In order to investigate the effects of Na(2)SeO(3) on expression of VEGF in K562/ADR cells, K562 and K562/ADR cells were treated with Na(2)SeO(3) at dose of 5 and 10 micromol/L. The expressions of VEGF in K562 and K562/ADR cells were detected by ELISA before and at the different time point after treatment. The mutiplie of reversion of resistance was detected by MTT method. The results showed that Na(2)SeO(3) at dose of 10 micromol/L could increase the sensitivity of K562/ADR cell to adriamycin, the multiple of reversion was 3.48. The expression levels of VEGF in K562 and K562/ADR cells increased with prolongation of time cultured, and the VEGF expression levels in K562/ADR cells at the different time points were higher than that in K562 cells (P < 0.05); 5 and 10 micromol/L Na(2)SeO(3) did not suppress expression of VEGF in K562 cells at 72 hours (P > 0.05), and the VEGF level in K562 cells at 96 hours decreased without statistical significance; 5 and 10 micromol/L Na(2)SeO(3) acting for 48 hours did not show suppressive effect on expression of VEGF in K562/ADR cells (P > 0.05), 5 micromol/L Na(2)SeO(3) could decrease the expression of VEGF in K562/ADR cell after treatment for 96 hours, while 10 micromol/L Na(2)SeO(3) could significantly decrease the expression of VEGF in K562/ADR cells treated for 72 hours and 96 hours (P < 0.01). It is concluded that VEGF would be involved in the multidrug resistance of leukemia. Na(2)SeO(3) decreasing expression of VEGF in leukemic cells may be one of the mechanisms reversing multidrug resistance.
Doxorubicin ; pharmacology ; Drug Resistance, Neoplasm ; Humans ; K562 Cells ; Sodium Selenite ; pharmacology ; Vascular Endothelial Growth Factor A ; metabolism

OBJECTIVETo explore the effects and mechanisms of ascorbic acid (AA) and sodium selenite (SS) on growth inhibition and redifferentiation in human gastric cancer cells.

METHODSIn the present study, trypan blue dye exclusion method was used to determine the cell growth curve and mitotic index, cell electrophoresis and colonogenic potential were used as the indexes of redifferentiation. In order to find out the mechanisms of redifferentiation, the activities of superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase (CAT) were assayed, the content of malondialdehyde (MDA), reduced glutathione (GSH) and H2O2 were evaluated.

RESULTSAfter treatment with AA 3 mol/L + SS 2 mu mol/L, the growth rate and mitotic index of human gastric cancer cells (MGc-803) decreased remarkably. The indexes related with cell malignancy were alleviated. For example, cell surface charge was obviously decreased, the electrophoresis rate was dropped from 2.21 to 1.15 mu m.s-1.V-1.cm-1. The indexes related with cell redifferentiation were promoted. For example, the colonogenic potential was decreased to 93.5%. These results indicated that redifferentiation of human gastric cancer cells was successfully induced by AA + SS. The activities of SOD and GPX were significantly higher, while the activity of CAT was slower in treated group than that in the control. The content of MDA was slightly decreased, GSH was sharply decreased, and H2O2 content was dramatically increased.

CONCLUSIONThese results indicated that combination of ascorbic acid and sodium selenite may induce the redifferentiation of human gastric cancer cells and inhibit cell growth by virtue of enhancing the activities of antioxidative enzymes and inducing the formation of H2O2, and altering the cell redox status. Combination of ascorbic acid and sodium selenite may be a potent anticancer agent for human gastric cancer.

Antioxidants ; pharmacology ; Ascorbic Acid ; pharmacology ; Catalase ; pharmacology ; Cell Differentiation ; Glutathione Peroxidase ; pharmacology ; Humans ; Mitotic Index ; Sodium Selenite ; pharmacology ; Stomach Neoplasms ; pathology ; Superoxide Dismutase ; pharmacology ; Tumor Cells, Cultured

OBJECTIVETo explore the effects of sodium selenite on the expressions of beta-catenin and cyclin D1 in colorectal cancer cells HCT 116 and SW480.

