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Structural modification of a compound discovered during screening using an HRE-dependent reporter assay has revealed a novel class of HIF-1 inhibitors, which potently inhibit the HIF-1 protein accumulation and its target gene expression under hypoxic conditions in human hepatocellular carcinoma Hep3B cells. [ABSTRACT FROM AUTHOR]

In the course of our program to search for antithrombotic and anti-inflammatory agents from plants, twelve phenolics (1-12) were isolated from the stems of Parthenocissus tricuspidata. Their structures were elucidated on the basis of spectroscopic (1D and 2D NMR, and MS) data analyses, and comparison with published data. At the concentration of 100 µg/mL, compounds 2, 4, 6 and 10 possessed potential effects on anti-blood coagulation, with inhibitory percentage of 216, 174, 148 and 225%, respectively; while aspirin used as positive control showed 181% inhibition at the same concentration. Furthermore, the anti-inflammatory activity of isolated compounds (1-12) was investigated on lipopolysaccharide (LPS)-induced murine macrophage cells (RAW264.7). Compounds 2, 4 and 6 also potential inhibited the production of nitric oxide, with IC50 values of 11.9 ± 0.3, 2.9 ± 0.2 and 29.0 ± 0.6 µM, respectively. Celastrol, the positive control used, gave an IC50 value of 1.0 ± 0.1 µM. [ABSTRACT FROM AUTHOR]

The integrin-linked kinase (ILK)-PINCH1-αw-parvin (IPP) complex functions as a signaling platform for integrins that modulates various cellular processes. ILK functions as a central adaptor for the assembly of 11W complex. We report here that mda-9/syntenin, a positive regulator of cancer metastasis, regulates the activation of Akt (also known as protein kinase B) by facilitating ILK adaptor function during adhesion to type Icollagen (COL-I) in human breast cancer cells. COL-I stimulation induced the phosphorylation arid plasma membrane translocation of Akt. Inhibition of mda-9/syntenin or expression of mutant ILK (E359K) significantly blocked the translocation of both ILK and Akt to the plasma membrane. mda-9/syntenin associated with ILK, and this association was increased at the plasma membrane by COL-I stimulation. Knockdown of mda9/syntenin impaired COL-I-induced association of ILK with Akt and plasma membrane targeting of ILK-Akt complex. These results demonstrated that mda-9/syntenin regulates the activation of Akt by controlling the plasma membrane targeting of Akt via a mechanism that facilitates the association of Akt with ILK at the plasma membrane during adhesion to COL-I. On a striking note, inhibition of mda-9/syntenin impaired COL-I-induced plasma membrane translocation of the IPP complex and assembly of integrin βl-IPP signaling complexes. Thus, our study defines the role of mda-9/syntenin in ILK adaptor function and describes a new mechanism of mda-9/syntenin for regulation of cell migration. [ABSTRACT FROM AUTHOR]

Caesalpinia sappan (C. sappan) is a medicinal plant used for promoting blood circulation and removing stasis. During a screening procedure on medicinal plants, the ethylacetate extract of the lignum of C. sappan (CLE) showed inhibitory activity on arginase which has recently been reported as a novel therapeutic target for the treatment of cardiovascular diseases such as atherosclerosis. CLE inhibited arginase II activity prepared from kidney lysate in a dose-dependent manner. In HUVECs, inhibition of arginase activity by CLE reciprocally increased NOx production through enhancement of eNOS dimer stability without any significant changes in the protein levels of eNOS and arginase II expression. Furthermore, CLE-dependent arginase inhibition resulted in increase of NO generation and decrease of superoxide production on endothelium of isolated mice aorta. These results indicate that CLE augments NO production on endothelium through inhibition of arginase activity, and may imply their usefulness for the treatment of cardiovascular diseases associated with endothelial dysfunction. [ABSTRACT FROM AUTHOR]

The epithelial-mesenchymal transition (EMT) is a hallmark of cancer metastasis, and the associated molecular signaling pathways are regarded as therapeutic targets for cancer treatment. Thus, suppressing EMT with a natural chemical compound may be of therapeutic benefit. Eupatolide is a natural chemical compound extracted from the medicinal plant Inula britannica, which is used in Eastern Asia to treat bronchitis, disorders of the digestive system and inflammation. Besides the anti-inflammatory function of eupatolide, the present study found that eupatolide suppressed the migration and invasion of breast cancer cells, which was associated with the downregulation of vimentin in MDA-MB-231 cells and the upregulation of E-cadherin in MCF-7 cells. Treatment with eupatolide also significantly inhibited the migration and invasion of breast cancer cells that had been stimulated with transforming growth factor-β1 (TGF-β1). Eupatolide also suppressed TGF-β1-induced EMT via downregulation of mothers against decapentaplegic homolog 3 (SMAD3) phosphorylation and transcriptional repression of TGF-β receptor 1 (ALK5). In addition to this canonical pathway, the non-canonical protein kinase B (AKT) and extracellular signal-regulated kinase (ERK) pathways were also inhibited by eupatolide treatment. In summary, the results suggest that eupatolide suppresses the migration and invasion of breast cancer cells by blocking the canonical ALK5-SMAD3 signaling pathway and the non-canonical ERK and AKT signaling pathways. [ABSTRACT FROM AUTHOR]

