DCC 基因对人结直肠癌细胞株 SW1116生物学行为的影响

Effects of DCC gene on biological behaviors of colorectal carcinoma cell line SW1116

目的：研究外源性 DCC 基因稳定转染对人结直肠癌 SW1116细胞株的作用。方法采用反转录-聚合酶链反应从人正常结肠组织中扩增 DCC 基因功能区片段，构建 pcDNA3.1（＋）-DCC 重组质粒并鉴定。将重组质粒转染入 DCC 基因缺失的结直肠癌 SW1116细胞中，用四甲基偶氮唑蓝（MTT）比色法观察其抑制结直肠癌细胞 SW1116的作用；用免疫荧光方法研究 pcDNA3.1（＋）-DCC 质粒转染人结直肠癌细胞 SW1116后对结直肠癌细胞的影响及癌胚抗原（ CEA）表达。结果转染pcDNA3.1（＋）-DCC 质粒的 SW1116细胞在转染后第3~6天，其细胞数显著低于转染 pcDNA3.1（＋）质粒的 SW1116细胞和正常细胞对照（t =3.645，P ﹤0.05；t =3.132，P ﹤0.05）；转染 pcDNA3.1（＋）-DCC 质粒的 SW1116细胞生长增殖速度低于转染 pcDNA3.1（＋）质粒的 SW1116细胞和正常细胞对照（t =2.134，P ﹤0.05；t =2.736，P ﹤0.05）。转染 pcDNA3.1（＋）-DCC 质粒的 SW1116细胞在转染后第2-6天，其总细胞活力显著低于正常细胞对照（t =3.053，P ﹤0.05）；转染 pcDNA3.1（＋）-DCC 质粒的SW1116细胞在转染后第2、4、5、6天，其总细胞活力显著低于转染空质粒对照（t =2.816，P ﹤0.05）。转染 pcDNA3.1（＋）-DCC 质粒的 SW1116细胞呈黄绿色荧光的细胞数量和荧光强度明显低于转染pcDNA3.1（＋）质粒的 SW1116细胞和对照组细胞。结论转染 DCC 基因能抑制结直肠癌细胞的生长增殖，降低 CEA 表达，从而降低结直肠癌细胞浸润转移能力。

Objective To investigate the effects of exogenous wild DCC gene stably transfection on growth of colorectal carcinoma cell line SW1116 in vitro. Methods DCC gene domain was amplified from human normal colon tissue by reverse transcript-polymerase chain reaction（RT-PCR）. At first,a recombinant expression plasmid pcDNA3. 1（ ＋ ）-DCC was constructed. Human colorectal carcinoma cell line SW1116 with-out DCC gene was transfected with pcDNA3. 1-DCC. Cell viability was tested by methyl thiazolyl tetrazolium （MTT）assay. Immunofluorescence staining was used to determine the effects of pcDNA3. 1-DCC and expres-sion of carcino-embryonic antigen（CEA）in human colorectal carcinoma cell line SW1116 which was transfected with pcDNA3. 1-DCC. Results The population of cells transfected with pcDNA3. 1（ ＋ ）-DCC plasmid was lower than those with pcDNA3. 1（ ＋ ）-DCC plasmid and normal cells（t = 3. 645,P ﹤ 0. 05;t = 3. 132,P ﹤0. 05）at 3 - 6 days after transfection,and the proliferation rate of cells transfected with pcDNA3. 1（ ＋ ）-DCC plasmid was lower than those with pcDNA3. 1（ ＋ ）plasmid and normal cells（t = 2. 134,P ﹤ 0. 05;t = 2. 736, P ﹤ 0. 05）. Cell line SW1116 transfected with pcDNA3. 1（ ＋ ）-DCC plasmid total viability was lower than normal cells（t = 3. 053 ,P ﹤ 0. 05）at 2 - 6 days after transfection. Cell line SW1116 transfected with pcDNA3. 1 （ ＋ ）-DCC plasmid total viability was lower than those with pcDNA3. 1（ ＋ ）plasmid（t = 2. 816,P ﹤ 0. 05）at 2,4,5,6 days after transfection. The population of flavo-green colour cells transfected with pcDNA3. 1（ ＋ ）-DCC plasmid and the fluorescent intensity of these cells were lower than those with pcDNA3. 1（ ＋ ）plasmid and normal control cells. Conclusion Transfected DCC gene can suppress the cell proliferation and make CEA expression of cell line SW1116 down regulation to weaken its infiltration and metastasis abilities.