中文摘要：

目的初步探讨神经生长因子Netrin-1对人肝癌细胞HepG2抗失巢凋亡的作用及相关机制。方法采用脂质体转染的方法,将Netrin-1的真核表达质粒转染到肝癌细胞HepG2中,Western blot检测Netrin-1的表达;用软琼脂集落试验、悬浮培养模型及流式细胞检测的方法观察肝癌细胞HepG2抗失巢凋亡的特性。结果肝癌细胞HepG2在失巢状态下可以聚集成团生长,并与贴壁生长有相似的凋亡比例。与对照组细胞相比,稳定转染Netrin-1真核质粒的HepG2细胞在软琼脂中形成细胞集落的数量明显增加,在悬浮培养模型中形成细胞团的直径更大,在失粘附状态下的细胞凋亡比例明显降低;磷脂酰肌醇3-激酶（PI3K）通路的抑制剂LY294002能增加转染细胞在失粘附状态下的凋亡比例。结论肝癌细胞HepG2具有抗失巢凋亡的特性,Netrin-1可以增强HepG2细胞抗失巢凋亡的能力,其机制可能与PI3-K通路相关。

英文摘要：

Objective Anoikis,which is a special form of programmed cell death,plays an important role in cell development,tissue homeostasis,disease pathogenesis,and tumor metastasis.In this study,we use hepatocellular carcinoma HepG2 cells to investigate the effects of the nerve growth factor Netrin-1 on anoikis. Methods Netrin-1 was stably transfected into HepG2 cells.The Netrin-1 expression level was detected by Western blot.The apoptosis of HepG2 cells was assayed by soft agar colony model and suspension culture model. Results The HepG2 cells in suspension culture model had the similar apoptosis ratio with the cells in attached culture model.Netrin-1 could increase the number of HepG2 cell colonies in soft agar colony model,increase the diameters of HepG2 cell colonies and decrease the apoptosis ratio of HepG2 cells in suspension culture model.PI3K inhibitor LY294002 could antagonize the reduced HepG2 cell apoptosis induced by Netrin-1. Conclusion The HepG2 cell is anoikis resistant.Netrin-1 can enhance the ability of anoikis resistance of HepG2 cells,which may be associated with the activation of PI3K.