Hormonal-receptor positive (HRP) breast cancer patients with positive metastatic axillary lymph nodes are characterized by poor prognosis and increased mortality rate. The mechanisms by which cancer cells invade lymph nodes have not yet been fully explored. Several studies have shown that expression of IL-6 and the proteolytic enzyme cathepsin B (CTSB) was associated with breast cancer poor prognosis. In the present study, the effect of different concentrations of recombinant human IL-6 on the invasiveness capacity of HRP breast cancer cell line MCF-7 was tested using an in vitro invasion chamber assay. The impact of IL-6 on expression and activity of CTSB was also investigated. IL-6 treatment promoted the invasiveness potential of MCF-7 cells in a dose-dependent manner. Furthermore, MCF-7 cells displayed elevated CTSB expression and activity associated with loss of E-cadherin and upregulation of vimentin protein levels upon IL-6 stimulation. | Hormonal-receptor positive breast cancer: IL-6 augments invasion and lymph node metastasis via stimulating cathepsin B expression
