siRNA-mediated antizyme inhibitor down-regulates the expression of ornithine decarboxylase of prostate cancer cell PC3 / 基础医学与临床

Objective To evaluate whether down-regulating antizyme inhibitor(AZIN) can regulate the expression of ornithine decarboxylase(ODC) and the proliferation of prostate cancer cell PC3 or not.Methods siRNA-AZIN transfected prostate cancer cell PC3,the level of antizyme(AZ),AZIN and ODC were measured by RT-PCR and westernblot. MTT was used to measure the proliferation of cells. Results The mRNA level of AZIN declined(P<0.01);the protein level of AZIN and ODC declined(P<0.05). Knockdown of AZIN significantly inhibited the proliferation of PC3(P<0.05). Conclusions Transfecting siRNA-AZIN can decrease the level of AZIN, then the decline level of ODC inhibits the proliferation of PC3.

Characterization of OAZ1 and its potential functions in goose follicular development

Background: Ornithine decarboxylase antizyme 1 (OAZ1) is an important regulator of polyamine synthesis and uptake. Our previous studies indicated that high OAZ1 expression in the ovaries of laying geese is responsible for poor egg production. In the present study, the molecular characterization of goose OAZ1 gene was analyzed, as well as the expression profile in various follicular tissues. Results: An 873-bp cDNA sequence of the OAZ1 gene (Accession No. KC845302) with a +1 frameshift site (+175T) was obtained. The sequence consisted of a 652-bp two overlapping open reading frames (a putative protein with 216 amino acids). The OAZ domain, OAZ signature and OAZ super family domain were prominent conserved regions among species. As the follicle size increased, OAZ1 abundance showed an increasing trend during follicular development, while it decreased during follicular regression. The level of OAZ1 mRNA expression was the lowest in the fifth largest preovulatory follicle, and was 0.65-fold compared to the small white follicle (P b 0.05). OAZ1 mRNA expression in the largest preovulatory and postovulatory follicle was 2.11- and 2.49-fold compared to the small white follicle, respectively (P b 0.05). Conclusions: The goose OAZ1 structure confirms that OAZ1 plays an important role in ornithine decarboxylase-mediated regulation of polyamine homeostasis. Our findings provide an evidence for a potential function of OAZ1 in follicular development, ovulation and regression.

OAZI-1 enhances the immunogenicity of Melan-A vaccine in mice / 基础医学与临床

Objective To investigate whether ornithine decarboxylase antizyme inhibitor-1(OAZI-1) can enhance the immunogenicity of Melan-A and induce antitumor immune effect in the experimental animals.Methods The eukaryotic expression plasmid pcDNA3.1(-) /OAZI-1, pcDNA3.1 (-)/Melan-A and pcDNA3.1(-)/Melan-A-OAZI-1 were constructed and used to immunize BALB/c mice.The spleen lymphocytes were prepared from the immunized mice and then used to determine the lymphocyte subsets by flow cytometry assay and tumor-killing activity by LDH release assay.The blood samples were collected from the immunized mice and used to test the serum INF-γ by ELISA.Results The eukaryotic expression plasmid pcDNA3.1(-)/OAZI-1, pcDNA3.1(-)/Melan-A and pcDNA3.1(-)/Melan-A-OAZI-1 were successfully constructed.All three gene vaccines could increaseCD4+ T cell ratio (P<0.05), among of them, the ratio in the pcDNA3.1(-)/Melan-A-OAZI-1 and pcDNA3.1(-)/Melan-A immunized groups increased more significantly than other groups but no obvious differences was observed between these two groups.Similarly, all three gene vaccines could also increased CD8+T cells ratio significantly (P<0.05), but, comparing with all other groups, the highest increase was observed in the pcDNA3.1(-)/Melan-A-OAZI-1 immune group (P<0.05).The pcDNA3.1(-)/Melan-A-OAZI-1 gene vaccines significantly increased cytotoxic activity of the spleen lymphocyte in the immune mice(P<0.05).Among the three gene vaccines only pcDNA3.1(-)/Melan-A-OAZI-1 could significantly increased the INF-γ level in the mice serum (P<0.05).Conclusions OAZI-1 can improve antitumor immunity by promoting tumor antigen presentation.

