Expression Of C-myc Correlates With Expression Of C-myb Gene In Bone Marrow Stromal Cells

Objective:To investigate the level of transcription factor c-myc and c-myb oncogenes in the leukemia cells and leukemia bone marrow stromal cells and the correlation with each other. The study is expected to provide a solid foundation for molecular mechanism by which bone microenvironment influences hematoiesis.Methods:The bone marrow mononuclear cells of 18 patients without blood diseases as control group and 46 patients with hematologic disease (27 cases of acute leukemia (AL),19 cases of chronic leukemia (CL)) were comprehensive analyzed with flow cytometry, chromosome banding technique and reverse transcription polymerase chain reaction (RT-PCR). Based on the immunity typing of acute leukemia (AL), the membrane surface antigens of leukemia cells and bone marrow stromal cells were identified. The semi-quantitative expression levels of oncogenes in those cells were also examined by reverse transcription polymerase chain reaction (RT-PCR). Experimental study of exploring the expression c-myc and c-myb genes in different types of acute and chronic leukemias combined with chromosome banding techniques and the relationship of oncogenes.Results:We found that c-myc and c-myb gene both expressed in the normal control group and the leukemia cells and BMSCs of patients group. The mean expression levels of the c-myb mRNA and c-myc mRNA in abnormal chromosomal leukemia cells were 1.03±0.48 and 1.15±0.38 respectively, which was significantly higher than those of control cases (P<0.05). In the abnormal karyotype stromal cells, the mean expression level of the c-myb mRNA and c-myc mRNA were 2.08±0.82 and 1.46±0.29 respectively (P<0.05). The expression level of c-myb mRNA was closely associated with patients'peripheral blood RBC counts (P<0.05). There was no significant difference between the leukemia cells group and stromal cells group, the level of which were well correlated to Plt. c-myb and c-myc expression was positively correlated with each other in leukemia cells and acute leukemia stromal cells. The result was obtained that the expression of c-myc mRNA was linearly correlated to the expression of c-myb mRNA in different prognostic groups. In this study, we firs found that the expression of c-myc in leukemia cells correlate with the expression of c-myc and c-myb in bone marrow stromal cells, respectively.The elevated expression of the two genes may contribute to megakaryocytopoiesis and erythrocyte differentiation, and may involve in carcinogenesis of leukemia.Conclusions:The data we present here confirmed overexpression of c-myc or c-myb in a panel of leukemia patients and demonstrated relationships between the level of two proto-oncogenes expression and some of the clinical characteristics of patients, c-myb and c-myc expression was positively correlated with each other. A reduction in the level of c-myc or c-myb expression should be a therapeutic goal since such reduction may result in reduced growth of leukemic cells.