Leptin and leptin receptor expression in patients with breast cancer and fibroadenoma of different hormonal status

Introduction: Leptin (LEP) is a multifunctional hormone which plays an important role in angiogenesis, cell proliferation induction, cell survival and anchorage-independent growth. These activities are mediated via leptin receptor (LEPR) that binds leptin molecule and stimulates Jak/STAT 3, ERK, cyclin D1 expression and other signal pathways. According to the recent data, targeting leptin signaling may reduce mammary carcinogenesis and breast cancer (BC) progression. However, the link between obesity and leptin expression in serum/breast tumor as well as its role in modulation of estrogen receptor (EsR) and HER2/neu expression is not clear.