Multiple oncogenic changes (K-RASV12, p53 knockdown, mutant EGFRs, p16 bypass, telomerase) are not sufficient to confer a full malignant phenotype on human bronchial epithelial cells
Multiple oncogenic changes (K-RASV12, p53 knockdown, mutant EGFRs, p16 bypass, telomerase) are not sufficient to confer a full malignant phenotype on human bronchial epithelial cells
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DOI：
10.1158/0008-5472.can-05-2521
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发表时间：
2006-02-15
期刊：
影响因子：
11.2
通讯作者：
Minna, JD
中科院分区：
文献类型：
--
作者：
Sato, M;Vaughan, MB;Minna, JD
我们使用端粒酶永生化的人支气管上皮细胞（HBEC）和Cdk 4介导的p16旁路评估了三种遗传改变（p53敲低、K-RAS（V12）和突变型EGFR）对肺肿瘤发生的贡献。RNA干扰p53敲低或致癌K-RAS（V12）导致HBEC的锚定非依赖性生长增强和饱和密度增加。p53敲除和K-RASV 12的组合进一步增强了致瘤表型，在软琼脂中生长增加，在三维器官型培养物中具有侵袭性表型，但未能导致HBEC在裸鼠中形成肿瘤。HBEC的生长高度依赖于表皮生长因子（EGF），并被表皮生长因子受体（EGFR）酪氨酸激酶抑制剂完全抑制，从而诱导G 1停滞。引入EGFR突变E746-A750 del和L 858 R使HBEC向恶性发展，如通过软琼脂生长测量的，包括EGF非依赖性生长，但未能诱导肿瘤形成。EGFR突变体与磷酸化Akt、磷酸化信号转导子和转录激活子3水平升高[但不与磷酸化细胞外信号调节激酶（ERK）1/2水平升高]以及DUSP 6/MKP-3磷酸酶（磷酸化ERK 1/2抑制剂）表达增加相关。这些结果表明：（a）HBEC模型系统是评估个体和组合遗传改变对肺癌发病机制的贡献的一种强有力的新方法;（B）四种遗传改变的组合，包括人端粒酶逆转录酶过表达、p16/RB和p53途径的旁路以及突变型K-RAS（V12）或突变型EGFR，仍然不足以使HBEC完全转化为癌症;和（c）EGFR酪氨酸激酶抑制剂抑制癌前HBEC细胞的生长，表明它们具有化学预防的潜力。
We evaluated the contribution of three genetic alterations (p53 knockdown, K-RAS(V12), and mutant EGFR) to lung tumorigenesis using human bronchial epithelial cells (HBEC) immortalized with telomerase and Cdk4-mediated p16 bypass. RNA interference p53 knockdown or oncogenic K-RAS(V12) resulted in enhanced anchorage-independent growth and increased saturation density of HBECs. The combination of p53 knockdown and K-RASV12 further enhanced the tumorigenic phenotype with increased growth in soft agar and an invasive phenotype in three-dimensional organotypic cultures but failed to cause HBECs to form tumors in nude mice. Growth of HBECs was highly dependent on epidermal growth factor (EGF) and completely inhibited by EGF receptor (EGFR) tyrosine kinase inhibitors, which induced G, arrest. Introduction of EGFR mutations E746-A750 del and L858R progressed HBECs toward malignancy as measured by soft agar growth, including EGF-independent growth, but failed to induce tumor formation. Mutant EGFRs were associated with higher levels of phospho-Akt, phospho-signal transducers and activators of transcription 3 [but not phospho-extracellular signal-regulated kinase (ERK) 1/2], and increased expression of DUSP6/MKP-3 phosphatase (an inhibitor of phospho-ERK1/2). These results indicate that (a) the HBEC model system is a powerful new approach to assess the contribution of individual and combinations of genetic alterations to lung cancer pathogenesis; (b) a combination of four genetic alterations, including human telomerase reverse transcriptase overexpression, bypass of p16/RB and p53 pathways, and mutant K-RAS(V12) or mutant EGFR, is still not sufficient for HBECs to completely transform to cancer; and (c) EGFR tyrosine kinase inhibitors inhibit the growth of preneoplastic HBEC cells, suggesting their potential for chemoprevention.