抑癌基因ARHI与胶质瘤病理级别相关性及促凋亡功能研究

Relationship between tumor suppressor aplasia Ras homologue member I and glioma pathological grades and influence of aplasia Ras homologue member I on apoptosis of glioma cells

目的观察ARHI基因与胶质瘤病理级别相关性及ARHI基因过表达对细胞凋亡的影响。方法应用免疫组织化学技术检测7例脑外伤患者的新鲜脑组织及56例胶质瘤组织中ARHI蛋白的表达；包装ARHI过表达的慢病毒并用来感染人胶质瘤细胞株U251，通过电镜技术分析ARHI过表达对自噬泡的形成和细胞凋亡的影响，采用膜联蛋白V（AnnexinV）一抗原提呈细胞（APC）＆碘化丙锭（PI）双染法和流式细胞仪分析ARHI过表达对U251细胞凋亡的影响。结果脑组织切片的免疫组织化学染色显示，高级别胶质瘤ARHI阳性表达率（35．34％和30．16％）明显低于正常脑组织（94．07％）及低级别胶质瘤（93．08％和82．11％，P〈0．01），提示ARHI蛋白的阳性率与脑胶质瘤的恶性程度成反比。通过电镜分析，ARHI过表达的U251细胞中自噬泡数目显著多于对照组。凋亡实验显示ARHI过表达组凋亡率为[（10．79±3．28）％]，明显高于U251细胞组[（2．80±0．59）％，P〈0．01]。结论ARHI通过促进自噬泡的形成促进脑胶质瘤细胞株U251的凋亡。

Objective To investigate the relationship between aplasia Ras homologue member I （ARHI） and glioma pathological grades, and the impact of ARHI overexpression on cell apoptosis. Meth- ods Immunohistochemistry was used to detect the expression of ARHI in fresh brain tissues from 7 brain injury patients and 56 glioma tissues. The lentivirus expressing ARHI was used to infect U251 cells and e- lectron microscope was used to explore the impact of ARHI overexpression on the formation of autophagic vacuoles. Annexin V - angtigen - preoesenting cell （APC） ＆ propidium iodide （PI） double staining and flow cytometry were used to determine the influence of ARHI overexpression on apoptosis of U251 cells. Results Immunohistochemistry results showed that ARHI positive percentage in high grade gliomas （grade llI 35.34%, grade 1V 30. 16% ） was significantly reduced as compared with that in normal brain tissues （94. 07%, P 〈0. 01 ） and low grade gliomas （grade I 93.08%, grade 1I 82. 11%, P 〈0. 01）. There was a significant association between ARHI positive percentage and the pathological grades. More autophag- ic vacuoles formed in U251 cells overexpressing ARHI than control cells. ARHI overexpression in U251 cells promoted cell apoptosis [ （ I0. 79 ± 3.28 ） % ] as compared with normal U251 ceils [ （ 2. 80 ± 0. 59）%, P 〈 0. 01 ]. Conclusion ARHI promoted the formation of autophagic vacuoles and then in- duced cell apoptosis in human glioma cell line U251.