This study aims to examine the levels of circulating endothelial progenitor cells (cEPCs) in the peripheral blood of patients with non-Hodgkin lymphoma (NHL) and their correlation with the tumor stage. Forty-one patients with biopsy-proven NHL and 16 healthy individuals were recruited. Pe- ripheral blood mononuclear cells (PBMCs) were isolated by density gradient centrifugation, and cEPCs were characterized by triple staining using antibodies against CD133, CD34 and vascular endothelial growth factor receptor-2 (VEGFR-2, CD309) and quantified by flow cytometry. In NHL patients, the number of cEPCs was significantly greater than in control group (P=-0.000). The cEPCs counts in patients with NHL of stage III-1V were significantly greater than in stage I -II (P=-0.010). FACS analysis revealed that the number of cEPCs in NHL patients had no correlation with the gender (P=0.401) or the pathological category (P=0.852). It was suggested that the over-expression of cEPCs in NHL patients may serve as a novel biomarker for disease progression in NHL.
Summary: The underlying mechanism of deguelin regulating the cell cycle in human Burkitt's lym phoma cell line Raji cells in vitro, and the cytotoxicity of deguelin to Raji cells and human peripheral blood monocular cells (PBMCs) were investigated. The effects of deguelin on the growth of Raji cells were studied by 3-(4, 5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium (MTT) assay. Apoptosis was detected through Hoechst 33258 staining. The effect of deguelin on the cell cycle of Raji cells was studied by a propidium iodide method. The expression levels of cyclin D1, P21 and pRb were examined by using Western blotting. The results showed that the proliferation of Raji cells was inhibited in the de guelin-treated group, with a 24-h IC5o value of 21.61 nmol/L and a 36-h IC50 value of 17.07 nmol/L. Proliferation in Raji cells was inhibited significantly by deguelin, while little change was observed in PBMCs. Deguelin induced G2/M arrest in Raji cells. The expression of cyclin D1, P21 and pRb was dramatically down-regulated by deguelin in a dose-dependent manner. It was concluded that deguelin could inhibit the proliferation of Raji cells by arresting the cells at GE/M phase and inducing the cell apoptosis. Moreover, deguelin selectively induced apoptosis of Raji cells with low toxicity to PBMCs. The antitumor effects of deguelin were related to the down-regulated expression of cyclin D1, P21 and pRb proteins.