肌动蛋白细丝桥梁蛋白(Girdin)在垂体瘤中的表达及促细胞增殖作用

目的 检测肌动蛋白细丝桥梁蛋白(Girdin)在垂体瘤中的表达,并探讨其促进细胞增殖的作用及相关分子机制.方法 收集泌乳素腺瘤、生长激素腺瘤和无功能垂体瘤样本各2例,以及正常垂体样本1例.分别提取各样本组织蛋白,用蛋白质印迹法检测样本中Girdin的表达水平,并用免疫荧光实验进一步验证.通过过表达和RNA干扰Girdin分别构建Girdin过表达和敲低的大鼠垂体瘤细胞系GH3细胞模型.用蛋白质印迹法检测Girdin过表达或敲低的GH3细胞中的Girdin和Akt蛋白及其磷酸化水平.通过细胞增殖实验和凋亡实验研究Girdin在垂体瘤中的功能和生物学行为.结果 蛋白质印迹分析结果显示Girdin在无功能垂体瘤中表达最高,生长激素腺瘤次之;免疫荧光实验也验证了Girdin在无功能垂体瘤中的高表达.过表达和RNA干扰实验分别提高和敲低了GH3细胞中Girdin的表达水平,Akt的磷酸化水平也发生同样变化.此外,Girdin的过表达能够促进GH3细胞增殖.结论 Girdin在无功能垂体瘤中高表达,并通过调控Akt磷酸化水平促进垂体瘤细胞的增殖.

Expression of girders of actin filaments (Girdin) in pituitary adenomas and its role in promoting cell proliferation

Objective To investigate the expression of girders of actin filaments (Girdin) in pituitary adenomas, and its role in promoting cell proliferation and the related molecular mechanism. Methods Two prolactinoma, growth hormone adenoma and non-functioning pituitary adenoma tissues, and one normal pituitary gland tissue were collected. The protein expression of Girdin in the different tissues was detected by Western blotting, and then the expression of Girdin was further confirmed by immunofluorescence. Rat pituitary tumor cell lines GH3 cell model with Girdin knockdown and overexpression was established by RNA interference and overexpression of Girdin, respectively. The protein expression of Girdin and Akt and phosphorylation level of Akt in the GH3 cell models were detected by Western blotting. The function and biological behavior of Girdin in pituitary adenomas tissues were studied by cell proliferation assay and cell apoptosis assay. Results The expression of Girdin in the non-functioning pituitary adenomas was the highest, followed by growth hormone pituitary adenomas. The high expression of Girdin in the non-functioning pituitary adenomas was also verified by immunofluorescence assay. RNA interference and overexpression of Girdin effectively knocked down and increased the expression of Girdin, respectively, accompanied by the simultaneous changes of Akt phosphorylation. In addition, overexpression of Girdin promoted the proliferation of GH3 cells. Conclusion Girdin is highly expressed in non-functioning pituitary adenomas and can promote the proliferation of pituitary adenoma cell by regulating the Akt phosphorylation.