expression analysis of both AML1-a and AML1-total was performed by RT-PCR in 19 children with acute lymphoblastic leukemia (ALL) at diagnosis. AML1-a expression was assessed in 16 bone marrow (BM) and 13 peripheral blood (PB) samples whereas AML1-total was assessed in 17 BM and 16 PB samples. These analyses were also carried out in 15 PB samples of healthy controls. In addition, 18/19 patients were karyotyped: 11 had an unmodified constitutional karyotype (CK) and seven exhibited acquired chromosomal abnormalities (ACA). The expression of AML1-a was significantly increased in BM and PB when compared with the controls (p < 0.013 and p < 0.035, respectively). A significant increase was found in the expression of AML1-a in BM of the ACA group compared with the CK group (p < 0.0009). The expression of AML1-a in BM and PB showed a significant increase in the ACA group compared with controls (p < 0.00001 and p < 0.012, respectively); in contrast, the CK group did not differ from the controls. These observations may mean that the increase of AML1-a favours the progression of leukemia.