AML1/ETO gene fusion formed by chromosome 8 and chromosome 21 translocation is a common cytogenetic abnormality in patients with acute myeloid leukemia (AML), and about 12% to 20% of patients with acute myeloid leukemia have AML1/ETO gene fusion. While the positive rate of AML-M2 leukemia is 20% to 40%, and the positive rate of M2b subtype is as high as 90%, which is rare in other types of leukemia. The AML1/ETO protein fusion is a transcriptional repressor that inhibits normal AML1 protein-mediated function, alters the process of self-renewal and maturation of hematopoietic progenitor cells, and also signals the initiation of abnormal hematopoietic cell proliferation, causing the proliferation of leukemia cells.
ETO probe is labeled with an orange-red fluorescein, and AML1 probe with a green fluorescein. The two probes combine to the target detection site by in situ hybridization. Under normal conditions (AML1/ETO gene is not fused), it shows two orange-red signals and two green signals under a fluorescence microscope. When a fusion gene is present, the green and orange-red signals form a yellow fusion signal due to recombination.
AML1/ETO gene fusion can be used as AML diagnostic assistant and prognosis assessment means. Clinically, t(8;21) leukemia represents a type of acute leukemia with good prognosis. Adult patients have good response to treatment, high complete remission rate, long median survival time, but prone to recurrence. Children’s treatment and prognosis are not as good as adult patients.
References