干扰素诱导跨膜蛋白1协同干扰素抑制结肠癌细胞增殖

Interferon induced transmembrane protein 1 with interferonαsynergistically inhibited proliferation of colorectal cancer cell line SW480

目的：研究干扰素诱导跨膜蛋白1(interferon induced transmembrane protein 1,IFITM1)协同干扰素对结肠癌细胞株SW480增殖的影响。方法：将IFITM1基因亚克隆到真核表达载体pEGFP-C3,IFITM1/pEGFP-C3重组质粒转染结肠癌细胞株SW480,G418 500mg/L筛选阳性克隆细胞。激光共聚焦显微镜及RT-PCR检测IFITM1的表达。实验设pEGFP- C3/SW 480组、IFITM1/SW 480组、IFITM1/anti-IFITM1/SW 480、空白组,除空白组外,每组加入IFN_(-α) 1000 U/mL。MTT检测细胞的增殖性。结果：IFITM1/pEGFP-C3重组质粒转染SW480细胞后,激光共聚焦显微镜观察到绿色荧光融合蛋白位于细胞膜周围,RT-PCR在IFITM1/SW 480细胞中检测到IFITM1 mRNA表达,SW 480细胞及pEGFP-C3/SW480细胞中未见IFITM1 mRNA表达。MTT分析细胞增殖示pEGFP-C3/SW 480组、IFITM1/SW 480组、IFITM1/anti-IFITM1/SW 480组的D_(570mm)处值分别0.745±0.0267、0.346±0.0316、0.696±0.0613,空白组的D_(570mm)值是0.835±0.0362,IFITM1/SW 480细胞增殖比pEGFP-C3/SW 480细胞及IFITM1/anti-IFITM1/SW 480细胞低(P＜0.05)。而pEGFP-C3/SW 480细胞的增殖与IFITM1/anti-IFITM1/SW 480细胞增殖相比无显著差异(P＞0.05)。结论：IFITM1可协同IFN-α抑制SW 480细胞体外增殖。

Objective： To study whether interferon induced transmembrane protein 1 （IFITM1） combined with interferon α has synergistic effect on the proliferation of colorectal cancer SW480 cells. Methods：IFITM1 gene was subcloned to the eukaryotic expression vector pEGFP-C3,and then the recombinant IFITM1/pEGFP-C3 vector was transfected into SW480 cells by lipofectamine 2000. The positive cell clones were selected by 500 mg/L G418. The IFITM1 gene expression was detected by using the laser confocal microscopy （LCSM） and RT-PCR. The cells were divided into pEGFP-C3/SW480 group, IFITM1/SW480 group,IFITM1/anti-IFITM1/SW480 group,and control group. IFITM1/anti-IFITM1/SW480 group were treated with IFITM1 and rabbit anti-human IgG IFITM1 antibody 10 mg/mL. Each group were treated with IFNα 1000 unit/mL except control group. The cell proliferation was evaluated by MTT assay. Results： After the recombinant IFITM1/pEGFP-C3 vectors were transfected into SW480 cells,green fluorescence protein（GFP-IFITM1） was observed around the cell membrane under the laser confocal microscope and IFITM1 mRNA expression was detected in IFITM1/SW480 cells but not in control group and pEGFP/ SW480 group. The optical density at 570 nm was 0.745±0.0267, 0.346±0.0316,0.696±0.0613, and 0.835±0.0362 in pEGFP-C3/SW480 group, IFITM1/SW 480 group, IFITM1/anti-IFITM1/SW480 group,and control group, respectively. Proliferation of SW480 cells in IFITM1/SW480 group was lower than that in pEGFP-C3/SW480 group and IFITM1/antiIFITM1/ SW480 group （P〈0.05）. The difference between pEGFP-C3/SW480 group and IFITM1/antiIFITM1/SW480 group was not significant （P〉0.05）. Conclusion： IFITM1 has a synergistic effect with IFNα in inhibiting proliferation of SW480 cells in vitro.