Bmi-1在神经母细胞瘤中的表达及意义

The expression and significance of Bmi-1 in the neuroblastoma（NB）

目的通过检测原癌基因Bmi-1在神经母细胞瘤（NB）中的表达以及观察其表达水平对神经母细胞瘤的影响，探讨其在神经母细胞瘤中的作用。方法用免疫组织化学和免疫印迹法检测方法分别检测人神经母细胞瘤标本和神经母细胞瘤细胞系细胞中Bmi-1的表达情况；采用逆转录病毒转染法将目的基因Bmi-1／si转染至Ⅰ型神经母细胞瘤细胞系BE-2-C细胞，通过Western免疫印迹法监测转染效果，并用软琼脂实验观察转染后的BE-2-C克隆形成能力。结果在32例人神经母细胞瘤标本中29例有Bmi-1的高表达（90．63％），且Bmi-1的表达程度的高低和NB的临床分期和临床预后密切相关（P〈0．05），Western免疫印迹实验也显示9种不同病理类型的神经母细胞瘤细胞系细胞中均有Bmi-1的高表达，其表达水平和病理类型有密切相关。在软琼脂实验中，与对照组（空白载体转染组）比较，Bmi-1／si转染后的BE-2-C细胞所形成的克隆数目不仅显著减少，克隆也明显变小。结论Bmi-1在神经母细胞瘤中高表达，其表达水平与肿瘤恶性程度密切相关，它在神经母细胞瘤的形成中起重要作用。

Objective To investigate the expression of Bmi-1 in neuroblastoma（NB）. Methods The protein expression of Bmi-1 was detected with immunohistochemistry （IHC） in human primary NB and with Western blot in NB cell lines. Ⅰ type neuroblastoma cells-BE-2-C cells ,which has the potency of stem cells,is a good object for researching neural crest stem cells. The human Bmi-lsiRNA was introduced into BE-2-C cells by retroviral infection for downregulating the expression of Bmi-1. The Bmi-1 expression of infected cells was detected by Western blot. Infected cells were either untreated or treated with doxorubicin for 24 hours ,adherent and floating cells were collected and analyzed for soft agax to detect the ablity of cloning formation. Results Of all the 32 samples, Bmi-1 expressed in 29 cases primary NB （90.63%） with IHC , the degree of the expression of Bmi-1 is correlation with the clinical stage of NB and the prognosis （ P 〈 0.05 ）. High-level expression of Bmi-1 in all 9 NB cell lines with Western blot, and is corralation with the 3 pathlogical types. Downregulation of Bmi-1 abolishes the tumorigenic activity of BE-2-C cells in soft agar. Condusion That the increased expression of oncogene Bmi-1 has relationship of the malignancy degree of NB. It may be a crucial role of Bmi-1 in the development of NB.