Animals ; Humans ; Integrin alphaVbeta3 ; physiology ; Receptors, Virus ; physiology ; Signal Transduction ; Virus Diseases ; etiology

BACKGROUNDPeriostin originally designated osteoblast-specific factor 2 (OSF-2) is frequently found to be highly expressed in various types of human cancer cell lines in vitro and human cancer tissues in vivo. We proposed that periostin was a key factor during the process of proliferation and invasion in cancer cells. We investigated the effect of periostin on the function of human osteosarcoma cell line (U2OS), such as proliferation, apoptosis, invasion and the associated signal pathway.

METHODSA human PGCsi/U6 promoter-driven DNA template was adopted to induce short hairpin RNA (shRNA)-triggered RNA interference (RNAi) to block periostin gene expression in the cell line U2OS. U2OS cells were divided into three groups: cells transfected with phosphate buffered saline as control group (the U2OS group), cells transfected with pGCsi as negative control group (the NC group) and cells transfected with periostin/pGCsi as experimental group (the pGCsi-periostin group). Then, transfection efficiency of cell was observed under fluorescent microscope. The expressions of periostin and the related genes in cells were detected by reverse transcription polymerase chain reaction and Western Blotting. Cell viability was determined using the methyl-thiazolyl tetrazolium bromide (MTT) quantitative colorimetric assay. The invasion and migration capability of cells were tested by transwell plates with or without extracellular matrix gel. Furthermore, the changes of cell cycle and apoptosis were analyzed by flow cytometry.

RESULTSThe transfection efficiency of periostin/pGCsi to U2OS cells was about 70% - 80%. When compared with the NC group, the levels of mRNA and protein of periostin in the pGCsi-periostin group decreased by 82% (F = 564.71, P < 0.001) and 58% (F = 341.51, P < 0.001), respectively. Meantime, the earlier apoptosis value increased by 417% (F = 28.69, P < 0.001). The percentage of S phase pGCsi-periostin cells decreased by 21% (F = 47.00, P < 0.001), however, that of G0 - G1 phase cells increased by 12% (F = 14.50, P < 0.001). The capability of migration and invasion reduced by 41% (F = 17.79, P < 0.001) and 72% (F = 197.08, P < 0.001), respectively. The cell proliferation in the pGCsi-periostin group decreased by 59% and 72% at 48 and 120 hours after transfection, respectively. The mRNA expressions of transforming growth factor-β and vascular endothelial growth factor decreased by 17% (F = 73.99, P < 0.001) and 47% (F = 30.25, P < 0.001), respectively. A tendency of lower focal adhesion kinase (FAK) was shown in pGCsi-periostin cells but without any statistically significant difference. Otherwise the expression of p-FAK in those cells had markedly decreased by 21% (F = 16.81, P < 0.001).

CONCLUSIONSRNAi against periostin can effectively down-regulate periostin gene expression. Periostin increases the hyperplasia and invasion of cancer cells. Periostin might be involved in and served as a tumor promoter gene in the pathogenesis of osteosarcoma.

Apoptosis ; Bone Neoplasms ; etiology ; pathology ; Cell Adhesion Molecules ; antagonists & inhibitors ; genetics ; physiology ; Cell Cycle ; Cell Line, Tumor ; Cell Proliferation ; Focal Adhesion Protein-Tyrosine Kinases ; metabolism ; Humans ; Integrin alphaVbeta3 ; physiology ; Neoplasm Invasiveness ; Osteosarcoma ; etiology ; pathology ; Phosphorylation ; RNA Interference ; Transfection

Integrin alphavbeta3 plays a major role in various signaling pathways, cell apoptosis, and tumor angiogenesis. To examine the functions and roles of alphavbeta3 integrin, a stable CHO-677 cell line expressing the murine alphavbeta3 heterodimer (designated as "CHO-677-malphavbeta3" cells) was established using a highly efficient lentiviral-mediated gene transfer technique. Integrin subunits alphav and beta3 were detected at the gene and protein levels by polymerase chain reaction (PCR) and indirect immunofluorescent assay (IFA), respectively, in the CHO-677-malphavbeta3 cell line at the 20th passage, implying that these genes were successfully introduced into the CHO-677 cells and expressed stably. A plaque-forming assay, 50% tissue culture infective dose (TCID50), real-time quantitative reverse transcription-PCR, and IFA were used to detect the replication levels of Foot-and-mouth disease virus (FMDV) in the CHO-677-malphavbeta3 cell line. After infection with FMDV/O/ZK/93, the cell line showed a significant increase in viral RNA and protein compared with CHO-677 cells. These findings suggest that we successfully established a stable alphavbeta3-receptor-expressing cell line with increased susceptibility to FMDV. This cell line will be very useful for further investigation of alphavbeta3 integrin, and as a cell model for FMDV research.
Animals ; Animals, Suckling ; CHO Cells ; Cloning, Molecular ; Cricetulus ; DNA, Complementary/genetics/metabolism ; Disease Susceptibility/virology ; Foot-and-Mouth Disease/*genetics/virology ; Foot-and-Mouth Disease Virus/*physiology ; Integrin alphaVbeta3/*genetics/metabolism ; Mice

OBJECTIVETo explore the design and activity determination of small molecular inhibitors of integrin alphavbeta3 through structure-based virtual screening.

