GATA6在胰岛素瘤中的表达及与胰岛素瘤细胞增殖和凋亡的关系

Expression of GATA6 in insulinoma and its relationship with proliferation and apoptosis of insulinoma cells

摘要:

目的 探究锌指转录因子GATA6在胰岛素瘤中的表达及与胰岛素瘤细胞增殖和凋亡的关系。方法 收集2009年1月至2014年9月于上海交通大学附属第六人民医院确诊的3例胰岛素瘤患者的瘤体及其相应瘤旁组织，应用蛋白印迹法（Western blotting）检测GATA6在胰岛素瘤瘤体及瘤旁的表达差异。另外收集正常胰腺组织标本2例，免疫荧光法观察GATA6在胰岛素瘤组织及正常胰腺组织中的表达及定位。培养小鼠胰岛素瘤细胞系MIN6细胞，小干扰RNA（siRNA）干扰GATA6表达后，用流式细胞仪观察细胞凋亡及细胞周期的变化。结果 胰岛素瘤瘤体组织GATA6表达水平较瘤旁组织异常升高（P＜0.05）；免疫荧光法显示胰岛素瘤正常胰岛结构丧失，GATA6主要位于胰岛素瘤细胞的细胞核中，在胰岛素瘤中大量表达，在正常胰岛β细胞中少量表达。沉默GATA6表达后胰岛素瘤细胞凋亡显著增加（P＜0.05），且细胞增殖受抑制（P＜0.05）。结论 GATA6在胰岛素瘤中异常高表达，与胰岛素瘤细胞增殖凋亡关系密切，提示GATA6可能在胰岛素瘤的发病机制中起重要的作用。

Abstract:

Objective To determine the expression of zinc finger transcription factor GATA6 in insulinoma and its relationship with the proliferation and apoptosis of inslulinoma cells. Methods Tumor tissue and adjacent normal tissue specimens of 3 cases of insulinoma were collected from Jan. 2009 to Sep. 2014 in the Sixth People’s Hospital Affiliated to Shanghai Jiaotong University. Expression of GATA6 in the insulinoma and para-insulinoma tissue was evaluated by Western blotting. In addition, normal pancreas tissues of 2 cases were collected, and immunofluorescence staining was employed to detect the expression and localization of GATA6 in insulinoma and normal pancreatic tissues. Mouse insulinoma MIN6 cells were transfected by small interference RNA (siRNA) interference against GATA6, and then cell cycle and apoptosis were measured by flow cytometry. Results GATA6 was significantly highly expressed in the insulinoma than in para-insulinoma (P＜0.05). Immunofluorescence staining showed that normal islet structure had been disrupted in inulinoma tissue, and GATA6 was mainly localized in the nucleus of insulinoma cells and highly and extensively expressed in insulinoma tissue, and mildly in normal pancreatic islet β cells. After siRNA interference against GATA6 expression, there were significantly more apoptotic cells compared with the control group (P＜0.05), and cell proliferation was obviously inhibited (P＜0.05). Conclusion GATA6 is abnormally highly expressed in insulinoma, and closely related with the cell proliferation and apoptosis, indicating that it may play an important role in insulinoma pathogenesis.