Inflammation and cancer stem cells

• Cancer stem cells (CSCs) have the ability to propagate and sustain tumourigenesis.
• The bulk cancer cells, CSCs, the microenvironment and the immune system interact with each other through chemical stimuli, such as cytokines.
• Inflammation is evident at the earliest stages of cancer progression and is capable of fostering growth of small tumours into metastatic cancers.
• Aberrant pathway activation, such as NF-KB and Notch, occurs following inflammatory stimuli, such as IL-6 .
• Stimuli from tumour cells and immune cells causes cancer cells to dedifferentiate/convert into CSCs which have the ability to metastasize.

Cancer stem cells are becoming recognised as being responsible for metastasis and treatment resistance. The complex cellular and molecular network that regulates cancer stem cells and the role that inflammation plays in cancer progression are slowly being elucidated. Cytokines, secreted by tumour associated immune cells, activate the necessary pathways required by cancer stem cells to facilitate cancer stem cells progressing through the epithelial–mesenchymal transition and migrating to distant sites. Once in situ, these cancer stem cells can secrete their own attractants, thus providing an environment whereby these cells can continue to propagate the tumour in a secondary niche.