Fabrication of Ag-doped ZnO/PAN composite nanofibers by electrospinning: Photocatalytic and antiviral activities.

Ag-doped ZnO nanoparticles (AZNs) were directly synthesized using sol-gel method to embed into polyacrylonitrile (PAN) nanofibers by electrospinning. The synthesized AZNs were optically and structurally characterized by UV-VIS spectroscopy, photoluminescence spectroscopy, high resolution HR-TEM and XRD. The photocatalytic activity of the AZNs was examined by photocatalytic degradation of methylene blue to correlate with their antiviral efficacy in PAN nanofibers fabricated via electrospinning technique. The PAN nanofibers containing AZNs were characterized using SEM and EDS. Finally, antiviral activity of AZNs/PAN nanofibers was investigated by using virus ϕx174 under visible light irradiation. As a result, the antiviral efficacy of nanofibers increased as the concentration of Ag in AZNs increased. The results show that better antiviral efficacy was obtained in AZNs/PAN nanofibers prepared with AZNs of higher photocatalytic performance.

Potential contrasting effects of platelets on the migration and invasion of sarcomas versus carcinomas.

The ability of platelets to promote carcinoma and melanoma progression has been thoroughly studied and occurs in numerous ways. In contrast, the effect of platelets on sarcomas, tumors arising from mesenchymal cells, has received very little attention. This study was undertaken to simultaneously compare the effects of platelets on murine and human sarcomas and carcinomas. In contrast to their effect on carcinomas, platelets inhibited the invasion of some murine- and all human sarcomas tested in vitro. Further invasion studies with TGFß treatment only partially recapitulated the results seen with whole platelets. In a spontaneous tumor growth and lung metastasis model, platelets promoted 4T1 mammary carcinoma metastasis but not MCA-1 fibrosarcoma metastasis. Gene expression analysis of the platelet-promoted MDA-MB-231 breast carcinoma, and the platelet-inhibited HT1080 fibrosarcoma cell lines revealed that exposure of MDA-MB-231 to platelets, resulted in upregulation of oncogenes and EMT-associated genes whereas in HT1080 a tumor-suppressor gene was significantly upregulated. Thus, this study has revealed a potential diametrically opposing effect of platelets on mesenchymal and epithelial cancers, a finding that warrants further investigation.

Fabrication of biodegradable cellulose acetate nanofibers containing Rose Bengal dye by electrospinning technique and their antiviral efficacy under visible light irradiation.

Biodegradable cellulose acetate (CA) nanofibers containing Rose Bengal (RB) dye were fabricated by electrospinning technique. RB dye, an anionic photosensitizer, has been used in photodynamic therapy due to its excellent biocompatibility and ability to absorb light to generate reactive oxygen species (ROS), but has a decisive disadvantage of water solubility on infection prevention. Firstly, water-insoluble RB dye was synthesized through complexation with cationic ionic liquid (IL) for antiviral agents. The synthesized water-insoluble RB dyes were embedded into biodegradable CA nanofibers by electrospinning. The electrospun nanofibers passed both antiviral test for φx174 virus under visible light irradiation and biodegradability-test using enzymes. The fabricated RB nanofibers absorbed light and generated ROS to inactivate the virus. As a result, the log reduction (-Log10(N/N0)) of φx174 titer under visible light reached a detection limit of 5.00 within 30 min. Also, the fabricated nanofibers were degraded up to 34 wt % in 9 weeks by lipase and cellulase enzymes compared with non-biodegradable nanofibers.

A Rapid and Accurate Bioluminescence-Based Migration Assay Permitting Analysis of Tumor Cell/Stromal Cell Interactions.

Bioluminescent tumor cell lines are used extensively in vivo to monitor tumor growth and metastasis but rarely used in vitro to follow tumor cell behavior. Tumor cell migration is frequently studied in vitro using transwell assays, however, current methods do not permit the co-incubation of tumor cells with different stromal cell types for analysis of the effects of intercellular cross-talk on tumor cell migration. We describe a novel migration assay using bioluminescent tumor cell lines that is rapid, accurate, and permits the study of the effects of tumor cell-stromal cell interactions on tumor cell migratory behavior.