Studies on OAZI-1 protein complex in inducing specific antitumor effects in mice / 中国免疫学杂志

Objective:To analyze whether the OAZI-1 (ornithine decarboxylase antizyme inhibitor-1) protein complex isolated from tumor cells could induce specific antitumor effects in the experiment mice .Methods:OAZI-1 protein complexes were isolated from B16-F1 melanoma cells by immune magnetic beads coated with OAZI-1 antibody and used as the vaccine to immune the C 57BL/6 mice.After immunization,the mice were inoculated subcutaneously with live B 16-F1 cells and then tumor formation and growth were ob-served.ELISA was used to determine the level of cytokine IFN-γin the serum of immunized mice.Lactate dehydrogenase assay (LDH) was performed to evaluate killing effect of spleen lymphocytes on B 16-F1 cells.The mice immunized by purified OAZI-1 from prokaryotic expression and PBS were used as controls in the animal experiment .Results: Compared with the control mice ,the spleen lymphocytes ( effector cells ) from the mice inoculated with OAZI-1 protein complexes had stronger killing ability on B 16-F1 cells (target cells).At three different effector:target ratio (10:1,50:1,100:1),the killing ability of these spleen lymphocytes were 46.2%, 59.5%and 92.5% respectively,which was significantly higher than the spleen lymphocytes from the mice inoculated with purified AZIN-1 protein (36.1%,26.8% and 45.9%) or inoculated with PBS (24.6%,24.0% and 27.2%).In addition,the content of serum anti-tumor cytokine IFN-γwas also significantly higher in the mice inoculated with OAZI-1 protein complexes (538.3 pg/ml) than the mice inoculated with purified AZIN-1 ( 256.2 pg/ml ) or with PBS ( 131.0 pg/ml ) .When B16-F1 live cells were subcutaneously inoculated into the immunized mice described above ,the tumor formation rate was only 40%in the mice immunized with OAZI-1 protein complex ,but 100%in the mice immunized with PBS or purified OAZI-1.The growth of inoculated tumors in the mice immunized with OAZI-1 protein complex was also much slower than the control mice .Conclusion:The results in this study suggest that the OAZI-1 protein complex isolated from B 16-F1 tumor cells could contain some tumor antigens .When used as tumor vaccine to inoculate mice ,this complex can induce anti-tumor immune killing activity in experimental animals .

Control of ornithine decarboxylase activity in jute seeds by antizyme.

The control of ornithine decarboxylase activity by antizyme was studied during early germination of jute seeds (Corchorus olitorius). When 2 mM of putrescine and spermidine were applied to the germinating medium, the enzyme activity was markedly inhibited (1.7-fold) during 16 h imbibition. This inhibition could be attributed to the formation of an inhibitory protein termed antizyme. The antizyme was partially purified from jute and barley seedlings. The activity of jute ornithine decarboxylase antizyme was weaker than that of barley.

Modulation of ovarian ornithine decarboxylase activity during follicular differentiation/maturation.

The role of gonadotropins and estrogen on the regulation of ovarian ornithine decarboxylase was studied during follicular differentiation/maturation. In intact immature rats follicular differentiation/maturation was initiated with sequential administration of estrogen and follicle stimulating hormone. Ornithine decarboxylase activity in response to human chorionic gonadotropin was markedly enhanced (2-fold) in rats with preovulatory antral follicles when compared to rats with non-ovulatory follicles. This increase could be attributed to the alteration in the turnover of the enzyme. Following follicle maturation the half life of the human chorionic gonadotropin stimulated ornithine decarboxylase was increased from 18 to 62 min. This increase in half life was associated with differentition of follicles. In the estrogen treated group (which does not induce follicular differentiation), the half life of the enzyme remained unaltered. The regulation of ornithine decarboxylase through the formation of protein inhibitor antizyme induced by diamino hexane, was unaltered during follicular differentiation.

Analysis of the expression of ornithine decarboxylase antizyme inhibitor in mouse tissues / 重庆医科大学学报

Objective:Analysis of the expression of Ornithine decarboxylase antizyme inhibitor in mouse tissues.Methods:RT-PCR,Northern blot,immunostaining.Results:RT-PCR,Northern blot reveal that the expression of Ornithine decarboxylase antizyme inhibitor gene(AZI) is ubiquitous,especially high in brain,heart,kidney,muscle,thymus and testis.Immunostaining reveals that AZI expresses on valve cells in heart,mesenchyme cells in kidney and liver.Conclusion:The expression of AZI in mouse tissues was identified by using RT-PCR,Northern blot and immunostaining.