Effects of DL111-IT or combined with RU486 on uterine polyamines biosynthesis in rats during early gestation

Effects of ODC on polyamine metabolism, hormone levels, cell proliferation and apoptosis in goose ovarian granulosa cells

Ornithine decarboxylase (ODC) plays an indispensable role in the process of polyamine biosynthesis. Polyamines are a pivotal part of living cells and have diverse roles in the regulation of cell proliferation and apoptosis, aging and reproduction. However, to date, there have been no reports about ODC regulating follicular development in goose ovaries. Here, we constructed ODC siRNA and overexpression plasmids and transfected them into goose primary granulosa cells (GCs) to elucidate the effects of ODC interference and overexpression on the polyamine metabolism, hormone levels, cell apoptosis and proliferation of granulosa cells. After interfering with ODC in GCs, the mRNA and protein levels of ODC and the content of putrescine were greatly decreased (P < 0.05). When ODC was overexpressed, ODC mRNA and protein levels and putrescine content were greatly increased (P < 0.05). The polyamine-metabolizing enzyme genes ornithine decarboxylase antizyme 1 (OAZ1) and spermidine / spermine-N1-acetyltransferase (SSAT) were significantly increased, and spermidine synthase (SPDS) was significantly decreased when ODC was downregulated (P < 0.05). OAZ1, SPDS and SSAT were significantly increased when ODC was upregulated (P < 0.05). In addition, after interference with ODC, progesterone (P4) levels in the culture medium of GCs increased greatly (P < 0.05), while the overexpression of ODC caused the P4 level to decrease significantly (P < 0.05). After ODC downregulation, granulosa cell activity was significantly reduced, the apoptosis rate was significantly increased, and the BCL-2 / BAX ratio was downregulated (P < 0.05). Under ODC overexpression, the activity of GCs was notably increased, the apoptosis rate was significantly reduced, and the BCL-2 / BAX protein ratio was upregulated (P < 0.05). Our study successfully induced ODC interference and overexpression in goose ovarian GCs, and ODC regulated mainly putrescine content in GCs with a slight influence on spermidine and spermine. Moreover, ODC participated in the adjustment of P4 levels in the culture medium of GCs, promoted granulosa cell proliferation and inhibited granulosa cell apoptosis.

Antiproliferative activity of contragestazol (DL111-IT) in murine and human tumor models in vitro and in vivo

PURPOSES

To evaluate the antiproliferative activity of contragestazol (DL111-IT) in vitro and in vivo and to elucidate potential molecular mechanisms.

METHODS

Cell killing ability of DL111-IT was measured by MTT/Trypan blue exclusion method and murine and human tumor models; cell cycle was analyzed by flow cytometry; pRb, CDK4 and Cyclin D1 expressions were detected by western blotting.

RESULTS

DL111-IT exhibited high efficiency on cell growth inhibition of 12 cancer cell lines, the IC50 values were 4.1-19.7 microg/ml. In Sarcoma-180 (S180) and Hepatoma-22 (H22) tumor bearing mice models, the inhibition rates were 55.9 and 55.6%, respectively, at the doses of DL111-IT 12.5-50.0 mg/kg for 9 days consecutive administration. Human ovarian carcinoma (HO-8910) xenograft study showed that, nine administrations (within 15 days) of DL111-IT (12.5-50.0 mg/kg) significantly inhibited tumor growth with the inhibition rates ranging from 17.0 to 64.3%. DL111-IT induced G1 arrest and overexpression of pRb, CDK4 and Cyclin D1 were observed in HO-8910 cell line, suggesting that cell cycle regulation might contribute to the anticancer property of DL111-IT.

CONCLUSIONS

DL111-IT could inhibit the proliferation of cancer cells both in vitro and in vivo via a cell cycle regulation pathway.

Synergistic effects of DL111-IT in combination with mifepristone and misoprostol on termination of early pregnancy in preclinical studies

This study evaluated the effectiveness and acute toxicity of DL111-IT combined with mifepristone (RU486) and misoprostol (MISO) on early pregnancy termination. In the pregnant rats experiments, the ED(50) values of RU486 in two-drug combinations were 0.16 (combined with DL111-IT) and 0.40 (combined with MISO) mg x kg(-1) x d(-1), while in three-drug combination treatment group (DL111-IT 9.0 mg x kg(-1) (<ED(5)) + MISO 0.30 mg x kg(-1) + RU486 0.012-0.5 mg x kg(-1) x d(-1)), the ED(50) of RU486 was decreased to 0.07 (0.04-0.10) mg x kg(-1) x d(-1). In guinea pigs, significant enhancement of early pregnancy termination was only observed in three-drug combination treatment with MISO 0.10 mg x kg(-1) + RU486 0.05 mg x kg(-1) (<minimum effective doses) + high dosages of DL111-IT (0.05-0.10 mg x kg(-1)). DL111-IT induced pregnant rat uterine contraction in vitro, and the contractive efficacy was 60% of that induced by MISO. Multiple intramuscular injections of DL111-IT in vivo could significantly enhance the MISO-stimulated uterine contractions of pregnant rats in vitro. DL111-IT 600 mg x kg(-1) or RU486 1000 mg x kg(-1) induced pigeon vomiting, with latent periods of 32.3 +/- 12.0 min and 50.4 +/- 16.0 min, respectively. In three-drug combination group, the latent period of vomiting was significantly extended to 86.3 +/- 36.2 min. MISO also significantly decreased the frequency of vomiting within 4 h after administration of DL111-IT and RU486. In the experiment of mice acute toxicity, the LD(50) values and 95% confidence limit of DL111-IT (i.p.) alone and in combination with RU486 and MISO were 1379.4 (1278.2-1514.7) mg x kg(-1) and 1574.1 (1407.8-1762.7) mg x kg(-1), respectively. There was no significant difference. All data suggested that DL111-IT in combination with RU486 and MISO significantly increased the effect on early pregnancy termination without increasing acute toxicity compared to the treatment of DL111-IT alone, and this combination may be a promising regimen for early pregnancy termination.

Analysis of polyamines as markers of (patho)physiological conditions

The aliphatic polyamines, putrescine, spermidine and spermine, are normal cell constituents that play important roles in cell proliferation and differentiation. The equilibrium between cellular uptake and release and the balanced activities of biosynthetic and catabolic enzymes of polyamines are essential for normal homeostasis in the proliferation and functions of cells and tissues. However, the intracellular polyamine content increases in hyperplastic or neoplastic growth. Although the involvement of polyamines in physiological and pathological cell proliferation and differentiation has been well established, the role they play is quite different in relation to cell systems and animal models and is dependent on inducer agents and stimuli. Also, the experimental procedures used to deplete polyamines have been shown to influence the cell responses. In this paper, the assay methods currently in use for polyamines are reviewed and compared with respect to sensitivity, reproducibility and applicability to routine analysis. The relevance of polyamine metabolism and the uptake/release process in many physiological and pathological processes is highlighted, and the cellular polyamine pathways are discussed in relation to the possible diagnostic and therapeutic significance of these mediators.