Human Umbilical Vein Endothelial Cells/metabolism; Hypoxia-Inducible Factor 1, alpha Subunit/metabolism; Hypoxia; Lung Neoplasms/secondary; Melanoma/pathology; Neovascularization, Pathologic/pathology; Vascular Endothelial Growth Factor A/metabolism; Animals; Apoptosis; Blotting, Western; Cell Proliferation; Cells, Cultured; Fluorescent Antibody Technique; Gene Expression Regulation, Neoplastic; Heterografts; Human Umbilical Vein Endothelial Cells/cytology; Humans; Hypoxia-Inducible Factor 1, alpha Subunit/genetics; Immunoenzyme Techniques; Immunoprecipitation; Lung Neoplasms/blood supply; Lung Neoplasms/metabolism; Melanoma/blood supply; Melanoma/metabolism; Mice; Mice, Nude; Neovascularization, Pathologic/metabolism; Protein Interaction Domains and Motifs; Protein Structure, Tertiary; Proto-Oncogene Proteins c-bcl-2/genetics; Proto-Oncogene Proteins c-bcl-2/metabolism; RNA, Messenger/genetics; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; Vascular Endothelial Growth Factor A/genetics; Wound Healing