1-2-dioleoyloxy-3-(trimethylammonium)propane and Carcinoma--Lewis-Lung

Immunization with synthetic mRNA encoding tumor-associated antigens is an emerging vaccine strategy for the treatment of cancer. In order to prevent mRNA degradation, promote antigen-presenting cells antigen presentation, and induce an anti-tumor immune response, we investigated the nasal administration of mRNA vaccines with positively charged protamine to concentrate mRNA, form a stable polycation-mRNA complex, and encapsulate the complex with DOTAP/Chol/DSPE-PEG cationic liposomes. Cationic liposome/protamine complex (LPC) showed significantly greater efficiency in uptake of vaccine particles in vitro and stronger capacities to stimulate dendritic cell maturation, which further induced a potent anti-tumor immune response. Intranasal immunization of mice with cationic LPC containing mRNA encoding cytokeratin 19 provoked a strong cellular immune response and slowed tumor growth in an aggressive Lewis lung cancer model. The results of this study provide evidence that cationic LPC can be used as a safe and effective adjuvant and this mRNA formulation provides a basis for anti-cancer vaccination of humans.

Topics: Administration, Intranasal; Animals; Cancer Vaccines; Carcinoma, Lewis Lung; Cell Differentiation; Dendritic Cells; Fatty Acids, Monounsaturated; Female; Humans; Immunotherapy; Keratin-19; Liposomes; Lung Neoplasms; Lymphocyte Activation; Mice; Mice, Inbred C57BL; Neoplasm Transplantation; Protamines; Quaternary Ammonium Compounds; RNA, Messenger; Tumor Burden

Interleukin-27 (IL-27), a novel IL-6/IL-12 family cytokine, plays an important role in the early regulation of Th1 responses. The cytokine IL-27 can exert a variety of immune-regulatory functions including cytotoxic T lymphocyte (CTL), CD4+, CD8+ T lymphocytes activation and interferon-γ (IFN-γ) production. In this study, we developed an effective and gene modified tumor cell vaccine. Lewis lung cancer cell LL/2 transfected with the DOTAP:cholesterol cationic liposome could express the mouse IL-27 (mIL-27) gene at a relative high level. The resultant transfectants were then irradiated with X-ray and used as a tumor cell vaccine. This tumor cell vaccine not only contained tumor associated antigen (TAA) of LL/2 cells but also secreted mIL-27 which could induce immune response in mice. The mice vaccinated with LL/2-mIL-27 performed strong tumor inhibiting effect accompanied with a high IFN-γ production. Both CD4+ and CD8+ T lymphocytes were significantly elevated in these mice vaccinated with LL/2-mIL-27 cell vaccine. Moreover, after depletion of CD4+, CD8+ T lymphocytes by injection of antibodies against CD4 and CD8, the vaccinated mice inoculated with autologous LL/2 cells were not protected from tumor challenge. In contrast, vaccinated mice inoculated with autologous LL/2 cells were treated with antibody against natural killer (NK)cells or normal rat IgG still possessed strong antitumor activity. Our data suggested that DOTAP:cholesterol cationic liposome was quite useful in generating an autologous tumor cell vaccine and mIL-27 could be therapeutically used to potentiate the host antitumor immunity.

Topics: Animals; Cancer Vaccines; Carcinoma, Lewis Lung; Cell Line, Tumor; Fatty Acids, Monounsaturated; Female; Genetic Engineering; Immunotherapy, Adoptive; Interleukins; Liposomes; Mice; Mice, Inbred C57BL; Quaternary Ammonium Compounds; Rats; T-Lymphocyte Subsets; Transfection

Radiosensitivity of tumors is due to a complex interaction of various factors, it has been reported that survivin also acts as a constitutive and inducible radioresistance factor in a panel of tumor cells and approaches designed to inhibit survivin expression or function may lead to tumor sensitisation to chemical and physical agents. Previously, we found that the plasmid encoding the phosphorylation-defective mouse survivin threonine 34-->alanine mutant complexed to DOTAP-chol liposome (Lip-mS) can suppress murine primary breast carcinoma. However, little is known regarding the biological effect of Lip-mS combined with radiation. The present study was designed to determine whether Lip-mS could enhance the anti-tumor activity of radiation. The Lewis Lung Carcinoma (LLC) cells treated with a combination of Lip-mS and radiation displayed apparently increased apoptosis compared with those treated with Lip-mS or radiation alone. Mice bearing LLC tumors were treated with intravenous injections of Lip-mS and radiation, the combined treatment significantly reduced mean tumor volume compared with either treatment alone. Moreover, the anti-tumor effect of Lip-mS combined with radiation was greater than their additive effect when compared with the expected effect of the combined treatment. These data suggest that inhibition of survivin using a dominant-negative mutant, survivin T34A, could sensitize LLC cells to radiation efficiently and the synergistic anti-tumor activity may in part result from increasing the apoptosis of tumor cells, inhibiting tumor angiogenesis and inducing a tumor-protective immune response in the combined treatment.

Topics: Animals; Apoptosis; Carcinoma, Lewis Lung; Cholesterol; Combined Modality Therapy; Fatty Acids, Monounsaturated; Genes, Dominant; Inhibitor of Apoptosis Proteins; Liposomes; Mice; Mice, Inbred C57BL; Microtubule-Associated Proteins; Plasmids; Platelet Endothelial Cell Adhesion Molecule-1; Quaternary Ammonium Compounds; Radiation Tolerance; Radiotherapy; Repressor Proteins; Survivin; Tetrazolium Salts; Thiazoles