Acceleration of apoptosis by transfection of bak gene in multi-drug resistant (MDR) bladder cancer cellsI

Objective To observe the effects of bak gene on killing MDR bladder cancer cells and to study its mechanisms. Methods Bak gene was transfected into MDR bladder cancer cells by liposome. The mRNA of bak and bcl-2 were detected by in situ hybridization. The protein of bak and bcl-2 were detected by SABC immunohistochemistry. The growth rate of human bladder cancer cells was studied by constructing the growth curve, cell apoptosis being observed by flow cytometry, and the outline of cells observed by fluorescence stain. Results The expression of bak mRNA was positive in EJ/bak cells (64% ,P【0.05).Bak protein expression of EJ/bak cells was positive (60 % ) and bcl-2 protein expression was de creased (P【0.05). The growth of MDR bladder cancer cells was significantly inhibited by 32% after bak gene was transfected (P 【 0. 05 ). Apoptosis cells increased significantly. The apoptosis rate was 35 %. Apoptotic bodies can be found in these cells on fluorescence stain. Conclusion Bak gene could inhibit the growth

Expression of X-linked Inhibitor of Apoptosis Protein and Its Effect on Chemotherapeutic Sensitivity of Bladder Carcinoma

The expression of X-linked inhibitor of apoptosis protein (XIAP) gene and its effect on chemotherapeutic sensitivity in bladder carcinoma was explored. By using immunohistochemistry, the expression of XIAP was detected in 47 bladder carcinomas and 5 normal bladder tissues. The XIAP gene was transfected into bladder cancer cell line T24 by liposome and the positive clone was screened by G418. Cellular XIAP mRNA level was detected by RT-PCR. Low-dose mitocycin C was administered to induce the apoptosis of T24 cells. The in vitro growth of bladder carcinoma cells was analyzed by MTT colorimetry, and the apoptosis rate was assayed by TUNEL methods. It was found XIAP was moderately expressed in bladder carcinomas with the the positive rate being 78.73% (37/47), but the positive rate was not correlated with carcinoma stages and grades (P<0.05). XIAP mRNA level in transfected T24 cells was significantly increased by 3.8 times as compared with that in the cells not transfected with XIAP. After treatment with low-dose mitomycin C (0.005 and 0.05 mg/mL), the growth rate in XIAP no-transfected control group was increased by (11.60±0.25)% and (16.51±0.87)% (P<0.05), and the apoptosis rate was decreased by (10.1±0.2)% and (11.9±0.2%) (P<0.05) respectively as compared with XIAP transfected group. It was concluded that XIAP was expressed in most of bladder carcimoma samples. Overexpression of XIAP in T24 could significantly reduce the MMC-induced apoptosis of bladder carcinoma, suggesting its effect on the chemothera- peutic sensitivity of T24 cells.

Recombinant adeno-associated virus delivered human thioredoxin-PR39 prevents hypoxia-induced apoptosis of ECV304 cells

Human thioredoxin and antibacterial peptide, PR39, have been shown to have potent antioxidant effects that may prolong survival of cells during hypoxia. The pSSCMV/human thioredoxin-PR39 vector was successfully constructed in this study and used to infect ECV304 cells. Transfected ECV304 cells were incubated at 1%, 5% hypoxic, and normal oxygen conditions. We found that the number of apoptotic cells after transfection with recombinant adeno-associated virus-human thioredoxin -PR39 was significantly lower than controls, suggesting a protective effect of the recombinant human thioredoxin-PR39 protein on hypoxic cells.

EFFECTS OF ANTI-PML/RARα OR ANTI-PML ANTISENCE ON THE GROWTH, DIFFERENTIATION AND APOPTOSISOF NB4 CELL LINES

Objectire To investigate the ellects of anti - PML/RARx or anti - PML antisence on the growth,dtherentiation and apoptosis of NB4 cell lines. Methods Wright’s stain for cell morphology, flow cytometry andDNA gel electronphoresis for cell apoptosis, methylcellulose assays for leukemic colony forming unit andtrypan - blue exclusion for cell counts. Results Both the start cordon region of the PML or PML - RARx mRNA(STAS) and the fusion point region of the long type PML - RARx mRNA (FUAS) could inhibit cell growth. Cellsbecame partially differentiated at 5d of treatment, and FUAS - treated cells showed more significant differentiationthan STAS- treated cells. Morphology of typical apoptosis could be seen at 7, 9d incubation with antisenceoligodeoxynucleotides (AS). In contrast, no cell growth inhibition, no morphology changes were seen in Sen or Rantreated cells compared with untreated cells. The number of acute myelocytic leukemia colony forming unit(AML - CFU) markedly decreased in STAS and FUAS treated cells. Cell DNA content analyzed by flow cytometryshowed the typical profile of apoptotic cells, in which pre - G1 peak appear before G1 peak at 7,9d of treatment withSTAS or FUAS. Conclusion Anti - PML/RARx or anti- PML antisence inhibit the cell growth, inducedifferentiation and differentiated cell apoptosis of NB4 cells.