METHODSBased on the crystal structure of integrin ctv33 extracellular segment in complex with an ARG-GLY-ASP ligand, docking procedure against the receptor binding domain was performed on 3D database. Integrin alphavbeta3-mediated cell adhesion assay was performed to assess the adhesion-inhibiting ability of the candidate compounds. Cell migration assay and capillary-structure-like formation inhibition assay were used to estimate the effects of the compounds on integrin alphavbeta3. Analysis of molecular graphics was carried out to deduce a probable binding model of compound with integrin alphavbeta3.

RESULTSFrom the top 1000 compounds with the best DOCK energy score, 50 compounds were selected for biological assay based on chemical and drug-like diversity. Seven of 50 compounds showed notable inhibition activity on cell adhesion, and two with half-maximum inhibition concentration (IC50) values less than 100 mol/L. The compound with best activity (1-37) showed high inhibitory activity in cell migration assay and capillary-structure-like formation inhibition assay. Molecular graphics analysis indicated that metal ion-dependent adhesion site (MIDAS) might be involved in the compound 1-37-mediated inhibition of ligand binding with integrin alphavbeta3.

CONCLUSIONSThrough virtual screening combined with biological assay, a promising lead compound was discovered to inhibit integrin alphavbeta3, which embodies the rational drug design with computation aid and brings a new thought and approach to find novel inhibitors of integrin.

Cell Adhesion ; drug effects ; Cell Movement ; drug effects ; Cells, Cultured ; Endothelial Cells ; drug effects ; physiology ; High-Throughput Screening Assays ; Humans ; Integrin alphaVbeta3 ; antagonists & inhibitors ; chemistry ; Neovascularization, Physiologic ; drug effects ; Quantitative Structure-Activity Relationship ; Umbilical Veins ; cytology

We made fusion protein of fastatin and FIII 9-10, termed tetra-cell adhesion molecule (T-CAM) that can interact simultaneously with alphavbeta3 and alpha5beta1 integrins, both playing important roles in tumor angiogenesis. T-CAM can serve as a cell adhesion substrate mediating adhesion and migration of endothelial cells in alphavbeta3 and alpha5beta1 integrin-dependent manner. T-CAM showed pronounced anti-angiogenic activities such as inhibition of endothelial cell tube formation, endothelial cell proliferation, and induction of endothelial cell apoptosis. T-CAM also inhibited angiogenesis and tumor growth in mouse xenograft model. The anti-angiogenic and anti-tumoral activity of molecule like fastatin could be improved by fusing it with integrin-recognizing cell adhesion domain from other distinct proteins. The strategy of combining two distinct anti-angiogenic molecules or cell adhesion domains could facilitate designing improved anticancer agent of therapeutic value.
Angiogenesis Inhibitors/chemistry/*pharmacology ; Animals ; Antineoplastic Agents/chemistry/*pharmacology ; Base Sequence ; Benzocaine/chemistry/*pharmacology ; Cell Line, Tumor ; Cell Movement ; Cell Proliferation ; Cells, Cultured ; Chloramphenicol/chemistry/*pharmacology ; DNA Primers ; Drug Combinations ; Factor VIII/chemistry/*pharmacology ; Humans ; Integrin alpha5beta1/*physiology ; Integrin alphaVbeta3/*physiology ; Male ; Mice ; Mice, Inbred BALB C ; Nitrofurazone/chemistry/*pharmacology ; Recombinant Fusion Proteins/chemistry/*pharmacology

OBJECTIVETo study the anti-invasion effect of SEPT7 gene on U251MG glioma cells and its possible molecular mechanism.

METHODSRecombinant adenovirus vector carrying SEPT7 gene (rAd5-SEPT7) was transduced to human glioma cell line U251MG, and empty adenovirus vector was used as control. Tumor invasion was examined by Transwell method and 3 D-Matrigel assay, and tumor cell migration by wound-healing method and 2 D-Matrigel assay. Three major molecular events associated with cell motility and migration, including changes of expression in MMP2, MMP9, MT1-MMP, TIMP1 and TIMP2, the alteration of integrin alpha(v)beta(3) expression, and the structural change of cytoskeleton protein, tubulin-alpha, in U251 cells transduced with rAd5-SEPT7 were studied by Western blotting, immunofluorescence and laser scanning confocal microscope, respectively.

