Activin A, a member of the transforming growth factor (TGF)-beta superfamily, is involved in the regulation of erythroid differentiation. Previous studies have shown that activin A inhibited the colony-forming activity of mouse Friend erythroleukemia cells, however, the mechanism remains unknown. First, we show herein that activin A induced the expression and activated the promoters of alpha-gl...

methods s. cerevisiae was cultured and then disrupted by sonication. after centrifugation, the harvested supernatant was considered to be a cytoplasmic extract. the protein concentration was determined by the biuret method and the extract was diluted to concentrations of 500, 1000, and 2000 µg protein/ml. the frequencies of apoptosis and necrosis were assessed in extract-treated k562 cells by e...

Using human acute leukemia HL-60/Bcr-Abl (with ectopic expression of p185 Bcr-Abl) and K562 cells (with endogenous expression of p210 Bcr-Abl) subjected to a continuous selection pressure of up to 1.0 micro M Gleevec (imatinib mesylate, STI-571), we have isolated Gleevec-resistant K562 R (+Bcr-Abl), K562 R (-Bcr-Abl), and HL-60/Bcr-Abl R cells, which display disparate level and activity of Bcr-...

Thymosin beta 4 (T beta 4) was originally isolated as a thymic hormone. Its functional properties remain obscure; however, the N-terminal peptidic sequence could have a regulatory function on hematopoietic stem cell proliferation. To investigate the mechanism of T beta 4 expression, we studied T beta 4 gene expression in various leukemic cells and in established cell lines. Among leukemic cell ...

objective: β-thalassemia is caused by absence or reduction of β-globin chain synthesis. one of the effective therapeutic methods for this disease can be gene therapy by viral vectors. the capacity of lentiviral vectors is approximately 8 kb, we designed a 6 kb construct containing mini lcr and β-globin gene instead of lcr region. the aim of this study is to make a recombinant lentiviruses conta...

Pironetin, isolated from Streptomyces sp., is a potent inhibitor of microtubule assembly and the first compound identified that covalently binds to alpha-tubulin at Lys352. We examined whether pironetin is an effective agent against human small cell lung cancer H69 cells, including two cell lines resistant to the microtubule-targeted drugs vindesine (H69/VDS) and paclitaxel (H69/Txl) that inter...

Membrane currents were examined in a drug-sensitive human leukemia cell line (K562) and its multidrug-resistant cell line (K562/ADM) under the whole-cell variation of the patch electrode voltage clamp technique. Most K562 cells showed only the outward current, which was completely suppressed by internal Cs* ions and 20 HIMethyleneglycol bis(0-aminoethyl ctht-r)-.V..V..V. V'-tetraacelkacid. In c...

Adenosine deaminase (ADA) deficiency is associated with a fatal severe combined immunodeficiency. Because most patients do not have a suitable marrow donor, the introduction of a normal ADA gene into the patient's marrow cells is a potentially useful alternative therapy. To identify vectors that provide optimal gene expression in human hematopoietic cells, we investigated retroviral vectors con...