沉默特异性核基质蛋白1基因对裸鼠前列腺癌DU145移植瘤的抑制作用

The effects of silencing Special AT-rich binding protein-1 gene on implanted human prostate cancer DU145 cell carcinoma in nude mice

目的 观察沉默特异性核基质蛋白1（SATB1）基因对裸鼠前列腺癌DU145移植瘤的抑制作用.方法 利用LipofectamineTM2000将pSilencer3.1-SATB1、pSilencer3.1转染至人前列腺癌DU145细胞,建立前列腺癌DU145荷瘤鼠模型,分为3组：转染pSilencer3.1-SATB1 DU145组、转染空质粒pSilencer3.1 DU145组和未转染DU145组,每组各8只.取浓度为2×1010/L转染pSilencer3.1-SATB1的DU145、转染空质粒pSilencer3.1的DU145和未转染的DU145细胞悬液0.2ml分别注射至各组裸鼠左腋皮下.每隔4d测量皮下移植瘤体积,绘制瘤体生长曲线.免疫组织化学法和Western blot法检测各组瘤体SATB1表达.免疫组织化学法检测各组瘤体E-钙黏蛋白（E-cadherin）、波形蛋白（Vimentin）、基质金属蛋白酶（MMP）-2的表达.原位缺口末端标记法（TUNEL）法检测移植瘤凋亡.结果 Western blot结果表明：转染pSilencer3.1-SATB1 DU145组可有效沉默SATB1基因并成功构建了人前列腺癌DU145细胞裸鼠皮下移植瘤模型.第27天时处死裸鼠后,转染pSilencer3.1-SATB1 DU145组移植瘤体积（mm3）为708.9±69.1,显著小于对照组,差异有统计学意义（P＜0.05）;原位缺口末端标记法（TUNEL）结果显示：转染pSilencer3.1-SATB1 DU145组平均凋亡率为（67.6±6.2）％,与对照组比较,差异有统计学意义（P＜0.05）;免疫组织化学法显示：Vimentin、MMP-2、E-cadherin在转染pSilencer3.1-SATB1 DU145组的平均值分别为102.8 ±9.7、120.3±17.8、407.0±13.9,与对照组比较,蛋白表达差异均有统计学意义（P＜0.05）.结论 成功构建沉默SATB1基因的前列腺癌DU145细胞荷瘤鼠模型.沉默SATB1可抑制前列腺癌细胞的增殖生长、促进其凋亡.沉默SATB1可能通过调控侵袭相关蛋白E-cadherin、Vimentin、MMP-2的表达水平.

Objective To investigate the effects of silencing special AT-rich binding protein-1 （SATB1） gene on implanted human prostate cancer DU145 cells carcinoma in nude mice.Methods The pSilencer3.1-SATB1,and pSilencer3.1 were transfected into human prostate cancer DU145 cells by LipofectamineTM2000,respectively.The xenografts prostate cell carcinoma cancer models were established by subcutaneously injecting 2 × 107 untransfected DU145,pSilencer3.1-SATB1 transfected DU145 and pSilencer3.1 transfected DU145 cells into the right flank of BALB/c nude mice.Immunohistochemistry and Western blotting were used to detect the expression of SATB1.The volume of tumor was firstly measured every four days.TdT-mediated dUTP nick end labeling （TUNEL） was used to assay the apoptosis of tumor cells in each group.Immunohistochemistry was used to detect the expression of Vimentin,E-cadherin and matrix metalloproteinase （MMP）-2 in each group.Results Immunohistochemistry and Western blotting showed the transfection of pSilencer3.1-SATB1 into DU145 cells could effectively silence SATB1 gene in nude mice,and tunor models of human prostate cancer DU145 cells were successfully constructed.Final volumes （mm3） of tumor in pSilencer3.1-SATB1 transfected group was 708.9 ± 69.1,significantly less than in the control group （P ＜ 0.05）.TUNEL assay revealed that the average apoptosis rate in the pcDNA3.1-transfected group was （67.6 ± 6.2） ％,significantly different from that in the control groups （P ＜ 0.05）.The average integral optical density （IOD） of Vimentin,MMP-2 and E-cadherin expression in the pcDNA3.1-transfected group was 102.8 ± 9.7,120.3 ± 17.8,and 407.0 ± 13.9 respectively,significantly different from that in the control groups （P ＜ 0.05）.Conclusion The tumor models of human prostate cancer DU145 cells overexpressing SATB1 gene were successfully constructed.SATB1 can inhibit the growth of tumor and promote its apoptosis.SATB1 may regulate the proteins related to invasion and metastasis,such as E-cadherin,Vimentin,and MMP-2.