Objective To investigate the Influence of Survivin and hTERT gene on cell proliferation and apoptosis in human colorectal carcinoma cell line SW 480 and to find experiment evidence for gene therapy of colorectal carci-noma .Methods Plasmids carrying shRNAs targeting survivin and hTERT were designed , constructed and trans-fected into SW480 cells.SW480 cells were then divided into blank group , blank Plasmid control group , survivin RNAi group , hTERT RNAi group and Survivin-hTERT RNAi group .The telomerase activity was examined by TRAP-PCR-ELISA analysis 48h after hTERT-shRNA transfection.Survivin and hTERT mRNA and protein expres-sion was analyzed by RT-PCR and Western blot .Cell apoptosis , proliferation were measured by flow cytometry , CCK-8 assay.Results Telomerase activity of SW480 cells in Survivin-hTERT RNAi groups were significantly decreased compared with the blank group ( P<0.01 ) .The expression of survivin and hTERT mRNA, proteins in the Survivin-hTERT RNAi group was reduced by 82.8%and 73.6%( P<0.01 ) ,79.2%and 66.7%( P<0.01 ) respectively .The inhibitory rate of cell proliferation of Survivin-hTERT RNAi group was 43.6% ±0.1%( P <0.01 ) .The apoptosis rate was 39.2%±2.3%( P<0.01 ) in the Survivin-hTERT RNAi group .Conclusions The Survivin-hTERT RNAi group could significantly reduces the protein expression of survivin and hTERT mRNA, in-hibit cell proliferation and induces cell apoptosis in human colorectal carcinoma cell line SW 480 .

The binding of microorganisms to platelets is a critical step in the development of infective endocarditis. In Streptococcus gordonii, this binding is mediated in part by serine-rich repeat proteins, which interact directly with sialic acid residues located on GPIIb receptors in the platelet membrane. In this study, we found that S. gordonii DL1 strain binds to platelets through bridging between sialic acid residue of fibronectin and serine-rich repeat protein (Hsa). Pretreatment of fibronectin with sialidases specific for alpha(2-3)-linked sialic acids was shown to significantly inhibit binding of the DL1 strain and the binding region(BR) of Hsa protein. Similarly, pre-incubation of bacteria or BR of Hsa with alpha(2-3)-sialyl-N-acetyllactosamine blocked fibronectin binding in the DL1 strain, but not the M99 strain. Together, these data show that the alpha(2-3)-sialic acid residues of fibronectin play an important role in the binding of S. gordonii DL1 to fibronectin through interactions with the Hsa receptor. This interaction is thought to play an important role in the development of pathogenic endocarditis, and may represent an important therapeutic target for the treatment of infective endocarditis.
Bacteria ; Blood Platelets ; Endocarditis ; Etorphine ; Fibronectins* ; Membrane Glycoproteins* ; Membranes ; N-Acetylneuraminic Acid* ; Sialic Acids ; Streptococcus gordonii*

OBJECTIVE: To determine the feasibility of labeling human mesenchymal stem cells (hMSCs) with bifunctional nanoparticles and assessing their potential as imaging probes in the monitoring of hMSC transplantation. MATERIALS AND METHODS: The T1 and T2 relaxivities of the nanoparticles (MNP@SiO2[RITC]-PEG) were measured at 1.5T and 3T magnetic resonance scanner. Using hMSCs and the nanoparticles, labeling efficiency, toxicity, and proliferation were assessed. Confocal laser scanning microscopy and transmission electron microscopy were used to specify the intracellular localization of the endocytosed iron nanoparticles. We also observed in vitro and in vivo visualization of the labeled hMSCs with a 3T MR scanner and optical imaging. RESULTS: MNP@SiO2(RITC)-PEG showed both superparamagnetic and fluorescent properties. The r1 and r2 relaxivity values of the MNP@SiO2(RITC)-PEG were 0.33 and 398 mM-1 s-1 at 1.5T, respectively, and 0.29 and 453 mM-1 s-1 at 3T, respectively. The effective internalization of MNP@SiO2(RITC)-PEG into hMSCs was observed by confocal laser scanning fluorescence microscopy. The transmission electron microscopy images showed that MNP@SiO2(RITC)-PEG was internalized into the cells and mainly resided in the cytoplasm. The viability and proliferation of MNP@SiO2(RITC)-PEG-labeled hMSCs were not significantly different from the control cells. MNP@SiO2(RITC)-PEG-labeled hMSCs were observed in vitro and in vivo with optical and MR imaging. CONCLUSION: MNP@SiO2(RITC)-PEG can be a useful contrast agent for stem cell imaging, which is suitable for a bimodal detection by MRI and optical imaging.
Animals ; Biocompatible Materials ; Cells, Cultured ; Cobalt ; Feasibility Studies ; Ferric Compounds ; Humans ; Magnetic Resonance Imaging/*methods ; *Mesenchymal Stem Cells ; Mice ; Mice, Nude ; Microscopy, Confocal ; Microscopy, Electron ; Nanoparticles/*chemistry ; Phantoms, Imaging ; Polyethylene Glycols ; Rats ; Rhodamines ; Silicon Dioxide ; Staining and Labeling/methods