RESUMO
Objective:By detecting the level changes of CXC chemokine ligand 8(CXCL8)in acute myelogenous leukemia(AML)patients at different disease stages,to analyze its correlation with the clinical condition and prognosis of AML patients,and to explore the effect of CXCL8 in the bone marrow microenvironment on the occurrence and development of AML and the regulatory mech-anism of malignant biological behavior of AML cell lines,to provide novel reference for the basic research and clinical diagnosis and treatment of AML.Methods:Bone marrow specimens from AML patients at different disease stages were collected,and ELISA was used to detect the content of CXCL8;quantitative real-time PCR(qRT-PCR)was used to detect the expression of CXCL8-specific receptor CXCR1/2 in different AML cell lines.U937 cells were selected as the AML disease model,and different concentrations of exogenous rCXCL8 were intervened in U937 cells,and the morphological changes of the cells were observed under the microscope.BM-MSCs from newly diagnosed AML patients were co-cultured with U937 cells,and ELISA was used to detect the difference in the content of CXCL8 in the co-culture system;Annexin V/PI double staining flow cytometry was used to detect the effects of rCXCL8 and anti-CXCL8 on the apoptosis of U937 cells respectively,and Western blot was used to reveal the accompanying molecular protein mechanism.Results:The level of CXCL8 in newly diagnosed and relapsed AML patients was significantly higher than that in healthy people(P<0.05),the level of CXCL8 in relapsed stage of AML was significantly higher than that in other disease stages of AML(P<0.01),and the level of CXCL8 in AML patients with CR stage and no infection was significantly higher than that in healthy people(P>0.05).The content of CXCL8 in the co-culture system of BM-MSC and U937 cells and the level of CXCL8 mRNA in U937 cells in the co-culture system were significantly higher than those in the monoculture group without BM-MSC(P<0.05).Intervention of rCXCL8 in U937 cells could promote cell proliferation by up-regulating Bcl-2 expression and down-regulating Bax expression,and up-regulate the expression of CXCL8-specific receptors CXCR1/2.After antagonizing CXCL8(anti-CXCL8),it will induce U937 cell apoptosis by up-regulating of Bax expression and down-regulating of Bcl-2 expression while inhibiting the activation level of ERK1/2 signaling pathway.Conclusion:CXCL8 is closely related to the disease and prognosis of AML,and is an effective monitoring indicator for disease pro-gression and prognosis evaluation of AML patients.CXCL8 in the bone marrow microenvironment is an important chemokine for malig-nant proliferation and immune escape of leukemia cells.By antagonizing CXCL8,U937 cells can be induced to undergo apoptosis,whose mechanism may be related to the expression changes of Bcl-2 family proteins and the inhibition of ERK1/2 signaling pathway activation.