REGγ Mediated Regulation of p21^Waf/Cip1, p16^INK4a and p14^ARF/p19^ARF in Vivo

Lei Li, Pei Zhang, Haibin Wei, Weicang Wang, Liangfang Yao, Yubing Li, Lei Zhou, Zhuo Wang, Jiang Liu, Li Zhou, Ali Amjad, Bianhong Zhang, Tiantian Jing, Jianru Xiao, Yongyan Dang, Xiaotao Li

Department of Orthopaedic Oncology, Changzheng Hospital, The Second Military Medical University, Shanghai, China.
Department of Pathology, The Second Chengdu Municipal Hospital, Chengdu, China.
The Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, East China Normal University, Shanghai, China.

DOI: 10.4236/jct.2013.45104                

Abstract

p21^Waf/Cip1, p16^INK4a and p14^ARF (p19^ARF in mice) have been demonstrated to be degraded by REGγ-proteasome pathway in an ATP- and ubiquitin-independent manner in vitro. However, the in vivo roles of REGγ mediated-degradation of p21^Waf/Cip1, p16^INK4a and p14^ARF remain unclear. In this study, we showed enhanced expression of p21^Waf/Cip1, p16^INK4a and p19^ARF in multiple tissues from REGg^–/– mice compared to REGg^+/+ mice. Furthermore, we examined the expression of p21^Waf/Cip1, p16^INK4a and p14^ARF in different cancer tissues and observed that the REGγ protein levels were highly expressed in different human cancers while the level of p21^Waf/Cip1, p16^INK4a and p14^ARF appears to be inversely correlated. These results demonstrate that REGγ may exert its function in physiological and pathological conditions through degradation of p21^Waf/Cip1, p16^INK4a and p14^ARF in vivo.

Keywords

REGγ; p21^Waf/Cip1;p16^INK4a; p14^ARF; p19^ARF; Cancer

Conflicts of Interest

The authors declare no conflicts of interest.

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