The paper will be made available online ahead of print at www.genesdev.org.
Innate immune cells, including macrophages, comprise a large fraction of the cellular environment that infiltrates tumours - the so-called "tumour microenvironment". Tumours have a dynamic relationship with their microenvironment, communicating via secreted factors to modulate cellular growth and cancer progression.
In their upcoming G&D paper, Dr. Joyce and colleagues delineate how tumour-associated macrophages (TAMs) promote tumour growth and invasion. The researchers found that macrophage cells infiltrating pancreatic, mammary and lung tumours produce high levels of the proteases cathepsin B and S (Cts B and S), which enhances tumour growth and invasion. Interestingly, the researchers discovered that increased Cts B and S activity is stimulated by the tumours, themselves - through the release of interleukin (IL)-4.
The study is highly anticipated because it provides novel and compelling evidence for the therapeutic targeting of the tumour microenvironment -- specifically TAMs -- to disrupt communication and ultimately impede cancer progression.
Dr. Joyce is optimistic that "the identification of factors that are differentially produced by conscripted cells in the tumour microenvironment provides a strategy to selectively target these cells in combination with targeting the cancer cells, an approach that could have significant therapeutic potential."
