Feedback inhibitors of the epidermal growth factor receptor signaling pathways.

The epidermal growth factor receptor family tyrosine kinases transduce signals for cell proliferation and migration and contribute to tumorigenesis. A recent extensive research has highlighted the major roles of the negative regulators of complex epidermal growth factor receptor signaling networks. These regulators fine-tune signaling under physiological conditions. When their expression is downregulated, the resultant aberrant epidermal growth factor receptor signaling may promote cell proliferation and migration, leading to increased tumorigenesis. In this paper, I review specific feedback inhibitors that target epidermal growth factor receptors preferentially, via multiple modes of action. The inhibitors include mitogen-inducible gene-6 (Mig-6)/receptor-associated late transducer (RALT)/Gene 33, fibroblast growth factor receptor substrate 2beta (FRS2beta)/suc1-associated neurotrophic factor target-2 (SNT-2)/FRS3, suppressor of cytokine signaling 3 (SOCS3)/SOCS4/SOCS5, and leucine-rich repeats and immunoglobulin-like domains 1 (LRIG1). Although only fragmentary evidence is available regarding these inhibitors, they might be useful as cancer biomarkers, and the development of drugs that target them would certainly advance personalized medicine in the near future.