Carcinoma, Hepatocellular ; genetics ; pathology ; Gene Expression Profiling ; Genomics ; Humans ; Liver Neoplasms ; genetics ; pathology ; Neoplasm Metastasis ; genetics ; Neoplasm Recurrence, Local ; genetics

OBJECTIVETo investigate whether proteasome inhibitor MG-132 induces apoptosis of human erythroleukemia cell line K562 and possible mechanisms.

METHODSK562 cells were incubated with RPMI 1640 and exposed to 0, 1, 5, 10, 15 micromol/L of MG-132 for 24 hrs, respectively. The apoptosis of cells were detected by fluorescence microscope, DNA fragments and flow cytometry. The NF-kappaB mRNA expression was quantified by reverse transcription-polymerase chain reaction (RT-PCR). Expression of NF-kappaB and caspase-3 was semiquantitatively analyzed with SABC techniques. Caspase-3 activities were measured with a colorimetric method.

RESULTSThe growth of K562 cells was inhibited and the apoptosis of the cells increased after MG-132 treatment in a dose-dependent manner. After 24 hrs of 15 micromol/L MG-132 treatment, the percentage of apoptotic cells (26.5+/-0.6%) increased significantly when compared with the untreated controls (1.2+/-0.1%) (P<0.01). MG-132 treatment decreased the mRNA and protein expression of NF-kappaB, and increased the protein expression of caspase-3.

CONCLUSIONSMG-132 can induce apoptosis of human erythroleukemia cell line K562 through the down-regulation of NF-kappaB expression and up-regulation of caspase-3 expression.

Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Cysteine Proteinase Inhibitors ; pharmacology ; Dose-Response Relationship, Drug ; Humans ; K562 Cells ; Leupeptins ; pharmacology ; NF-kappa B ; Proteasome Inhibitors ; Reverse Transcriptase Polymerase Chain Reaction

OBJECTIVETo study the molecular mechanism of apoptosis of leukemic cells (K562 cells) induced by iron chelating agent deferoxamine (DFO).

METHODSThe exponentially growing K562 cells were used (1×10(6)/mL) in this study. The K562 cells were treated with different concentrations of DFO (10, 50 and 100 mmol/L), DFO+FeCl3 (10 μmol/L each) or normal saline (blank control). The cellular labile iron pool was measured with a fluorimetric assay using the metalsensitive probe calcein-AM. The viable count and cell viability were determined by typanblue assay. Cell apoptosis was determined by morphological study and flow cytometry assay. Caspase-3 activity in K562 cells was detected by colorimetry.

RESULTSAfter DFO treatment, the cellular labile iron pool and the viability of K562 cells were reduced and the cell apoptosis increased in a time- and dose-dependent manner compared with the blank control group. The apoptosis rate of K562 cells in the DFO+FeCl3 treatment group was not significantly different from that in the blank control group. The caspase-3 activity in K562 cells increased significantly 24 hrs after 50 and 100 μmmol DFO treatment when compared with the blank control group (P<0.01). There was a negative correlation between cellular labile iron pool and caspase-3 activity of K562 cells (r=-0.894, P<0.05).

CONCLUSIONSDFO induces apoptosis of leukemic cells possibly through decreasing cellular labile iron pool and increasing caspase-3 activity of the cells.

Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Deferoxamine ; pharmacology ; Flow Cytometry ; Humans ; Iron Chelating Agents ; pharmacology ; K562 Cells

Objective To observe the relationship between apoptosis of K562 cell induced by iron-deprivation and activation of Caspase-3.Methods K562 cells were treated with desferrioxamine(DFO) in different dosages were collected at different time points.K562 cells were labelled with Annexin V/PI,and then the rate of apoptosis was measured by flow cytometry;The activation of Caspase-3 were detected by colorimetric method with pAN labelled substrate;The active protein of Caspase-3 were analyzed by Western blot.Results When K562 cells were treated with different concentrations of DFO,the apoptosis rate and the activity of Caspase-3 increases gradually.When K562 cells were incubated with DFO(50 ?mol/L and 100 ?mol/L) 24 h later,the enzymatic activity of Caspase-3 increases dramatically more than that of control group,and the difference was significantly(P0.05).All those effect above can be counteracted by equal mole concentration of FeCl_3.Conclusion Iron-deprivation maybe induce the apoptosis of K562 cell by chelating intracellular iron and activing Caspase-3.

