Decreased P27 protein expression is correlated with the progression and poor prognosis of nasopharyngeal carcinoma

Qingping Jiang,Huiling Yang,Zhen Liu,Hanzhen Xiong,Yajie Zhang,Chao Cheng,Jie Long,Weiyi Fang,Shaoyan Liu

doi:10.1186/1746-1596-8-212

Abstract

BackgroundTo determine the correlation of cyclin-dependent kinase inhibitor 1B (p27) expression with clinicopathologic features in nasopharyngeal carcinoma (NPC), including patient prognosis.MethodsReal-time PCR and immunohistochemistry were used to examine the mRNA and protein expressions of p27 in NPC and nasopharyngeal tissues. The relationship of p27 expression levels with clinical features and prognosis of NPC patients was analyzed.ResultsThe expression level of p27 mRNA was markedly lower in NPC tissues than that in the nasopharyngeal tissues (P = 0.0006). Specific p27 protein staining by immunohistochemistry was found in the nuclei and cytoplasm of nasopharyngeal and malignant epithelial cells but decreased expression was observed in NPC samples compared to normal epithelium samples (P = 0.002). In addition, low levels of p27 protein were inversely correlated with the status of T classification (p = 0.002) and clinical stage (p = 0.019) of NPC patients. Patients with lower p27 expression had a significantly shorter overall survival time than did patients with high p27 expression. Multivariate analysis suggested that the level of p27 expression was not an independent prognostic indicator (p = 0.682) for NPC survival.ConclusionLow level of p27 expression is a potential unfavorable prognostic factor for patients with NPC.Virtual slidesThe virtual slide (s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1915282782109343.

Highlights

To determine the correlation of cyclin-dependent kinase inhibitor 1B (p27) expression with clinicopathologic features in nasopharyngeal carcinoma (NPC), including patient prognosis
Cyclin-dependent kinase inhibitor 1B (P27) mRNA is expressed at low levels in NPC tissue In order to assess the role of p27 in NPC, we performed real-time Polymerase chain reaction (PCR) to measure the expression of p27 mRNA transcripts in 61 fresh NPC tissues and 20 fresh collected normal nasopharyngeal tissues
Decreased expression of p27 was observed in NPC samples compared to NP tissues (P = 0.002) (Table 2)

Summary

Introduction

To determine the correlation of cyclin-dependent kinase inhibitor 1B (p27) expression with clinicopathologic features in nasopharyngeal carcinoma (NPC), including patient prognosis. Nasopharyngeal carcinoma (NPC) is a squamous cell carcinoma derived from mucosal epithelium of the nasopharynx correlated with EBV infection, environmental factors and genetic aberrance. EBV infection is the most important for NPC, when other cancers in upper digestive tract have something with to do with it [1]. P27 is an enzyme inhibitor that in humans is encoded by the CDKN1B gene. It encodes a protein which belongs to the Cip/Kip family of cyclin dependent kinase (Cdk) inhibitor proteins. P27 was observed to act as a significant role in suppressing tumor pathogenesis [11,12]. Based on the above reports mentioned, p27 was taken as an important gene participating in tumor pathogenesis. The role p27 plays in NPC has been reported in several references [13,14].p27 was found the low expression level may contribute to the aggressive behavior of NPC by immunohistochemistry

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Results

Discussion

Conclusion