lipofectamine and Brain-Neoplasms

High expression of multidrug resistance-associated protein 1 (MRP1) in tumor cells reduces effectiveness of chemotherapy drugs. In this study, we screened MRP1 interfering RNA (MRP1-siRNA) molecules that are able to reverse etoposide (VP16) resistance in multidrug resistance rat glioma cell line C6/VP16, and identified one siRNA molecule that is able to effectively deplete the expression of MRP1 gene and reverse tumor cells resistance to etoposide. Since siRNA instability limits its application in treatment of diseases, we next tested silencing effect of chitosan-MRP1-siRNA nanoparticles and found that the nanoparticles with N:P ratio 175 are able to effectively inhibit MRP1 mRNA and protein expression. Our data demonstrate that chitosan can be used as siRNA carrier for high efficient gene silencing in tumor cells.

Topics: Animals; Brain Neoplasms; Cell Line, Tumor; Chitosan; Down-Regulation; Drug Resistance, Multiple; Drug Resistance, Neoplasm; Etoposide; Gene Expression Regulation, Neoplastic; Gene Silencing; Glioma; Inhibitory Concentration 50; Lipids; Multidrug Resistance-Associated Proteins; Nanoparticles; Rats; RNA, Small Interfering; Transfection

We have further defined mechanism(s) by which the drug OSU-03012 (OSU) kills brain cancer cells. OSU toxicity was enhanced by the HSP90 inhibitor 17-N-Allylamino-17-demethoxygeldanamycin (17AAG) that correlated with reduced expression of ERBB1 and ERBB2. Inhibition of the extrinsic apoptosis pathway blocked the interaction between 17AAG and OSU. OSU toxicity was enhanced by the inhibitor of ERBB1/2/4, lapatinib. Knock down of ERBB1/2/4 in a cell line specific fashion promoted OSU toxicity. Combined exposure of cells to lapatinib and OSU resulted in reduced AKT and ERK1/2 activity; expression of activated forms of AKT and to a lesser extent MEK1 protected cells from the lethal effects of the drug combination. Knock down of PTEN suppressed, and expression of PTEN enhanced, the lethal interaction between OSU and lapatinib. Downstream of PTEN, inhibition of mTOR recapitulated the effects of lapatinib. Knock down of CD95, NOXA, PUMA, BIK or AIF, suppressed lapatinib and OSU toxicity. Knock down of MCL-1 enhanced, and overexpression of MCL-1 suppressed, drug combination lethality. Lapatinib and OSU interacted in vivo to suppress the growth of established tumors. Collectively our data argue that the inhibition of ERBB receptor function represents a useful way to enhance OSU lethality in brain tumor cells.

Topics: Apoptosis; Apoptosis Regulatory Proteins; Autophagy-Related Protein 5; Beclin-1; Benzoquinones; Brain Neoplasms; Celecoxib; Cell Line, Tumor; Drug Synergism; Endoplasmic Reticulum Chaperone BiP; ErbB Receptors; Genes, erbB-1; Heat-Shock Proteins; Humans; Lactams, Macrocyclic; Lapatinib; Lipids; MAP Kinase Kinase 1; Membrane Proteins; Microtubule-Associated Proteins; Myeloid Cell Leukemia Sequence 1 Protein; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins c-bcl-2; PTEN Phosphohydrolase; Pyrazoles; Quinazolines; Receptor, ErbB-2; Receptor, ErbB-4; RNA Interference; RNA, Small Interfering; Signal Transduction; Sulfonamides

