PO.MCB06.03 · 分子与细胞生物学
SNP rs4381241 通过 FAF1-HDAC3-PDGFB 轴促进肾细胞癌进展
SNP rs4381241 promotes renal cell carcinoma progression via the FAF1-HDAC3-PDGFB axis
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
背景 肾细胞癌（RCC）是一种高度致死性的癌症，治疗选择有限。由基因组改变驱动的遗传异质性在肿瘤进展和治疗耐药中发挥关键作用。全基因组关联研究（GWAS）已鉴定出与癌症易感性和预后相关的单核苷酸多态性（SNP）。然而，这些 SNP 在调控 RCC 发生发展中的功能机制仍不清楚。研究这些 SNP 有望揭示新的治疗靶点。
方法 采用 EMSA、双荧光素酶报告基因实验和 CRISPRa/i 评估该 SNP 的功能相关性，以确认其对 FAF1 表达的影响。3C/4C 分析证实其与 FAF1 增强子区域的物理相互作用。使用 qPCR 和 Western blot 在 TCGA 数据集和 RCC 组织中检测 FAF1 表达。基因集富集分析（GSEA）鉴定出 PDGFB 为下游靶点。在 RCC 细胞系中进行功能获得和功能缺失实验，包括 CCK-8、划痕愈合、transwell 迁移和集落形成实验，并结合体内皮下异种移植瘤模型。采用 Co-IP、CUT&Tag 和 ChIP-qPCR 研究 FAF1 与 HDAC3 的相互作用及其在 PDGFB 转录中的作用。
结果 位于 FAF1 内含子区域的 SNP rs4381241 作为增强子调控 FAF1 转录。T>C 替换降低了 FAF1 表达。在 TCGA 数据和 RCC 组织中，肿瘤中 FAF1 的 mRNA 和蛋白水平均低于相邻正常组织，且较高的 FAF1 水平与更好的预后相关。功能实验表明，FAF1 过表达在体外抑制细胞增殖和迁移，在体内抑制肿瘤生长，证实了其抑癌作用。在机制上，FAF1 与 HDAC3 相互作用，将其募集至 PDGFB 启动子，导致 H3K9ac 和 H3K27ac 处的组蛋白去乙酰化，抑制 PDGFB 转录并抑制 PDGFRB/PI3K-AKT 信号通路。
结论 内含子 SNP rs4381241 是调控 RCC 中 FAF1 表达的功能性增强子变异。FAF1 抑制 RCC 细胞增殖和迁移，并与 HDAC3 相互作用抑制 PDGFB 转录，从而抑制 PDGFRB/PI3K-AKT 通路。这些发现凸显了 rs4381241 通过 FAF1-HDAC3-PDGFB 轴作为 RCC 进展关键调控因子的作用。
关键词 肾细胞癌，rs4381241，FAF1，HDAC3，PDGFB
查看英文原文 English abstract
Background Renal cell carcinoma (RCC) is a highly lethal cancer with limited therapeutic options. Genetic heterogeneity, driven by genomic alterations, plays a key role in tumor progression and resistance to treatment. Genome-wide association studies (GWAS) have identified single nucleotide polymorphisms (SNPs) linked to cancer susceptibility and prognosis. However, the functional mechanisms of these SNPs in regulating RCC development remain unclear. Investigating these SNPs could reveal new therapeutic targets.
Methods The functional relevance of the SNP was assessed using EMSA, dual-luciferase reporter assays, and CRISPRa/i to confirm its impact on FAF1 expression. 3C/4C analyses confirmed physical interaction with the FAF1 enhancer region. FAF1 expression was measured in TCGA datasets and RCC tissues using qPCR and Western blot. Gene set enrichment analysis (GSEA) identified PDGFB as a downstream target. Gain- and loss-of-function assays were conducted in RCC cell lines, including CCK-8, wound healing, transwell migration, and colony formation assays, along with in vivo subcutaneous xenograft models. Co-IP, CUT&Tag, and ChIP-qPCR were used to study FAF1's interaction with HDAC3 and its role in PDGFB transcription.
Results The SNP rs4381241, in the intronic region of FAF1, acts as an enhancer that regulates FAF1 transcription. The T>C substitution reduces FAF1 expression. In both TCGA data and RCC tissues, FAF1 mRNA and protein levels were lower in tumors compared to adjacent normal tissues, with higher FAF1 levels linked to better prognosis. Functional assays showed that FAF1 overexpression suppressed cell proliferation and migration in vitro, and tumor growth in vivo, confirming its tumor-suppressive role. Mechanistically, FAF1 interacts with HDAC3 to recruit it to the PDGFB promoter, leading to histone deacetylation at H3K9ac and H3K27ac, suppressing PDGFB transcription and inhibiting PDGFRB/PI3K-AKT signaling.
Conclusion The intronic SNP rs4381241 is a functional enhancer variant regulating FAF1 expression in RCC. FAF1 suppresses RCC cell proliferation and migration and interacts with HDAC3 to repress PDGFB transcription, inhibiting the PDGFRB/PI3K-AKT pathway. These findings highlight rs4381241 as a key modulator of RCC progression through the FAF1-HDAC3-PDGFB axis.
Keywords renal cell carcinoma, rs4381241, FAF1, HDAC3, PDGFB
利益披露 Disclosure
H. Liu, None..
X. Yu, None..
Z. Mi, None..
K. Chen, None.