P16基因在涎腺肿瘤中表达的研究

EXPRESSION OF P16 GENE IN SALIVARY GLAND TUMORS

目的 :P1 6基因是新近发现的直接参与细胞周期的抑癌基因 ,研究发现在许多肿瘤中存在着突变和缺失 ,但在涎腺肿瘤中的研究尚未见报道。本实验通过对P1 6基因在涎腺肿瘤中的表达研究 ,从分子水平上探讨涎腺肿瘤的发生机制和从组织水平上探索P1 6基因与涎腺肿瘤生物学特性的关系 ,以期在判断预后及恶性度上为临床提供指导。方法 :本研究用PCR SSCP检测 2 1例新鲜涎腺肿瘤组织及每一例相同病例癌旁的正常涎腺组织的P1 6基因点突变 ;用免疫组织化学ABC法检测 6 2例正常涎腺及其肿瘤存档蜡块标本P1 6蛋白的表达情况。结果 :全部新鲜组织标本的P1 6基因第 1及第 2外显子经PCR扩增后均出现相应扩增产物。SSCP分析结果显示 2 1例涎腺正常组织、炎症和肿瘤均未发现外显子异常。从免疫组织化学染色结果可以看出 ,P1 6蛋白在涎腺及其肿瘤的几乎所有腺管和有腺管形成趋势的上皮结构中呈现阳性表达 ,且其表达有随着肿瘤恶性度的增加而减少的负性相关变化趋势。在全部涎腺肿瘤中 ,P1 6蛋白表达阳性率占 6 8 3% ( 4 1 /6 0 ) ;在 2 6例良性肿瘤中 ,阳性表达率为92 3% ( 2 4 /2 6 ) ;在 34例恶性肿瘤中 ,阳性表达率为 5 0 % ( 1 7/34) ,三者之间差异显著 (P <0 0 1 )。结论 :本研究表明P1

Objective:P16 gene was found recently as suppressor gene of carcinoma which take part in cell cycle.The study found that P16 gene had mutation and deletion in many tumors,but no study in salivary gland tumors.This paper study generation mechanism of salivary gland tumors in molecular and relation of P16 gene and biologic characteristics of salivary gland tumors through expression of P16 gene in salivary gland tumors,and provide guide for clinic in prognosis and malignancy.Methods:Point mutation of P16 gene were examined by PCR—SSCP in 21 cases of fresh salivary gland tumor tissue and normal salivary tissue in periphery of tumors in the same case.Expression of P16 protein were examined by immunohistochemistry in 62 cases of wax block keeping in the archive of normal salivary gland tissue and salivary gland tumors.Results:Exon Ⅱ and exon Ⅰ P16 gene of all fresh tissue speciman have amplicatory products after PCR amplification.Analysis of SSCP show that there are no abnormal exon in 21 cases of normal salivary gland tissue,inflammantory and tumors.According to immunohistochemistry,P16 protein has postive expression in almost all epithelial structure of glandular duct and formed glandular duct trend with salivary gland and salivary gland tumors,and has negative correlation trend with raising of tumor malignant degree,reducing of P16 protein expression.Positive rate of P16 protein expression is 68 3%(41/60),92 3%(24/26) and 50%(17/34)in all salivary gland tumors,benign tumors and malignant tumors.The difference of the three is significant by x 2 test,P<0 01.Conclusion:This study show that P16 gene locate regular in epithelial of glandular duct and formed glandular duct trend,and strength of positive and differetiation is negative correlation,indicate that P16 protein may have relation in biologic behavior of salivary histogenesis,different degree,prognosis,etc.There are no abnormal of P16 gene by SSCP.Abnormal of P16 gene may be in relative advanced stage.