Pit-1与垂体腺瘤发生关系的研究

Relationship between pituitary transcription activator Pit-1 and development of human pituitary adenomas

目的通过定量研究Pit-1 mRNA在不同类型的垂体腺瘤中的表达,探讨Pit-1 mRNA与垂体腺瘤发生的关系。方法34例垂体腺瘤手术中取出,迅速冻于液氮中保存。根据血清激素水平、临床表现以及垂体组织免疫组化染色结果确定腺瘤类型。用异硫氢酸胍一步法提取垂体腺瘤组织总RNA,用RT-PCR方法检测Pit-1 mRNA在各组垂体腺瘤组织中的表达。结果Pit-1 mRNA在所有PRL瘤、GH+PRL瘤、GH瘤、寂静PRL瘤以及寂静GH瘤中有表达。在ACTH腺瘤和零细胞瘤中无表达。PRL瘤术前血清PRL值与腺瘤组织Pit-1表达量呈明显的正相关(γ=0.90,P<0.01),GH腺瘤术前血清GH值与腺瘤组织Pit-1表达量呈明显的正相关(γ=0.96,P<0.01)。结论Pit-1 mRNA在垂体腺瘤中呈细胞特异性表达,提示对垂体GH和PRL腺瘤的细胞特异分化及分泌功能有一定的作用。

Objective To study the relationship between Pit - 1 and development of human pituitary adenomas by analyzing Pit- 1 mR- NA levels in such tumors. Meth^ls Samples were obtained from 34 patients. The types of pituitary adenomas were determined according to serum hormone levels, clinical features, and immunohistochemistry analysis. Expression of Pit- 1 mRNA was studied by reverse transcriptase - polymerase chain reaction method.Results Pit- 1 mRNA was expressed in all iactotropic, somatotropic , mixed somatotropic- lactotropic adenomas, silent lactotropic adenomas, and silent somraotropic adenomas. No Pit- 1 mRNA expression was found in either ACTH- secreting adenomaz or null cell adenomas. Serum prolacfin（PRL） levels were positively correlated with Pit- 1 mRNA levels （ r =0.90, P 〈0.01）in lactotropic adenomas and serum growth honnone（GH） levels were positively correlated with Pit- 1 expression levels in somatotropic adenomas （ r =0.96, P 〈0.01）.Conclusion Celltype- specific expression of pit - 1 mRNA in pituitary adenomas indieates that Pit- 1 plays a role in cytodifferenfiation of some types of human pituitary adenomas.