METHODSHCT 116 and SW480 cells were treated by 10 micromol/L sodium selenite at different time points. The expressions and transcription of beta-catenin and cyclin D1 were detected by Western blot analysis and reverse transcriptase polymerase chain reaction (RT-PCR), respectively. Meanwhile, the impact of MG132 (a proteasome inhibitor) pretreatment on the expressions of beta-catenin and cyclin D1 was observed through Western blot analysis. The interaction between beta-catenin and T cell factor 4 (TCF4) after selenite treatment was evaluated using co-immunoprecipitation assay.

RESULTSSodium selenite inhibited the expression of beta-catenin and transcription of its target such as cyclin D1. MG132 pretreatment prevented the inhibition of beta-catenin signaling triggered by selenite in HCT 116 and SW480 cells. Furthermore, selenite treatment disrupted the interaction between beta-catenin and TCF4 in HCT 116 and SW480 cells.

CONCLUSIONSSodium selenite can lower the expression levels of beta-catenin and its target cyclin D1, during which the proteasome-mediated degradative pathway may be involved. The decreased interaction between beta-catenin and TCF4 due to sodium selenite may be also involved in the regulation of beta-catenin signaling.

Cell Line, Tumor ; Colorectal Neoplasms ; metabolism ; Cyclin D1 ; metabolism ; HCT116 Cells ; Humans ; Sodium Selenite ; pharmacology ; beta Catenin ; metabolism

OBJECTIVEThe aim of this study was to observe the human hair follicle apoptosis status affected by fluorine and the antagonism effect by selenium in vitro.

METHODSThe single hair follicles were separated and cultured, then they were added in different concentrations of sodium fluoride and sodium selenite. Chosen the appropriate concentrations, they were divided into 7 groups. The TUNEL was used to investigate the apoptotic cells of different parts. The morphous of hair follicles was observed consecutively and electron microscope was used.

RESULTSWe found that in 1 mmol/L and 10 mmol/L sodium fluoride groups, when the human hair follicles in vitro were cultured on the 5th day, the apoptotic cells of outer root sheath (ORS), dermal sheath and hair papilla, hair bulb were obviously increased. But 0.01 mmol/L sodium selenite weakened the toxicity of 1 mmol/L sodium fluoride at the outer root sheath and hair bulb (P < 0.05).

CONCLUSIONSDifferent concentrations of sodium fluoride had different effect on the growth of human hair follicle in vitro which were cultured on 5th day. Sodium fluoride of certain concentration could accelerate the apoptosis of human hair follicle in vitro. Sodium selenite of certain concentration could act antagonism to the toxicity of sodium fluoride.

Adolescent ; Adult ; Apoptosis ; drug effects ; Hair Follicle ; drug effects ; Humans ; Middle Aged ; Sodium Fluoride ; pharmacology ; Sodium Selenite ; pharmacology ; Tissue Culture Techniques ; Young Adult

In order to investigate the effect of non-medullar toxicity drug - all trans retinoid acid (ATRA) and cancer preventive trace element-selenium compound - sodium selenite (Na(2)SeO(3)) on the expression of vascular endothelial growth factor (VEGF) and its receptor in HL-60 cells, the expression of VEGF and its receptor in HL-60 cells were detected by ELISA technique and flow cytometry before and after treatment with two drugs. The results showed that the mean VEGF concentrations in the cultural supernatant of 5 and 10 micro mol/L ATRA-treated HL-60 cells for 48 and 72 hours were lower than those of the control group without adding ATRA. The differences between the ATRA-treated groups and the control group were statistically significant (P = 0.001, P = 0.000, P < 0.01, respectively). The levels of VEGF-R on the surface of HL-60 cells also decreased after treatment with ATRA of 5 and 10 micro mol/L for 72 hours, but at 48 hours the expression rates of VEGF-R on HL-60 cells of the two ATRA treated groups were not significantly decreased. At 48 and 72 hours, Na(2)SeO(3) of 5 and 10 micro mol/L had no obvious effect on HL-60 secreting VEGF, but notablely inhibited the expression of VEGF-R. In conclusion, ATRA could inhibit the expression of VEGF and its receptor in HL-60 cell. Na(2)SeO(3) could not inhibit the expression of VEGF in HL-60 cell, but could decrease the receptor expression of VEGF, which mechanism should be further studied. ATRA and Na(2)SeO(3) had not obvious medullar-inhibition, but anti-angiogenesis activity. It is suggested that combination of two drugs with conventional therapy may enhance the effect of radiotherapy and chemotherapy, and reduce the dose and thus toxicity of chemotherapeutic agents.
Dose-Response Relationship, Drug ; Flow Cytometry ; HL-60 Cells ; Humans ; Receptors, Vascular Endothelial Growth Factor ; analysis ; Sodium Selenite ; pharmacology ; Tretinoin ; pharmacology ; Vascular Endothelial Growth Factor A ; analysis

