endothelin-1 and Carcinoma--Lewis-Lung

One strategy to increase tissue specificity of gene therapy is to use promoters or enhancers.. (1) To enhance the selectivity of a murine preproendothelin-1 (PPE-1) promoter in tumor angiogenesis by using a positive endothelial transcription-binding element. (2) To test the specificity and efficiency of the modified PPE-1 promoter [PPE-1(3X)] in vitro and in vivo by using reporter genes, and the therapeutic gene herpes simplex virus-thymidine kinase (HSV-TK) in a mouse model of Lewis lung carcinoma (LLC).. The modified PPE-1 promoter specifically induced expression in the tumor angiogenic vascular bed with a 35-fold higher expression compared to the normal vasculare bed of the lung. Thus, when the HSV-TK gene controlled by the modified PPE-1 promoter was used systemically, it induced tumor-specific necrosis, apoptosis and mononuclear infiltrates, leading to massive destruction of the neovasculature of the pulmonary metastasis, which suppressed metastasis development.. These results show that an adenoviral vector armed with HSV-TK controlled by the endothelial-selective murine PPE-1(3X) promoter is efficient and safe to target tumor neovasculature.

Topics: Adenoviridae; Animals; Carcinoma, Lewis Lung; Endothelin-1; Endothelium, Vascular; Genes, Viral; Genetic Therapy; Genetic Vectors; Lung; Male; Mice; Mice, Inbred C57BL; Neovascularization, Pathologic; Promoter Regions, Genetic; Simplexvirus; Thymidine Kinase

Oxygenases are a family of enzymes that dioxygenate unsaturated fatty acids, thus initiating membrane oxidation and signaling molecule synthesis. The lipoxygenases (LOs), a family of lipid-peroxidizing enzymes that induce structural and metabolic changes in the cell in a number of pathophysiological conditions, belong to the oxygenases family. This class of enzymes has several subgroups, named 5-, 8-, 12- and 15-LOs, and these LO-isoforms are capable of oxygenating arachidonic and linoleic acid. 15-LOs were reported to play an inhibitory role in tumor angiogenesis and, consequently, they slow down carcinogenesis. It has been suggested that its anti-carcinogenic effect is conferred by promoting cell differentiation and apoptosis. Using transgenic mice that over-express 15-LO-1 in endothelial cells under the regulation of the murine preproendothelin-1 promoter, we studied its effect on tumor and metastasis growth. We found that 15-LO-1 inhibited tumor and metastasis growth in the transgenic mice in two different models of cancer (mammary gland and Lewis lung carcinoma). This inhibition was concomitant with a higher number of apoptotic cells in the metastases of the transgenic mice and with a complicated network of multiple small blood vessels. This finding targets 15-LO as a new candidate in the treatment of carcinogenesis.

Topics: Animals; Apoptosis; Arachidonate 15-Lipoxygenase; Blood Vessels; Carcinoma, Lewis Lung; Cell Transformation, Neoplastic; Endothelin-1; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Transgenic; Neoplasm Metastasis; Neovascularization, Pathologic; Promoter Regions, Genetic; Up-Regulation

Gene therapy directed specifically to the vascular wall, particularly to angiogenic endothelial cells is a prerequisite in vascular disease treatment. Angiogenesis is a major feature in many pathological conditions including wound healing, solid tumors, developing metastases, ischemic heart diseases and diabetic retinopathy. In the present study we developed a tissue-specific gene therapy to the angiogenic blood vessels of tumor metastasis using an adeno-based vector containing the murine preproendothelin-1 (PPE-1) promoter. Genes activated by the PPE-1 promoter were highly expressed in bovine aortic endothelial cells in vitro. Systemic injection of the adenoviral vectors AdPPE-1-luciferase and AdCMV-luciferase to normal C57BL/6 mice, resulted in higher activity of PPE-1 promoter compared with CMV promoter in the aorta and vascularized tissues such as heart, kidney, lung and pancreas. Systemic administration of the adenoviral vector, in mice bearing Lewis lung carcinoma, resulted in high and specific activity of PPE-1 in the new vasculature of primary tumors and lung metastasis. Cellular distribution of the delivered gene revealed highest expression of GFP in angiogenic endothelial cells of the metastasis. We expect that this approach of 'vascular-directed' gene therapy will be applicable to both vascular diseases and cancer.

Topics: Adenoviridae; Analysis of Variance; Animals; Aorta; Carcinoma, Lewis Lung; Cattle; Cells, Cultured; Endothelin-1; Endothelins; Endothelium, Vascular; Gene Expression; Gene Targeting; Genetic Therapy; Genetic Vectors; Green Fluorescent Proteins; Liver; Luminescent Proteins; Lung Neoplasms; Male; Mice; Mice, Inbred C57BL; Microscopy, Fluorescence; Microscopy, Phase-Contrast; Neovascularization, Pathologic; Promoter Regions, Genetic; Protein Precursors; Statistics, Nonparametric