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Hydroxyurea (HU) is an FDA-approved drug used to treat a variety of diseases, especially malignancies, but is harmful to fertility. We used porcine oocytes as an experimental model to study the effect of HU during oocyte maturation. Exposure of cumulus-oocyte complexes (COCs) to 20 µM (P<0.01) and 50 µM (P<0.001) HU reduced oocyte maturation. Exposure to 20 µM HU induced approximately 1.5- and 2-fold increases in Caspase-3 (P<0.001) and P53 (P<0.01) gene expression levels in cumulus cells, respectively, increased Caspase-3 (P<0.01) and P53 (P<0.001) protein expression levels in metaphase II (MII) oocytes and increased the percentage of apoptotic cumulus cells (P<0.001). In addition, HU decreased the mitochondrial membrane potential (Δφm) (P<0.01 and P<0.001) and glutathione (GSH) levels (P<0.01 and P<0.001) of both cumulus cells and MII oocytes, while increasing their reactive oxygen species (ROS) levels (P<0.001). Following parthenogenetic activation of embryos derived from MII oocytes, exposure to 20 µMHU significantly reduced total blastocyst cell numbers (P<0.001) and increased apoptosis of blastocyst cells (P<0.001). Moreover, HU exposure reduced the rate of development of two-celled, four- to eight-celled, blastocyst, and hatching stages after parthenogenetic activation (P<0.05). Our findings indicate that exposure to 20 µM HU caused significant oxidative stress and apoptosis of MII oocytes during maturation, which affected their developmental ability. These results provide valuable information for safety assessments of HU. [ABSTRACT FROM AUTHOR]

Curcumin suppresses proliferation, migration, invasion, metastasis and angiogenesis and induces apoptosis by regulating multiple signalling pathways and miRNAs in a wide variety of human malignancies. miRNAs play crucial roles in various steps of carcinogenesis in nasopharyngeal carcinoma (NPC); thus, they could serve as critical therapeutic targets for NPC treatment. Curcumin could provide a novel strategy to block or induce specific miRNAs for miRNA-based gene therapies. Nevertheless, there are no reports to date on the miRNAs regulated by curcumin in NPC. In the present study, we have carried out an miRNA microarray to identify the miRNAs regulated by curcumin in NPC. Curcumin treatment down-regulated the expression of hsa-miR-125a-5p, hsa-miR-574-3p and hsa-miR-210 as determined by miRNA microarray analysis and qPCR (real-time quantitative reverse transcription-PCR). Forced expression of miR-125a-5p enhanced proliferation, migration and invasion of HONE1 cells. Primary NPC exhibited a significantly higher expression level of miR-125a-5p than healthy controls. miR-125a-5p inhibited the expression of tumour protein 53 (TP53), and curcumin treatment up-regulated the expression of TP53. Taken together, these results indicate that curcumin exerted inhibitory effects on NPC by inhibiting the expression of miR-125a-5p and, subsequently, enhancing the expression of TP53. Curcumin could provide a novel strategy to block miR-125a-5p for miRNA-based gene therapies in NPC. [ABSTRACT FROM AUTHOR]

Recently, acetylcholinesterase (AChE) has been studied as an important apoptosis regulator. We previously showed that cellular calcium mobilization upregulated AChE expression by modulating promoter activity and mRNA stability. In this study, we have identified a potential Smad3/4 binding element, TGCCAGACA, located within the −601 to −571 bp fragment of the AChE promoter, as an important calcium response motif. Smad2/3 and Smad4 were shown to bind this element. Overexpression of human Smad3 increased AChE transcription activity in a dose-dependent manner in HeLa cells, whereas dominant-negative Smad3 blocked this activation. Upon A23187 and thapsigargin treatment, nuclear Smad3 accumulation was observed, an effect that was blocked by the intracellular Ca2+ chelator BAPTA–AM. Calcium-induced AChE transcriptional activation was significantly blocked when the nuclear localization signal of Smad3 was destroyed. Taken together, our data suggest Smad3 can regulate AChE transcriptional activation following calcium-induced nuclear accumulation. [ABSTRACT FROM AUTHOR]