Differential effects of tetrahydropyridinol derivatives on ß-catenin signaling and invasion in human hepatocellular and breast carcinoma cells.

In continuation of previous efforts to investigate the biological potency of tetrahydropyridinol derivatives, the present study synthesized three target compounds: N-(bromoacetyl)-3-carboxyethyl-2,6-diphenyl-4-O-(pentafluorobenzoyl)-Δ3-tetra-hydropyridine (5a), N-(chloroacetyl)-3-carboxyethyl-2,6-diphenyl-4-O-(pentafluorobenzoyl)-Δ3-tetrahydropyridine (5b) and N-(2-bromopropanoyl)-3-carboxyethyl-2,6-diphenyl-4-O-(pentafluorobenzoyl)-Δ3-tetrahydropyridine (5c), and examined their anticancer potency. Experiments were performed using the Sk-Hep1 and Hep3B human hepatocellular carcinoma cell lines and MDA-MB-231 breast adenocarcinoma cell line. Among the three compounds, 5a and 5b were comparably and significantly cytotoxic to the Sk-Hep1, Hep3B and MDA-MB-231 cells. The highest level of cytotoxicity was detected in theSk-Hep1 cells with half maximal inhibitory concentrations for compounds 5a and 5b at 12 and 6 µM, respectively. These two compounds induced cell cycle arrest in the Sk-Hep1 and MDA-MB-231 cells through the downregulation of ß-catenin and upregulation of glycogen synthase kinase-3ß and E-cadherin. By contrast, 5a and 5b induced G1 arrest in the Hep3B cells by modulating the p21 and p27 cell cycle regulatory molecules and cyclin-dependent kinase 2. In addition, 5a and 5b significantly inhibited the invasion of Sk-Hep1 and MDA-MB-231 cells. These results suggested that the 5a and 5b compounds induce cell cycle arrest by suppressing Wnt/ß-catenin signaling in highly invasive Sk-Hep1 and MDA-MB-231 cells, and by inducing p53 independent cell cycle arrest in Hep3B cells.

Induction of the endoplasmic reticulum stress and autophagy in human lung carcinoma A549 cells by anacardic acid.

Anacardic acid (AA, 2-hydroxy-6-pentadecylbenzoic acid), a constituent of the cashew-nut shell, has a variety of beneficial effects on the treatment of cancer and tumors. However, the fact that AA induces ER stress and autophagy in cancer cell is not known. We investigated the effect of AA on ER-stress and autophagy-induced cell death in cancer cells. Because of our interest in lung cancer, we used the non-small cell lung adenocarcinoma A549 cells treated with 3.0 µg/ml of AA for this research. In this research we found that AA induces intracellular Ca(2+) mobilization and ER stress. AA induced the ER stress-inducing factors, especially IRE1α, and the hallmarks of UPR, Grp78/Bip and GADD153/CHOP. AA inhibited the expression of p-PERK and its downstream substrate, p-elF2α. We also demonstrated that AA induces autophagy. Up-regulation of autophagy-related genes and the appearance of autophagosome in transfected cells with green fluorescent protein (GFP)-LC3 and GFP-Beclin1 plasmids showed the induction of autophagy in AA-treated A549 cells. The morphological analysis of intracellular organelles by TEM also showed the evidence that AA induces ER stress and autophagy. For the first time, our research showed that AA induces ER stress and autophagy in cancer cells.

Dieckol, isolated from Ecklonia stolonifera, induces apoptosis in human hepatocellular carcinoma Hep3B cells.

