lipofectamine and Adenocarcinoma

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.

Topics: Adenocarcinoma; Apoptosis; Cell Line, Tumor; Colonic Neoplasms; DNA-Binding Proteins; Down-Regulation; Drug Screening Assays, Antitumor; Flow Cytometry; Genetic Vectors; Gold Colloid; Humans; Lipids; Magnets; Nanoparticles; Neoplasm Proteins; Particle Size; Plasmids; RNA Interference; RNA, Messenger; RNA, Neoplasm; RNA, Small Interfering; Transcription Factors; Transfection

RNA interfere (RNAi)-based technology holds great promise in cancer treatment. The use of small interfering RNA (siRNA), however, is hampered by its low delivery efficiency in vivo when they are diluted in blood biofluids and in the presence of serum and salt. In this study, we developed the polyglutamate derivative polymer brush, poly(ethyleneglycol) monomethyl ether-b-polyglutamate-g-spermine (mPEG-b-PG-g-spermine, PPGS), which could efficiently deliver survivin-siRNA under ultra-high dilution and in the presence of salt (NaCl 150mM) and serum (10% FBS), most likely due to its PEG-shelled polymer brush structure. On the contrary, aggregation occurred when PEI/siRNA polyplex dispersed in saline and serum-containing media and PEI polyplex dissociated after making a 256-fold dilution. PPGS/si-survivin polyplex exhibited high cellular uptake efficiency and efficiently down-regulated the expression of survivin mRNA in the cisplatin-resistance of non-small cell human lung adenocarcinoma (A549/DDP) cells in the presence of serum. However, either PEI polyplex or Lipofectmine 2000 complex was unstable in serum and salt-containing media and at high dilution rates, which resulted in their dramatical decrease of cellular uptake and gene-silencing efficiency in these conditions. The PPGS/si-survivin polyplex also exhibited synergistic effects of killing the cancer cells by combination treatment with cisplatin. Therefore, the PPGS gene carrier showed great potential in systemic siRNA delivery, and its combination with chemotherapeutic drug is promising in treating drug resistant cancers.

Topics: Adenocarcinoma; Antineoplastic Agents; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Cisplatin; Down-Regulation; Drug Resistance, Neoplasm; Gene Transfer Techniques; Humans; Inhibitor of Apoptosis Proteins; Lipids; Lung Neoplasms; Polyethylene Glycols; Polyglutamic Acid; RNA Interference; RNA, Small Interfering; Spermine; Survivin

The aim of this study was to assess the herceptin efficacy in ex vivo cultures of MCF-7 breast carcinoma cells. Herceptin was used with perfluorooctyl bromide (PFOB) and conjugated with lipoplex, containing plasmid DNA and lipofectamine (LipA), to allow fluorine-19 magnetic resonance imaging ((19)F MRI) study. Treatments such as herceptin, herceptin/PFOB and herceptin/PFOB/lipoplex were used for ex vivo targeting of MCF-7 cells cultured in three-dimensional (3D) geometry using hollow fiber bioreactor (HFB) device. The viability of MCF-7 cells after 72h treatments decreased to 54+/-2%, 50+/-3% and 45+/-1% for herceptin, herceptin/PFOB and herceptin/PFOB/Lipoplex, respectively. The EC(50) values were 1000microg/ml, 930microg/ml and 730microg/ml, respectively. The significant correlation between the treatment concentration and efficacy was observed in MCF-7 cell cultures.

Topics: Adenocarcinoma; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Antineoplastic Agents; Bioreactors; Breast Neoplasms; Cell Line, Tumor; Cell Survival; Chemistry, Pharmaceutical; Contrast Media; Dose-Response Relationship, Drug; Emulsions; Female; Fluorocarbons; Humans; Hydrocarbons, Brominated; Inhibitory Concentration 50; Lipids; Magnetic Resonance Imaging; Time Factors; Trastuzumab