鹿角脱盘对辐射诱发小鼠胸腺淋巴瘤Notch2基因表达和免疫功能的影响

目的：观察鹿角脱盘对辐射诱发小鼠胸腺淋巴瘤Notch2基因的表达和免疫功能的影响，探讨其在辐射致癌过程中的作用。方法：将90只近交系BALB/c小鼠随机分成对照组、照射组和照射给药组，每组30只。照射组和照射给药组小鼠采用X射线照射，建立胸腺淋巴瘤动物模型，照射后给予照射给药组小鼠喂饲含鹿角脱盘超微粉的鼠粮。6个月后，取全血和胸腺，采用RT-PCR和Western blotting法分别检测胸腺淋巴瘤组织中Notch2 mRNA和蛋白表达水平；采用ELISA法检测血清免疫球蛋白（IgG、IgA和IgM）水平，应用SOD试剂盒检测血清中SOD活性。结果：照射组和照射给药组小鼠胸腺瘤发生率分别为53.33%（16/30）和36.67%（11/30）；照射组小鼠胸腺瘤组织中Notch2 mRNA和蛋白表达水平较对照组小鼠正常胸腺组织均明显升高（P<0.05），而照射给药组小鼠胸腺瘤组织中Notch2 mRNA和蛋白表达水平均低于照射组（P<0.05）；照射组小鼠血清中IgG、IgA和IgM水平均低于对照组（P<0.05），而照射给药组小鼠血清中IgG、IgM和血红蛋白水平及SOD活性均高于照射组（P<0.05）。结论：电离辐射激活Notch2基因和蛋白的高表达及降低小鼠免疫功能可能是辐射诱发胸腺淋巴瘤的发生机制之一；鹿角脱盘可通过抑制Notch2基因和蛋白的表达及提高小鼠免疫功能而降低辐射致癌的发生率，起到抑制肿瘤的作用。

Influence of antlerbase on Notch2 gene expression and immune function of mice with thymic lymphomas induced by ionizing radiation

Objective:To investigate the effect of antlerbase on the radiation carcinogenesis by observing the effect of antlerbase on the expressions of Notch2 gene and immune function of the mice with thymic lymphomas induced by ionizing radiation.Methods:Ninety BALB/c mice were randomly divided into control group,irradiation group and irradiation combined with drug group (combined group)(n=30).The thymic lymphoma models of mice were made by X-ray irradiation in irradiation group and combined group;after establishing the animal models,the mice in combined group were fed with chow containing antlerbase superfine powder.After 6 months,the whole blood and thymic tissue were taken,then RT-PCR and Western blotting methods were used to detect the mRNA and protein expressions levels of Notch2 gene in the thymic lymphoma tissue;ELISA method was used to detect the serum immunoglobulin (IgG,IgA,IgM)levels and SOD kit was used to detect the serum SOD activities of the tumor mice.Results:The incidences of thymic lymphoma in irradiation group and combined group were 53.33%(16/30)and 36.67% (11/30),respectively.Compared with control group,the expression levels of mRNA and protein of Notch2 gene in thymic lymphoma of the mice in irradiation group were significantly increased (P <0.05);compared with irradiation group,the expression levels of mRNA and protein of Notch2 gene in combined group were decreased (P <0.05);compared with control group,the levels of IgG,IgA,and IgM in serum of the mice in irradiation group were decreased (P < 0.05 ); compared with irradiation group, the levels of IgG, IgM, hemoglobin and the activity of SOD in serum of the mice in combined group were increased (P < 0.05 ). Conclusion:Ionizing radiation can activate the high expression of Notch2 gene and protein and decrease the immune function of mice,it might be one of the mechanisms for the occurrence of radiation carcinogenesis;antlerbase can decrease the incidence of radiation carcinogenesis by inhibiting the expression of Notch2 gene and increasing the immune function of mice,which might play an role in restraining tumor.