通过肿瘤坏死因子I的CD40信号传导抑制肺癌细胞增殖。
Inhibition of lung cancer cell proliferation by CD40 signaling through tumor necrosis factor I.
作者信息
Lu Xu-Dong, Zhu Xiao-Lan, Chen Cheng, Zhang Guang-Bo, Zhang Xue-Guang, Huang Jian-An
机构信息
Department of Respiratory Medicine, First Affiliated Hospital, Soochow University, Suzhou, Jiangsu, PR China.
出版信息
Ai Zheng. 2009 Jan;28(1):20-3. Epub 2009 Jan 12.
BACKGROUND AND OBJECTIVE
CD40 signaling induces growth inhibition in some tumor cells in vitro, but the precise molecular mechanism remains unclear. This study was to investigate the biological effects and mechanisms of CD40 stimulation on proliferation of lung cancer cell lines NCI-H460 and A549, changes in tumor necrosis factor receptors (TNFRs) and membrane tumor necrosis factor alpha (mTNF-alpha).
METHODS
The expression of CD40 on the cell surface, and changes in TNFR and mTNF-alpha expression after CD40 stimulation were detected by the immunofluorescence technique and flow cytometry. Changes in protein contents of TNFR as well as mTNF-alpha expression after CD40 stimulation were measured by western blot. The cell proliferation rate was determined by MTT assay. The content of soluble TNF-alpha(sTNF-alpha) in the supernatant of lung cancer cells was measured by ELISA assay.
RESULTS
The expression rates of CD40 in NCI-H460 and A549 were (89.0 +/- 3.2)% and (62.2 +/- 4.5)%, respectively. After 48 h of CD40 stimulation, the expression rates of TNFRI in NCI-H460 and A549 became significantly higher [(36.2 +/- 4.6)% and (38.5 +/- 5.9)%] than those in the corresponding control cells [(15.2 +/- 3.1)% and (7.2 +/- 1.9)%] (p < 0.05); while the expression rates of TNFRII were significantly lower than those in the control cells [(18.0 +/- 1.6)% and (5.8 +/- 1.2)% vs. (58.1 +/- 3.6)% and (38.8 +/- 4.3)%] (p < 0.05); the expression rates of mTNF-alpha were decreased in the two cell lines [(8.7 +/- 1.1)% and (7.0 +/- 0.9)%] as compared to those in control cells [(15.0 +/- 2.1)% and (26.5 +/- 3.2)%] (p < 0.05). The level of TNFRI protein was elevated with the downregulation of TNFRII protein in NCI-H460 and A549. The level of mTNF-alpha protein remained unchanged in the two cell lines. TNF-alpha was not detectable in the supernatant of lung cancer cells. Moreover, cell proliferation of NCI-H460 and A549 were inhibited after CD40 stimulation (p < 0.05), but the inhibition effect disappeared after blocking TNFRI. Blocking of TNF-alpha inhibited cell proliferation of the two cell lines (p < 0.05), but a synergistic effect was not observed after simultaneous stimulation with CD40.
CONCLUSION
CD40 signaling inhibits the proliferation of CD40-positive lung cancer cells through mTNF-alpha/TNFRI in vitro.
背景与目的
CD40信号传导在体外可诱导某些肿瘤细胞生长抑制，但确切的分子机制仍不清楚。本研究旨在探讨CD40刺激对肺癌细胞系NCI-H460和A549增殖、肿瘤坏死因子受体（TNFRs）及膜肿瘤坏死因子α（mTNF-α）变化的生物学效应及机制。
方法
采用免疫荧光技术和流式细胞术检测细胞表面CD40的表达以及CD40刺激后TNFR和mTNF-α表达的变化。通过蛋白质印迹法检测CD40刺激后TNFR的蛋白质含量以及mTNF-α的表达。采用MTT法测定细胞增殖率。用ELISA法检测肺癌细胞上清液中可溶性TNF-α（sTNF-α）的含量。
结果
NCI-H460和A549中CD40的表达率分别为（89.0±3.2）%和（62.2±4.5）%。CD40刺激48小时后，NCI-H460和A549中TNFRI的表达率显著高于相应对照细胞[（36.2±4.6）%和（38.5±5.9）%比（15.2±3.1）%和（7.2±1.9）%]（p<0.05）；而TNFRII的表达率显著低于对照细胞[（18.0±1.6）%和（5.8±1.2）%对（58.1±3.6）%和（38.8±4.3）%]（p<0.05）；与对照细胞[（15.0±2.1）%和（26.5±3.2）%]相比，两种细胞系中mTNF-α的表达率均降低[（8.7±1.1）%和（7.0±0.9）%]（p<0.05）。NCI-H460和A549中TNFRI蛋白水平升高，TNFRII蛋白水平下调。两种细胞系中mTNF-α蛋白水平保持不变。肺癌细胞上清液中未检测到TNF-α。此外，CD40刺激后NCI-H460和A549的细胞增殖受到抑制（p<0.05），但阻断TNFRI后抑制作用消失。阻断TNF-α可抑制两种细胞系的细胞增殖（p<0.05），但与CD40同时刺激未观察到协同作用。
结论
体外CD40信号传导通过mTNF-α/TNFRI抑制CD40阳性肺癌细胞的增殖。
Zotero 插件