Epithelial-Mesenchymal Transition and Immune Evasion during Lung Cancer Progression: The Chicken or the Egg?

Abstract

Epithelial-mesenchymal transition (EMT) is a complex process involved in metastasis. Immune evasion is required for tumor progression and is characterized by an ineffective antitumor immune response and upregulation of immune-suppressive signals. The coexistence of EMT and adaptive immune evasion opens the possibility of a mechanistic link between these processes. Clin Cancer Res; 22(14); 3422-4. ©2016 AACRSee related article by Lou et al., p. 3630.

Figure 1. Possible association between EMT and anti-tumor immune response during (epithelial) cancer progression

Although EMT and tumor immune rejection/evasion are continuous, heterogeneous and potentially reversible processes, they frequently co-exist in lung adenocarcinomas suggesting a mechanistic link between them. Key EMT-mediators such as Snail, Twist, Zeb and aberrant β-catenin signaling can induce immune suppressive features in tumors. However, diverse inflammatory mediators such as TGF-β, TNF-α, IL-6, IL-8 and IL-10 or immune suppressive cells can promote an EMT-program in carcinoma cells. APC, antigen-presenting cell.