Objective To investigate the expression of inducible nitric oxide synthase ( iNOS) and the levels of nitric oxide (NO) in THP-1 and J774A. 1 cells during Leptospira interrogans (L. interrogans) infection for a better understanding of the mechanism of macrophages involved defense against L. interrogans strains in different hosts. Methods The human mononuclear macrophages (THP-1) and the murine mono-nuclear macrophages (J774A. 1) were infected with L. interrogans strain 56601. The expression of iNOS at mRNA and protein levels were determined by using real-time RT-PCR and flow cytometry analysis. The lev-els of NO were detected with Griess test. Results The expression of iNOS at mRNA level in J774A. 1 and THP-1 cells infected with L. interrogans strains for 2, 4, 12 and 24 hours were respectively 1. 37, 2. 82, 25. 76, 27. 47 times and 1. 59, 3. 98, 3. 89, 8. 81 times than that of cells without infection (P<0. 05). The expression rates of iNOS protein in J774A. 1 cells were increased from 34. 16% to 85. 85%, 93. 82%, 91. 77% and 93. 65% along with the increased time of infection time (P<0. 05). The expression rates of iNOS protein in THP-1 cells were up-regulated from 22. 08% to 72. 64%, 81. 33%, 80. 03% and 65. 72%after 2, 4, 12 and 24 hours of infection (P<0. 05), respectively. Results of the Griess test indicated that the levels of NO in J774A. 1 and THP-1 cells were respectively increased from 0. 1588 μmol/L to 0. 2208μmol/L, 0. 2668μmol/L, 0. 3808μmol/L, 0. 3828μmol/L and from 0. 0988μmol/L to 0. 2848μmol/L,0. 3228 μmol/L, 0. 2608μmol/L and 0. 3308μmol/L after infection with L. interrogans strains for 2, 4, 12 and 24 hours (P<0. 05). Conclusion The expression of iNOS and the levels of NO in J774A. 1 and THP-1 cells were significantly increased during L. interrogans infection. This study might help to explain the bactericidal mechanism of macrophages derived from different hosts against L. interrogans infection.

Objective To analyze the effects of Leptospira interrogans ( L. interrogans) infection on the activation of NLRP3 in THP-1 and J774A. 1 cells and to further understand the mechanism of inflam-mation caused by L. interrogans in different hosts. Methods Human mononuclear macrophage cell line (THP-1) and murine mononuclear macrophage cell line (J774A. 1) were infected with L. interrogans strain 56601. The expression of NLRP3 at mRNA and protein levels were measured by using real-time RT-PCR and flow cytometry analysis, respectively. The NLRP3-mediated secretion of IL-1β, IL-18 and IL-33 was detec-ted by ELISA combined with the NLRP3 inhibitory test. Results Compared with the normal cells, the ex-pression of NLRP3 at mRNA level in L. interrogans-infected THP-1 cells was respectively increased by 4. 05, 0. 34, 0. 33, 0. 06 and 1. 66 times at the time points of 1 h, 2 h, 4 h, 12 h and 24 h after infection ( P<0. 05), while that in L. interrogans-infected J774A. 1 cells was respectively increased by 12. 98, 16. 19, 10. 68, 5. 8 and 0. 57 times (P<0. 05). The expression rates of NLRP3 protein in THP-1 and J774A. 1 cells respectively increased from 9. 26% to 94. 01%, 89. 24%, 31. 80%, 19. 74%, 11. 28% and from 18. 71%to 58. 78%, 43. 64%, 36. 42%, 76. 46%, 85. 21% at the time points of 1 h, 2 h, 4 h, 12 h and 24 h af-ter L. interrogans infection (P<0. 05). The level of IL-1β in L. interrogans-infected THP-1 cells was 73. 07 pg/ml, 939. 24 pg/ml, 939. 24 pg/ml, 843. 22 pg/ml and 851. 06 pg/ml at the time points of 1 h, 2 h, 4 h, 12 h and 24 h, respectively (P<0. 05), while the level of IL-1β in L. interrogans-infected J774A. 1 cells began to rise at the time point of 12 h from 191. 17 pg/ml to 254. 4 pg/mL at the time point of 24 h (P<0. 05). The level of IL-18 in L. interrogans-infected THP-1 cells was 913. 89 pg/ml, 808. 19 pg/ml, 483. 54 pg/ml, 204. 19 pg/ml and 189. 09 pg/ml at the time points of 1 h, 2 h, 4 h, 12 h and 24 h, re-spectively (P<0. 05), while the level of IL-18 in L. interrogans-infected J774A. 1 cells increased at the time point of 24 h, which was 113. 37 pg/ml (P<0. 05). A slight increase in the level of IL-33 was detected in L. interrogans-infected J774A. 1 cells at the time points of 12 h and 24 h to 201. 14 pg/ml and 155. 68 pg/ml, respectively (P<0. 05), but no significant change was detected in L. interrogans-infected THP-1 cells (P>0. 05). Results of the inhibitory test showed that the up-regulation of IL-1β , IL-18 and IL-33 in THP-1 and J774A. 1 cells were effectively inhibited by the specific inhibitor of NLRP3. Conclusion NL-RP3 inflammasome was activated and involved in the production of specific inflammatory cytokines IL-1βand IL-18 in both THP-1 and J774A. 1 cells after L. interrogans infection, but the inflammatory cytokines induced by L. interrogans infection varied in different cells. L. interrogans induced earlier and higher level of IL-1βand IL-18 production in human macrophages than in murine macrophages.

