ShcA Family of Adaptor Proteins: Dual Role in Cell Growth

ShcA proteins are the family of adaptor proteins that mediate biological responses by transducing extracellular signals into intracellular signals. ShcA family consists of three different alternatively spliced or alternative translational initiated isoforms known as p66Shc, p52Shc and p46Shc. The p52and p46Shc isoforms are usually involved in promoting cell growth, mediating their action by activating mitogen-activated protein kinases (MAPK) and phosphoinositide-3-kinase/Akt signalling pathways. However, the p66Shc isoform acts as a dual player in cell development and is involved in stimulating both cell proliferative and apoptotic pathways. Any deregulation in the expression of ShcA proteins and pathways regulated by ShcA proteins results in the occurrence of different types of cancerous diseases, including breast cancer, thyroid cancer, prostate cancer and lung cancer. Aberrations in the expression of ShcA proteins have been demonstrated to promote key elements of cancer progression, including cell migration, cell proliferation, metabolic reprogramming, angiogenesis and tumorigenesis. Based on all these studies, the present chapter focuses on the structure of ShcA proteins and their role in promoting metastasis and progression of various cancers. Understanding the role of ShcA proteins may provide new tools for therapeutic interventions in dreadful cancer disease.

Keywords: Adaptor proteins, Apoptosis, Aging, Cell proliferation, Cell differentiation, Cell signalling, Cell survival, Metabolism, Modular domains, Neoplasms, Oxidative stress, Reactive oxygen species, Vascularization.