P53R2 as a novel prognostic biomarker in nasopharyngeal carcinoma

Jiewei Chen,Xinke Zhang,Xuan Zou,Muyan Cai,Mingshu Zhu,Dan Xie,Yongbo Xiao,Shuman Li

doi:10.1186/s12885-017-3858-4

Abstract

Backgroundp53R2 is a target of p53 gene, which is essential for DNA repair, mitochondrial DNA synthesis, protection against oxidative stress, chromosomal instability, chronic inflammation and tumorigenesis. This study is aimed to investigate the expression of ribonucleotide reductase (RR) subunit p53R2 in nasopharyngeal carcinoma and its significance in the prognosis.MethodsThe expression levels of p53R2 in 201 patients with NPC were examined by immunohistochemical assay. The correlations of p53R2 expression and clinicopathological features of nasopharyngeal carcinoma patient were analysed by chi-square test. The Kaplan-Meier survival analysis and Cox multivariate regression model were used to analyze the prognostic significance of the patients with NPC.ResultsImmunohistochemical results showed that p53R2 was positively expressed in 92.5% (186/201) of nasopharyngeal carcinoma and the high expression rate was 38.3% (77/201). Further analysis observed that the negative correlation between expression of p53R2 and pT status had statistical significance (P < 0.05). Kaplan-Meier survival analysis found that the mean survival time of patients with high expression of p53R2 was 143.32 months, while the patients with low expression level of p53R2 was 121.63 months (P < 0.05). Cox regression analysis suggested that p53R2 protein expression could be used as an independent prognostic factor for nasopharyngeal carcinoma (P < 0.05).ConclusionsThis study drew a conclusion that p53R2 could be used as a prognostic biomarker indicative of the favorable outcome for patients with nasopharyngeal carcinoma.

Highlights

Nasopharyngeal carcinoma (NPC) is the malignant cancer occurring on the top and lateral wall of nasopharynx cavity [1], which is prevalent in southeast Asia especially in southern China
It has been proved that EpsteinBarr virus infection, genetic susceptibility, environmental factors, dysfunction of oncogenes or suppressor genes and life styles are all associated with NPC tumorigenesis [3]
Independent prognostic factors for NPC patients The factors that had a significant difference in univariate analysis were further tested in the cox regression analysis, and the results suggested that p53R2 was an independent prognostic factor

Summary

Introduction

Nasopharyngeal carcinoma (NPC) is the malignant cancer occurring on the top and lateral wall of nasopharynx cavity [1], which is prevalent in southeast Asia especially in southern China. Most of the NPC patients are diagnosed at the stage of III or IV, and the 5 years survival rate is 50%–60% [2]. It has been proved that EpsteinBarr virus infection, genetic susceptibility, environmental factors, dysfunction of oncogenes or suppressor genes and life styles are all associated with NPC tumorigenesis [3]. Chen et al BMC Cancer (2017) 17:846 good outcome for the patients, suggesting that p53R2 may be a tumor suppressor [10, 11]. It’s still unclear what’s the expression status of p53R2 expression in NPC and its clinicopathological significance. We used IHC to evaluate the protein level of p53R2 in nasopharyngeal carcinoma tissues and apply the statistic analysis methods to identify the association between p53R2 and the prognostic significance of nasopharyngeal carcinoma

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