Li Q, Yu Y-Y, Zhu Z-G, Ji Y-B, Zhang Y, Liu B-Y, Chen X-H, Lin Y-Z
Shanghai Institute of Digestive Surgery, Ruijin Hospital, Shanghai Second Medical University, Shanghai, China.
Eur Surg Res. 2005 Mar-Apr;37(2):105-10. doi: 10.1159/000084541.
To observe whether there is constitutive activation of nuclear transcription factor kappaB (NF-kappaB) and its effect on proliferation and apoptosis of human gastric cancer cell lines.
Nuclear/cytoplasmic protein expression of NF-kappaB was analyzed by Western blot in four different gastric cancer cell lines. Trans AM(TM) NF-kappaB p65 Kit was used for detecting the difference of p65 activity. The effect of PDTC (pyrrolidine dithiocarbamate), a specific inhibitor of NF-kappaB on the proliferation of gastric cancer cells, was measured by MTT (3-[4,5-dimethythiazol-2-yl]-2,5-diphenyltetrazolium bromide) method. The apoptotic rates of AGS and SGC-7901 gastric cancer cell lines were measured with flow cytometer (FCM) after treatment by PDTC.
The constitutive activations of NF-kappaB were identified in four gastric cancer cell lines. The expression of activated subunit of p50 was lower in AGS cell line, and higher in MKN28, MKN45 and SGC-7901 cell lines. The expression of activated subunit of p65 was lower in MKN28 and MKN45 cell lines, and higher in AGS and SGC-7901 cell lines. Both the activity of NF-kappaB and the cell proliferation were significantly inhibited in experimental group treated by PDTC, compared with control groups (p<0.01). An increased apoptotic rate and a decreased proliferating activity were observed after the gastric cancer cells were exposed to PDTC for 24 h.
These results suggested that the constitutive activation and the protein expression of NF-kappaB are different in gastric cancer cell lines. PDTC can inhibit NF-kappaB activity and cell proliferation, which related to an increased cell apoptosis. The results disclosed that NF-kappaB could be a potential therapeutic target for solid tumor therapy.
观察核转录因子κB（NF-κB）是否存在组成性激活及其对人胃癌细胞系增殖和凋亡的影响。
采用蛋白质免疫印迹法分析4种不同胃癌细胞系中NF-κB的核/细胞质蛋白表达。使用Trans AM（TM）NF-κB p65试剂盒检测p65活性差异。采用MTT（3-[4,5-二甲基噻唑-2-基]-2,5-二苯基四氮唑溴盐）法检测NF-κB特异性抑制剂吡咯烷二硫代氨基甲酸盐（PDTC）对胃癌细胞增殖的影响。用流式细胞仪（FCM）检测PDTC处理后AGS和SGC-7901胃癌细胞系的凋亡率。
在4种胃癌细胞系中均鉴定出NF-κB的组成性激活。p50激活亚基在AGS细胞系中的表达较低，在MKN28、MKN45和SGC-7901细胞系中的表达较高。p65激活亚基在MKN28和MKN45细胞系中的表达较低，在AGS和SGC-7901细胞系中的表达较高。与对照组相比，PDTC处理的实验组中NF-κB活性和细胞增殖均受到显著抑制（p<0.01）。胃癌细胞暴露于PDTC 24小时后，观察到凋亡率增加和增殖活性降低。
这些结果表明，NF-κB的组成性激活和蛋白表达在胃癌细胞系中存在差异。PDTC可抑制NF-κB活性和细胞增殖，这与细胞凋亡增加有关。结果表明，NF-κB可能是实体瘤治疗的潜在靶点。
