1-2-dielaidoylphosphatidylethanolamine and Lung-Neoplasms

Recent data on the application of dendritic cells (DCs) as anti-tumor vaccines has shown their great potential in therapy and prophylaxis of cancer. Here we report on a comparison of two treatment schemes with DCs that display the models of prophylactic and therapeutic vaccination using three different experimental tumor models: namely, Krebs-2 adenocarcinoma (primary tumor), melanoma (B16, metastatic tumor without a primary node) and Lewis lung carcinoma (LLC, metastatic tumor with a primary node). Dendritic cells generated from bone marrow-derived DC precursors and loaded with lysate of tumor cells or transfected with the complexes of total tumor RNA with cationic liposomes were used for vaccination. Lipofectamine 2000 and liposomes consisting of helper lipid DOPE (1,2-dioleoyl-sn-glycero-3-phosphoethanolamine) and cationic lipid 2D3 (1,26-Bis(1,2-de-O-tetradecyl-rac-glycerol)-7,11,16,20-tetraazahexacosan tetrahydrocloride) were used for RNA transfection. It was shown that DCs loaded with tumor lysate were ineffective in contrast to tumor-derived RNA. Therapeutic vaccination with DCs loaded by lipoplexes RNA/Lipofectamine 2000 was the most efficient for treatment of non-metastatic Krebs-2, where a 1.9-fold tumor growth retardation was observed. Single prophylactic vaccination with DCs loaded by lipoplexes RNA/2D3 was the most efficient to treat highly aggressive metastatic tumors LLC and B16, where 4.7- and 10-fold suppression of the number of lung metastases was observed, respectively. Antimetastatic effect of single prophylactic DC vaccination in metastatic melanoma model was accompanied by the reductions in the levels of Th2-specific cytokines however the change of the levels of Th1/Th2/Th17 master regulators was not found. Failure of double prophylactic vaccination is explained by Th17-response polarization associated with autoimmune and pro-inflammatory reactions. In the case of therapeutic DC vaccine the polarization of Th1-response was found nevertheless the antimetastatic effect was less effective in comparison with prophylactic DC vaccine.

Topics: Animals; Cancer Vaccines; Carcinoma, Lewis Lung; Cell Line, Tumor; Cytokines; Dendritic Cells; Liposomes; Lung Neoplasms; Male; Melanoma, Experimental; Mice; Mice, Inbred C57BL; Neoplasm Metastasis; Phosphatidylethanolamines; Transfection; Vaccination

We describe the development of an aerosol system for topical gene delivery to the lungs of C57BL/6 mice. This system is based on the combination of the commercial cationic lipid Lipofectin with a novel amphiphilic triblock copolymer, poly(p-dioxanone-co-L-lactide)-block-poly(ethylene glycol) (PPDO/PLLA-b-PEG, and abbreviated in the text as polymeric micelles). After optimizing conditions for DNA delivery to the lungs of mice using the combination of polymeric micelles with Lipofectin and LacZ DNA, we used the Lipofectin/polymeric micelle system to deliver the tumor suppressor gene PTEN to the lungs of C57BL/6 mice bearing the B16-F10 melanoma. Lipofectin/PTEN/polymeric micelles significantly improved gene expression of PTEN in the lungs of mice with no evidence of cell toxicity or acute inflammation. Importantly, lung metastasis, as measured by lung weight, was significantly reduced (P<0.001), as were total tumor foci in the lungs (P<0.001) and size of individual tumor nodules in animals treated with Lipofectin/PTEN/polymeric micelles compared with control animals. Survival time was also extended. These results suggest that the Lipofectin/polymeric micelle system is appropriate for enhancing gene delivery in vivo and that it can be applied as a non-invasive gene therapy for lung cancer.

Topics: Aerosols; Animals; Female; Gene Expression; Genetic Therapy; Immunohistochemistry; Lung Neoplasms; Melanoma, Experimental; Mice; Mice, Inbred C57BL; Micelles; Phosphatidylethanolamines; Polyesters; Polyethylene Glycols; PTEN Phosphohydrolase; Transfection; Transgenes

A monoclonal antibody, LC-1, recognizing lung cancer associated common antigens was obtained in authors' laboratory. Its single chain Fv fragment (ScFv) named LC-1 ScFv was constructed based on recombinant phage displayed techniques. For expression on cell membrane, LC-1 ScFv was cloned into pDisplay vector, which directed the cloned gene to express as cell membrane bound protein. The resulting plasmid was sequenced and then introduced by the lipofectin method into a lung adenocarcinoma cell line SPC-A-1. G418 resistant cells were obtained by G418 selection. After transfection, LC-1 ScFv expression was observed by Western blot analysis and the expression of cognate antigens was down-regulated as shown in ELISA assay. SPC-A-1-pDisplay-ScFv cells grew in vitro at lower speed than the control intact cells and the cells transfected with vacant vector. Flow cytometry analysis detected a substantial increase in G1 phase and decrease in S phase in population of SPC-A-1-pDisplay-ScFv cells compared to SPC-A-1 and SPC-A-1-pDisplay cells. Semi-quantitative RT-PCR analysis showed that c-myc expression was down-regulated in SPC-A-1-pDisplay-ScFv cells. It seems that the antigens recognized by LC-1 may be in some way involved in a growth stimulating pathway and the antibody blocking of the function of the antigens shut down the pathway and thus down-regulate the expression of c-myc and growth of the cells.