Polyamidoamine (PAMAM) dendrimer and Tat peptides were conjugated to bacterial magnetic nanoparticles (BMPs) for the construction of an efficient and targeted gene delivery system with transmembrane ability for the gene therapy of brain tumors. Tat-BMPs-PAMAM was complexed with small interfering RNA expression plasmid (psiRNA) corresponding to the open reading frame of the human epidermal growth factor receptor gene (psiRNA-EGFR) to downregulate the EGFR gene by electrostatic interaction. The antitumor effect of psiRNA-EGFR delivered via Tat-BMPs-PAMAM was assessed both in human glioblastoma U251-MG cells and in nude mouse models. Compared with control groups, Tat-BMPs-PAMAM/psiRNA-EGFR resulted in better suppression of EGFR expression and a more obviously arrested effect on the proliferation and invasion ability of U251 cells in vitro. In addition, the growth rate of tumor in the U251 subcutaneous nude mouse model treated with Tat-BMPs-PAMAM/psiRNA-EGFR was slower than in those treated with phosphate-buffered saline or Lipofectamine 2000/psiRNA-Scr. Also, compared with control groups, the expression of oncoproteins (EGFR, p-AKT, MMP2/9, PCNA, VEGF, Bcl-2, and cyclin D1) was obviously downregulated and the number of apoptotic cells was clearly increased in the Tat-BMPs-PAMAM/psiRNA-EGFR treatment groups. In addition, there was no significant difference between the results in vitro and in vivo for the Tat-BMPs-PAMAM/psiRNA-EGFR treatment groups and those of the Lipofectamine 2000/psiRNA-EGFR treatment groups. These results show that Tat-BMPs-PAMAM, with its targeted delivery and transmembrane ability, may be a novel gene delivery system with potential applications in the targeted gene therapy of brain tumors.

Topics: Animals; Brain Neoplasms; Dendrimers; Drug Delivery Systems; ErbB Receptors; Genetic Therapy; Glioma; Humans; Lipids; Metal Nanoparticles; Mice; Mice, Nude; Peptide Fragments; RNA Interference; RNA, Small Interfering; tat Gene Products, Human Immunodeficiency Virus; Treatment Outcome; Xenograft Model Antitumor Assays

A retroviral vector constructed from the murine leukemia virus (MLV) can only express transgenes in cells undergoing mitosis, indicating its suitability as a delivery vehicle for cancer gene therapy. However, the transduction efficiency (TE) of retroviruses embedding endogenous envelope proteins in human cancer cells was found to be unsatisfactory. Recently, several research groups have demonstrated the feasibility of a retroviral vector pseudotyped with a vesicular stomatitis virus G (VSV-G) protein. In this study, the potential of VSV-G pseudotyped MLV-based retrovirus was examined as a delivery vehicle in a variety of human cancer cells including brain tumor cells in vitro and in vivo. The transduction efficiency of the 293T/G/GP/LacZ retrovirus in cell culture was superior in most cancer cells, particularly in brain tumor cells, compared with that of other retroviruses, such as PA317- or PG13-derived. The relative growth rate and phosphatidylserine expression level on the plasma membrane of target cells mainly influenced the transduction efficiency of VSV-G pseudotyped retrovirus, which suggested that both the relative growth rate and phosphatidylserine expression level were major determinants of TE. Furthermore, 293T/G/GP/LacZ could efficiently transduce human cancer cells regardless of the presence of chemical additives, whereas in other retroviruses, cationic chemical additives such as polybrene or liposomes were essential during virus infection. Finally, an average of 10% gene expression was routinely obtained exclusively in the tumor mass when 293T/G/GP/LacZ concentrated by simple ultracentrifugation was directly administrated to pre-established brain tumors in animal models (U251-N nu/nu mice or C6 Wistar rats). All told, the present study suggests that the VSV-G pseudotyped retrovirus is a suitable vector for brain tumor gene therapy.

