泛素代谢系统相关基因FBG2在胃癌细胞系中功能意义的研究

目的初步探讨泛素代谢系统相关基因FBG2对于胃癌细胞生长、增殖、凋亡等生物学特性及成瘤、浸润转移能力等恶性表型的影响。方法将FBG2基因插入载体pcDNA3．1构建pc-FBG2真核表达载体。以脂质体介导转染MKN45胃癌细胞并以G418压力筛选法筛出稳定表达的克隆，对稳定表达株进行鉴定，然后使用流式细胞仪、生长曲线法、平板克隆形成实验法、细胞迁徙实验法等分析稳定表达株相关生物学特性与恶性表型的变化，每种检测实验均设立pc-FBG2稳定转染细胞组、pcDNA3．1稳定转染细胞组和空白MKN45细胞组。结果与转染pcDNA3．1空载体及空白MKN45胃癌细胞相比，转染pc-FBG2载体的稳定表达细胞株生长有所加快，开始计数后第4、5、6、7天平均细胞计数显著增高（P〈0．05），细胞周期检测显示pc-FBG2转染组G2／M期比例显著高于其他两组（P〈0．05），而S期比例显著低于其他两组（P〈0．05）。细胞凋亡检测显示pc-FBG2转染组凋亡比例与其他两组相比无显著差异（P〉0．05），平板克隆形成实验结果显示pc-FBG2转染组平均克隆形成率显著高于其他两组（P〈0．05），细胞迁徙实验结果显示pc-FBG2转染组穿膜率与其他两组相比无显著差异（P〉0．05）。结论FBG2基因在一定程度上可促进细胞生长及有丝分裂，对维持细胞恶性表型具有一定意义，但对细胞凋亡及浸润转移能力可能影响较小。

Studies on the function of FBG2 in gastric cancer cell lines

Objective To investigate the influence of FBG2 on the growth, proliferation, apoptosis, infiltration and cell cycle of the gastric cancer line MKN45. Methods A critical component ubiquitin-protein ligase complex, FBG2 cDNA, was subcloned into a constitutive vector pcDNA3.1, followed by transfection in MKN45 by using liposome. Then stable expression clones were selected and appraised. The apoptosis and cell cycles were detected using flow cytometry. The growth and proliferation were analyzed by plotting cell growth curves and colony formation assay respectively. The ability of infiltration was tested using cancer cell migration assay. The MKN-FBG2 group and two control groups were included in the study. Results MKN-FBG2 grew faster than MKN45 and MKN-PC. The cell counts of MKN-FBG2 on the fourth, fifth, sixth and seventh day were significantly larger than that of others (P<0.05). Cell cycle analysis showed that MKN-FBG2 proliferated faster, and proportions of cells in G_2/M and S were higher significantly (P<0.05). Results of colony formation assay showed that the colony formation rate of MKN-FBG2 was higher than that of control groups (P<0.05). Results of cell migration assay were negative. Conclusion FBG2 can promote the growth and proliferation of gastric cancer cells and help tumor cell maintain malignant phenotype. But it can exert a negative influence on the apoptosis or the ability of infiltration of gastric cancer cells.