Inhibition of epidermal growth factor receptor gene expression and function decreases proliferation of head and neck squamous carcinoma but not normal mucosal epithelial cells
Inhibition of epidermal growth factor receptor gene expression and function decreases proliferation of head and neck squamous carcinoma but not normal mucosal epithelial cells
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DOI：
10.1038/sj.onc.1201188
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发表时间：
1997-07-24
期刊：
影响因子：
8
通讯作者：
Tweardy, DJ
中科院分区：
文献类型：
--
作者：
Grandis, JR;Chakraborty, A;Tweardy, DJ
先前的报道已经表明，头颈部鳞状细胞癌（SCCHN）患者的新鲜组织和细胞系在mRNA和蛋白质水平上过度表达转化生长因子α（TGF-α）及其受体，表皮生长因子受体（EGFR）。蛋白定位研究证实，TGF-α和EGFR是由头颈癌患者组织中的相同上皮细胞产生的，进一步支持自分泌生长途径。使用三种策略，我们研究了下调EGFR会降低SCCHN细胞增殖的假设。我们使用反义寡核苷酸和成熟EGFR蛋白在两个位点（配体结合域和激酶域）靶向EGFR mRNA，并确定这种靶向对SCCHN增殖的影响。用一对针对人EGFR基因的翻译起始位点和第一内含子-外显子剪接点的反义寡核苷酸治疗几种SCCHN细胞系，导致EGFR蛋白产生减少，生长抑制86%，而用正义寡核苷酸治疗的细胞减少13%（P=0.03）。生长抑制对癌细胞是特异性的，因为相同的EGFR反义寡核苷酸对从非癌患者收集的正常粘膜细胞的增殖没有影响。阻断配体与EGFR结合的两种单克隆抗体（MAb 425和528）抑制了几种SCCHN细胞系的生长高达97%，这表明EGFR参与了SCCHN中的自分泌途径，至少部分是外部的。EGFR特异性酪氨酸激酶抑制剂（PD 153035）被发现抑制SCCHN细胞系中的EGFR磷酸化并使生长减少68%，尽管其对正常粘膜上皮细胞的生长速率没有影响。这些实验表明，EGFR基因的表达和功能是至关重要的SCCHN细胞的生长，但不是正常粘膜细胞的生长，因此可以作为一个肿瘤特异性的目标，在头颈部癌症的预防和治疗策略。
Previous reports have shown that fresh tissues and cell lines from patients with squamous cell carcinoma of the head and neck (SCCHN) overexpress transforming growth factor alpha (TGF-alpha) and its receptor, the epidermal growth factor receptor (EGFR) at both the mRNA and protein levels. Protein localization studies confirm that TGF-alpha and EGFR are produced by the same epithelial cells in tissues from head and neck cancer patients further supporting an autocrine growth pathway. Using three strategies, we examined the hypothesis that downmodulation of EGFR would reduce the proliferation of SCCHN cells. We targeted EGFR mRNA using antisense oligonucleotides and the mature EGFR protein at two sites, the ligand-binding domain and the kinase domain, and determined the effects of this targeting on SCCHN proliferation. Treatment of several SCCHN cell lines with a pair of antisense oligodeoxynucleotides directed against the translation start site and first intron-exon splice junction of the human EGFR gene resulted in decreased EGFR protein production and inhibited growth by 86% compared to a 13% reduction in cells treated with sense oligonucleotides (P=0.03). Growth inhibition was specific for carcinoma cells since the same EGFR antisense oligonucleotides had no effect on the proliferation of normal mucosa cells harvested from non-cancer patients. Two monoclonal antibodies which block ligand binding to EGFR (MAbs 425 and 528) inhibited the growth of several SCCHN cell lines by up to 97% which suggests that EGFR is participating in an autocrine pathway in SCCHN that is, at least in part, external. An EGFR-specific tyrosine kinase inhibitor (PD 153035) was found to inhibit EGFR phosphorylation in SCCHN cell lines and to reduce growth by 68% although it had no effect on the growth rate of normal mucosal epithelial cells. These experiments indicate that EGFR gene expression and function is critical for SCCHN cell growth but not for growth of normal mucosa cells and therefore may serve as a tumor-specific target for preventive and therapeutic strategies in head and neck cancer.