The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform

Hiroaki Tada - One of the best experts on this subject based on the ideXlab platform.

Nianfeng Sun - One of the best experts on this subject based on the ideXlab platform.

  • silencing bag 1 gene via magnetic Gold Nanoparticle delivered sirna plasmid for colorectal cancer therapy in vivo and in vitro
    Tumor Biology, 2016
    Co-Authors: Wenbai Huang, Zhanao Liu, Guanzhou Zhou, Ailing Tian, Jianmin Ling, Nianfeng Sun
    Abstract:

    Apoptosis disorder is generally regarded as an important mechanism of carcinogenesis. Inducement of tumor cell apoptosis can be an effectual way to treat cancer. Bcl-2-associated athanogene 1 (Bag-1) is a positive regulator of Bcl-2 which is an anti-apoptotic gene. Bag-1 is highly expressed in colorectal cancer, which plays a critical role in promoting metastasis, poor prognosis, especially in anti-apoptotic function, and is perhaps a valuable gene target for colorectal cancer therapy. Recently, we applied a novel non-viral gene carrier, magnetic Gold Nanoparticle, and mediated plasmid pGPH1/GFP/Neo-Bag-1-homo-825 silencing Bag-1 gene for treating colorectal cancer in vivo and in vitro. By mediating with magnetic Gold Nanoparticle, siRNA plasmid was successfully transfected into cell. In 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay, magnetic Gold Nanoparticle had no significant cytotoxicity and by which delivered RNA plasmid inhibited cell viability significantly (P < 0.05). Downregulation of Bag-1 promoted cell apoptosis (∼47.0 %) in vitro and significantly decreased tumor growth when the cells were injected into nude mice. Based on the studies in vivo, the relative expression of Bag-1 was 0.165 ± 0.072 at mRNA level and ∼60 % at protein level. In further study, C-myc and β-catenin, mainly molecules of Wnt/β-catenin pathway, were decreased notably when Bag-1 were silenced in Nanoparticle plasmid complex-transfected Balb c/nude tumor xenograft. In conclusion, Bag-1 is confirmed an anti-apoptosis gene that functioned in colorectal cancer, and the mechanism of Bag-1 gene causing colorectal cancer may be related to Wnt/β-catenin signaling pathway abnormality and suggested that magnetic Gold Nanoparticle-delivered siRNA plasmid silencing Bag-1 is an effective gene therapy method for colorectal cancer.

  • magnetic Gold Nanoparticle mediated small interference rna silencing bag 1 gene for colon cancer therapy
    Oncology Reports, 2016
    Co-Authors: Wenbai Huang, Zhanao Liu, Guanzhou Zhou, Ailing Tian, Nianfeng Sun
    Abstract:

    Abstract Bcl-2-associated athanogene 1 (Bag-1) is a positive regulator of Bcl-2 which is an anti-apoptotic gene. Bag-1 was very slightly expressed in normal tissues, but often highly expressed in many tumor tissues, particularly in colon cancer, which can promote metastasis, poor prognosis and anti-apoptotic function of colon cancer. We prepared and evaluated magnetic Gold Nanoparticle/Bag-1 siRNA recombinant plasmid complex, a gene therapy system, which can transfect cells efficiently, for both therapeutic effect and safety in vitro mainly by electrophoretic mobility shift assays, flow cytometric analyses, cell viability assays, western blot analyses and RT-PCR (real-time) assays. Magnetic Gold Nanoparticle/Bag-1 siRNA recombinant plasmid complex was successfully transfected into LoVo colon cancer cells and the exogenous gene was expressed in the cells. Flow cytometric results showed apoptosis rate was significantly increased. In MTT assays, magnetic Gold Nanoparticles revealed lower cytotoxicity than Lipofectamine 2000 transfection reagents (P<0.05). Both in western blot analyses and RT-PCR assays, magnetic Gold Nanoparticle/Bag-1 siRNA recombinant plasmid complex transfected cells demonstrated expression of Bag-1 mRNA (P<0.05) and protein (P<0.05) was decreased. In further study, c-myc and β-catenin which are main molecules of Wnt/β‑catenin pathway were decreased when Bag-1 were silenced in Nanoparticle plasmid complex transfected LoVo cells. These results suggest that magnetic Gold Nanoparticle mediated siRNA silencing Bag-1 is an effective gene therapy method for colon cancer.

Shinichi Naya - One of the best experts on this subject based on the ideXlab platform.

Paresh Chandra Ray - One of the best experts on this subject based on the ideXlab platform.

