ABSTRACT
OBJECTIVE@#To explore whether thrombopoietin (TPO) can rescue megakaryopoiesis by protecting bone marrowderived endothelial progenitor cells (BM-EPCs) in patients receiving chemotherapy for hematological malignancies.@*METHODS@#Bone marrow samples were collected from 23 patients with hematological malignancies 30 days after chemotherapy and from 10 healthy volunteers. BM-EPCs isolated from the samples were identified by staining for CD34, CD309 and CD133, and their proliferation in response to treatment with TPO was assessed using CCK8 assay. DiL-Ac-LDL uptake and FITC-UEA-I binding assay were performed to evaluate the amount of BM-EPCs from the subjects. Tube-formation and migration experiments were used for functional assessment of the BM-EPCs. The BM-EPCs with or without TPO treatment were co-cultured with human megakaryocytes, and the proliferation of the megakaryocytes was detected with flow cytometry.@*RESULTS@#Flow cytometry indicated that the TPO-treated cells had high expressions of CD34, CD133, and CD309. CCK8 assay demonstrated that TPO treatment enhanced the proliferation of the BM-EPCs, and the optimal concentration of TPO was 100 μg/L. Double immunofluorescence assay indicated that the number of BM-EPC was significantly higher in TPO-treated group than in the control group. The TPO-treated BM-EPCs exhibited stronger tube-formation and migration abilities ( < 0.05) and more significantly enhanced the proliferation of co-cultured human megakaryocytes than the control cells ( < 0.05).@*CONCLUSIONS@#TPO can directly stimulate megakaryopoiesis and reduce hemorrhage via protecting the function of BM-EPCs in patients following chemotherapy for hematological malignancies.
Subject(s)
Humans , Bone Marrow , Bone Marrow Cells , Cells, Cultured , Hematologic Neoplasms , Megakaryocytes , ThrombopoietinABSTRACT
To explore the efficacy of sorafenib combined with chemotherapy and donor lymphocyte infusion (DLI) in patients with FLT3-positive acute myeloid leukemia (AML) relapsed after allogeneic hematopoietic stem cell transplantation (allo-HSCT).Of the 14 patients relapsed after allo-HSCT,9 achieved complete remission after salvage therapy of sorafenib combined with chemotherapy and DLI,6 with complete molecular remission,2 with partial remission,and 3 with no response.With a median follow up of 220 (range,30-1 782) days after post-transplantation relapse,7 patients were still alive and 7 died.Salvage therapy of sorafenib combined with chemotherapy and DLI shows a decent therapeutic effect for FLT3-positive AML relapsed after allo-HSCT.
ABSTRACT
Objective To investigate the effect of histone deacetylase inhibitor LBH589 on proliferation,apoptosis and drug resistance of chemoresistant acute myeloid leukemia cells HL60/ADM.Methods HL60/ADM cells were treated with LBH589.Proliferation,apoptosis and adriamycin IC50 were evaluated by MTT assay and AnnexinV-FITC/PI stain.The change in MRP1 expression and intercellular adriamycin accumulatiom were analyzed by flow cytometry.Results Effective proliferative inhibition and apoptotic induction in HL60/ADM cells were observed after treatment with 10-80 nmol/L LBH589 with maximal effect detected after treatment with 70 nmol/L LBH589 for 60 hours.However,inhibition ratio remain unchanged with the further increase of drug dose and incubation time (P ＞ 0.05).Downregulation of MRP1 [(93.90±4.20) ％ vs (76.19±6.53) ％],upregulation of adriamycin accumulation [(8.53±0.68) ％ vs (25.67±1.34) ％] and decrease in adriamycin IC50 [(6.833±0.319) μg/ml vs (1.382±0.104) μg/ml] were induced by the treatment with 20 nmol/L LBH589 (P ＜ 0.01),whose reversal fold was 4.9.The expression of acetylated histone 3 after treatment with LBH589 was higher than that before treatment (P ＜ 0.01).However,relative p-Akt levels after treatment for 24 h and 48 h were 1.07±0.09 and 0.59±0.01,respectively,which were lower than that before treatment (2.03±0.12) (P ＜ 0.01).Meanwhile,expression levels of p53 were 0.57±0.04 and 1.31±0.09,respectively,which were higher than that before treatment (0.21 ±0.02) (P ＜ 0.01).Conclusion Treatment with LBH589 has the capability of inhibiting proliferation and inducing apoptosis,as well as increasing intercellular adriamycin accumulation and sensitivity through downregulation of MRP1 expression and inhibition of PI3K-Akt signaling pathway in HL60/ADM cells.