Effect of adenovirus-mediated p27 gene expression on the proliferation and apoptosis of HL-60 and Raji cell lines

Background p27 is an essential mediator of cell cycle control,which plays a key negative role in the proliferation and tumorigenesis of certain cell types. Here, we designed this study to explore the possible effects of p27 on the proliferation and apoptosis of HL-60 and Raji cell lines.Methods HL-60 and Raji cells were transfected with p27 via an adenovirus-mediated approach. The efficiency of Adp27 infection and the expression of p27 mRNA and protein were evaluated by X-gal staining, RT-PCR, and flow cytometry. The proliferation and apoptosis of HL-60 and Raji cells were estimated by means of trypan blue staining, MTT assay, Annexin V/PI, and DNA ladder electrophoresis. Results The infection efficiencies in HL-60 and Raji cells were 40.3% and 32.0%, respectively. RT-PCR and flow cytometry showed that there was significant expression of p27 mRNA and protein in HL-60 and Raji cells infected with Adp27; on the other hand, uninfected HL-60 cells showed faint traces of p27 mRNA and protein and Raji cells showed nearly no signs of p27 mRNA and protein. As demonstrated by a cell growth curve and by an MTT assay, strong time-dependent proliferation inhibition was apparent in HL-60 and Raji cells infected by Adp27. After 72 hours of infection, the Annexin V+/PI- apoptotic cell rates in HL-60 and Raji cell lines were 46.9% and 35.7%, respectively, significantly higher than in the control groups (4.7% and 5.6%, respectively). Typical DNA ladder bands were detectable in HL-60 and Raji cells after 48 hours of Adp27 infection. Conclusions Adenoviral vector-mediated p27 gene transfection of HL-60 and Raji cells leads to the inhibition of cellular proliferation and the promotion of cell apoptosis. This technique may provide an approach to gene therapy for leukemia or lymphoma.

MicroRNA-219 alleviates glutamate-induced neurotoxicity in cultured hippocampal neurons by targeting calmodulin-dependent protein kinase Ⅱ gamma

Septic encephalopathy is a frequent complication of sepsis,but there are few studies examining the role of micro RNAs（mi Rs） in its pathogenesis.In this study,a mi R-219 mimic was transfected into rat hippocampal neurons to model mi R-219 overexpression.A protective effect of mi R-219 was observed for glutamate-induced neurotoxicity of rat hippocampal neurons,and an underlying mechanism involving calmodulin-dependent protein kinase II γ（Ca MKIIγ） was demonstrated.mi R-219 and Ca MKIIγ m RNA expression induced by glutamate in hippocampal neurons was determined by quantitative real-time reverse transcription-polymerase chain reaction（q RT-PCR）.After neurons were transfected with mi R-219 mimic,effects on cell viability and apoptosis were measured by 3-（4,5-dimethylthiazolyl-2）-2,5-diphenyltetrazolium bromide（MTT） assay and flow cytometry.In addition,a luciferase reporter gene system was used to confirm Ca MKIIγ as a target gene of mi R-219.Western blot assay and rescue experiments were also utilized to detect Ca MKIIγ expression and further verify that mi R-219 in hippocampal neurons exerted its effect through regulation of Ca MKIIγ.MTT assay and q RT-PCR results revealed obvious decreases in cell viability and mi R-219 expression after glutamate stimulation,while Ca MKIIγ m RNA expression was increased.MTT,flow cytometry,and caspase-3 activity assays showed that mi R-219 overexpression could elevate glutamate-induced cell viability,and reduce cell apoptosis and caspase-3 activity.Moreover,luciferase Ca MKIIγ-reporter activity was remarkably decreased by co-transfection with mi R-219 mimic,and the results of a rescue experiment showed that Ca MKIIγ overexpression could reverse the biological effects of mi R-219.Collectively,these findings verify that mi R-219 expression was decreased in glutamate-induced neurons,Ca MKIIγ was a target gene of mi R-219,and mi R-219 alleviated glutamate-induced neuronal excitotoxicity by negatively controlling Ca MKIIγ expression.

Study on Intervenient Effect of Angelica Sinensis Polysaccharide on Immunological Liver Injury and Its Mechanism in Mice

Objective: To study the changes of expressions of nitric oxide synthase (NOS) of the constitutive type (cNOS) and inducible type (iNOS), the apoptosis related genes bax and bcl 2, as well as the tumor necrosis factor (TNF α) in immunological liver injury (ILI) and to explore the preventive effects of Angelica sinensis polysaccharide (ASP) on ILI and its mechanism in mice.Methods: ILI model mice induced by intraperitoneal injection of lipo polysaccharide (LPS) and BCG vaccine were treated with ASP of different doses (30mg/kg, 60mg/kg) by gastrogavage every day for 7 days. The serum alanine transaminase (ALT) and glutathione S transferase (GST) activities and NO content in the liver were detected; the expressions of cNOS, iNOS, bcl 2, bax were assessed with immuno histochemical method, and the TNF α mRNA expression in the liver was observed by reverse transcriptase polymerase chain reaction (RT PCR).Results: Compared with the normal mice , the NO production and ALT, GST levels were raised significantly in the model mice, the TNF α mRNA expression was also raised significantly. But no obvious changes of cNOS was found. Small dose ASP (30mg/kg) could reduce NO production and ALT, GST levels in model mice by 19.5%, 23.7% and 40.0% respectively, decrease the expression of iNOS and bax by 48.3%, and 26.4%, and increase the expression of cNOS, bcl 2 by 66.9% and 337.3%, respectively, but it could not reduce the TNF α mRNA expression in the liver. Large dose of ASP (60mg/kg) was not more effective than that of small dose.Conclusion: Changes of NO production and TNF α mRNA may play an important role in ILI. The mechanism of ASP in intervening ILI may be through modulation on cNOS, iNOS, bax, bcl 2 expression to block the damage of BCG vaccine and LPS on hepatocytes.