TUSC 3: a novel tumour suppressor gene and its functional implications

The tumour suppressor candidate 3 ( TUSC 3) gene is located on chromosome region 8p22 and encodes the 34 kD TUSC 3 protein, which is a subunit of the oligosaccharyl transferase responsible for the N ‐glycosylation of nascent proteins. Known to be related to autosomal recessive mental retardation for several years, TUSC 3 has only recently been identified as a potential tumour suppressor gene. Based on the structure and function of TUSC 3, specific mechanisms in various diseases have been investigated. Several studies have demonstrated that TUSC 3 is an Mg 2+ ‐transporter involved in magnesium transport and homeostasis, which is important for learning and memory, embryonic development and testis maturation. Moreover, dysfunction or deletion of TUSC 3 exerts its oncological effects as a modulator by inhibiting glycosylation efficiency and consequently inducing endoplasmic reticulum stress and malignant cell transformation. In this study, we summarize the advances in the studies of TUSC 3 and comment on the potential roles of TUSC 3 in diagnosis and treatment of TUSC 3‐related diseases, especially cancer.