Search

Anfibatide (ANF) is a GPIb antagonist derived from the protein complex agglucetin. Previous studies have showed that it has protective effect on cerebral ischemia/reperfusion injury, the mechanism of which is still unclear, however. The present study was designed to investigate the protective effect of ANF on cerebral I/R injury in rats and the possible mechanisms. Focal cerebral ischemia was induced by 90 min of transient middle cerebral artery occlusion (MCAO). ANF (1, 2, 4 μg/kg) was achieved by intravenous injection after 120 min of MCAO followed by 1 h, 24 h ,48 h and 72 h reperfusion. Neurological deficit, infarct volume, histopathology, neuronal apoptosis, NeuN and the expression of TLR4, total and phosphorylated c-Jun NH 2 -terminal kinase (JNK/p-JNK), Bcl-2, Bax, caspase-3, NF-κB protein in rat brain, the levels of IL-1β, IL-6 and TNF-α in serum were evaluated 72 h after reperfusion. ANF could significantly decrease neurological score, reduce the infarct volumes, ameliorate the histopathological alteration, attenuate the neuronal apoptosis and increase the fluorescence density of NeuN in the rat brain. Furthermore, ANF could obviously decrease the expression of TLR4, p-JNK, caspase-3, NF-κB , relative ratio of Bax/Bcl-2 in brain and the levels of IL-1β, IL-6 and TNF-α in serum. The results indicate that ANF has protective effect against cerebral I/R injury in rats and the underlying mechanism may be associated with the suppression of apoptosis through inhibiting TLR4/JNK/caspase-3 signaling pathway. [ABSTRACT FROM AUTHOR]

Background: and Aims The MUC13 transmembrane mucin is highly and constitutively expressed in the small and large intestine. Although MUC13 polymorphisms have been associated with human inflammatory bowel diseases and susceptibility to Escherichia coli infection in pigs, the biological functions of MUC13 are unknown. This study aimed to explore whether MUC13 modulates intestinal inflammation. Methods: Muc13-/- mice were generated, phenotyped and challenged with the colitis-inducing agent, dextran sodium sulphate (DSS). Colitis was assessed by clinical symptoms and intestinal histopathology. Intestinal epithelial cell apoptosis and proliferation, macrophage infiltration and cytokine production were also quantified. Apoptosis of human LS513 intestinal epithelial cells in response to apoptotic agents, including DSS, was also measured, following knockdown of MUC13 with siRNA. Results: Muc13-/- mice were viable, fertile and developed normally, with no spontaneous intestinal pathology except mild focal neutrophilic inflammation in the small and large intestines of old mice. In response to DSS challenge, Muc13-/- mice developed more severe acute colitis, as reflected by increased weight loss, rectal bleeding, diarrhoea and histological colitis scores compared with wild-type mice. Increased numbers of F4/80+ macrophages in inflamed mucosa of Muc13-/- mice were accompanied by increased expression of intestinal IL-1b and TNFa mRNA. Muc13-/- mice had significantly increased intestinal epithelial cell apoptosis within 3 days of DSS exposure. LS513 cells were more susceptible to DSS, actinomycin-D, ultraviolet irradiation and TRAIL-induced apoptosis when MUC13 was knocked down by siRNA. Conclusions These novel findings indicate a protective role for Muc13 in the colonic epithelium by inhibiting toxin-induced apoptosis and have important implications for intestinal infections, inflammatory diseases and the development of intestinal cancer. INSET: Significance of this study. [ABSTRACT FROM AUTHOR]

In this paper, 17 compounds (1–17) were isolated from the leaves of Hemp (Cannabis sativa f. sativa). Among the isolates, two were determined to be new spirans: cannabispirketal (1), andα-cannabispiranol 4’-O-β-D-glucopyranose (2) by 1D and 2D NMR spectroscopy, LC-MS, and HRESIMS. The known compounds7,8,10,13,15, and16were isolated from Hemp (C. sativa f. sativa) for the first time. Furthermore, compounds8and13were isolated from the nature for the first time. All isolated compounds were evaluated for cytotoxicity on different tissue-derived passage cancer cell lines through cell viability and apoptosis assay. Among these compounds, compounds5,9and16exhibited a broad-spectrum antitumor effect via inhibiting cell proliferation and promoting apoptosis. These results obtained have provided valuable clues to the understanding of the cytotoxic profile for these isolated compounds from Hemp (C. sativa f. sativa). [ABSTRACT FROM PUBLISHER]