Topics: Adenocarcinoma; Amino Acid Sequence; Antibodies, Monoclonal; Base Sequence; Cell Line, Tumor; Cell Membrane; Cloning, Molecular; Gene Expression Regulation, Neoplastic; Humans; Immunization; Immunoglobulin Heavy Chains; Immunoglobulin Light Chains; Immunoglobulin Variable Region; Kinetics; Lung Neoplasms; Molecular Sequence Data; Peptide Library; Phosphatidylethanolamines; Proto-Oncogene Proteins c-myc; Recombinant Proteins; Transfection

Survivin, an inhibitor of apoptosis protein, deserves attention as a selective target for cancer therapy because it lacks expression in differentiated adult tissues but is expressed in a variety of human tumors. We designed 20-mer phosphorothioate antisense oligonucleotides targeting different regions of survivin mRNA and investigated their ability to down-regulate survivin mRNA and induce apoptosis in the lung adenocarcinoma cell line A549. Oligonucleotide 4003, which targets nucleotides 23-251 of survivin mRNA, was identified as the most potent compound. As measured by real-time PCR, 4003 down-regulated survivin mRNA in a dose-dependent manner with an IC50 of 200 nM. Its maximum effect was achieved at a concentration of 400 nM, at which mRNA was down-regulated by 70%. As revealed by increased caspase-3-like protease activity, nuclear condensation and fragmentation, and trypan blue uptake, treatment with 4003 induced apoptosis and sensitized tumor cells to the chemotherapeutic agent etoposide. Oligonucleotide 4003 did not reduce the viability of normal blood leukocytes with marginal levels of survivin mRNA.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Cell Division; Cell Survival; Dose-Response Relationship, Drug; Down-Regulation; Etoposide; Humans; Inhibitor of Apoptosis Proteins; Inhibitory Concentration 50; Lung Neoplasms; Microtubule-Associated Proteins; Neoplasm Proteins; Oligonucleotides, Antisense; Phosphatidylethanolamines; Polymerase Chain Reaction; Proteins; RNA, Messenger; Survivin; Transfection; Tumor Cells, Cultured

The human interleukin-2 (IL-2) gene was successfully delivered into established human tumor xenografts in SCID (severe combined immunodeficient) mice by cationic liposome-mediated DNA delivery. A bicistronic mammalian expression vector containing a reporter gene (beta-galactosidase) and human IL-2 cDNA was complexed with either lipofectin or DC-cholesterol liposomes and transferred to tumor xenografts by direct intratumoral injection. Transfection of tumors was confirmed by staining of tumor sections for beta-galactosidase activity and by reverse transcription-polymerase chain reaction (RT-PCR) for the presence of IL-2 mRNA. Growth suppression of tumor xenografts was observed in animals injected with plasmid-liposome complexes but not in animals that received liposomes or naked plasmid only. Complete tumor regression, mediated by the mouse natural killer cells, was observed in 50-80% of the mice treated with the plasmid containing the IL-2 cDNA. The effectiveness of the treatment was dependent on the transfection efficiency and the tumor size at the start of therapy. An initial IL-2 independent suppression of tumor growth was also observed with a plasmid carrying only the beta-galactosidase gene but this effect was temporary and did not lead to tumor regression. These results establish that human tumor xenografts growing in SCID mice can be transfected in vivo by liposome mediated gene delivery and that both IL-2-dependent and IL-2-independent factors may contribute to the tumor suppression observed here.

Topics: Animals; Cell Division; Cholesterol; Cloning, Molecular; DNA; Genetic Therapy; Humans; Interleukin-2; Liposomes; Lung Neoplasms; Mice; Mice, SCID; Phosphatidylethanolamines; Plasmids; Transplantation, Heterologous; Tumor Cells, Cultured

The cisplatin induced enhancement of in situ lipofection was optimized by considering the factors that can increase the degree of sensitization. Two other anticancer drugs, mechlorethamine (nitrogen mustard) and taxol, enhanced CAT gene expression but the degree of sensitization was not as great as cisplatin. Besides human 2008 ovarian cancer cells we also found that human lung (A549) and head and neck cancer cells (SCC 25) were transiently sensitized by cisplatin. The transfectability of the two commercially available cationic liposomes, Lipofectin and LipofectAmine, was either weak or not consistent among tumors tested. In vivo transfection efficiency of 2008 cells was the highest at 1 microgram DNA per nmol or microgram liposome with all three cationic liposomes. In vitro transfection efficiency of 2008 cells at 1:1 (microgram of DNA:nmole of DC-chol/DOPE liposome) increased in a dose-dependent manner while at 1:10, an optimal ratio for in vitro lipofection, rapidly decreased with an increase in dose. This result indicated that there was a correlation between in vivo and in vitro lipofection at 1:1 ratio for delivering liposomal DNA. Most of the DNA injected into the tumor was concentrated in the tumor and in the skin above the tumor whether cisplatin was preinjected or liposomes were used as carriers.

Topics: Animals; Antineoplastic Agents; Bleomycin; Cation Exchange Resins; Chloramphenicol O-Acetyltransferase; Cholesterol; Cisplatin; DNA; Female; Head and Neck Neoplasms; Lipids; Liposomes; Lung Neoplasms; Mechlorethamine; Mice; Mice, SCID; Ovarian Neoplasms; Paclitaxel; Phosphatidylethanolamines; Transfection