Expression of multidrug resistance protein P-glycoprotein in correlation with markers of hypoxia (HIF-1α EPO EPO-R) in invasive breast cancer with metastasis to lymph nodes

摘要

IntroductionOverexpression of the mdr-1 gene is the earliest discovered mechanism of multidrug resistance, which is associated with P-glycoprotein (P-gp) – a cell membrane protein responsible for the efflux of drugs of various structures out of cancer cells. Although the expression of P-glycoprotein has been demonstrated in many cancer types, its relation to markers of hypoxia such as HIF-1α, EPO-R or EPO in invasive breast cancer is not well established. The aim of this research was to analyze the co-expression of P-glycoprotein and the markers of tissue hypoxia HIF-1α, EPO, and EPO-R by immunohistochemistry in invasive breast cancer classified according to the presence of steroid receptors and the HER2 receptors.