The aim of the present study was to investigate the effect of solanine on promoting human hepatocellular carcinoma HepG2 cells to produce reactive oxygen species (ROS), and the molecular mechanisms leading to tumor cell apoptosis. Solanine was administered to HepG2 cells in vitro. A selection of probes targeting various cellular localizations of ROS were used to detect ROS expression using flow cytometry. The expression levels of apoptosis-associated proteins, including apoptosis signal-regulating kinase 1 (ASK1) and thioredoxin binding protein 2 (TBP-2), and proliferation-associated proteins, including histone deacetylase 1 (HDAC1), were detected using western blotting. The percentage of cells undergoing apoptosis was measured using an Annexin V-fluorescein isothiocyanate/propidium iodide assay, and cell morphology was examined using Wright's stain followed by inverted microscopy analysis. ROS detection probes 2',7'-dichlorofluorescin diacetate and dihydrorhodamine 123 identified that abundant ROS, including hydroxyl radical (OH-) and hydrogen peroxide (H2O2), were produced in the cytoplasm and mitochondria of the solanine-treated HepG2 cells compared with the control cells (P<0.05). Superoxide anion specific probes dihydroethidium and MitoSOXTM demonstrated that there were no significant alterations in the HepG2 cells following solanine treatment compared with the control cells (P>0.05). Western blotting results revealed that solanine upregulated the expression levels of ASK1 and TBP-2 and enhanced their kinase activities, whereas solanine decreased the expression level of the proliferation-associated protein, HDAC1. The cell apoptotic rate was significantly increased (P<0.0001) in the solanine-treated HepG2 cells compared with the control cells. (P<0.05). Overall, the study indicated that solanine induces HepG2 cells to produce ROS, mainly OH- and H2O2, in a mitochondria-dependent and - independent manner. In addition, solanine stimulates the expression of ASK1 and TBP-2, and their kinase activities, but inhibits the expression of proliferation-associated proteins, such as HDAC1, thus contributing to HepG2 cell apoptosis. [ABSTRACT FROM AUTHOR]

Abstract: Inducing apoptosis is a promising therapeutic approach to overcome cancer. Here we described that a novel synthesized compound, 3-amino-N-(4-chlorobenzyl)-6-(3-methoxyphenyl)thieno[2,3-b]pyridine-2-carboxamide (SKLB703), exhibits antitumor activity via inducing apoptosis both in vitro and in vivo. Our results showed that SKLB703 inhibited the proliferation of a panel of human cancer cell lines, and human hepatocellular carcinoma cell line HepG2 was the most sensitive. The proliferation inhibitory effect of SKLB703 was associated with its apoptosis-inducing effect by activating caspase-3 and caspase-9 rather than caspase 8. Exposure of HepG2 to SKLB703 also resulted in Bax upregulation, Bcl-2 downregulation, cytochrome c release and mitochondrial transmembrane potential change in mitochondrial apoptotic pathway. Moreover, the decrease of phosphorylated p 44/42 mitogen-activated protein kinase and phosphorylated Akt was observed. SKLB703 suppressed the growth of established tumors in xenograft models in mice, whereas no toxicity was exhibited. TUNAL analysis showed that SKLB703 induced HepG2 tumor apoptosis. Taken together, the present study demonstrates that SKLB730 exhibits its antitumor activity through inducing apoptosis via mitochondrial apoptotic pathway. Its potential to be a candidate of anticancer agent is worth being further investigated. [Copyright &y& Elsevier]

In a cell-based screen of novel anticancer agents, the hit compound 1a which bears a pyrazolo[3,4-d]pyrimidine scaffold exhibited high inhibitory activity against a panel of four different types of tumor cell lines. In particular, the IC50 for A549 cells was 2.24 μM, compared with an IC50 of 9.20 μM for doxorubicin, the positive control. Four synthetic routes of the key intermediate 3 of 1a were explored and 1a was prepared via route D on the gram scale for further research. Two analogs of 1a were synthesized and their preliminary structure-activity relationships were studied. Flow cytometric analysis revealed that compound 1a could significantly induce apoptosis in A549 cells in vitro at low micromolar concentrations. These results suggest that the target compound 1a and its analogs with the pyrazolo[3,4-d]pyrimidine scaffold might potentially constitute a novel class of anticancer agents, which requires further studies. [ABSTRACT FROM AUTHOR]