OBJECTIVETo biodegrade the diesel pollution in aqueous solution inoculated with Mycobacterium and filamentous fungi.

METHODSBacteria sampled from petroleum hydrocarbons contaminated sites in Karamay Oilfield were isolated and identified as Mycobacterium hyalinum (MH) and cladosporium. Spectrophotometry and gas chromatography (GC) were used to analyze of the residual concentrations of diesel oil and its biodegradation products.

RESULTSFrom the GC data, the values of apparent biodegradation ratio of the bacterial strain MH to diesel oil were close to those obtained in the control experiments. Moreover, the number of MH did not increase with degradation time. However, by using n-octadecane instead of diesel oil, the real biotic degradation ratio increased to 20.9% over 5 days of degradation. Cladosporium strongly biodegraded diesel oil with a real degradation ratio of up to 34% after 5 days treatment. When the two strains were used simultaneously, a significant synergistic effect between them resulted in almost complete degradation of diesel oil, achieving a total diesel removal of 99% over 5 days of treatment, in which one part of about 80% and another part of about 19% were attributed to biotic and abiotic processes, respectively.

CONCLUSIONThe observed synergistic effect was closely related to the aromatics-degrading ability of Cladosporium, which favored the growth of MH and promoted the bioavailability of diesel oil.

Biodegradation, Environmental ; Cladosporium ; metabolism ; Environmental Pollutants ; metabolism ; Gasoline ; Mycobacterium ; metabolism

This review presents the state of the art of pH-responsive polymeric micelles for cancer drug delivery. Solid tumors have a weakly acidic extracellular pH (pH < 7), and cancer cells have even more acidic pH in endosomes and lysosomes (pH 4-6). The pH-gradients in tumor can be explored for tumor targeting and drug release in cancer drug delivery by applying pH-responsive polymeric micelles. The pH-responsive polymeric micelles consist of a corona and a core, and are made of amphiphilic copolymers, in which there are pH-responsive polymeric blocks. Two types of pH-responsive polymers-protonizable polymers and acid-labile polymers have been mainly used to make pH-responsive micelles for drug delivery. The protonizable polymers are polybases or polyacids, and their water-soluble/insoluble or charge states undergo changes with the protonation or deprotonation stimulated by external acidity, while the acid-labile polymers change their physical properties by chemical reaction stimulated by the acidity. Polymeric micelles whose core or coronas respond to the tumor extracellular acidity can be explored for triggering the fast release of the carried drug, activating the targeting group and accelerating the endocytosis of drug-loaded polymeric micelles, and those whose core or coronas respond to the tumor lysosomal acidity can be used for facilitating their escape from the lysosomes and targeting the nucleus. Various in vivo and in vitro experiments demonstrated that pH-responsive polymeric micelles are effective for cellular targeting, internalization, fast drug release and nuclear localization, and hence enhancing the therapeutic efficacy and reducing the side effect of cancer chemical therapy.
Antineoplastic Agents ; administration & dosage ; therapeutic use ; Drug Delivery Systems ; Humans ; Hydrogen-Ion Concentration ; Micelles ; Nanoparticles ; Neoplasms ; drug therapy ; Polymers ; chemistry