The study was purposed to explore the quantity, morphology and immunophenotype of dendritic cells (DC) acquired by co-cultivated system with 3 types of cytokines and sodium selenite (Se) from peripheral blood mononuclear cells (PBMNCs), and to investigate the effects of Se on inducing the cytotoxic T lymphocyte (CTL) to get specific anti-leukemic activity in vitro by DC pulsed with K562 cell frozen-thawed antigen (antigen cell loading). PBMNCs isolated from healthy donors were cultured in RPMI 1640 medium contained 10% FBS supplied with 3 cytokines (rhGM-CSF, rhIL-4, TNF-alpha) for 4 days, DCs harvested were divided into 4 groups, DCI: DC alone; DCII: DC + Se (adding 0.5 micromol/L of Se); DCIII: DC + K562 (pulsed with lysed K562 cells); DCIV: DC + Se + K562. Morphology of DCs was observed under microscope at day 7. The CD1a, CD40, CD83, and CD86 were detected by FCM. Cytotoxicity of T cells induced by DC were measured with LDH release test at day 12. The level of IL-12 in supernatant of cultured DCs were determined with ELISA. The results indicated that at 7th day DC in 4 groups showed characteristic morphology, the colony numbers of 4 groups were all higher than those before cultivation. There were no obvious differences of morphology and colony counts between DCI group and DCII group. The colony numbers of DCIII group and DCIV group increased, as well as the ratio of suspended cells enhanced. The expressions of CD1a, CD40, CD83 and CD86 in 4 groups of DC were significantly higher than those in PBMNC group (p < 0.01), the expressions of CD1a and CD40 in 4 groups of DC did not display significant difference (p > 0.05), the expressions of CD83 and CD86 in both DCIII group and DCIV group were all higher than those in DCI group and DCII group (p < 0.01), but their expressions of CD83 and CD86 in DCI and DCII were not significantly different (p > 0.05), as well as those in DCIII group and DCIV group. With the ratio of 25:1 between E:T, killing rate of CTL on K562 cells in 4 DC groups were 15.3 +/- 2.3%, 26.3 +/- 3.7%, 28.2 +/- 4.5% and 36.2 +/- 3.7% respectively, all obviously higher than those of T cell group without being sensitized by DCs (5.9 +/- 2.4%) (p < 0.01), The CTL effect in DCIV group was the highest, which was higher than those in other 3 DC groups (p < 0.01); the effects in both DCII and DCIII group were also higher than that in DCI group (p < 0.01), but their difference between DCII and DCIII groups did not show significance (p > 0.05). The levels of IL-12 in supernatant of DCI, DCII, DCIII and DCIV groups were 257.0 +/- 64.2, 328.1 +/- 43.9, 323.0 +/- 53.5 and 353.9 +/- 46.2 pg/ml respectively, all significantly higher than that in supernatant of T cell alone group without being sensitized by DCs (35.27 +/- 27.1 pg/ml) (p < 0.01), The levels in DCII, DCIII and DCIV groups were all higher than that in DCI group (p < 0.01), but their levels between DCII, DCIII and DCIV groups were not of significant difference (p > 0.05). It is concluded that matured DCs can be successfully obtained from PBMNCs by a culture system contained rhGM-CSF, rhIL-4 and TNF-alpha with or without low-dose of Se (0.5 micromol/L) in vitro. Using K562 cell frozen-thawed antigen, DC express more adhesive molecules and co-stimulating molecules (CD83, CD86), and increase the secretion of IL-12, as well as the killing effects of CTL on special target cells. Low dose of Se did not showed effects on quantity and morphology of matured DC harvested, as well as their expression of mature phenotypes, it raised levels of IL-12 secreted by DCs, reaching the same level as using K562 cell frozen-thawed antigen, and it showed synergistic effect on induction of CTL with K562 cell frozen-thawed antigen.
Cells, Cultured ; Cytokines ; pharmacology ; Dendritic Cells ; cytology ; immunology ; Humans ; K562 Cells ; Leukocytes, Mononuclear ; cytology ; Sodium Selenite ; pharmacology ; T-Lymphocytes ; immunology ; T-Lymphocytes, Cytotoxic ; cytology ; immunology