FAK (focal adhesion kinase), which plays a pivotal role in mediating cell proliferation, survival and migration, is frequently overexpressed in human malignant glioma. The expression of FAK increases with the advance of tumour grade and stage. Based on these observations, we hypothesized that attenuation of FAK expression may have inhibitory effects on the growth of malignant glioma. In the present study, human glioma cell line U251 was transfected with plasmids containing U6 promoter-driven shRNAs (small-hairpin RNAs) against human FAK using cationic liposome. The effects of FAK knockdown in U251 cells in vitro were analysed by using flow cytometry and PI (propidium iodide)-staining assays. Based on the encouraging in vitro results with FAK silencing, plasmids encoding FAK-targeted shRNA were encapsulated by DOTAP (dioleoyltrimethylammonium propane): Chol (cholesterol) cationic liposome and injected via tail vein to evaluate its therapeutic efficiency on suppressing tumour growth in a human glioma xenograft model. PCNA (proliferating-cell nuclear antigen), CD34 immunostaining and TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling) assay were used to assess the changes in tumour angiogenesis, apoptosis and proliferation respectively. The results indicated that DOTAP:Chol cationic liposome could deliver therapeutic plasmids systemically to tumour xenografts, resulting in suppression of tumour growth. Treatment with plasmid encoding FAK-targeted shRNA reduced mean tumour volume by approx. 70% compared with control groups ( P<0.05), accompanied with angiogenesis inhibition ( P<0.05), tumour cell proliferation suppression ( P<0.05) and apoptosis induction ( P<0.05). Taken together, our results demonstrated that shRNA-mediated silencing of FAK might be a potential therapeutic approach against human malignant glioma. [ABSTRACT FROM AUTHOR]

Abstract: A series of novel benzothiazole-2-thiol derivatives were synthesized, and their anti-proliferative activities on HepG2 and MCF-7 cells were investigated. Most compounds had inhibitory effects on cell growth, and some of them were more effective than cisplatin. Compounds 6m and 6t displayed good inhibitory activities against a panel of different types of human cancer cell lines, with IC50 values in the low micromolar range. Further biological evaluation indicated that 6m induced apoptosis in HepG2 cancer cells. Structure–activity relationships were also proposed. [Copyright &y& Elsevier]

Abstract: Novel thienopyridine derivatives 1b–1r were synthesized, based on a hit compound 1a that was found in a previous cell-based screening of anticancer drugs. Compounds 1a–1r have the following features: (1) their anticancer activity in vitro was first reported by our group. (2) The most potent analog 1g possesses hepatocellular carcinoma (HCC)-specific anticancer activity. It can specifically inhibit the proliferation of the human hepatoma HepG2 cells with an IC50 value of 0.016μM (compared with doxorubicin as a positive control, whose IC50 was 0.37μM). It is inactive toward a panel of five different types of human cancer cell lines. (3) Compound 1g remarkably induces G0/G1 arrest and apoptosis in HepG2 cells in vitro at low micromolar concentrations. These results, especially the HCC-specific anticancer activity of 1g, suggest their potential in targeted chemotherapy for HCC. [ABSTRACT FROM AUTHOR]

Chloroquine is an antimalarial drug that has been used in the treatment and prophylaxis of malaria since the 1950s. The present study was undertaken to examine the effects of chloroquine on Bcap-37 human breast cancer cells’ growth, cell cycle modulation, apoptosis induction, and associated molecular alterations in vitro. The chloroquine treatment decreased the viability of Bcap-37 cells in a concentration- and time-dependent manner, which correlated with G2/M phase cell cycle arrest. The chloroquine-mediated cell cycle arrest was associated with a decrease in protein levels/activity of polo-like kinase 1 (Plk1), phosphorylated cell division cycle 25C (Cdc25C), phosphorylated extracellular signal-regulated kinase 1/2 (ERK1/2), phosphorylated Akt. The chloroquine-treated Bcap-37 cells exhibited a marked decrease in the level of mitochondrial transmembrane potential (ΔΨm), which was accompanied by the activation of caspase-3 and cleaved poly(ADP-ribose) polymerase (PARP). Exposure of Bcap-37 cells to chloroquine also resulted in the induction of spindle abnormalities. In conclusion, the findings in this study suggested that chloroquine might have potential anticancer efficacy, which could be attributed, in part, to its proliferation inhibition and apoptosis induction of cancer cells through modulation of apoptosis and cell cycle-related proteins expressions, down-regulation of mitochondrial transmembrane potential (ΔΨm), and induction of spindle abnormalities. Copyright © 2008 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]