K562-R, a pleiotropic drug-resistant cell line established in vitro, and K562-S, the chemotherapy-sensitive parent line, were used as targets in the natural killer cell (NK) system. At each of the effectortarget ratios studied, the K562-R demonstrated a decrease in their susceptibility to both unstimulated and interferon-activated NK cells, as compared to the K562-S line. This difference did no...

A subpopulation of low density granular lymphocytes that express the natural killer (NK) cell-associated Leu-11 antigen (IgG Fc receptor) were stimulated directly by coculture with an NK-sensitive tumor cell, K562. T lymphocytes (Leu-11-) responded only weakly when cocultured with K562. The response of Leu-11+ cells apparently did not require exogeneous factors or accessory cells. The K562-acti...

Physicochemical and immunologic properties of 6-aminolevulinate (ALA) dehydratase in human K562 erythroleukemia cells were examined. ALA dehydratase activity was found to increase in K562 cells after treatment with butyric acid or selenium oxide. Enzyme activity in untreated K562 cells was comparable to that in normal adult erythrocytes but was increased threeto six-fold in K562 cells treated w...

BACKGROUND Leukemia seriously threats human health and life. MicroRNA regulates cell growth, proliferation, apoptosis, and cell cycle. Whether microRNA could be treated as a target for leukemia is still unclear and the mechanism by which microRNA143 regulates K562 cells needs further investigation. MATERIAL AND METHODS miRNA143 and its scramble miRNA were synthesized and transfected to K562 cel...

The tumor-promoting phorbol ester, 12-O-tetradecanoylphorbol-13-acetate (TPA), induced specific changes in the cell surface glycoprotein profile of K562 human leukemic cells. TPA-treated K562 cells were examined by cell surface labeling followed by immunoprecipitation with anti-glycophorin antiserum or anti-K562 antiserum. TPA-treated K562 cells lost glycophorin and glycoprotein with a molecula...

The role of ROS in hydroquinone-induced inhibition of K562 cell erythroid differentiation was investigated. After K562 cells were treated with hydroquinone for 24 h, and hemin was later added to induce erythroid differentiation for 48 h, hydroquinone inhibited hemin-induced hemoglobin synthesis and mRNA expression of γ-globin in K562 cells in a concentration-dependent manner. The 24-h exposure ...

BACKGROUND miRNA is a microRNA that negatively regulates protein expression at post-transcriptional or translational level. It is widely involved in the pathogenesis of tumors. miR-98 belongs to the let-7 family, and its overexpression can increase the sensitivity to drugs in solid cancer cells. However, the function of miR-98 in leukemia is still unclear. In this study, the effect of miR-98 on...

Objective(s): β-thalassemia is one of the most common genetic disorders in the world. As one of the promising treatment strategies, fetal hemoglobin (Hb F) can be induced. The present study was an attempt to reactivate the γ-globin gene by introducing a gene construct containing KLF1 binding sites to the K562 cell line. Materials and Methods: A plasmid containing a 192 bp sequence with two repe...

In this study, we investigated the growth inhibitory effects of IFN-α, 5-FU, HU and their combinations on Daudi (Human Burkitt lymphoma) and K562 (Human erythroblastic leukemia) cell lines. Sensitivity of two leukemia cell lines to IFN-α has shown large disparities. While Daudi cells were very sensitive to the antiproliferative effects of IFN-α, K562 cells were more resistant. After showing dif...