Histone deacetylase inhibitors (HDACi) are novel clinical anticancer drugs that inhibit HDAC gene expression and induce cell apoptosis in human cancers. Nevertheless, the detailed mechanism or the downstream HDAC targets by which HDACi mediates apoptosis in human breast cancer cells remains unclear. Here, we show that HDACi reduce tumorigenesis and induce intrinsic apoptosis of human breast cancer cells through the microRNA miR-125a-5p in vivo and in vitro. Intrinsic apoptosis was activated by the caspase 9/3 signaling pathway. In addition, HDACi mediated the expression of miR-125a-5p by activating RUNX3/p300/HDAC5 complex. Subsequently, miR-125a-5p silenced HDAC5 post-transcriptionally in the cells treated with HDACi. Thus, a regulatory loop may exist in human breast cancer cells involving miR-125a-5p and HDAC5 that is controlled by RUNX3 signaling. Silencing of miR-125a-5p and RUNX3 inhibited cancer progression and activated apoptosis, but silencing of HDAC5 had a converse effect. In conclusion, we demonstrate a possible new mechanism by which HDACi influence tumorigenesis and apoptosis via downregulation of miR-125a-5p expression. This study provides clinical implications in cancer chemotherapy using HDACi.
Ghrelin is a newly discovered gastric peptide which stimulates food intake, energy balance, and growth hormone release. Recent reports have also shown that circulating ghrelin can efficiently reach the brain. However, the molecular mechanisms and pathophysiologic roles underlying ghrelin-induced glioma migration remain unclear. Glioma is the most common primary adult brain tumor with poor prognosis because of the spreading of tumor cell to the other regions of brain easily. In present study, we found that application of recombinant human ghrelin enhances the glioma cell migration in both rat C6 and human U251 cells. Ghrelin and its receptor GHS-R (growth hormone secretagogue receptor) are expressed in a wide variety of tissues and cell types, including various cancer cells. However, little is known about the expression of ghrelin or GHS-R in brain tumors. Here, we found that ghrelin increased GHS-R receptor up-regulation, and the enhancement of ghrelin-induced glioma cell motility markedly inhibited by a GHS-R antagonist. In addition, ghrelin-mediated migration was attenuated by treatment of CaMKII inhibitor, and AMPK inhibitors and pre-transfection with AMPK siRNA. Moreover, ghrelin stimulation also increased the phosphorylation of CaMKII and AMPK. Treatment with three different types of NF-κB inhibitors or pre-transfection with KM-IKKα, or KM-IKKβ also reduced ghrelin-induced glioma cell migration. Moreover, treatment of ghrelin also induced IKKα/β activation, IκBα phosphorylation, p65 phosphorylation at Ser(536), and increased NF-κB-DNA binding activity and κB-transcriptional activity. These results indicate that ghrelin enhances migration of glioma cells is mainly regulated by the GHS-R, CaMKII, AMPK, and NF-κB pathway.
Recent evidence indicating that phthalates promote cancer development, including cell proliferation, migration, and invasion, has raised public health concerns. Here, we show that bis(2-ethylhexyl) phthalate promotes the migration, invasion, and epithelial-mesenchymal transition of hepatocellular carcinoma cells. In addition, bis(2-ethylhexyl) phthalate increased the proportion of cancer stem cell (CSC)-like cells and stemness maintenance in vitro as well as tumor growth and metastasis in vivo. The various activities of curcumin, including anticancer, anti-inflammation, antioxidation, and immunomodulation, have been investigated extensively. Curcumin suppressed phthalate-induced cell migration, invasion, and epithelial-mesenchymal transition, decreased the proportion of CSC-like cells in hepatocellular carcinoma cell lines in vitro, and inhibited tumor growth and metastasis in vivo. We also reveal that curcumin suppressed phthalate-induced migration, invasion, and CSC-like cell maintenance through inhibition of the aryl hydrocarbon receptor/ERK/SK1/S1P3 signaling pathway. Our results suggest that curcumin may be a potential antidote for phthalate-induced cancer progression.
The objective of this research was to improve the solubility of chitosan by Maillard reaction with 1% chitosan and 2% reducing sugar (glucose or glucosamine) dissolved in 0.2 M acetic acid, which was adjusted to pH 6.0, and incubated at either 50°C or 70°C for 1-7 days. The physicochemical and rheological properties of the chitosan-saccharide derivatives were also investigated. Results indicated that the solubility of modified chitosan derivatives was significantly greater than that of native chitosan. The solubility of chitosan-glucosamine was higher than that of chitosan-glucose, and the chitosan-glucosamine derivative remained soluble at pH 10. The degree of deacetylation of the derivatives decreased with increasing reaction time. Rheological investigation revealed that the apparent viscosity of the water-soluble chitosan derivatives in aqueous solution depended upon system conditions such as pH, ionic strength, and solution temperature. The measured apparent viscosity decreased as all system conditions increased. As calculated by the Arrhenius equation, the activation energy (E a ) of the derivatives in aqueous solution generally decreased with increasing the extent of Maillard reaction with respect to the reducing sugars used.
