BACKGROUND: Nitrous oxide concentration is easily controlled by respiratory ventilation. It suppresses bone marrow via the inhibition of thymidylate synthesis. The aim of this work was to determine the optimal pressure and exposure duration of nitrous oxide, as well as methotrexate concentration that maximizes the suppression of 4 cancer cells: CCRF-CEM, K562, A549 and MDA-MB-231. METHODS: Each cancer cell was cultured in a hyperbaric chamber at 1, 2 and 3 atmosphere of 74% nitrous oxide for 24, 48, and 72 hours at 0, 0.3, 0.7, 1, 2, 5 and 10 microM methotrexate (MTX), respectively. The results were expressed in the ratio of the number of cancer cells cultured under specific conditions (S cells) to that under normal conditions (N cells). RESULTS: The S/N ratio of CCRF-CEM cells was 87.4% in 24-hour culture, 95.0% in 48-hour culture and 115.9% in 72-hour culture (P < 0.05). The S/N ratio of K562 cells was 103.6% at 1 atm, 102.4% at 2 atm and 115.6% at 3 atm (P < 0.05). The S/N ratio of A549 cells was 94.3% at 1 atm, 94.1% at 2 atm, 99.3% at 3 atm, 96.2% in 24-hour culture, 99.2% in 48-hour culture and 99.3% in 72-hour culture (P > 0.05). However, the S/N ratio of MDA-MB 231 cells was 66.9% in 24-hour culture, 83.1% in 48 hour culture and 87.8% in 72-hour culture (P < 0.05). CONCLUSIONS: Only the growth of the MDA-MB-231 cells was significantly reduced after a longer exposure time to nitrous oxide, but those of the other cells were not.
Atmosphere ; Bone Marrow ; K562 Cells ; Methotrexate ; Nitrous Oxide ; Ventilation

OBJECTIVETo investigate the role of Ara-C in regulating anti-CD3/anti-Pgp mediating T-lymphocytes activities against multi-drug resistant leukemia cells.

METHODSThe diabody of anti-CD3/anti-Pgp was purified by E-tag affinity chromatography. K562 and K562/A02 cells were treated with Ara-C. The expressions of B7-1 and B7-2 on K562 and K562/AO2 cells were detected by FACS. The cytotoxicity of T-lymphocytes combined with anti-CD3/anU-Pgp plus Ara-C was analyzed by CytoTox 96 nonradioactive method.

RESULTSThe expressions of B7-1 and B7-2 on K562 and K562/A02 cells treated by Ara-C was significantly higher than those untreated. The effect/target ratio was from 0.39:1 to 25:1, and the killing rate of activated T cells to anti-drug-resistant leukemia cells was from (16.44 +/- 1.20)% to (60.49 +/- 2.90)%. The killing rates were increased gradually, with both the effect/target ratio and the antibody concentration increasing (P < 0.05).

CONCLUSIONAra-C may be an important adjuvant for improving anti-CD3/anti-Pgp mediating T-lymphocytes activities against multi-drug resistant leukemia cells.

Derris eriocarpa, a traditional Chinese medicine belonging to the family of Leguminosae, is widely distributed mainly over Yunnan, Guangxi and Guizhou of China. Modern pharmacological researches on this herb showed that it had extensive bioactivities, such as promoting urination, removing dampness and cough and reducing inspissated mucus and other biological activities. The extensive studies on the chemical constituents of this plant have resulted in the isolation of triterpenoids, steroids, fatty acid and others, but the flavone compounds haven't reported before. In our further research on the ethyl acetate of this plant, nine flavone compounds were obtained by column chromatography on silica gel, Sephadex LH-20, semi-prep HPLC, polyamide column chromatography and recrystallization for separation and purification. The structures were determined on the basis of extensive spectroscopic analysis, including MS, NMR experiments and comparison with spectroscopic data in the literature, respectively, as diosmetin (1), 3, 3'-di-O-methylquercetin (2), afromosin (3), 6, 3'-dihydroxy-7, 4'-dimethoxyisoflavone (4), odoratin (5), 7, 3'-dihydroxy-8, 4'-dimethoxyisoflavone (6), 6, 4'-dihydroxy-7, 3'-dimethoxyisoflavone (7), 5, 7, 4'-trihydroxy-3, 3', 5'-trimethoxyflavone (8), and alpinumisoflavone (9). All these compounds were isolated from Derris eriocarpa How for the first time. And the in vitro assays showed that compound 2 possessed moderate inhibitory activity against human cancer cells K562 and HEL.
Derris ; chemistry ; Flavonoids ; chemistry ; isolation & purification ; pharmacology ; Humans ; K562 Cells

Cell Differentiation ; Cell Polarity ; Ginsenosides ; Humans ; K562 Cells ; Leukemia

OBJECTIVE: To screen the differentially expressed proteins at the early stage of K562 cells treated with meisoindigo by using tandem mass tags (TMT)-based proteomics technology, and to explore the mechanism for meisoindigo-inducing apoptosis. METHODS: The half inhibitory concentration (IC) of mesoindigo on K562 cells was determined by CCK8. The flow cytometry was used to assay the apoptosis of K562 cells treated by meisoindigo or DMSO. Total proteins were extracted from the cells treated with 0.2% DMSO (control) or 20 μmol/L meisoindigo (Test) for 2 hours. Then, the TMT-labeling HPLC-MS/MS was used to identify and quantify the peptides and their abundance, all the tests were repeated for 3 times. The Mascot software was used to identify the proteins; the GO annotations, enrichment and cluster analysis were used to analyze the differentially expressed proteins. RESULTS: Meisoindigo-induced K562 cell apoptosis in a dose-dependent manner (r=0.98), 5 544 proteins were identified, 4792 of which were quantified. The protein with expression difference>1.5-folds in Test group accoanted for 8, out of which the expression of 4 proteins were up-regulated and 4 were down-regulated. The differentially expressed proteins mainly associated with reactive oxygen species (ROS). CONCLUSION Several proteins including DDIT4 were found to have dramatic changes in the early stage of K562 cells treated with meisoindigo by using quantitative proteomics technology. The ROS metabolic process may play important roles in meisoindigo-inducing apoptosis of K562 cells.
Apoptosis ; Humans ; Indoles ; K562 Cells ; Proteomics ; Tandem Mass Spectrometry

Apoptosis ; drug effects ; Asparaginase ; pharmacology ; HL-60 Cells ; Humans ; K562 Cells ; U937 Cells

OBJECTIVETo investigate the apoptosis of NK cells induced by the erythroleukemia cell line K562 in vitro.

