Overexpression of MMP-9 and HIF-1α in Breast Cancer Cells under Hypoxic Conditions

摘要

PurposeHypoxia, which is a loss of oxygen in tissues, is a common condition in solid tumors due to the tumor outgrowing existing vasculature. Under hypoxic conditions, hypoxia-inducible factor (HIF)-1α rapidly accumulates and transactivates hundreds of genes, such as matrix metalloproteinases (MMPs). MMPs contribute to invasion and metastasis of tumor cells by degrading the surrounding basement membrane and extracellular matrix barriers, which enables the easy migration and spread of cancer cells. We examined whether hypoxia increases tumor cell invasion, and whether increased invasiveness was due to HIF-1α and MMP-9 expression.