• Twenty- five coumarin-isoxazole derivatives were highly synthesized by [3+ 2] cycloaddition reaction. • The benzene ring of oximes (b4 - b5) was chlorinated to obtain imidoyl chlorides (c4-c5). • The structure of MC-16 was confirmed by X- ray. • MC-14 (IC50 = 12.85 μM/ L, SI= 11.23) exhibited selecteive cytotoxicity against HepG2 cell line. • Docking study between bioactive compounds and protein residue of tubulin (PDB ID: 6O5N) was performed. In here, a series of coumarin-isoxazole derivatives were synthesized, characterized by spectroscopy technologies and evaluated for their cytotoxicity against HepG2 cell lines. Meanwhile, eight bioactive compounds were also evaluated for their toxicity on normal Vero cell lines. MC-16 , a monoclinic crystal with P21/c space group, was further confirmed by X-ray and 2D-NMR. Results demonstrated that b5 was reacted with 7 equivalents NCS to given c5, and then MC-16 was obtained by the reaction of nitrile oxides derivatized from c5 with e1 , passing intermediate state TS1. Bioactive results indicated that eight compounds (MC-2, MC-4, MC-5, MC-9, MC-10, MC-14, MC-19 and MC-20) exhibited weak to strong cytotoxicity against HepG2 cell lines, and their toxicity to Vero cells was much lower than that of Cisplatin (IC 50 (HpeG2) = 8.44 μM/ L, IC 50 (Vero) = 28.63 μM/ L, SI= 3.39). Among them, MC-14 (IC 50 (HpeG2) = 12.85 μM/ L, IC 50 (Vero) = 144.32 μM/ L, SI= 11.23) owned the strongest anti- HepG2 activity and obviously induced apoptosis under 48 μM. Structure-relationship analysis displayed that substituent group R = Cl or Br was the key factors to enhance the anti-HepG2 activity. The docking results revealed that bioactive compounds can effectively interacted with protein (PDB ID: 6O5N). [Display omitted] [ABSTRACT FROM AUTHOR]

Background It has been demonstrated that platycodin D (PD) exhibits anti-cancer activities. This study aims to investigate the anti-proliferative effects of the combination of PD and doxorubicin (DOX) on human breast cancer cells (MCF-7 and MDA-MB-231 cells). Methods The anti-proliferative effects of different dosages of PD, DOX, and PD + DOX on MCF-7 and MDA-MB-231 cells were determined by the MTT assay. The 10 μM PD, 5 μM DOX, and 10 μM PD + 5 μM DOX induced-protein expression of apoptosis-related molecules on MCF-7 and MDA-MB-231 cells were detected by western blot. The 10 μM PD, 5 μM DOX and 10 μM PD + 5 μM DOX-induced mitochondrial membrane potential changes on MCF-7 and MDA-MB-231 cells were stained with JC-1 before visual determination. The intracellular accumulations of DOX, induced by 10 μM PD, 5 μM DOX and 10 μM PD + 5 μM DOX, were detected by flow cytometry. Results PD enhanced anti-cancer activities of DOX were observed in both MCF-7 and MDA-MB- 231 cell lines. Compared with mono treatment, the combined treatment increased the protein expression of cleaved poly (ADP-ribose) polymerase and decreased the mitochondrial membrane potential. The combined treatment with PD did not obviously increase the accumulation of DOX in MCF-7 cells (1.66 ± 0.13 in DOX-treated group, and 1.69 ± 0.06 in PD + DOX-treated group, P = 0.76), but it significantly increased the accumulation of DOX in MDA-MB-231 cells (1.76 ± 0.17 in DOX-treated group, 2.09 ± 0.02 in PD + DOX-treated group, P = 0.027). Conclusion The combined treatment of DOX and PD exhibited stronger anti-proliferative effects on MCF-7 and MDA-MB-231 cells than DOX and PD treatment did. [ABSTRACT FROM AUTHOR]

Background and aims: Aspirin is associated with a reduced risk of colorectal cancer (CRC), and it showed inhibited effects on interleukin 6 (IL-6)/signal transducer and activator of transcription 3 (STAT3) signaling pathway which is thought to play an important role in intestinal inflammation and the tumorigenesis of CRC. Methods: Mouse model for inflammation-related CRC was induced by a combined treatment with azoxymethane (AOM) and dextran sodium sulfate (DSS) in BALB/c mice. Effects of aspirin on tumor number and size and apoptosis of CRC cells were investigated. Key molecules of IL-6-STAT3 pathway, such as IL-6, sIL-6R, phosphorylated STAT3, and their downstream anti-apoptotic genes Bcl- 2 and Bcl- xl, were assessed by ELISA and Western blot. Results: Treatment with aspirin significantly promoted CRC cell apoptosis in AOM/DSS-induced CRC mice in vivo. The expression level of IL-6, which is an upstream molecule of STAT3 and capable of activating STAT3, was reduced in aspirin-treated mice. Furthermore, the phosphorylated form of STAT3 and the levels of STAT3's target gene products such as Bcl- xl and Bcl- 2, which are essential for cell growth and survival, were also decreased in aspirin-treated mice. Conclusions: Our data suggested that the protective mechanisms of aspirin in CRC may be associated with its effects on induction of CRC cell apoptosis and suppression of IL-6-STAT3 signaling pathway, which implied that aspirin has a potential therapeutic activity in CRC. [ABSTRACT FROM AUTHOR]