METHODSPrimary NK cells isolated from the peripheral blood of healthy donors by magnetic-activated cell sorting were cultured with stem cell medium containing recombinant human interleukin-2 (rhIL-2). The NK cells and K562 cells were mixed and co-cultured at different E:T ratios for different time lengths. The apoptosis of NK cells and K562 cells were detected using PE-AnnexinV/7-AAD labeling and flow cytometry.

RESULTSThe purity of isolated NK cells reached (93.99∓4.22)%. At the same E: T ratio, the apoptotic rate of NK cells induced by K562 cells increased significantly with time. As the E:T ratio reduced, the apoptotic rate of the NK cells increased and their cytotoxic activity against K562 cells was attenuated.

CONCLUSIONK562 cells can induce the apoptosis of activated NK cells, which is one of the probable mechanisms of immune escape of tumors.

Nine triterpenes compounds were isolated from the male flowers of Eucommia ulmoides by recrystallization and chromatographic techniques over silica gel, Sephadex LH-20, and RP-18 gel. Their chemical structures were identified on the basis of spectral analysis and as 3-oxo-12-en-ursane-28-O-α-L-arabinofuranosyl (1 --> 6) -β-D-glucopyranoside (1), 2α, 3β-dihydroxyurs-12-en-28-oic acid(28 --> 1) -β-D-glucopyranosyl ester (2), ursolic acid (3), α-amyrin (4), uvaol (5), ursolic acid acetate (6), 3-O-acetate oleanoic acid (7), betulinic acid (8), and betulinol (9). Compound 1 was a new compound, and compounds 2, 4-7 were isolated from the Eucommiu genus for the first time. Cytotoxic activity was tested for all the compounds against K562 and HepG2 cells. The results showed that only compound 3, exhibited cytotoxic activity.
Antineoplastic Agents, Phytogenic ; pharmacology ; Eucommiaceae ; chemistry ; Hep G2 Cells ; Humans ; K562 Cells ; Triterpenes ; analysis ; pharmacology

OBJECTIVETo explore the differentiation-inducing potentiality of Pulsatilla saponin A on K562 cells.

METHODSPulsatilla saponin A of different concentrations was used to treat K562 cells; the benzidine staining and the hemoglobinometry were applied to measure the change of hemoglobin content; the flow cytometry (FCM) was used to detect the expression of CD71 and GPA on K562 cells.

RESULTSK562 cells treated with 4 µg/ml pulsatilla saponin A differentiated into the erythroid lineage. With the treatment of pulsatilla saponin A, the hemoglobin content in K562 cells increased significantly; CD71 and GPA expression on the K562 cell surface were up-regulated.

CONCLUSIONPulsatilla saponin A can induce K562 cells to differentiate into erythroid lineage.

The purpose of study was to investigate the in vitro proliferation ability of PHA-induced CIK cells and traditionally prepared CIK cells, the effector cell level and its influence on killing activity to K562 cells, and to analyze the difference between them. The peripheral blood mononuclear cells(PBMNC) of healthy persons were isolated and divided into A and B group. The CIK cells in A group were obtained by using traditional culture method, the CIK cells in B group were prepared by PHA induction. During the cultivation, the cell survival rate and cell absolute value in the cell culture system were counted every 3 days. On day 15 of culture, the cell immunophenotype of 2 groups were detected by flow cytometry, and the ratios of CD3(+)CD56(+), CD3(+)CD8(+) and CD3(+)CD4(+) cells in total cell amount of culture system were accounted. Meantime, the killing activity to K562 cells in different effector-target ratios was detected by using CCK-8 kit between the 2 groups. The results showed that the method of preparing CIK by PHA induction promoted the cell proliferation more than that of the traditional method (P < 0.05), moreover, both the survival rate of cells in 2 groups was more than 90%. The CD3(+)CD8(+), CD3(+)CD56(+) cell ratio in 2 groups obviously increased. As compared with traditional method, the CD3(+)CD8(+) cell level in B group was enhanced (P < 0.05); but there were no statistical differences in increase of CD3(+)CD56(+) cell level and decrease of CD3(+)CD4(+) cell level between 2 groups. while the effector-target ratio is 5:1, 10:1, 20:1 and 40:1, the killing activity of PHA-induced CIK cells to K562 cells was more stronger than traditionally-prepared CIK cells (P < 0.05), moreover, along with increase of effector-target ratio, the difference of killing activity to K562 cells in 2 groups significantly increased. It is concluded that compared with traditional method for preparing CIK cells, the new way by PHA induction can increase the proliferation of CIK cells obviously, enhance the ratio of CD3(+)CD8(+) cells and strengthen the killing activity to the K562 cells. This new way provides a new source of CIK cells and reliable evidence for cyto-immune therapy of leukemia and other tumors.
Cell Proliferation ; Cytokine-Induced Killer Cells ; cytology ; Humans ; K562 Cells ; Leukocytes, Mononuclear ; Phytohemagglutinins ; pharmacology