p53抑癌基因的异常在肺癌的发生发展中至关重要，p53可能通过调节靶基因启动子来对抗癌症。最近的研究表明 p53 与增强子元件有广泛的结合。然而，p53 是否通过塑造增强子景观发挥肿瘤抑制作用仍知之甚少。在当前的研究中，我们基于我们建立的 TP53 敲除人支气管上皮细胞 (BEAS-2B)，采用了几种功能基因组学方法来评估整个基因组中 p53 结合位点的增强子活性。总共 943 个活性常规增强子和 370 个超级增强子 (SE) 在 p53 删除后消失，表明 p53 调节数百个增强子元件的活性。我们发现，位于 9 号染色体上的一种 p53 依赖性 SE 被命名为 KLF4-SE，它调节 Krüppel 样因子 4 (KLF4) 基因的表达。此外，在亚硝胺4-(甲基亚硝基氨基)-1-(3-吡啶基)-1-丁酮诱导的细胞转化模型中，p53的缺失显着降低了KLF4-SE增强子活性和KLF4表达，但增加了集落形成能力。随后，在TP53敲除细胞中，KLF4的过度表达部分逆转了p53缺陷引起的克隆形成能力的增加。一致的是，KLF4 表达在肺癌组织和细胞系中也下降。 KLF4的过度表达显着抑制肺癌细胞的增殖和迁移。总的来说，我们的结果表明 p53 对增强子形成和活性的调节是 p53 肿瘤抑制功能的一个组成部分。因此，我们的研究结果为 p53 在肺肿瘤发生中的调节机制提供了新的见解，并为筛选治疗靶点提供了新的策略。

The abnormality of p53 tumor suppressor is crucial in lung cancer development, and p53 may regulate target gene promoters to combat cancer. Recent studies have shown extensive p53 binding to enhancer elements. However, whether p53 exerts a tumor suppressor role by shaping the enhancer landscape remains poorly understood. In the current study, we employed several functional genomics approaches to assess the enhancer activity at p53 binding sites throughout the genome based on our established TP53 knockout human bronchial epithelial cells (BEAS-2B). A total of 943 active regular enhancers and 370 super-enhancers (SEs) disappeared upon the deletion of p53, indicating that p53 modulates the activity of hundreds of enhancer elements. We found that one p53-dependent SE, located on chromosome 9 and designated as KLF4-SE, regulated the expression of the Krüppel-like factor 4 ( KLF4) gene. Furthermore, deletion of p53 significantly decreased the KLF4-SE enhancer activity and the KLF4 expression, but increased colony formation ability in the nitrosamines 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone-induced cell transformation model. Subsequently, in TP53 knockout cells, the overexpression of KLF4 partially reversed the increased clonogenic capacity caused by p53 deficiency. Consistently, KLF4 expression also decreased in lung cancer tissues and cell lines. Overexpression of KLF4 significantly suppressed lung cancer cell proliferation and migration. Collectively, our results suggest that the regulation of enhancer formation and activity by p53 is an integral component of the p53 tumor suppressor function. Therefore, our findings offer novel insights into the regulation mechanism of p53 in lung oncogenesis and introduce a new strategy for screening therapeutic targets.