. Author manuscript; available in PMC: 2013 Apr 1.

Published in final edited form as: Future Oncol. 2012 Jun;8(6):713–722. doi: 10.2217/fon.12.59

Table 1.

Cytokine loops that initiate/maintain tumor epithelial–mesenchymal transition.

EMT-secreted factors	Function during tumor EMT
IL-8	Induction of EMT
	Induction of tumor stemness
	Maintenance of EMT by an autocrine IL-8 loop
	Angiogenesis
	Recruitment of TANs

IL-6	Induction of EMT
IL-6	Maintenance of EMT by an autocrine IL-6 loop

VEGF	Angiogenesis
VEGF	Induction of EMT in epithelial tumor cells

TGF-β	Induction of EMT
	Maintenance of EMT by an autocrine TGF-β loop
	Impairment of antitumor immune responses

MMPs	Degradation of ECM
	Activation of growth factors
	Inactivation of protease inhibitors
	Induction of EMT

ECM: Extracellular matrix; EMT: Epithelial–mesenchymal transition; MMP: Matrix metalloproteinase; TAN: Tumor-associated neutrophil.