Expression of Proteasome Activator REGγ in Human Laryngeal Carcinoma and Associations with Tumor Suppressor Proteins

Abstract

The functional significance of the proteasome activator REGγ in the regulation of cell proliferation andapoptosis has been recognized. However, pathological contributions to tumor development remain to be elucidated.Both oncogenic proteins and tumor suppressors are targeted by REGγ for proteasomal degradation. It has beenproposed that the role of the REGγ in the pathogenesis of cancer is cell- and context-specific. In this study, weaimed to explore the potential involvement of REGγ in laryngeal carcinomas, comparing protein expression intumor and adjacent tissues by immunohistochemical staining and Western blot analysis. We also characterizedthe correlation between the expression of REGγ and the previously identified substrates p53 and p21. Weshowed that REGγ was abnormally highly expressed in cancer tissues. Statistical analysis revealed that therewas a positive relationship between the level of REGγ and the expression of p53 and p21. Our study suggeststhat REGγ overexpression can facilitate the growth of laryngeal cancer cells.