He Yingqiu, Pan Junfan, Chen Sufang, Lin Ying, She Peiwei, Chen Yusheng, Xu Nengluan, Li Hongru
Shengli Clinical Medical College of Fujian Medical University, Fujian Provincial Hospital, Fuzhou University Affiliated Provincial Hospital, Fuzhou, Fujian Province, China.
Department of Pathology, Shengli Clinical Medical College of Fujian Medical University, Fujian Provincial Hospital, Fuzhou University Affiliated Provincial Hospital, Fuzhou, Fujian Province, China.
FASEB J. 2025 Sep 15;39(17):e70954. doi: 10.1096/fj.202501354R.
The regulatory mechanisms driving brain metastasis (BM) in non-small cell lung cancer (NSCLC) are complex, with Ceramide synthase 1 (Cers1) playing a critical role. However, the upstream factors controlling Cers1 expression remain unclear. Additionally, Kruppel-like factor 9 (KLF9) has been implicated as a potential tumor suppressor transcription factor (TF) in lung cancer. Our study aims to explore the physiological effects and molecular mechanisms of Cers1 upstream regulatory TFs in NSCLC BM, focusing on the link between KLF9 and Cers1. TFs regulating Cers1 expression were screened via GENECARD and UCSC databases. KLF9 expression and survival analysis in NSCLC were analyzed using TCGA and GEO data sets. Dual-luciferase assays were conducted to investigate the specific binding site of KLF9 on the Cers1 promoter. KLF9 genetic modulation impact on NSCLC BM was assessed through in vitro assays for proliferation, migration, and invasion, along with in vivo orthotopic xenograft models to evaluate tumor growth and metastasis. Our study revealed a significant downregulation of KLF9 in vitro, correlating with poor prognosis. KLF9 has a direct positive transcriptional regulation on Cers1, particularly on its promoter region (-711 nt/+22 nt). In vitro, KLF9 overexpression inhibited the ability of cells to penetrate a blood-brain barrier model. Moreover, in vivo experiments demonstrated a marked suppression of BM tumor formation upon KLF9 expression. This study reports KLF9's direct control over Cers1 expression by acting on its promoter. KLF9 demonstrates inhibitory effects on NSCLC BM, presenting a promising therapeutic avenue for NSCLC BM treatment.
驱动非小细胞肺癌（NSCLC）脑转移（BM）的调控机制复杂，其中神经酰胺合酶1（Cers1）起关键作用。然而，控制Cers1表达的上游因素仍不清楚。此外，Kruppel样因子9（KLF9）被认为是肺癌中一种潜在的肿瘤抑制转录因子（TF）。我们的研究旨在探讨NSCLC脑转移中Cers1上游调控转录因子的生理效应和分子机制，重点关注KLF9与Cers1之间的联系。通过GENECARD和UCSC数据库筛选调控Cers1表达的转录因子。利用TCGA和GEO数据集分析NSCLC中KLF9的表达和生存情况。进行双荧光素酶测定以研究KLF9在Cers1启动子上的特异性结合位点。通过体外增殖、迁移和侵袭试验以及体内原位异种移植模型评估KLF9基因调控对NSCLC脑转移的影响，以评估肿瘤生长和转移。我们的研究表明，体外KLF9显著下调，与预后不良相关。KLF9对Cers1有直接的正向转录调控作用，特别是对其启动子区域（-711 nt/+22 nt）。在体外，KLF9过表达抑制细胞穿透血脑屏障模型的能力。此外，体内实验表明，KLF9表达后可显著抑制脑转移瘤的形成。本研究报道了KLF9通过作用于Cers1启动子直接控制其表达。KLF9对NSCLC脑转移具有抑制作用，为NSCLC脑转移治疗提供了一条有前景的治疗途径。
