中文摘要：

目的探讨磷酸酶及张力蛋白同系物（PTEN）基因5′端非编码区（5′-UTR）-9C→G多态性位点与鼻咽癌发生风险及疾病严重程度的相关性。方法应用PCR-RFLP方法对593例鼻咽癌患者和480例健康对照PTEN基因的-9C→G多态性位点进行分型。采用非条件Logistic回归分析,校正性别、年龄、饮酒状态、吸烟状态、吸烟量的影响,计算比数比（OR）和95%置信区间（CI）,评价多态性位点与表型的遗传相关性。结果PTEN基因-9C→G多态性位点与鼻咽癌发生风险无关联,进一步按性别、年龄、饮酒状态、吸烟状态和吸烟量风险因素进行分层分析,仍无相关性。在疾病严重程度分析中,按临床分级及T、M、N分级均未发现-9C→G多态性位点与鼻咽癌疾病严重程度相关。结论PTEN基因-9C→G多态性位点与鼻咽癌的易感性及其严重程度均无关联,该多态性位点可能在鼻咽癌的易感性和疾病严重程度机制中不发挥重要作用。

英文摘要：

Objective PTEN gene is located on chromosome 10q23,and codes for a tyrosine phosphatase with putative tumor suppressive abilities as p53.Mutations in PTEN have been implicated in the tumorigenesis of several types of cancers.Furthermore,PTEN expression has also been implicated in the tumorigenesis and malignancy of nasopharyngeal carcinoma（NPC）in several studies.The aim of the present study was to determine the association of PTEN-9C→G polymorphism with the susceptibility and malignancy of NPC in a southern Chinese population.Methods PTEN-9C→G polymorphism was genotyped in a case-control population including 593 patients with NPC and 480 healthy subjects by PCR-RFLP.Logistic regression analysis adjusted for age,sex,amount of smoking,status of drinking and pack-years of smoking was performed to calculate odds ratio（OR）and 95% confidence interval（95% CI）.Results On the basis of logistic regression analysis with adjustment for age,sex,status of smoking,status of drinking,and pack-years of smoking,no significant association with the risk of NPC was observed with PTEN-9C→G polymorphism.When the analyses were stratified by age,sex,status of smoking and drinking,pack-years of smoking and family history of NPC,still there was no significant association between this polymorphism and NPC risk.Furthermore,the distributions of the PTEN-9C→G genotypes were also not significantly different among the subgroups with different clinical stage,or different T,N and M classification of the cancer.Conclusion The findings of present study suggest that the PTEN-9C→G polymorphism may not play a major role in mediating susceptibility and malignancy of NPC in the southern Chinese population.