Expression of E-cadherin on bone marrow mononuclear cell surface and in plasma of patients with extra-myeloid leukemia and their clinical significance

Abstract

Objective To investigate the expression and clinical significance of soluble E-cadherin(sE-cad)and E-cadherin(E-cad)in acute leukemia(AL), and to explore their relationship with the pathogenesis, development and diagnosis of extra-myeloid leukemia. Methods 87 newly diagnosed or relapsed AL patients(19 cases of L1, 29 L2, 14 M2, 20 M3, 4 M4, 1 M5)were collected from hospitalized patients in hematology department of Harbin Medical University Cancer Hospital. The plasma from 20 healthy volunteers was used as control group. The bone marrow was from 15 non-AL patients hospitalized in hematology department(7 cases of thrombocytopenic purpura, 4 iron deficiency anemia, and 4 fever). The expression of sE-cad in the plasma of 47 patients and 20 healthy volunteers was detected by ELISA; the expression of E-cad on the membrane surface of bone marrow MNC in 40 patients and 15 controls was determined by flow cytometry. Results The plasma level of sE-cad in AL group was significantly higher than that in healthy control group[(66.812 ± 52.712)ng/ml vs.(17.976 ± 14.206)ng/ml, P<0.01]. The plasma level of sE-cad in extra-myeloid infiltration AL group was significantly higher than that in no-extra-myeloid infiltration AL group[(83.545 ± 60.759)ng/ml vs.(42.152 ± 22.043)ng/ml, P<0.01]. The plasma level of sE-cad in high leukocytes AL group was higher than that in no-high leukocytes AL group[(85.166 ± 57.828)ng/ml vs.(41.933 ± 32.064)ng/ml, P<0.05]. The percentage of E-cad expression in AL group was significantly lower than that in control group[(13.615 ± 14.038)% vs.(31.700 ± 16.213)%, P<0.01]. The percentage of E-cad expression in no-extra-myeloid infiltration AL group was significantly higher than that in extra-myeloid leukemia infiltration AL group[(18.691± 14.917)% vs.(6.589± 8.959)%,P<0.01]. The percentage of E-cad in no-high-leukocytes AL group was significantly higher in high leukocytes AL group[(20.925±12.081)% vs.(7.446±11.118)%, P<0.01]. Conclusions The expression of E-cad on the membrane surface of bone marrow MNC and the expression of sE-cad in plasma may be closely associated with the occurrence of extra-myeloid leukemia and leukocytosis, which may be one of the important molecular mechanisms of leukemic cell infiltration and leukocytosis. High expression of sE-cad in plasma can be treated as one of index to diagnose extra-myeloid leukemia. Key words: Leukemia, acute; Leukemic infiltration; E-cadherin; Soluble E-cadherin; High leukocytes