BackgroundThe widespread use of phthalates as plasticizers has raised public health concerns regarding their adverse effects, including an association with cancer. Although animal investigations have suggested an association between phthalate exposure and hepatocellular carcinoma, the mechanisms are unknown.MethodsThe hepatocellular carcinoma cell line Huh7 was treated with benzyl butyl phthalate (BBP), and then analyzed by total internal reflection fluorescence microscopy, confocal microscopy and double immunogold transmission electron microscopy. Following BBP treatment, mRNA levels were measured by RT-PCR, protein levels were measured using western blot, and vascular endothelial growth factor levels were measured by an enzyme-linked immunosorbent assay. Cell migration and invasion assays were evaluated by transwell, and angiogenesis were performed by a tube formation assay. Nude mice were used to investigate metastasis and angiogenesis in vivo.ResultsBBP affected hepatocellular carcinoma progression through the aryl hydrocarbon receptor (AhR) and that benzyl butyl phthalate (BBP) stimulated AhR at the cell surface, which then interacted with G proteins and triggered a downstream signaling cascade. BBP activated AhR through a nongenomic action involving G-protein signaling rather than the classical genomic AhR action. BBP treatment promoted cell migration and invasion in vitro and metastasis in vivo via the AhR/Gβ/PI3K/Akt/NF-κB pathway. In addition, BBP induced both in vitro and in vivo angiogenesis through the AhR/ERK/VEGF pathway.ConclusionsThese findings suggest a novel nongenomic AhR mechanism involving G-protein signaling induced by phthalates, which contributes to tumor progression of hepatocellular carcinoma.Electronic supplementary materialThe online version of this article (doi:10.1186/1471-2407-14-556) contains supplementary material, which is available to authorized users.
BackgroundStem cell therapy is a potential strategy to treat patients with Parkinson’s disease (PD); however, several practical limitations remain. As such, finding the appropriate stem cell remains the primary issue in regenerative medicine today. We isolated a pre-placental pluripotent stem cell from the chorionic villi of women with early tubal ectopic pregnancies. Our objectives in this study were (i) to identify the characteristics of hTS cells as a potential cell source for therapy; and (ii) to test if hTS cells can be used as a potential therapeutic strategy for PD.Methods and FindingshTS cells expressed gene markers of both the trophectoderm (TE) and the inner cell mass (ICM). hTS cells exhibited genetic and biological characteristics similar to that of hES cells, yet genetically distinct from placenta-derived mesenchymal stem cells. All-trans retinoic acid (RA) efficiently induced hTS cells into trophoblast neural stem cells (tNSCs) in 1-day. Overexpression of transcription factor Nanog was possibly achieved through a RA-induced non-genomic c-Src/Stat3/Nanog signaling pathway mediated by the subcellular c-Src mRNA localization for the maintenance of pluripotency in tNSCs. tNSC transplantation into the lesioned striatum of acute and chronic PD rats not only improved behavioral deficits but also regenerated dopaminergic neurons in the nigrostriatal pathway, evidenced by immunofluorescent and immunohistological analyses at 18-weeks. Furthermore, tNSCs showed immunological advantages for the application in regenerative medicine.ConclusionsWe successfully isolated and characterized the unique ectopic pregnancy-derived hTS cells. hTS cells are pluripotent stem cells that can be efficiently induced to tNSCs with positive results in PD rat models. Our data suggest that the hTS cell is a dynamic stem cell platform that is potentially suitable for use in disease models, drug discovery, and cell therapy such as PD.
Glioblastoma multiforme (GBM) is the most common and lethal type of primary brain tumor characterized by its rapid infiltration to surrounding tissues during the early stages. The fast spreading of GBM obscures the initiation of the tumor mass making the treatment outcome undesirable. Endothelin-1 is known as a secretory protein presented in various types of brain cells, which has been indicated as a factor for cancer pathology. The aim of the present study was to investigate the molecular mechanism of cell migration in GBM. We found that various malignant glioma cells expressed higher amounts of endothelin-1, ETA, and ETB receptors than nonmalignant human astrocytes. The application of endothelin-1 enhanced the migratory activity in human U251 glioma cells corresponding to increased expression of matrix metalloproteinase (MMP)-9 and MMP-13. The endothelin-1-induced cell migration was attenuated by MMP-9 and MMP-13 inhibitors and inhibitors of mitogen-activated protein (MAP) kinase and PI3 kinase/Akt. Furthermore, the elevated levels of phosphate c-Jun accumulation in the nucleus and activator protein-1 (AP-1)-DNA binding activity were also found in endothelin-1 treated glioma cells. In migration-prone sublines, cells with greater migration ability showed higher endothelin-1, ETB receptor, and MMP expressions. These results indicate that endothelin-1 activates MAP kinase and AP-1 signaling, resulting in enhanced MMP-9 and MMP-13 expressions and cell migration in GBM.
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