Identification of Circulating Micro RNA-155 as a Potential Biomarker for Detecting Acute Myeloid Leukemia

MicroRNA-155(MiR-155) is one of the important miRNAs that contributes greatly to the pathogenesis of diverse hematological malignancies with complex oncogenic as well as tumor repressor roles depending on the disease context and tissue type. It likely plays a very important role in the pathogenesis of acute myeloid leukemia (AML) through regulating cell signal transduction pathways of cell proliferation, differentiation and apoptosis. Several studies reported that the expression of miR-155 is low in normal hematopoietic cells and often upregulated in AML and it is an important indicator to assess the diagnosis, treatment and prognosis of patients with AML and further associated with tumor progression. 25 adult patients newly diagnosed with AML, their ages ranged from (18 to 60) years old, and 25 cases apparently healthy individuals, their ages were matched with patients, were included into the study.Complete blood count (CBC), Peripheral blood smear examination, bone marrow aspiration (BMA), immunophenotyping, cytogenetic analysis, molecular analysis, serum lactate dehydrogenase level (LDH) and MiR-155 expression level using Real-Time PCR were done. Significant upregulation in miR-155 gene expression in AML group when compared to control group. Hemoglobin concentration, and platelets count were lower in AML group than control group, however total leucocytic count (TLC) and LDH, were increased in AML group than control group. MiR-155 gene expression showed significant positive correlation with TLC, LDH, peripheral blasts and bone marrow blasts. Otherwise, no significant correlations were found between miR-155 gene expression with age, hemoglobin concentration and platelets count in AML patients. Upregulated miR-155 gene expression was significantly associated with failure of CR, relapse and death. AML cases with high miR-155 gene expression showed significantly shorter OS and DFS when compared to low miR-155 gene expression.