Resensitizing Paclitaxel-Resistant Ovarian Cancer via Targeting Lipid Metabolism Key Enzymes CPT1A, SCD and FASN.

Epithelial ovarian cancer (EOC) is a lethal gynecological cancer, of which paclitaxel resistance is the major factor limiting treatment outcomes, and identification of paclitaxel resistance-related genes is arduous. We obtained transcriptomic data from seven paclitaxel-resistant ovarian cancer cell lines and corresponding sensitive cell lines. Define genes significantly up-regulated in at least three resistant cell lines, meanwhile they did not down-regulate in the other resistant cell lines as candidate genes. Candidate genes were then ranked according to the frequencies of significant up-regulation in resistant cell lines, defining genes with the highest rankings as paclitaxel resistance-related genes (PRGs). Patients were grouped based on the median expression of PRGs. The lipid metabolism-related gene set and the oncological gene set were established and took intersections with genes co-upregulated with PRGs, obtaining 229 co-upregulated genes associated with lipid metabolism and tumorigenesis. The PPI network obtained 19 highly confidential synergistic targets (interaction score > 0.7) that directly associated with CPT1A. Finally, FASN and SCD were up-stream substrate provider and competitor of CPT1A, respectively. Western blot and qRT-PCR results confirmed the over-expression of CPT1A, SCD and FASN in the A2780/PTX cell line. The inhibition of CPT1A, SCD and FASN down-regulated cell viability and migration, pharmacological blockade of CPT1A and SCD increased apoptosis rate and paclitaxel sensitivity of A2780/PTX. In summary, our novel bioinformatic methods can overcome difficulties in drug resistance evaluation, providing promising therapeutical strategies for paclitaxel-resistant EOC via taregting lipid metabolism-related enzymes.

Silencing Bag-1 gene via magnetic gold nanoparticle-delivered siRNA plasmid for colorectal cancer therapy in vivo and in vitro.

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 ß-catenin, mainly molecules of Wnt/ß-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/ß-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.

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 ß-catenin which are main molecules of Wnt/ß­catenin 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.

The research of nanoparticles as gene vector for tumor gene therapy.

With the development of molecular biology, the application of the gene therapy becomes a tendency in the development of oncotherapy. The gene therapy has been acknowledged as the major progress of modern medicine, also a focus in the oncotherapy research. Commonly vectors of the gene therapy mainly include two categories, namely, viral vectors and nonviral vectors. Nanoparticles gene vector of various different kinds of materials, which belong to non-viral carriers. It presents excellent abilities of adsorption, concentration and protection of DNA, which can be attributed as a main reason of the adsorption and operation of nano-gene vector on exogenous genes. In this article, we mainly reviewed the recent studies of the characteristics of nanoparticles, characteristics and transport mechanism of nanoparticles as gene vector, the progress on nanoparticles as gene vector in tumor gene therapy. Nano-gene vectors, as new drug and gene carriers, present characteristics such as the controlled-release, targeting, and the improvement of bioavailability. Nanoparticles for cancer imaging and therapy have evolved rapidly during the last decade and it is expected that more and more will become clinical practise. In the near future, as a new nanometer gene delivery vector will be in medical research and treatment play a bigger role.

Antiapoptotic gene BAG-1 vector structure of RNA interference and endogenous targeted screening in colon cancer cell lines.

The purposes of the present work were to construct the shRNA plasmids for BAG-1 gene of human and test the expression of mRNA and protein of BAG-1. Recombinant plasmids containing green fluorescent protein reporter genes are constructed using gene cloning methods. The shRNA plasmids for the BAG-1 gene are constructed by RNA interference technology. We applied fluorescent plasmid-transfected target cells in the cell transfection experiments and monitored the transfection rate of plasmids by observing the fluorescence amount. We transfected three synthesized shRNA in target screening cell and adopted RT-PCR and Western test to identify the difference of target gene transfection and translation level in cells. The specific shRNA plasmid for the BAG-1 gene was successfully recombined, and stably transfected colon cancer Lo Vo cell lines were obtained. The results present that the constructed shRNA plasmids significantly inhibited the expression of mRNA and protein of Lo Vo cell BAG-1, and can maintain the effect for a long term. pGPH1/GFP/Neo-BAG-1-homo-825 was screened as the optimum sequence of interference so as to lay a solid foundation to explore into the research on the BAG-1 gene and the biological behavior of colon cancer cells. It showed the remarkable advantage of RNAi in the generation of posttranscriptional gene silencing.