Metastasis is the primary cause of cancer-associated mortality. The ternary IPP complex of integrin-linked kinase, PINCH and parvin functions as a signaling platform for integrins, which modulate numerous cellular processes including cell migration and invasion. Chelidonine, isolated from Chelidonium majus, is a benzophenanthridine alkaloid that exhibits anticancer properties; however, the anti-migratory and anti-invasive effects of chelidonine remain unknown. The aim of the present study was to investigate the inhibitory effects of chelidonine on migration and invasion of MDA-MB-231 human breast cancer cells, and to determine the underlying mechanisms. Chelidonine was shown to inhibit the migration and invasion of MDA-MB-231 cells in a concentration-dependent manner, without affecting the cell viability. Chelidonine did not significantly inhibit the adhesion of the cells to type 1 collagen (COL-I), however it did affect cell spreading and reorganization of the actin cytoskeleton. Chelidonine also inhibited COL-I-induced protein kinase B (Akt) activation and translocation to the plasma membrane, however, it did not significantly inhibit the activation of focal adhesion kinase. Notably, chelidonine treatment significantly inhibited COL-I-induced formation of the IPP complex and activation of IPP downstream signaling molecules, such as extracellular signal-regulated kinase (ERK)1/2. These results suggest that chelidonine exhibits anti-migratory and anti-invasive effects in MDA-MB-231 cells, by suppressing COL-I-induced integrin signaling, through inhibiting the formation of the IPP complex and subsequent down-regulation of IPP downstream signaling molecules, such as Akt and ERK1/2. These results suggest that chelidonine may be a potential therapeutic agent against metastasis of invasive human cancer cells. [ABSTRACT FROM AUTHOR]

Presents a study that examined the overexpression of syntenin protein in metastatic human breast and gastric cancer cell lines. List of human breast cancer cell lines; Causes of human cancer deaths; Methods for comparing patterns of gene expression; Components of syntenin.

This article presents a study on the inactivation of the carbamoyltransferase gene which refines post-polyketide synthase modification steps in the biosynthesis of the antitumor agent, geldanarnycin. Geldanamycin and its closely related analogues, herbimycin B and macbecin, are naturally occurring antitumor antibiotics. Geldanamycin binds to the N-terminal ATP binding site of heat-shock protein (Hsp) 90, inhibiting its chaperone activity. Because Hsp90 client proteins are important in signal transduction and transcription, geldanamycin and its derivatives have the potential of serving as chemotherapeutic agents in a number of diseases.

Macrophage inhibitory cytokine-1 (MIC-1) is a member of the transforming growth factor-β superfamily, which is overexpressed in a variety of human cancers, including breast and gastric cancer. The function of MIC-1 in cancer remains controversial and its signaling pathways remain poorly understood. In this study, we demonstrate that MIC-1 induces the transactivation of ErbB2 in SK-BR-3 breast and SNU-216 gastric cancer cells. MIC-1 induced a significant phosphorylation of Akt and ERK-1/2, and also effected an increase in the levels of tyrosine phosphorylation of ErbB1, ErbB2 and ErbB3 in SK-BR-3 and SNU-216 cells. The treatment of these cells with AG825 and AG1478, inhibitors specific for ErbB2 tyrosine kinase, resulted in the complete abolition of MIC-1-induced Akt and ERK-1/2 phosphorylation. Furthermore, the small-interfering RNA-mediated downregulation of ErbB2 significantly reduced not only the phosphorylation of Akt and ERK-1/2 but also the invasiveness of the cells induced by MIC-1. Our results show that ErbB2 activation performs a crucial function in MIC-1-induced signaling pathways. Further investigations revealed that MIC-1 induced the expression of the hypoxia inducible factor-1α protein and the expression of its target genes, including vascular endothelial growth factor, via the activation of the mammalian target of rapamycin (mTOR) signaling pathway. Stimulation of SK-BR-3 with MIC-1 profoundly induces the phosphorylation of mTOR and its downstream substrates, including p70S6K and 4E-BP1. Collectively, these results show that MIC-1 may participate in the malignant progression of certain human cancer cells that overexpress ErbB2 through the transactivation of ErbB2 tyrosine kinase. [ABSTRACT FROM AUTHOR]