system
Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: BACKGROUND, METHODS, RESULTS. Meshes: Animals, Apoptosis, Blotting, Western, Cell Movement, Cell Proliferation, Gene Expression Regulation, Neoplastic, Humans, Hypoxia, Hypoxia-Inducible Factor 1, alpha Subunit, I-kappa B Proteins, Immunoenzyme Techniques, Luciferases, Male, Mice, Mice, Inbred BALB C, Mice, Nude, NF-KappaB Inhibitor alpha, NF-kappa B, Neoplasm Invasiveness, Neovascularization, Pathologic, RNA, Messenger, RNA, Small Interfering, Reverse Transcriptase Polymerase Chain Reaction, Signal Transduction, Stomach Neoplasms, Tumor Cells, Cultured, Vascular Endothelial Growth Factor A, Xenograft Model Antitumor Assays.
user
Does a hypoxia-dependent upregulation of hypoxia-inducible factor-1 by nuclear factor-κB promote gastric tumour growth and angiogenesis? Context: The underlying mechanisms involved in the activation of hypoxia-inducible factor-1 (HIF-1) in gastric cancer remain unclear. As nuclear factor-κB (NF-κB) as well as HIF-1 have been implicated in angiogenesis of various cancers, we investigated their relationship in gastric cancer. Nuclear expressions of HIF-1α and NF-κB/RelA were assessed in 251 human gastric carcinoma specimens by immunohistochemical tissue array analysis. Stable human gastric cancer cells, infected with a retroviral vector containing super-suppressive mutant form of IκBα (IκBαM), were used for animal studies as well as cell culture experiments. Xenografted tumours were measured and IκBαM effects on angiogenesis and HIF-1α activation were assessed by immunohistochemistry, western blotting, luciferase reporter assay, and semiquantitative reverse transcription-polymerase chain reaction. In addition, NF-κB effects on the HIF-1α degradation and synthesis were examined. Hypoxia-inducible factor-1α activation positively correlated with RelA activation in clinical gastric cancer samples (P<0.001). The IκBαM overexpression suppressed tumour growth, microvessel density, and HIF-1α activation in xenografted tumours. Cell culture experiments showed that hypoxia-induced HIF-1α expression was reduced by NF-κB inhibition under hypoxic conditions at the translational level.
assistant
The hypoxia-dependent activation of the NF-κB/HIF-1α/VEGF pathway contributes, at least in part, to gastric cancer promotion via enhancement of angiogenesis. Final Decision: yes