Expression of a Dominant-Negative Mutant Inhibitor-κBα of Nuclear Factor-κB in Human Head and Neck Squamous Cell Carcinoma Inhibits Survival, Proinflammatory Cytokine Expression, and Tumor Growth in Vivo
Expression of a Dominant-Negative Mutant Inhibitor-κBα of Nuclear Factor-κB in Human Head and Neck Squamous Cell Carcinoma Inhibits Survival, Proinflammatory Cytokine Expression, and Tumor Growth in Vivo
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发表时间：
1999-07
期刊：
影响因子：
11.2
通讯作者：
D. Duffey;Zhong Chen;G. Dong;F. Ondrey;J. S. Wolf;K. Brown;U. Siebenlist;C. Waes
中科院分区：
文献类型：
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作者：
D. Duffey;Zhong Chen;G. Dong;F. Ondrey;J. S. Wolf;K. Brown;U. Siebenlist;C. Waes
我们最近证明，头颈鳞状细胞癌中促炎细胞因子白细胞介素 (IL)-1α、IL-6、IL-8 和粒细胞-巨噬细胞集落刺激因子的组成型表达与转录因子核因子 (NF)-κB/Rel A (p50/p65) 的激活相关，后者与编码该细胞因子库的每个基因内的启动子区域结合。 NF-κB 可在信号依赖性磷酸化和抑制剂-κBα 降解后被激活，据报道可促进细胞存活和生长。在本研究中，我们在头颈鳞状细胞癌细胞系UM-SCC-9、-11B和-38中表达了抑制剂-κBα（IκBαM）的磷酸化位点突变体，以确定抑制NF-κB对细胞因子表达、体外细胞存活和体内生长的影响。转染IκBαM后，仅获得少数稳定表达突变IκB的UM-SCC-9克隆，这表明突变IκBα的表达可能影响转染的UM-SCC细胞系的存活。 IκBαM 与 Lac-Z 报告基因共转染后，我们发现与转染缺乏插入片段的载体的对照相比，三种细胞系中存活的 β-半乳糖苷酶阳性细胞数量减少了 70-90%。在稳定表达 IκBαM 的 UM-SCC-9 细胞中，观察到组成型因子和肿瘤坏死因子-α 的抑制诱导 NF-κB 激活，并观察到所有四种细胞因子的产生。尽管UM-SCC-9 IκBαM转染的细胞在体外以与载体转染的细胞相同的速率增殖，但在体内SCID小鼠中观察到肿瘤异种移植物的生长显着减少。 UM-SCC-9 IκBαM 转染的肿瘤细胞的生长减少伴随着原位激活形式的 NF-κB 免疫组织化学检测的减少。这些结果证明 NF-κB 和 IκBα 在鳞状细胞癌的存活、促炎细胞因子的组成型和诱导型表达以及生长中发挥重要作用。 NF-κB 可以作为针对细胞因子和其他早期基因反应的治疗干预的潜在靶标，这些反应有助于这些癌症的生存、生长和发病机制。
We demonstrated recently that constitutive expression of proinflammatory cytokines interleukin (IL)-1α, IL-6, IL-8, and granulocyte- macrophage colony-stimulating factor in head and neck squamous cell carcinoma is correlated with activation of transcription factor nuclear factor (NF)-κB/Rel A (p50/p65), which binds the promoter region within each of the genes encoding this repertoire of cytokines. NF-κB can be activated after signal-dependent phosphorylation and degradation of inhibitor-κBα and has been reported to promote cell survival and growth. In the present study, we expressed a phosphorylation site mutant of inhibitor-κBα (IκBαM) in head and neck squamous cell carcinoma lines UM-SCC-9, -11B, and -38 to determine the effect of inhibition of NF-κB on cytokine expression, cell survival in vitro , and growth in vivo . After transfection with IκBαM, only a few UM-SCC-9 clones were obtained that stably expressed the mutant IκB, suggesting that expression of a mutant IκBα may affect survival of the transfected UM-SCC cell lines. After cotransfection of IκBαM with a Lac-Z reporter, we found that the number of surviving β-galactosidase-positive cells in the three cell lines was reduced by 70–90% when compared with controls transfected with vector lacking the insert. In UM-SCC-9 cells that stably expressed IκBαM, inhibition of constitutive and tumor necrosis factor-α induced NF-κB activation, and production of all four cytokines was observed. Although UM-SCC-9 IκBαM-transfected cells proliferated at the same rate as vector-transfected cells in vitro , a significant reduction in growth of tumor xenografts was observed in SCID mice in vivo . The decreased growth of UM-SCC-9 IκBαM-transfected tumor cells accompanied decreased immunohistochemical detection of the activated form of NF-κB in situ . These results provide evidence that NF-κB and IκBα play an important role in survival, constitutive and inducible expression of proinflammatory cytokines, and growth of squamous cell carcinoma. NF-κB could serve as a potential target for therapeutic intervention against cytokine and other immediate-early gene responses that contribute to the survival, growth, and pathogenesis of these cancers.