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目的 探讨生长阻滞及DNA损伤诱导基因45g(Gadd45g)过表达及靶向沉默对垂体瘤AtT-20细胞及小鼠原代星型胶质细胞的增殖、凋亡及自噬等影响.方法 构建 Gadd45g 基因的CDS区序列克隆至真核表达质粒 p3XFLAG-Gadd45g及其shRNA真核表达质粒pLKO .1-sh-Gadd45g ,将p3XFLAG-Gadd45g转染至小鼠垂体瘤AtT-20细胞中.其shRNA真核表达质粒pLKO .1-puro-sh-Gadd45g进行慢病毒包装,病毒感染小鼠星形胶质细胞;Western blot检测FLAG-Gadd45g融合蛋白的表达及RT-PCR检测shRNA沉默效率,CCK-8检测细胞增殖活力 ,Western blot检测其对凋亡蛋白、自噬蛋白的影响.结果 Gadd45g及其特异性shRNA真核表达质粒构建成功.构建的p3XFLAG-Gadd45g质粒在垂体瘤AtT-20细胞中能够表达;Gadd45g shRNA具有沉默效率.在垂体瘤AtT-20细胞中过表达Gadd45g ,可明显抑制细胞增殖 ,并能诱导Caspase-3表达,降低Beclin 1表达及LC3-Ⅱ/Ⅰ的比值(P＜0 .05).与之相反,在原代培养的星形胶质细胞中,shRNA干扰Gadd45g表达,可促进细胞增殖,并降低Caspase-3表达,而增加Beclin 1表达及LC3-Ⅱ/Ⅰ的比值(P＜0 .05).结论 垂体瘤中Gadd45g的表达缺失可能使得垂体瘤A t T-20细胞凋亡受阻及自噬作用增强 ,从而促进垂体瘤的发生、发展.恢复垂体瘤细胞中Gadd45g的表达及抑制垂体瘤细胞自噬作用有望成为垂体瘤治疗的新方法.“,”Objective To investigate the effects of the overexpression and silencing of Gadd45g gene(growth arrest and DNA damage‐inducible gene 45g ) on the proliferation ,apoptosis and autophagy in pituitary tumor cells AtT‐20 and mouse primary astrocyte .Methods The mouse CDS sequence of Gadd45g gene was cloned into the eukaryotic expression plasmid p3XFLAG vector and its short hairpin RNA(shRNA) sequence was cloned into the pLKO .1‐TRC vector .p3XFLAG‐Gadd45g vector was transfected into the pituitary tumor cell AtT‐20 ,lentiviral packaging of Gadd45g shRNA eukaryotic expression vector pLKO .1‐puro‐sh‐Gadd45g and infected mice astrocytes .The FLAHGadd45g fusion protein expression was detected with Western blot ,shRNA silencing efficiency was tested by RT‐PCR ,cell proliferation activity was detected by CCK‐8 ,and Western blot was used to test the effects on apoptosis ,autophagy protein protein .Results Gadd45g and its specific shRNA eukaryotic expression plasmid was successfully constructed .p3XFLAG‐Gadd45g plasmid expressed in the AtT‐20 cells .Gadd45g shRNA had the silencing efficiency .The over expression of gadd45g could inhibit cell proliferation ,induce the expression of Caspase‐3 and decrease the expression of Beclin 1 and ratio of LC3‐ Ⅱ to LC3‐ Ⅰ in pituitary tumor cell AtT‐20 ( P< 0 .05 ) .In the primary cultured astrocytes ,the shRNA interference of gadd45g obviously promoted the cell proliferation ,and reduced the expression of Caspase‐3 ,and increase the expression of Beclin 1 and the ratio of LC3‐ Ⅱ to LC3‐ Ⅰ(P< 0 .05) .Conclusion The absence of Gadd45g expression in pituitary adenoma may hinder the apoptosis of tumor cells and enhance autophagy ,thus promote the occurrence and development of pituitary tumor .Restoration of Gadd45g expression in pituitary tumor cells and inhibition of pituitary tumor cell autophagy may become a new method in the therapy of pituitary adenoma.