RESULTSThe invasive and migratory capabilities of cells transduced with rAd5-SEPT7 were inhibited. The expression of extracellular matrix metalloproteinases MMP-2, MMP-9, MT1-MMP and integrin alpha(v)beta(3) was significantly decreased, while the expression of matrix metalloproteinase inhibitor TIMP1, TIMP2 was upregulated. Intracellular cytoskeleton protein-tubulin-alpha in U251 cells exhibited prominent morphological changes which including the appearance of distortion and aggregation resulting from redistribution of tubulin-alpha, and this feature of alteration was similar to the tubulin-alpha structure in normal non-tumor cells.

CONCLUSIONSEPT7 gene can inhibit the invasion and migration ability of U251 glioma cells. Its molecular mechanism may include that SEPT7 gene reverses the imbalanced state of MMPs/TIMPs, downregulates the expression of integrin alpha(v)beta(3) and alters the structure of tubulin-alpha of U251MG glioma cells. It is suggested that SEPT7 gene could be a good candidate for gene therapy of gliomas.

Adenoviridae ; genetics ; Blotting, Western ; Cell Cycle Proteins ; genetics ; physiology ; Cell Line, Tumor ; Cell Movement ; genetics ; Genetic Vectors ; genetics ; Glioma ; metabolism ; pathology ; Humans ; Integrin alphaVbeta3 ; metabolism ; Matrix Metalloproteinase 14 ; metabolism ; Matrix Metalloproteinase 2 ; metabolism ; Matrix Metalloproteinase 9 ; metabolism ; Microscopy, Confocal ; Neoplasm Invasiveness ; genetics ; Septins ; Tissue Inhibitor of Metalloproteinase-1 ; metabolism ; Tissue Inhibitor of Metalloproteinase-2 ; metabolism

OBJECTIVETo investigate the inhibitory effect of recombinant polypeptide CH50 of fibronectin on invasion and angiogenesis of tumors, and analyze the possible molecular mechanism of the therapeutic effect of polypeptide CH50 on tumors.

METHODSThe tumor model was established by inoculation of H22 hepatocarcinoma cells in mice. The tumor gene therapy was performed by in vivo gene transfection with a method based on hydrodynamics to express polypeptide CH50. After treatment, the inhibitory effect on tumor invasion and angiogenesis was observed by histotology with HE staining of tumor tissues. The expresison of MMP-9 mRNA and protein at the edge of tumor tissue was evaluated by RT-PCR and gelatin zymography, respectively. RT-PCR was used to detect the expression of the related genes in H22 cells treated with polypeptide CH50. Cell adhesion assay was used to analyze the influence of polypeptide CH50 on the binding of cells to fibrinogen.

RESULTS(1) Eukaryotic expression plasmid pCH510 was expressed in vivo in a non-targeting manner and produced a significant inhibitory effect on tumor growth. The therapy with polypeptide CH50 resulted in pronounced necrosis of tumor cells in pCH510 group, compared with that in control groups at histological level. (2) Polypeptide CH50 could inhibit the growth, invasion and angiogenesis of the tumor, and interfere the formation of new collateral circulation in the tumor. (3) The expression level of MMP-9 protein at the edge of tumor tissue was significantly decreased after treatment, especially the activation of pro-MMP-9 was inhibited significantly, whereas the expression level of MMP-9 mRNA was not influenced. (4) The expression of alphav, 33 and cdc2 mRNAs in H22 cells treated with polypeptide CH50 was down-regulated. (5) Cell adhesion assay manifested that polypeptide CH50 can affect the adhesion ability of H22 cells.

CONCLUSIONPolypeptide CH50 can inhibit tumor growth and angiogenesis by suppressing the functions of MMP-9 and integrin alphavbeta3.

Animals ; CDC2 Protein Kinase ; biosynthesis ; genetics ; Carcinoma, Hepatocellular ; metabolism ; pathology ; therapy ; Cell Adhesion ; genetics ; physiology ; Cell Line, Tumor ; Fibronectins ; biosynthesis ; genetics ; physiology ; Gene Expression Regulation, Neoplastic ; Genetic Therapy ; methods ; Humans ; Integrin alphaVbeta3 ; biosynthesis ; genetics ; Liver Neoplasms, Experimental ; metabolism ; pathology ; therapy ; Matrix Metalloproteinase 9 ; biosynthesis ; genetics ; Mice ; Mice, Inbred BALB C ; Neoplasm Invasiveness ; Neoplasm Transplantation ; Neovascularization, Pathologic ; genetics ; metabolism ; therapy ; RNA, Messenger ; biosynthesis ; genetics ; Random Allocation ; Recombinant Proteins ; biosynthesis ; genetics ; Reverse Transcriptase Polymerase Chain Reaction