Zheng Shi-Ying, Li De-Chun, Zhang Zhi-De, Zhao Jun, Ge Jin-Feng
Department of Cardiothoracic Surgery, The First Affiliated Hospital of Suzhou University, Suzhou 215006, Jiangsu Province, China. syzheng88@ sina.com
World J Gastroenterol. 2005 Jun 7;11(21):3204-11. doi: 10.3748/wjg.v11.i21.3204.
To study the activation of cytotoxic T lymphocytes (CTLs) against gastric cancer cells induced by FasL/B7-1 (FB-11) gene-modified tumor cells, and to explore whether co-expression of FasL and B7-1 in SGC-7901 tumor cells could initiate synergistic antitumor effect.
FasL and B7-1 genes were transfected into human SGC-7901 gastric cancer cells with adenovirus vectors. The positive clones were selected by G418. FasL and B7-1 genes were detected by flow cytometry and RT-PCR. Abdominal infiltrating lymphocytes and sensitized spleen cells were obtained from mice that were immunized with SGC-7901/FB-11 or wild type SGC-7901 cells intraperitoneally, and cytotoxicity of these CTLs against tumor cells was determined by MTT assay.
Flow cytometry and RT-PCR showed that FasL and B7-1 genes were highly expressed. FasL and B7-1 transfected cancer cells had a high apoptosis index. DNA laddering suggested that FasL and B7-1 genes induced gastric cancer cell apoptosis. FasL(+)/B7-1(+)SGC-7901 cells (SGC-7901/FB-11) were inoculated subcutaneously in the dorsal skin of C57BL/6 mice and then decreased their tumorigenicity greatly (z = 2.15-46.10, P<0.01). SGC-7901/FB-11 cell-sensitized mice obtained protective immune activity against the rechallenge of wild type SGC-7901 cells (z = 2.06-44.30, P<0.05). The cytotoxicity of CTLs induced by SGC-7901/FB-11 cells against SGC-7901 was significantly higher than that of CTLs activated by wild-type SGC-7901 cells (84.1+/-2.4% vs 30.5+/-2.3%, P<0.05).
FasL and B7-1 genes can effectively promote the activity of CTLs against gastric cancer cells. FasL/B7-1 molecules play an important role in CTL cytotoxicity.
研究FasL/B7-1(FB-11)基因修饰的肿瘤细胞诱导的细胞毒性T淋巴细胞(CTL)对胃癌细胞的激活作用,并探讨FasL和B7-1在SGC-7901肿瘤细胞中的共表达是否能引发协同抗肿瘤效应。
用腺病毒载体将FasL和B7-1基因转染入人SGC-7901胃癌细胞。通过G418筛选阳性克隆。采用流式细胞术和RT-PCR检测FasL和B7-1基因。从经腹腔注射SGC-7901/FB-11或野生型SGC-7901细胞免疫的小鼠中获取腹部浸润淋巴细胞和致敏脾细胞,通过MTT法测定这些CTL对肿瘤细胞的细胞毒性。
流式细胞术和RT-PCR显示FasL和B7-1基因高表达。FasL和B7-1转染的癌细胞具有较高的凋亡指数。DNA梯状条带表明FasL和B7-1基因诱导胃癌细胞凋亡。将FasL(+)/B7-1(+)SGC-7901细胞(SGC-7901/FB-11)皮下接种于C57BL/6小鼠背部皮肤,其致瘤性显著降低(z = 2.15 - 46.10,P<0.01)。SGC-7901/FB-11细胞致敏的小鼠对野生型SGC-7901细胞的再次攻击获得了保护性免疫活性(z = 2.06 - 44.30,P<0.05)。SGC-7901/FB-11细胞诱导的CTL对SGC-7901的细胞毒性显著高于野生型SGC-7901细胞激活的CTL(84.1±2.4%对30.5±2.3%,P<0.05)。
FasL和B7-1基因能有效促进CTL对胃癌细胞的活性。FasL/B7-1分子在CTL细胞毒性中起重要作用。