Phlorotannins have been reported to demonstrate several biological properties, including antioxidant activity, and activities useful in the treatment of diabetic complications and in chemoprevention of several vascular diseases. In this study, we focused on the apoptosis induced by dieckol, a marine algal phlorotannin isolated from Ecklonia stolonifera, on human hepatocellular carcinoma (HCC) Hep3B cells. Dieckol reduced the numbers of viable cells and increased the numbers of apoptotic cells in a dose-dependent manner. Immunoblotting analysis revealed that dieckol increased the expression levels of cleaved caspases-3, 7, 8, and 9, and cleaved poly(ADP-ribose) polymerase. Dieckol increased the permeability of mitochondrial membranes and the release of cytochrome c from mitochondria into the cytosol with apoptosis-inducing factor. In addition, dieckol induced increased expression of truncated Bid and Bim. The results indicate that dieckol induces apoptosis via the activation of both death receptor and mitochondrial-dependent pathways in HCC Hep3B cells.

Neferine isolated from Nelumbo nucifera enhances anti-cancer activities in Hep3B cells: molecular mechanisms of cell cycle arrest, ER stress induced apoptosis and anti-angiogenic response.

Hepatocellular carcinoma (HCC) is one of the most aggressive malignant diseases and is highly resistant to conventional chemotherapy. Neferine, a major bisbenzylisoquinoline alkaloid derived from the embryos of Nelumbo nucifera, has been reported a few physiological activities. However, the mechanisms of anticancer effects are not well understood and its detailed activities on Hep3B cells have not been determined. Our results suggest that neferine exhibited cytotoxicity against HCC Hep3B cells, but not against HCC Sk-Hep1 and THLE-3, a normal human liver cell line. In addition, consistent with the induction of G1/S phase cell population in flow cytometry, downregulation of c-Myc, cyclin D1, D3, CDK4, E2F-1, as well as dephosphorlyation of cdc2 by western blot analysis, as evidenced by the appearance of cell cycle arrest, were observed in Hep3B cells treated with neferine. Our results demonstrated neferine induced ER stress and apoptosis, acting through multiple signaling cascades by the activation of Bim, Bid, Bax, Bak, Puma, caspases-3, -6, -7, -8 and PARP, and the protein expression levels of Bip, calnexin, PDI, calpain-2 and caspase-12 were also upregulated dramatically by neferine treatment. Overexpression of GFP-LC3B by neferine resulted in a diffuse cytosolic GFP fluorescence and the strong fluorescent spots, representing autophagosomes. The significant reduction of the migration in Hep3B cells and the capillary tube-like formation of HUVECs by neferine were also determined. These observations reveal that the therapeutic potential of neferine in treating HCC Hep3B cells, containing copies of hepatitis B virus (HBV) genomes.

Prospective impact of 5-FU in the induction of endoplasmic reticulum stress, modulation of GRP78 expression and autophagy in Sk-Hep1 cells.

Hepatocellular carcinoma (HCC) is one of the most aggressive malignant diseases and is highly resistant to conventional chemotherapy. Therefore, HCC requires more effective prevention and treatment strategies. 5-fluorouracil (5-FU) remains the most widely used chemotherapeutic drug for the treatment of gastrointestinal, breast, head and neck, and ovarian cancers. In pursuit of a novel effective strategy, we have evaluated the potential of 5-FU to promote endoplasmic reticulum (ER) stress and autophagy in Sk-Hep1 HCC cells. We found that 5-FU profoundly induces ER stress in Sk-Hep1 cells and upregulates p53 and activates CHOP/GADD153 and caspase-12. Activation of CHOP/GADD153 and caspase-12 promotes mitochondrial cell death in Sk-Hep1 cells followed by ER stress. Changes in calcium homeostasis and the protein folding machinery cause stress in the ER, leading to apoptotic cell death. Stress in the ER activates autophagy to remove the misfolded protein aggregates and recover from the stress environment. Our study demonstrates that 5-FU-induced ER stress suppresses autophagy and also downregulates GRP78 expression. Activation of autophagy followed by ER stress facilitates the cell survival response. Therefore, the inhibition of protective autophagy may provide a useful pharmacological target. Taken together, these results indicate that 5-FU-induced ER stress activates the mitochondrial apoptotic cell death pathway by downregulating GRP78 and protective autophagy proteins in Sk-Hep1 cells, raising the possibility of using 5-FU as a therapeutic agent to target human HCC.