目的：探讨Bcl-3蛋白在人结直肠癌组织中的表达以及沉默Bcl-3基因后对结肠癌HCT 116细胞增殖与凋亡的影响。方法：选取2012年1月至2015年12月于江苏大学附属昆山医院行结直肠癌根治术的86例患者结直肠癌组织及相对应的癌旁组织标本，应用免疫组织化学法检测结直肠癌组织中Bcl-3蛋白的表达。将HCT 116细胞分为3组：空白对照组、Control siRNA组和Bcl-3 siRNA组，按分组转染Bcl-3 siRNA和Control siRNA，Western blotting法检测各组Bcl-3表达量以鉴定转染效率；MTT法、平板克隆实验、流式细胞术分别检测各组增殖能力、克隆形成能力、细胞周期分布及细胞凋亡率的变化。结果： Bcl-3蛋白在结直肠癌组织明显高于相应癌旁组织阳性表达率（72.09% vs 48.84%,P<0.05）。结直肠癌组织中Bcl-3蛋白的表达与组织学分级、淋巴结转移及Dukes分期有关（P<0.05）。转染48 h后，空白对照组、Control siRNA组Bcl-3相对蛋白量表达水平明显高于Bcl-3 siRNA组（P<0.05）。MTT实验中可见Bcl-3siRNA组光密度（D）值在转染24、48、72、96 h时均明显低于空白对照组和Control siRNA组（P<0.05），Bcl-3 siRNA组克隆形成率明显低于其他2组（P<005）。流式细胞术显示，Bcl-3 siRNA组G2期细胞比例及凋亡率高于空白对照组和Control siRNA组（P<0.05）。结论： 结直肠癌组织中Bcl-3蛋白的高表达与组织学分级、淋巴结转移及Dukes分期有关；沉默Bcl-3可能导致结肠癌HCT 116细胞的细胞周期停滞在G2期，抑制细胞增殖能力及克隆形成能力，并促进细胞凋亡。

Objective:To explore Bcl-3 protein expression in human colorectal cancer and the effects of Bcl-3 gene silencing on proliferation and apoptosis of colorectal cancer HCT 116 cell line. Methods: 86 colorectal cancer tissues and the corresponding adjacent tissues from patients treated in Kunshan Hospital Affiliated to Jiangsu University between January 2012 and December 2015 were collected to analyze the correlation between Bcl-3 expression and clinicopathological features of colorectal cancer. Immunohistochemistry was used to detect Bcl-3 protein expression in 86 samples. HCT 116 cells were cultivated and divided into three groups: blank control group, control siRNA group (transfecting with control siRNA) and Bcl-3 siRNA (transfecting with Bcl-3 siRNA); and then Western blotting was used to determine Bcl-3 expression to verify the transfection efficiency. In addition, MTT, plate clone formation assay, Flow cytometry and streaming apoptosis assay were used to detect the proliferation, cloning formation, cell cycle distribution and the rate of apoptosis in each group, respectively. Results: IHC showed the positive expression rate of Bcl-3 protein in cancer tissues and adjacent normal tissues was 72.09% and 48.84% (P<0.05), respectively. The Bcl-3 protein expression in colorectal cancer tissues was positively correlated with histological grade, lymph node metastasis and Dukes staging (P<0.05). After being transfected for 48 h, the relative Bcl-3 expression level of blank control group and control siRNA group was significantly higher than that of Bcl-3 siRNA group (P<0.05), indicating successful transfection. MTT assay showed the absorbance value in all groups increased in a time-dependent manner. The optical density of Bcl-3 siRNA group was significantly lower than that of blank control group and control siRNA group at 24, 48, 72 and 96 h after transfection (P<0.05), and colony formation rate of Bcl-3 siRNA group was obviously lower than the other two groups (P<0.05). Flow cytomety showed that the proportion of G2 phase cells and cell apoptosis rate of Bcl-3 siRNA group was higher than those of blank control group and the control siRNA group (P<0.05). Conclusions: Bcl-3 protein expression in colorectal cancer tissues was positively correlated with histological grade, lymph node metastasis and Dukes staging; Bcl-3silencing might induce HCT 116 cell cycle arrest at G phase, suppress cell proliferation and colony formation, and promote cell apoptosis.

苏州市科教青年科技基金资助项目（No.KJXW2015053），昆山市社会发展科技计划资助项目（No.KS1654）