  • Gold Nanoparticle based label free sers probe for ultrasensitive and selective detection of trinitrotoluene
    Journal of the American Chemical Society, 2009
    Co-Authors: Samuel S R Dasary, Anant Kumar Singh, Dulal Senapati, Paresh Chandra Ray
    Abstract:

    TNT is one of the most commonly used nitro aromatic explosives used for landmine and military purpose. Due to the significant detrimental effects, contamination of soil and groundwater with TNT is the major concern. Driven by the need to detect trace amounts of TNT from environmental samples, this article demonstrates for the first time a highly selective and ultra sensitive, cysteine modified Gold Nanoparticle based label-free surface enhanced Raman spectroscopy (SERS) probe, for TNT recognition in 2 pico molar (pM) level in aqueous solution. Due to the formation of Meisenheimer complex between TNT and cysteine, Gold Nanoparticles undergo aggregation in the presence of TNT via electrostatic interaction between Meisenheimer complex bound Gold Nanoparticle and cysteine modified Gold Nanoparticle. As a result, it formed several hot spots and provided a significant enhancement of the Raman signal intensity by 9 orders of magnitude through electromagnetic field enhancements. A detailed mechanism for termendous SERS intensity change has been discussed. Our experimental results show that TNT can be detected quickly and accurately without any dye tagging in lower pM level with excellent discrimination against other nitro compounds and heavy metals.

  • Gold Nanoparticle based FRET asssay for the detection of DNA cleavage
    Journal of Physical Chemistry B, 2006
    Co-Authors: Paresh Chandra Ray, Angela Fortner, Gopala Krishna Darbha
    Abstract:

    We report Gold Nanoparticle based FRET assay to monitor the cleavage of DNA by nucleases. Fluorescence signal enhancement is observed by a factor of 120 after the cleavage reaction in the presence of S1 nuclease. The mechanism of distant dependent fluorescence quenching has been discussed. Our experimental results on distance dependent fluorescence quenching match quite well with theoretical findings obtained from the fluorescence quenching model by Gersten and Nitzan (Surf. Sci. 1985, 158, 165). Our experimental observation paradigm for the design of optical based molecular ruler strategies at distances more than double the distances achievable using traditional dipole-dipole Columbic energy transfer based methods.

Samuel S R Dasary - One of the best experts on this subject based on the ideXlab platform.

  • Gold Nanoparticle based label free sers probe for ultrasensitive and selective detection of trinitrotoluene
    Journal of the American Chemical Society, 2009
    Co-Authors: Samuel S R Dasary, Anant Kumar Singh, Dulal Senapati, Hongtao Yu
    Abstract:

    TNT is one of the most commonly used nitro aromatic explosives used for landmine and military purpose. Due to the significant detrimental effects, contamination of soil and groundwater with TNT is the major concern. Driven by the need to detect trace amounts of TNT from environmental samples, this article demonstrates for the first time a highly selective and ultra sensitive, cysteine modified Gold Nanoparticle based label-free surface enhanced Raman spectroscopy (SERS) probe, for TNT recognition in 2 pico molar (pM) level in aqueous solution. Due to the formation of Meisenheimer complex between TNT and cysteine, Gold Nanoparticles undergo aggregation in the presence of TNT via electrostatic interaction between Meisenheimer complex bound Gold Nanoparticle and cysteine modified Gold Nanoparticle. As a result, it formed several hot spots and provided a significant enhancement of the Raman signal intensity by 9 orders of magnitude through electromagnetic field enhancements. A detailed mechanism for termendou...

  • Gold Nanoparticle based label free sers probe for ultrasensitive and selective detection of trinitrotoluene
    Journal of the American Chemical Society, 2009
    Co-Authors: Samuel S R Dasary, Anant Kumar Singh, Dulal Senapati, Paresh Chandra Ray
    Abstract:

    TNT is one of the most commonly used nitro aromatic explosives used for landmine and military purpose. Due to the significant detrimental effects, contamination of soil and groundwater with TNT is the major concern. Driven by the need to detect trace amounts of TNT from environmental samples, this article demonstrates for the first time a highly selective and ultra sensitive, cysteine modified Gold Nanoparticle based label-free surface enhanced Raman spectroscopy (SERS) probe, for TNT recognition in 2 pico molar (pM) level in aqueous solution. Due to the formation of Meisenheimer complex between TNT and cysteine, Gold Nanoparticles undergo aggregation in the presence of TNT via electrostatic interaction between Meisenheimer complex bound Gold Nanoparticle and cysteine modified Gold Nanoparticle. As a result, it formed several hot spots and provided a significant enhancement of the Raman signal intensity by 9 orders of magnitude through electromagnetic field enhancements. A detailed mechanism for termendous SERS intensity change has been discussed. Our experimental results show that TNT can be detected quickly and accurately without any dye tagging in lower pM level with excellent discrimination against other nitro compounds and heavy metals.