Contribution of PKB/AKT signaling to thyroid cancer

The family of serine/threonine kinases B/Akt (hereafter Akt) represents a central node in signalling pathways downstream of growth factors, cytokines, and other cellular stimuli. In mammalian cells the Akt family comprises three highly homologous members -known as Akt1/PKB alpha, Akt2/PKB beta, and Akt3/PKB gamma- that regulate several processes including cell proliferation and survival, growth and response to nutrient availability, migration, tissue invasion and angiogenesis. Aberrant activation of Akt is involved in a variety of human cancers including those arising in the thyroid gland. Here, we review the contribution of Akt-dependent pathway in the proliferation of normal thyrocytes, the different pathogenic mechanisms underlying aberrant Akt signalling in thyroid malignancies as well as the relative roles of Akt substrates that most likely contribute to the onset and/or progression of thyroid cancer. Finally, we discuss the current therapeutic strategies targeting the components of the PI3K/Akt pathway in the context of thyroid malignancy.