State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu, Sichuan, People's Republic of China.
PLoS One. 2011;6(12):e28930. doi: 10.1371/journal.pone.0028930. Epub 2011 Dec 14.
Despite many evidences supporting the concept of "oncogene addiction" and many hypotheses rationalizing it, there is still a lack of detailed understanding to the precise molecular mechanism underlying oncogene addiction. In this account, we developed a mathematic model of epidermal growth factor receptor (EGFR) associated signaling network, which involves EGFR-driving proliferation/pro-survival signaling pathways Ras/extracellular-signal-regulated kinase (ERK) and phosphoinositol-3 kinase (PI3K)/AKT, and pro-apoptotic signaling pathway apoptosis signal-regulating kinase 1 (ASK1)/p38. In the setting of sustained EGFR activation, the simulation results show a persistent high level of proliferation/pro-survival effectors phospho-ERK and phospho-AKT, and a basal level of pro-apoptotic effector phospho-p38. The potential of p38 activation (apoptotic potential) due to the elevated level of reactive oxygen species (ROS) is largely suppressed by the negative crosstalk between PI3K/AKT and ASK1/p38 pathways. Upon acute EGFR inactivation, the survival signals decay rapidly, followed by a fast increase of the apoptotic signal due to the release of apoptotic potential. Overall, our systems biology modeling together with experimental validations reveals that inhibition of survival signals and concomitant release of apoptotic potential jointly contribute to the tumor cell death following the inhibition of addicted oncogene in EGFR addicted cancers.
尽管有许多证据支持“癌基因成瘾”的概念,并且有许多假说对其进行了合理化,但对于癌基因成瘾背后的确切分子机制仍缺乏详细的了解。在本研究中,我们开发了一个表皮生长因子受体(EGFR)相关信号网络的数学模型,该模型涉及 EGFR 驱动的增殖/存活信号通路 Ras/细胞外信号调节激酶(ERK)和磷酸肌醇 3 激酶(PI3K)/蛋白激酶 B(AKT),以及促凋亡信号通路凋亡信号调节激酶 1(ASK1)/p38。在持续激活 EGFR 的情况下,模拟结果显示增殖/存活效应物磷酸化 ERK 和磷酸化 AKT 持续保持高水平,促凋亡效应物磷酸化 p38 保持低水平。由于活性氧(ROS)水平升高,p38 的激活潜力(凋亡潜力)受到 PI3K/AKT 和 ASK1/p38 通路之间的负反馈的抑制。急性 EGFR 失活后,存活信号迅速衰减,随后由于凋亡潜力的释放,凋亡信号迅速增加。总之,我们的系统生物学模型与实验验证表明,在 EGFR 成瘾性癌症中,抑制成瘾性癌基因后,抑制存活信号和同时释放凋亡潜力共同导致肿瘤细胞死亡。