We have investigated the molecular basis of the 100-fold resistance of mutant human erythroleukemia K562/PMEA-1 cells to the antiproliferative potential of 9-(2-phosphonylmethoxyethyl)adenine (PMEA). Upon exposure to high PMEA concentrations, comparable intracellular PMEA levels were initially observed in mutant K562/PMEA-1 and wild-type K562/0 cells, indicating that PMEA influx was unaltered. ...

OBJECTIVE A novel multi-drug resistance gene named as HA117 has been screened and cloned in multidrug resisitant leukemia cell lines in our previous research, but its function is still unknown. In this study, HA117 gene was investigated whether it could increase the drug resistance in chronic myelogenous myeloid leukemia cell line K562. METHODS HA117 was cloned and adenovirus vectors were con...

The K562/VCR cell line, exhibiting acquired multidrug resistance (MDR) with increased expression of a cell surface glycoprotein (P-glycoprotein), was isolated from human erythroleukemia K562 cells. Various compounds that induced erythroid differentiation of K562 cells were tested for their effects on growth and differentiation of these K562/VCR cells. Sodium butyrate, hemin, 1-beta-D-arabinofur...

Objective(s): Artemisia is a genus of herbs and small shrubs forms an important part of natural vegetation in Iran. It has been reported that several Artemisia species possess anti-proliferative effects. Considering the value of this genus in anti-cancer researches we have chosen Artemisia biennis for cytotoxic and mechanistic studies. Materials and Methods:In this study we have investigated th...

Purpose: To investigate anticancer effects of Momordica charantia L. (M. charantia) fruit and seed extracts on some cancer cell lines.
 Methods: Human lines, including lung (A549), breast (MCF-7), chronic myeloid leukemia (K562) T (Jurkat) were incubated with the (0 - 0.8 mg/mL) for 72 h. The cytotoxic determined using 3-(4,5-dimethylthiazol-2-yl)-2,5- dipenyltetrazolium bromide (MTT) assa...

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 mM ethyleneglycol bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid. In ...

We previously reported that natural killer (NK)-sensitive target cells, K562, kill interleukin-2-stimulated (lymphokine-activated killer [LAK]) but not unstimulated NK cells. We have now investigated the molecular basis of this phenomenon. Soluble monoclonal antibody (MoAb) to CD18 inhibited 75% of K562-induced DNA fragmentation and membrane disruption, whereas blocking MoAb to Fas partially in...

The recently discovered rTS gene is convergent with and overlaps the thymidylate synthase gene in the antisense orientation. K562 B1A and KB 1BT are two methotrexate-resistant cell lines that have amplified genes for dihydrofolate reductase. K562 B1A cells have increased levels of rTS mRNA and protein compared with their parental K562 cells, whereas KB 1BT cells show unaltered rTS expression co...

We previously isolated aaptamine, a benzonaphthyridine alkaloid, from marine sponge Aaptos suberitoids. In this study, we investigated the anti-proliferative effect of aaptamine on chronic myeloid leukemia (CML) K562 cells. Aaptamine inhibited growth of K562 with a GI50 as 10 μM, and arrested cell cycle at G2/M phase. Western blot analysis indicated that aaptamine induced p21 expression in K562...