The aim of our study was to investigate the effect of Patrinia scabra Bunge polysaccharide (PSB-P2) on cervical cancer cell (U14)-bearing mice. The tumor weight of mice treated with PSB-P2 (40, 80 mg/kg b.w.) was significantly lower than that of the control group and serum lactate dehydrogenase (LDH) activity was decreased, while serum alkaline phosphatase (AKP) level was only changed slightly. Meanwhile, the number of apoptotic tumor cells was significantly increased in the mice by the treatment of PSB-P2 (40, 80 mg/kg b.w.). At the same time, cell cycle analysis showed the accumulation of tumor cells in the G0/G1 phase and a relative decrease in the S phase. On the other hand, using the reverse transcription-polymerase chain reaction (RT-PCR) assay, PSB-P2 (40, 80 mg/kg b.w.) showed the up-regulation of p53 and Bax, and significant inhibition of Bcl-2 in tumor tissues. It suggests a possible mechanism of the inhibitory effect of PSB-P2 on tumor growth. [ABSTRACT FROM AUTHOR]

Sphingosine 1-Phosphate (S1P) modulates various cellular functions such as apoptosis, cell differentiation, and migration. Although S1P is an abundant signaling molecule in the central nervous system, very little is known about its influence on neuronal functions. We found that S1P concentrations were selectively decreased in the cerebrospinal fluid of adult rats in an acute and an inflammatory pain model. Pharmacological inhibition of sphingosine kinases (SPHK) decreased basal pain thresholds and SphK2 knock-out mice, but not SphK1 knock-out mice, had a significant decrease in withdrawal latency. Intrathecal application of S1P or sphinganine 1-phosphate (dihydro-S1P) reduced the pain-related (nociceptive) behavior in the formalin assay. S1P and dihydro-S1P inhibited cyclic AMP (cAMP) synthesis, a key second messenger of spinal nociceptive processing, in spinal cord neurons. By combining fluorescence resonance energy transfer (FRET)-based cAMP measurements with Multi Epitope Ligand Cartography (MELC), we showed that S1P decreased cAMP synthesis in excitatory dorsal horn neurons. Accordingly, intrathecal application of dihydro-S1P abolished the cAMP-dependent phosphorylation of NMDA receptors in the outer laminae of the spinal cord. Taken together, the data show that S1P modulates spinal nociceptive processing through inhibition of neuronal cAMP synthesis. [ABSTRACT FROM AUTHOR]

It has been reported that increasingly microRNAs are associated with diseases. However, the patterns among the microRNA-disease associations remain largely unclear. In this study, in order to dissect the patterns of microRNA-disease associations, we performed a comprehensive analysis to the human microRNA-disease association data, which is manually collected from publications. We built a human microRNA associated disease network. Interestingly,microRNAs tend to show similar or different dysfunctional evidences for the similar or different disease clusters, respectively. A negative correlation between the tissue-specificity of a microRNA and the number of diseases it associated was uncovered. Furthermore, we observed an association between microRNA conservation and disease. Finally, we uncovered that microRNAs associated with the same disease tend to emerge as predefined microRNA groups. These findings can not only provide help in understanding the associations between microRNAs and human diseases but also suggest a new way to identify novel disease-associated microRNAs. [ABSTRACT FROM AUTHOR]

Structure-based strategy was employed to design flavonoid compounds to mimic the Bim BH3 peptide as a new class of inhibitors of the anti-apoptotic Bcl-2 proteins. The most potent compound, 4(BI-33), binds to Bcl-2 and Mcl-1 with Kivalues of 17 and 18 nM, respectively. Compound 4inhibits cell growth in the MDA-MB-231 breast cancer cell line with an IC50value of 110 nM and effectively induces apoptosis. [ABSTRACT FROM AUTHOR]

This article presents a structure-based design of potent non-peptide MDM2 oncoprotein inhibitors. It is believed that the p53 tumor suppressor plays a central role in controlling cell cycle progression and apoptosis, and is an attractive cancer therapeutic target because its tumor suppressor activity can be stimulated to eradicate tumor cells. A new approach to stimulation of the activity of p53 is through blocking its interaction with the MDM2 oncoprotein, an endogenous cellular inhibitor of p53, using non-peptide small-molecule MDM2 inhibitors.