Dayanc Bengisu, Eris Sude, Gulfirat Nazife Ege, Ozden-Yilmaz Gulden, Cakiroglu Ece, Coskun Deniz Ozlem Silan, Karakülah Gökhan, Erkek-Ozhan Serap, Senturk Serif
Izmir Biomedicine and Genome Center, Izmir, Türkiye.
Izmir International Biomedicine and Genome Institute, Dokuz Eylul University, Izmir, Türkiye.
Cell Death Dis. 2025 May 25;16(1):414. doi: 10.1038/s41419-025-07711-z.
Osimertinib, a third-generation EGFR tyrosine kinase inhibitor (EGFR-TKI), has dramatically transformed the treatment landscape for patients with EGFR-mutant NSCLC. However, the long-term success of this therapy is often compromised by the onset of acquired resistance, with non-genetic mechanisms increasingly recognized as pivotal contributors. Here, we exploit a multi-omics approach to profile genome-wide chromatin accessibility and transcriptional landscapes between drug sensitive and resistant EGFR-mutant cells. Our findings reveal a robust concordance between epigenetic regulome and transcriptomic changes that characterize the osimertinib resistant state. Through CRISPR-based functional genomics screen targeting epigenetic regulators and transcription factors, we uncover a critical regulatory network featuring key members of the NuRD and PRC2 complexes that mediate resistance. Most critically, our screen identifies FOSL1 and JUN, two subunits of the AP-1 transcription factor within this network, as the most significant hits. Mechanistically, we demonstrate that cis-regulatory elements exhibiting altered chromatin accessibility in the resistant state are enriched for cognate AP-1 binding motifs, enabling AP-1 to orchestrate a gene expression program that underpins the druggable MEK/ERK signaling axis, potentially enhancing cell viability and fitness of resistant cells. Importantly, genetic depletion or pharmacological inhibition of AP-1 reinstates cellular and molecular sensitivity, and reverts resistance-associated phenotypes, such as epithelial-to-mesenchymal transition, upon anti-EGFR rechallenge by repressing AKT and ERK signaling. These findings provide novel insights into the epigenetic and transcriptional control of osimertinib resistance in EGFR-mutant NSCLC, highlighting AP-1 as a targetable vulnerability of resistance-related hallmarks and offering a promising avenue for developing resistance reversal strategies.
奥希替尼是一种第三代表皮生长因子受体酪氨酸激酶抑制剂（EGFR-TKI），它极大地改变了EGFR突变型非小细胞肺癌（NSCLC）患者的治疗格局。然而，这种疗法的长期成功往往因获得性耐药的出现而受到影响，非遗传机制越来越被认为是关键因素。在这里，我们采用多组学方法来描绘药物敏感和耐药的EGFR突变细胞之间全基因组染色质可及性和转录图谱。我们的研究结果揭示了表观遗传调控组与转录组变化之间的强烈一致性，这些变化表征了奥希替尼耐药状态。通过基于CRISPR的针对表观遗传调节因子和转录因子的功能基因组学筛选，我们发现了一个关键的调控网络，其特征是介导耐药性的NuRD和PRC2复合物的关键成员。最关键的是，我们的筛选确定了该网络中AP-1转录因子的两个亚基FOSL1和JUN是最显著的命中靶点。从机制上讲，我们证明在耐药状态下染色质可及性发生改变的顺式调控元件富含同源AP-1结合基序，使AP-1能够协调一个基因表达程序，该程序支撑可靶向的MEK/ERK信号轴，可能增强耐药细胞的活力和适应性。重要的是，AP-1的基因敲除或药理抑制恢复了细胞和分子敏感性，并在抗EGFR再次攻击时通过抑制AKT和ERK信号逆转了与耐药相关的表型，如上皮-间质转化。这些发现为EGFR突变型NSCLC中奥希替尼耐药的表观遗传和转录控制提供了新的见解，突出了AP-1作为耐药相关特征的可靶向弱点，并为开发耐药逆转策略提供了一条有前景的途径。
