Fas通路的激活促进结肠癌细胞迁移侵袭

目的探讨Fas通路激活对结肠癌细胞SW480和DLD1产生的非凋亡效应。方法流式细胞学检测结肠癌SW480及DLD1细胞系的Fas、FasL、抗凋亡蛋白c-FLIP、Bcl-2、Bcl-xl、XIAP等在细胞膜上的表达水平;对结肠癌SW480及DLD1细胞系予以梯度浓度（0ng/ml、12.5ng/ml、25ng/ml、50ng/ml）的FasL刺激,计数并比较各组细胞的增殖速率变化;对结肠癌SW480及DLD1细胞系予以低剂量FasL处理,分别对实验组和对照组进行细胞增殖速率及迁移侵袭能力测试,探讨低剂量FasL刺激对结肠癌细胞活力的影响;稳定敲除SW480和DLD1细胞的Fas基因表达,重复上述实验,以明确低剂量FasL刺激对结肠癌细胞活力的影响是否依赖于Fas通路的激活。结果 SW480及DLD1细胞系中均可检测到中等程度的Fas表达及抗凋亡蛋白FLIP、Bcl-2的表达,未检测到FasL表达,在SW480中可测到Bcl-xl表达;低剂量FasL不影响结肠癌SW480和DLD1细胞的增殖速率,但可促进两种细胞的迁移侵袭能力;稳定敲除Fas基因后,低剂量FasL对结肠癌细胞迁移侵袭能力的促进作用受到抑制。结论低剂量FasL可激活Fas通路的非凋亡途径从而增强结肠癌SW480和DLD1细胞的迁移侵袭能力。

Activation of Fas signaling enhances migration and invasion of colon cancer cell

Objective To investigate the non-apoptotic effect of Fas signaling pathway on colorectal cancer cell line SW480 and DLD1. Methods We used flow cytometry to detect the expression of Fas, FasL, and anti-apoptotic protein such as c-FLIP, Bcl-2, Bcl-xl and XIAP in cell membrane of colorectal cancer cells SW480 and DLD1; secondly, we tested and compared the proliferation rate of colon cancer cells SW480 and DLD1 under FasL stimulation of gradient concentration （0 ng/ml, 12.5 ng/ml, 25 ng/ml, 50 ng/ml）; thirdly, we tested the proliferation rate, migration ability and invasion ability in SW480 and DLD1 cells with or without low-dose FasL stimulation; finally, we repeated the above-mentioned experiment using Fas stably knocked- out SW480 and DLD1 cells. Result Moderate level of Fas, FLIP and Bcl-2 was detected in SW480 and DLD1 cell lines, while no measurable FasL was found. Low-dose FasL did not affect the proliferation rate ,but could promote the ability of migration and invasion in SW480 and DLD1 cells. The stable knock-out of FasL elimi- nated the effect mentioned above. Conclusion Low-dose FasL could enhance the migration and invasion abil- ity of colorectal cancer cell SW480 and DLD1 through the activation of Fas non-apoptotic signaling pathway.