The Mechanism Of Long Non-coding RNA-LLEST Inhibited Angiopoiesis Of Cells In Acute Myeloid Leukemia

[Objective]1.To study the expression of long non-coding RNA-LLEST in hematopoietic cell lines K562,U937 and SHI-1 and its effect on angiogenesis.2.To investigate the mechanism of long non-coding RNA-LLEST in inhibiting angiogenesis in hematopoietic cell lines K562,U937 and SHI-1.3.To detect the expression of long non-coding RNA-LLEST and PDGFA in patients with iron deficiency anemia,acute myeloid leukemia(M2)respectively.[Methods]Based on the previous results,LLEST was lower in malignant hematological diseases than patients with iron deficiency anemia.Firstly,the LLEST high expression stable cell line K562 and LLEST low expression stable cell lines U937 and SHI-1 were constructed.PDGFA was one of the genes which possibility interaction with LLEST through bioinformatics analysis.Then,the expression of LLEST and PDGFA was detected by qRT-PCR in BMMNCs from 8 patients with AML(M2)and 8 patients with iron deficiency anemia as the control.Next,the angiogenesis assay were used to declared the difference of tube formation in K562,U937 and SHI-1 cell lines.At the same time,ELISA was used to detect the expression level of PDGF in supertanatant.Tumor formation of high expressed LLEST K562 cell line were performed in vivo.Afterwards,the inhibitors,activators and dual-luciferase reporter assay were used to explore the mechanism of LLEST inhibit the angiogenesis in acute myeloid leukemia.[Results]1.Number of tubules and branches were significantly reduced compared with the control group when cultured with medium of high expression LLEST K562 cells.While increased in the medium of knockdown LLEST U937 and SHI-1 cells compared with control.In vivo,results of tumor formation were similar with in vitro.2.LLEST expressed lower in untreated AML(M2)than iron deficiency anemia.In 8 patients,LLEST was low before treated while it increased when got remission.However,PDGFA showed an opposed profile.In K562 cells when LLEST were high expressed,PDGFA was decreased,when LLEST were knockdown in U937 and SHI-1,PDGFA was increased both in qRT-PCR and ELISA.3.The dual-luciferase reporter assay proved that LLEST and PDGFA could interact with each other.4.The tube formation was significantly reduced in the inhibitor group compared with the control while the angiogenesis was increased in the agonist group compared with control.[Conclusion]1.Long non-coding RNA-LLEST inhibited angiogenesis both in vivo and in vitro.2.PDGFA was an important factor in process of LLEST inhibit angiogenesis.3.The expression of LLEST was different in patients from iron deficiency anemia,acute myeloid leukemia before and after treatment.PDGFA expressed the opposite profile.