结肠癌细胞通过Fas/FasL诱导淋巴细胞发生凋亡

背景与目的:研究发现,肿瘤组织中Fas配体阳性表达区肿瘤浸润淋巴细胞的凋亡率比FasL阴性区高,推测肿瘤细胞可通过增加表达FasL来杀伤肿瘤浸润淋巴细胞。本研究拟在体外验证结肠癌细胞SW480是否可以诱导淋巴细胞发生凋亡。方法:结肠癌细胞系SW480(效应细胞)与对Fas介导凋亡敏感的Jurkat细胞(靶细胞)共培养,分为3种效靶比20∶1,10∶1,5∶1。生长曲线法、流式细胞术、荧光显微镜观察分别检测Jurkat细胞的凋亡情况。结果:流式细胞仪检测结果显示,SW480接种浓度为0(对照)、0.5×105/ml、1×105/ml、2×105/ml时,Jurkat细胞凋亡率为(1.8±0.21)%、(5.49±0.17)%、(11.18±0.14)%、(18.22±0.11)%。荧光显微镜观察结果表明,SW480接种浓度为0(对照)、0.5×105/ml、1×105/ml、2×105/ml时,Jurkat细胞凋亡率为(1.58±0.12)%、(5.22±0.13)%、(9.74±0.21)%、(19.33±0.18)%。3种效靶比条件下,SW480细胞均能诱导Jurkat细胞发生凋亡。随着SW480接种浓度的升高及共培养作用时间的延长,Jurkat细胞凋亡率逐渐增加。每个实验组与对照组相比,P值均小于0.01。结论:结肠癌细胞SW480可以通过Fas系统诱导淋巴细胞发生凋亡,这为结肠癌的免疫逃逸、反击机制提供了又一证据。

Apoptosis of lymphocytes induced by Fas/FasL of colon cancer cells

BACKGROUND & OBJECTIVE: It has been reported that apoptotic rate of tumor infiltrating lymphocytes(TIL) in Fas ligand(FasL) positive region was higher than in FasL negative region, which indicated that tumor cells could kill tumor infiltrating lymphocytes through high-expressed FasL. This study was designed to determine whether colon cancer cells SW480 could induce apoptosis of lymphocytes by Fas system in vitro. METHODS: Colon cancer cells SW480 were co-cultured with Jurkat cells with different effector-target(E-T) ratios of 20:1, 10:1, 5:1. Growth curve method, flow cytometry(FCM) analysis, fluorescence microscope were used to detect apoptosis of Jurkat cells. RESULTS: Flow cytometry revealed that the apoptotic rate of Jurkat cells were 1.8 +/- 0.21, 5.49 +/- 0.17, 11.18 +/- 0.14, and 18.22 +/- 0.11 with the SW480 planting concentrations at 0(control), 0.5 x 10(5)/ml, 1 x 10(5)/ml, 2 x 10(5)/ml, respectively. Fluorescence microscopy showed that the apoptotic rate of Jurkat cells were 1.58 +/- 0.12, 5.22 +/- 0.13, 9.74 +/- 0.21, and 19.33 +/- 0.18 with the SW480 planting concentrations at 0(control), 0.5 x 10(5)/ml, 1 x 10(5)/ml, and 2 x 10(5)/ml, respectively. Based on the three different E-T ratios, SW480 cell could all induce apoptosis of Jurkat. Furthermore, Jurkat cell apoptosis rate increased with the increase of planting concentration of SW480 and co-culture time. There were significant difference between each test group and control(All values P < 0.01). CONCLUSION: Colon cancer cells SW480 could induce apoptosis of lymphocytes throught Fas system, which providing theoretical foundation for metastasis and counterattack of colon cancer.