TPA增强gsp癌基因阳性人垂体生长激素腺瘤GHRP促生长激素分泌的效应

TPA Enhances the Releasing Effect of GHRH on Somatotropinomas with Positive Gsp Oncogene

探讨细胞内ＰＫＣ信号传导系统在人垂体生长激素腺瘤ＧＨ分泌中的作用。方法：采用ＰＣＲ和直接序列分析法评价１０例肢端肥大症患者肿瘤组织的ｇｓｐ癌基因的表达。肿瘤组织取自手术切除标本，作细胞培养，进行体外生长激素释放激素（ＧＨＲＨ）和蛋白激酶Ｃ激活剂ＴＰＡ对ＧＨ释放效应研究。结果：１０例病人中有３例（３０％）为ｇｓｐ癌基因表达阳性，ＧＨＲＨ对ＧＨ刺激效应在本组中有２例表现出有统计学意义，ｇｓｐ阴性组７例中有４例表现出有统计学意义的刺激效应。ＴＰＡ可增强ＧＨＲＨ对ｇｓｐ阳性表达腺瘤细胞分泌的刺激作用，但是对阴性组细胞无此作用。结论：推测ＧＨＲＨ对ＧＨ的分泌效应除受腺苷酸环化酶－ｃＡＭＰ－蛋白激酶Ａ第二信使系统的调节外，尚有蛋白激酶Ｃ信号系统存在。

Objective:Evaluating the role of PKC transduction system on GH secretion of human pituitary somatotropinomas. Methods:PCR and direct sequencing analysis were used to evaluate the expression of gsp oncogene in 10 patients with active acromegaly.The pituitary somtotropinomas were obtained from the patients upon whom a transcranial or transsphenoidal adenomectomy was performed. After surgical resection,tissue were processed for cell culture and tested the releasing effects of GHRH and TPA,an activator of PKC,in vitro.Results: Of the 10 patients,3(30%) were gsp oncogene positive.GHRH releasing effect was statistically significant on 2 of the 3 patients,but of 7 patients with gsp oncogene negative,4 was statistically significant.TPA enhanced GHRH releasing effect on adenoma cells with gsp positive,but in vain on gsp negative ones.Conclusion: GHRH releasing effect is also regulated by PKC signal transduction system as well as by adenyl cyclase-cAMP-PKA transduction system in pituitary cells.