Xiao Xin Sun, Ph.D.

Xiaoxin Sun

During her PhD study at OHSU, Dr. Sun focused on molecular and biochemical mechanisms underlying the regulation of p53-MDM2 pathway. Particularly, she has discovered that aberrant expression of the nucleolar protein nucleostemin activates p53 signaling. She also identified that several chemotherapieutic agents induce p53 by triggering ribosomal stress. After graduation, Dr. Sun joined the Riley Heart Research Center at Indiana University School of Medicine to investigate the function of Phosphatase of regenerating liver family proteins (PRL1, PRL2, and PRL3) in animal development and relevant human diseases, including cancer, using knockout mice models. She received a postdoctoral fellowship from the Cancer Biology Training Program at Indiana University during this period. In 2009, Dr. Sun returned to OHSU and joined Mushui's lab. She is now continuing on the characterization of the regulation of p53-MDM2 pathway. She is currently supported by the Molecular Hematology Training Program at OHSU sponsored by NIH training grant.

Selected Publications

Sun X.-X., Challagundla K.B., Dai M.-S. (2012) Positive regulation of p53 stability and activity by the deubiquitinating enzyme Otubain 1. EMBO J, 31(3): 576-592

Challagundla K.B., Sun X.-X., Zhang X., DeVine T., Zhang Q., Sears R.C., Dai M.-S. (2011) Ribosomal protein L11 recruits miR-24/miRISC to repress c-Myc in response to ribosomal stress. Mol Cell Biol, 31(19): 4007-4021

Sun XX, DeVine T, Challagundla KB, Dai MS. (2011) Interplay between ribosomal protein S27a and MDM2 protein in p53 activation in response to ribosomal stress. J Biol Chem, 286(26): 22730-227416.  

Sun XX, Wang YG, Xirodimas DP, Dai MS. (2010) Perturbation of 60S ribosomal biogenesis results in ribosomal protein L5 and L11-dependent p53 activation. J Biol Chem, 285(33): 25812-258215.

Dai MS, Sun XX, Lu H. (2008) Aberrant expression of nucleostemin activates p53 and induces cell cycle arrest via inhibition of MDM2. Mol Cell Biol, 28(13): 5465-576 4.   

Sun XX, Dai MS, Lu H. (2008) Mycophenolic acid activation of p53 requires ribosomal proteins L5 and L11. J Biol Chem, 283(18): 12387-123923.   

Sun XX, Dai MS, Lu H. (2007) 5-Fluorouracil activation of p53 involves an MDM2-ribosomal protein interaction. J Biol Chem, 282(11): 8052-80592.