大鼠颌下腺肿瘤形成过程中端粒酶活性的变化

Changes of telomerase activity in the tumorigenesis of rat submandibular gland

目的 :检测SD大鼠颌下腺肿瘤形成过程中端粒酶活性的动态变化 ,探讨端粒酶在涎腺肿瘤发生、发展中所起的作用。方法 :SD大鼠 5 0只 ,麻醉后颈部切口暴露颌下腺 ,右侧腺体植入二甲基苯丙蒽 (DMBA)明胶海绵块 ,左侧为自身对照 ,每过 2周处死大鼠 2只 ,取颌下腺标本。用PCR TRAP法、聚丙烯酰胺凝胶电泳及银染法分析PCR产物 ,检测颌下腺标本中的端粒酶活性。结果 :共诱发肿瘤 2 1例 ,均为鳞状细胞癌 (早期 10例 ,晚期 11例 ) ,另有 3例导管上皮鳞状化生。 2 1例端粒酶活性均为阳性 ,实验侧明显高于自身对照侧 (P <0 .0 1)。鳞状上皮化生、鳞癌早期、鳞癌晚期 3组相比 ,端粒酶活性差异均有统计学意义 (P <0 .0 5 )。结论

Aim:To detect the changes of telomerase activity in the tumorigenesis of rat submandibular gland; to investigate the role of telomerase in genesis and development of salivary gland tumor. Methods:Submandibular glands of 50 SD rats were exposed after anesthesia and DMBA was used to induce tumor in right submandibular gland and opposite glands were used as control. The specimens from the submandibular glands were taken from 2 rats every 2 weeks. PCR TRAP was used to detect telomerase activity.Results: A total of 21 lateral tumors,which were all squamous cell carcinoma(10 at early stage,and 11 at late stage),and 3 cases of duct squamous metaplasia were induced. Telomerase activity in all 21 tumor samples were positive,and the values were obviously higher than that from control side ( P <0.01).Significant difference was noted among various stages of tumorigenesis ( P <0.05).Conclusion:The increase of telomerase activity might be a molecular probe for diagnosis of malignant salivary gland tumors.