To study the effect of Siwu decoction on the function and expression of P-glycoprotein (P-gp) in Caco-2 cells. The Real-time quantitative poly-merase chain reaction (Q-PCR) was used to analyze the mRNA expression of MDR1 gene in Caco-2 cells. Flow cytometer was used to study the effect of Siwu decoction on the uptake of Rhodamine 123 in Caco-2 cells, in order to evaluate the efflux function of P-gp. Western blotting method was used to detect the effect of Siwu decoction on the P-gp protein expression of Caco-2 cells. Compared with the blank control group, after Caco-2 incubation with Siwu decoction at concentrations of 3.3, 5.0, 10.0 g x L(-1) for 24, 48, 72 h, the mRNA expression of MDR1 was up-regulated, suggesting the effect of Siwu decoction in inducing the expression of MDR1. After the administration with Siwu decoction in Caco-2 cells for 48 h, the uptake of Rhodamine 123 in Caco-2 cells decreased by respectively 16.6%, 22.1% (P < 0.05) and 45.4% (P < 0.01), indicating that the long-term administration of Siwu decoction can enhance the P-gp efflux function of Caco-2 cells. After the incubation of Caco-2 cells with Siwu decoction for 48 h, the P-gp protein expression on Caco-2 cell emebranes, demonstrating the effect of Siwu decoction in inducing the protein expression of P-gp.
ATP Binding Cassette Transporter, Sub-Family B ; genetics ; metabolism ; ATP-Binding Cassette, Sub-Family B, Member 1 ; genetics ; metabolism ; Caco-2 Cells ; Drugs, Chinese Herbal ; pharmacology ; Humans ; Up-Regulation ; drug effects

OBJECTIVESTo analyze the relationship between oxidized low density lipoprotein (oxLDL), angiogenesis and stabilization of atherosclerotic plaques in human coronary arteries; and to investigate the role of oxLDL in creating vulnerable sites in atherosclerotic plaques.

METHODSSamples of coronary arteries were obtained at autopsies of 42 patients with acute coronary syndrome. Eighty randomly selected blocks were studied by immunohistochemistry using antibodies against oxLDL and endothelial cells (factor VIII). Computer-aided planimeter was used for quantitative analysis.

RESULTSIn unstable plaques, percentage of immunoreactive areas for oxLDL was significantly higher than that in stable plaques. Most of the oxLDL were located in shoulder region of these plaques, as compared to the fibrous cap and basal regions. The details of distribution of oxLDL were as follows: shoulder region (20.43 +/- 3.12 for unstable plaques and 17.65 +/- 4.22 for stable plaques), fibrous cap (4.77 +/- 2.03 for unstable plaque and 2.80 +/- 0.22 for stable plaques) and basal region (5.65 +/- 1.65 for unstable plaques and 3.22 +/- 1.02 for unstable plaques). OxLDL was also a main component in the lipid core. In the shoulder region, there was a significant positive correlation between neovascularization and oxLDL (r = 0.8247, P = 0.000).

CONCLUSIONSThe amount of oxLDL is significantly higher in unstable atherosclerotic plaques, especially over the shoulder region. OxLDL in coronary atherosclerotic plaques is thus an important factor in determining stabilization of the plaques. OxLDL may induce influx of inflammatory cells which subsequently leads to decreased plaque stabilization.

Angina, Unstable ; metabolism ; pathology ; Coronary Artery Disease ; metabolism ; pathology ; Humans ; Immunohistochemistry ; Lipoproteins, LDL ; metabolism ; Myocardial Infarction ; metabolism ; pathology ; Neovascularization, Pathologic ; metabolism ; pathology