OBJECTIVETo investigate the effects of sodium selenite on telomerase activity and expression of hTERT mRNA in cadmium-transformed 16HBE cells.

METHODSTelomerase activity and expression of genes were measured after cultured cadmium-transformed 16HBE cells were exposed to sodium selenite at different doses (0.625, 1.25, 2.50, 5.00 micromol/L) for 24 hours.

RESULTSSelenium decreased telomerase activity in cadmium-transformed 16HBE cells. There existed an obvious dose-effect relationship between the selenium concentration and these changes. The expression of hTERT and c-myc mRNA also decreased but the expression of mad1 mRNA increased after exposure to selenium for 24 hours. No difference was found in expression of hTRF1 and hTRF2 mRNA after incubated with sodium selenite for 24 hours, compared with control group.

CONCLUSIONSelenium inhibits telomerase activity by decreasing hTERT and c-myc mRNA expression and increasing mad1 mRNA expression in cadmium-transformed 16HBE cells and selenium concentration is significantly correlated with these changes.

Base Sequence ; Cadmium ; pharmacology ; Cell Line, Transformed ; DNA Primers ; Humans ; RNA, Messenger ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Sodium Selenite ; pharmacology ; Telomerase ; antagonists & inhibitors ; genetics

To study the effects of nano elemental selenium (Nano-Se) or sodium selenite (Na2SeO3) on the activities of glutathione peroxidase (GSH-Px) and Type-I deiodinase in the liver. A total of 234 weanling pigs (Duroc x Landrace x Yorkshire) at an average initial body weight of 8.3 kg were allocated to 13 treatments. The thirteen dietary treatments were basal diet only (containing 0.04 mg/kg Se), basal diet + 0.1, 0.2, 0.3, 0.4, 0.5, 1.0 mg/kg Se as Na2SeO3 or Nano-Se, respectively. The results were as follows: Supplementation with 1.0 mg/ kg Se as Na2SeO3 reduced (P < 0.05) growth performance and GSH-Px activities as compared with the addition of a concentration range of 0.20-0.40 mg/kg Se. When Nano-Se was added to the diet, the growth and GSH-Px activities remained steady at the peak value as at a concentration of 1.0 mg/kg Se; There were no difference in the activities of GSH-Px between the treatments of Nano-Se and Na2SeO3 when added concentration of Se was 0.10-0.40 mg/kg. The pigs had higher (P < 0.05) activities of GSH-Px at a concentration range of 0.50 and 1.0 mg/kg as Nano-Se than Na2SeO3; Supplentation with Se increased the activity of Type- I deiodinase in liver, however, the increased extent was affected by neither Se sources nor added concentration of Se. The results implicated that for the best concentration range of Weinberg curve, Nano-Se is wider than Na2SeO3.
Animals ; Dose-Response Relationship, Drug ; Glutathione Peroxidase ; metabolism ; Iodide Peroxidase ; metabolism ; Liver ; enzymology ; Metal Nanoparticles ; administration & dosage ; Selenium ; administration & dosage ; pharmacology ; Sodium Selenite ; administration & dosage ; pharmacology ; Swine

AIMTo explore sodium selenite-induced oxidative stress and apoptosis in human promyelocytic leukemia NB4 cells.

