Hamada K, Nishi T, Kuratsu J, Ushio Y
Department of Neurosurgery, Kumamoto University Medical School, Kumamoto City, Japan.
Neurosurgery. 1996 Feb;38(2):362-6. doi: 10.1097/00006123-199602000-00026.
Twenty-eight human pituitary adenomas were analyzed for the expression of Pit-1 messenger ribonucleic acid (mRNA) by using reverse transcriptase-polymerase chain reaction analysis of frozen-section mRNA. Pit-1 mRNA was detected in all functioning tumors and in 9 of 11 nonfunctioning tumors. Pit-1 beta, which is a more active isoform of transcriptional factor for growth hormone than Pit- alpha and which arises from an alternative splicing mechanism, was detected in 14 of 17 functioning tumors and in 5 of 11 nonfunctioning tumors. The transcript that corresponds to Pit-1T, which increases thyroid-stimulating hormone beta promoter activity in rat thyrotropic tumor cells, was not found. There was no significant difference in the total Pit-1 (alpha+beta) mRNA expression level between functioning tumors and nonfunctioning tumors. Growth hormone-producing tumors and other pituitary adenomas also showed no significant difference in the Pit-1 beta/Pit-1 alpha expression ratio. Our data suggest that the major role of Pit-1 gene in pituitary adenoma might not be involved in the regulation of hormone production.
通过对冰冻切片mRNA进行逆转录聚合酶链反应分析，对28例人类垂体腺瘤进行Pit-1信使核糖核酸（mRNA）表达分析。在所有功能性肿瘤以及11例无功能性肿瘤中的9例中检测到了Pit-1 mRNA。Pit-1β是一种比Pit-α更具活性的生长激素转录因子亚型，它通过可变剪接机制产生，在17例功能性肿瘤中的14例以及11例无功能性肿瘤中的5例中被检测到。未发现与Pit-1T相对应的转录本，Pit-1T可增加大鼠促甲状腺肿瘤细胞中促甲状腺激素β启动子的活性。功能性肿瘤和无功能性肿瘤之间的总Pit-1（α+β）mRNA表达水平无显著差异。产生生长激素的肿瘤和其他垂体腺瘤在Pit-1β/Pit-1α表达比值上也无显著差异。我们的数据表明，Pit-1基因在垂体腺瘤中的主要作用可能不涉及激素产生的调节。