Topics: Brain Neoplasms; Cation Exchange Resins; Cell Membrane; Cholesterol; Fatty Acids, Monounsaturated; Genetic Therapy; Genetic Vectors; Hexadimethrine Bromide; Humans; Leukemia Virus, Murine; Lipids; Phosphatidylserines; Protamines; Quaternary Ammonium Compounds; Transduction, Genetic; Tumor Cells, Cultured; Vesicular stomatitis Indiana virus

Malignant gliomas are the most common intracranial tumors and are considered incurable. Therefore, exploration of novel therapeutic modalities is essential. Telomerase is a ribonucleoprotein enzyme that is detected in the vast majority of malignant gliomas but not in normal brain tissues. We, therefore, hypothesized that telomerase inhibition could be a very promising approach for the targeted therapy of malignant gliomas. Thus, 2-5A (5'-phosphorylated 2'-5'-linked oligoadenylate)-linked antisense against human telomerase RNA component (2-5A-anti-hTER) was investigated for its antitumor effect on an intracranial malignant glioma model. 2-5A is a mediator of one pathway of IFN actions by activating RNase L, resulting in RNA degradation. By linking 2-5A to antisense, RNase L degrades the targeted RNA specifically and effectively. Prior to the experiments using intracranial tumor models in nude mice, we modified the in vitro and in vivo treatment modality of 2-5A-anti-hTER using a cationic liposome to enhance the effect of 2-5A-anti-hTER. Here we demonstrate that 2-5A-anti-hTER complexed with a cationic liposome reduced the viability of five malignant glioma cell lines to 20-43% within 4 days but did not influence the viability of cultured astrocytes lacking telomerase. Furthermore, treatment of intracranial malignant gliomas in nude mice with 2-5A-anti-hTER was therapeutically effective compared with the control (P < 0.01). These findings clearly suggest the therapeutic potentiality of 2-5A-anti-hTER as a novel approach for the treatment of intracranial malignant gliomas.

Topics: Adenine Nucleotides; Animals; Brain Neoplasms; Cation Exchange Resins; Cations; Female; Glioma; Humans; Lipids; Liposomes; Mice; Mice, Inbred BALB C; Mice, Nude; Neoplasm Transplantation; Oligoribonucleotides; Oligoribonucleotides, Antisense; RNA, Neoplasm; Telomerase; Tumor Cells, Cultured

Vascular endothelial growth factor (VEGF) is most promising in therapeutic angiogenesis for ischemic vascular disease. This paper aimed to study VEGF gene therapy for the treatment of cerebral ischemia. The glial cell was chosen as the target cell for gene transfer, and the expression of VEGF was studied in vitro. VEGF plasmid/liposome complexes were constructed by mixing VEGF plasmid with liposome, and then cultured C6 glioma cells were transfected with these complexes by lipofectamine method. As control, the same kind of cells were exposed to liposome only. Immunohistochemistry was performed to both groups at 24, 48 and 72 hours after transfection. The transfected cells expressed VEGF significantly higher than the control. The present result demonstrated the feasibility of choosing the glial cell as the target cell for VEGF gene transfer, and found the rationale for the cerebral VEGF gene therapy.

Topics: Animals; Brain Ischemia; Brain Neoplasms; Cation Exchange Resins; DNA, Complementary; Endothelial Growth Factors; Feasibility Studies; Genetic Therapy; Genetic Vectors; Glioma; Immunoenzyme Techniques; Lipids; Liposomes; Lymphokines; Neuroglia; Rats; Recombinant Fusion Proteins; Tumor Cells, Cultured; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factors

A synthetic polyamino polymer with a glucose backbone was used for gene transfer in vitro and in vivo. Gene transfer in vitro to various human carcinoma cell lines was achieved with an efficiency superior to a commercially available cationic liposome preparation. The polymer was resistant to inhibition by serum, which allowed for efficient gene transfer in vivo. Direct Intracranial tumor injection using this reagent resulted in reporter gene expression levels comparable to those achieved by a recombinant adenoviral vector. Thus, this compound represents a new class of agent that may have broad utility for gene transfer and gene therapy applications.

Topics: Animals; beta-Galactosidase; Biocompatible Materials; Brain Neoplasms; Cation Exchange Resins; Cell Survival; Gene Transfer Techniques; Genes, Reporter; Glioma; Green Fluorescent Proteins; Humans; Lipids; Liposomes; Luciferases; Luminescent Proteins; Mice; Mice, SCID; Plasmids; Polyamines; Sarcoma; Transfection; Transplantation, Heterologous; Tumor Cells, Cultured