Inflammatory breast cancer (IBC) spreads easily through the lymphatic and blood vessels, forming metastasis, which can cause several organs in the body to fail, IBC is also the deadliest form of breast cancer.

A new study shows how IBC cells use IL-8, a chemokine of the immune system secreted as part of the anti-inflammatory response by monocytes (a specific set of white blood cells), in order to increase fibronectin expression. The study is published in BioMed Central’s open access journal Cell Communication and Signaling.

Fibronectin is a cell-binding molecule commonly involved in cell migration during embryogenesis and wound healing. It is believed that over-expression of Fibronectin allow cancer to spread.

To identify which immune-regulating molecules, including cytokines, chemokines, and growth factors monocytes secreted, Prof Mona Mohamed from Cairo University, used a cytokine antibody array, and discovered that even though monocytes secreted small amounts of a wide range of molecules, there was up to 10 times more IL-8 and MCP-1.

The amount of fibronectin produced in IBC cells, as well as in 3D culture produced branch-like structures, common in fibronectin over-expression was increased by the combination of immune-regulating molecules from the monocytes. The researchers noted that IL-8 on alone also increased fibronectin expression in IBC cells.

Professor Mohamed said:

“Adding IL-8 on its own to IBC cells caused an increase in the signaling proteins P13K and AKT and it is this pathway which is responsible for fibronectin production.”

Furthermore, Mohamed found that the monocyte cocktail did not change expression of E-cadherin, another cell-binding molecule.

Prof. Mohamed explained:

“From what we already knew about cell adhesion and these results, it seems that IBC cells are help together in clumps by E-cadherin, but fibronectin, and the IL-8 signaling pathway, are involved in branching and invasion necessary for metastasis of IBC.”

Written by Grace Rattue