Breast Neoplasms/pathology; Cell Movement; Cell Nucleus/metabolism; Mitogen-Activated Protein Kinase 1/metabolism; Mitogen-Activated Protein Kinase 3/metabolism; NF-kappa B/metabolism; Proto-Oncogene Proteins c-akt/metabolism; Receptors, Immunologic/metabolism; Receptors, Purinergic P2X7/metabolism; Breast Neoplasms/metabolism; Cell Line, Tumor; Female; Humans; Hypoxia; Hypoxia-Inducible Factor 1, alpha Subunit/antagonists & inhibitors; Hypoxia-Inducible Factor 1, alpha Subunit/genetics; Hypoxia-Inducible Factor 1, alpha Subunit/metabolism; I-kappa B Kinase/antagonists & inhibitors; I-kappa B Kinase/genetics; I-kappa B Kinase/metabolism; Immunoblotting; Matrix Metalloproteinase 2/metabolism; Matrix Metalloproteinase 9/metabolism; NF-kappa B/genetics; Phosphorylation; Protein Transport; RNA, Small Interfering/genetics; Receptor for Advanced Glycation End Products; Receptors, Immunologic/antagonists & inhibitors; Receptors, Immunologic/genetics; Receptors, Purinergic P2X7/chemistry; Receptors, Purinergic P2X7/genetics; Signal Transduction