METHODSThe growth inhibition of NB4 cells was measured by MTT test. Apoptosis was determined morphologically by Giemsa stain and by DNA ladder formation in electrophoresis. Quantitation of apoptosis was determined by percentage of PI stained cells containing subdiploid amount of DNA measured by flow cytometry. Generation of reactive oxidative species (ROS) in NB4 cells was determined by lucigenin dependent chemoluminescent (CL) test. Spectrophotometer was used to measure the level of reduced glutathione, superoxide dismutase (SOD) and glutathione peroxidase in the cell.

RESULTSSodium selenite was shown to inhibit the growth of NB4 cells. Sodium selenite induced apoptosis with dose and time dependency: the ratio of subdiploid cells in control group was 1.3% +/- 0.7%. The 5 mumol.L-1 group was 10.4% +/- 1.4%, 10 mumol.L-1 group was 16% +/- 1%, and the 20 mumol.L-1 group was 27.3% +/- 0.8%. Sodium selenite (> or = 5 mumol.L-1) enhanced the ROS level markedly in NB4 cells (in 20 mumol.L-1 group ROS level was increased by 17 times, compared with control group), accompanied with decrease of reduced intracellular glutathione. These effects were time and dose dependent. N-acytlcysteine as an antioxidant was found to inhibit sodium selenite-induced oxidative stress and apoptosis in NB4 cells.

CONCLUSIONSodium selenite can induce apoptosis of NB4 cells and would possibly be used as an agent for the treatment of malignancy. The main mechanism of action might be related to oxidative stress induced by sodium selenite, thereby, leading to apoptosis as shown in NB4 cells.

Antineoplastic Agents ; pharmacology ; Apoptosis ; Cell Division ; drug effects ; Humans ; Leukemia, Promyelocytic, Acute ; pathology ; Oxidative Stress ; drug effects ; Reactive Oxygen Species ; metabolism ; Sodium Selenite ; pharmacology ; Tumor Cells, Cultured

OBJECTIVETo explore the effect of glutathione (GSH) and sodium selenite on the metabolism of arsenic in the liver, kidney and blood of mice exposed to iAsIII through drinking water.

METHODSThe mice were randomly divided into control, arsenic, GSH and sodium selenite group, respectively. And each group had eight mice and the mice were exposed to 50 mg/L arsenite by drinking water for 4 weeks. Mice were intraperitoneally injected with GSH (600 mg/kg) and sodium selenite (1 mg/kg) for seven days from the beginning of the fourth week. At the end of the fourth week, liver, kidney and blood were sampled to assess the concentrations of inorganic arsenic (iAs), monomethylarsenic acid (MMA), dimethylarsenic acid (DMA) by hydride generation trapping by ultra-hypothermia coupled with atomic absorption spectrometry.

RESULTSThe liver DMA (233.76 +/- 60.63 ng/g) concentration in GSH group was significantly higher than the arsenic group (218.36 +/- 42.71 ng/g). The concentration of DMA (88.52 +/- 30.86 ng/g) and total arsenic (TAs) (162.32 +/- 49.45 ng/g) in blood of GSH group was significantly higher than those [(45.32 +/- 12.19 ng/g), (108.51 +/- 18.00 ng/g), respectively] of arsenic groups(q values were 3.06, 6.40, 10.72 respectively, P < 0.05). The primary methylated index (PMI) (0.65 +/- 0.050) and secondary methylated index (SMI) (0.55 +/- 0.050) in liver sample of GSH group were significantly higher than those (0.58 +/- 0.056, 0.44 +/- 0. 093) in arsenic group. In blood samples, the PMI (0.85 +/- 0.066) in GSH group was significantly higher than that (0.54 +/- 0.113) in arsenic group (q values were 3.75, 5.26, 4.21 respectively, P < 0.05). However, no significant difference was identified between sodium selenite and arsenic groups in liver, kidney or blood samples. And no significant difference was detected in kidney samples among all arsenic exposing groups.

CONCLUSIONExogenous GSH could promote the methylated metabolism of iAsIII, but sodium selenite showed no significant effects.

Animals ; Arsenic ; analysis ; metabolism ; Arsenic Poisoning ; metabolism ; Environmental Exposure ; Female ; Glutathione ; pharmacology ; Male ; Mice ; Mice, Inbred Strains ; Sodium Selenite ; pharmacology ; Water Supply