Document Detail

Functional characterization of p53 in nasopharyngeal carcinoma by stable shRNA expression.
MedLine Citation:
PMID:  19287958     Owner:  NLM     Status:  MEDLINE    
Nasopharyngeal carcinoma (NPC) is a high-incidence malignancy in Southern China and Southeast Asia. Although mutation of p53 tumor-suppressor gene is a rare event in NPC, NPC has a high frequency of overexpressed/accumulated p53 protein, which was reported to be dysfunction or inactivation in most of NPC. We report here a functional characterization of p53 in an undifferentiated NPC cell line CNE2. To elucidate the biological function of p53, we employed the RNA interference (RNAi) approach to knockdown the endogenously expressed p53 in CNE2 cells. Interestingly, suppression of p53 expression in CNE2 cells was associated with significant down-regulation of p21WAF1/CIP1 expression and decreased HDM2 protein level in both steady state and genotoxic stress induced by ionizing radiation (IR). Consistent with these biochemical data were the accelerated cell cycle progression and the increased proliferation rate, suggesting that p53 retained growth inhibitory activity in CNE2 cells. Indeed, down-regulation of p53 in CNE2 enhanced the ability of CNE2 cells to grow anchorage-independently in vitro and to develop tumors in vivo. Together with the radioresistance acquired by CNE2sip53 cells, our data indicate that in contrast to a previous study, p53 in this NPC cell line remains functional, which may have an important therapeutical implication.
Yi Sun; Hong Yi; Yixuan Yang; Yanhui Yu; Yongmei Ouyang; Fang Yang; Zhiqiang Xiao; Zhuchu Chen
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  International journal of oncology     Volume:  34     ISSN:  1019-6439     ISO Abbreviation:  Int. J. Oncol.     Publication Date:  2009 Apr 
Date Detail:
Created Date:  2009-03-16     Completed Date:  2009-07-20     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  9306042     Medline TA:  Int J Oncol     Country:  Greece    
Other Details:
Languages:  eng     Pagination:  1017-27     Citation Subset:  IM    
Key Laboratory of Cancer Proteomics of Chinese Ministry of Health, Xiangya Hospital, Central South University, Changsha 410008, P.R. China.
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MeSH Terms
Carcinoma / genetics*,  metabolism*
Cell Differentiation
Cell Line, Tumor
Cell Proliferation
Gene Expression Regulation, Neoplastic*
Genes, p53*
Mice, Inbred BALB C
Nasopharyngeal Neoplasms / genetics*,  metabolism*
Neoplasm Transplantation
RNA / genetics*
Tumor Suppressor Protein p53 / genetics*
Reg. No./Substance:
0/TP53 protein, human; 0/Tumor Suppressor Protein p53; 63231-63-0/RNA

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