Department of Otolaryngology & Head and Neck Surgery, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei, 050035, China.
Department of Stomatology, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei, 050035 , China.
Curr Cancer Drug Targets. 2024;24(5):519-533. doi: 10.2174/0115680096258716231026063704.
Medullary thyroid carcinoma (MTC) is a rare but aggressive endocrine malignancy that originates from the parafollicular C cells of the thyroid gland. Enhancer RNAs (eRNAs) are non-coding RNAs transcribed from enhancer regions, which are critical regulators of tumorigenesis. However, the roles and regulatory mechanisms of eRNAs in MTC remain poorly understood. This study aims to identify key eRNAs regulating the malignant phenotype of MTC and to uncover transcription factors involved in the regulation of key eRNAs.
GSE32662 and GSE114068 were used for the identification of differentially expressed genes, eRNAs, enhancers and enhancer-regulated genes in MTC. Metascape and the transcription factor affinity prediction method were used for gene function enrichment and transcription factor prediction, respectively. qRT-PCR was used to detect gene transcription levels. ChIP-qPCR was used to assess the binding of histone H3 lysine 27 acetylation (H3K27ac)-enriched regions to anti- H3K27ac. RIP-qPCR was used to detect the binding between FOXQ1 and LINC00887. CCK8 and Transwell were performed to measure the proliferation and invasion of MTC cells, respectively. Intracellular reactive oxygen species (ROS) levels were quantified using a ROS assay kit.
Four eRNAs (H1FX-AS1, LINC00887, MCM3AP-AS1 and A1BG-AS1) were screened, among which LINC00887 was the key eRNA promoting the proliferation and invasion of MTC cells. A total of 135 genes controlled by LINC00887-regulated enhancers were identified; among them, and were significantly enriched in the "ROS metabolic process" term. As a transcription factor regulating genes enriched in the "ROS metabolic process" term, FOXQ1 could recruit LINC00887. Overexpression of FOXQ1 restored LINC00887 knockdown-induced downregulation of and transcription in MTC cells. Additionally, FOXQ1 overexpression counteracted the inhibitory effects of LINC00887 knockdown on the proliferation and invasion of MTC cells and the promotion of intracellular ROS accumulation induced by LINC00887 knockdown.
LINC00887 was identified as a key eRNA promoting the malignant phenotype of MTC cells. The involvement of FOXQ1 was essential for LINC00887 to play a pro-tumorigenic role in MTC. Our findings suggest that the FOXQ1/LINC00887 axis is a potential therapeutic target for MTC.
甲状腺髓样癌（MTC）是一种罕见但侵袭性的内分泌恶性肿瘤，起源于甲状腺滤泡旁 C 细胞。增强子 RNA（eRNA）是从增强子区域转录的非编码 RNA，是肿瘤发生的关键调节剂。然而，eRNA 在 MTC 中的作用和调节机制仍知之甚少。本研究旨在鉴定调节 MTC 恶性表型的关键 eRNA，并揭示参与关键 eRNA 调节的转录因子。
使用 GSE32662 和 GSE114068 鉴定 MTC 中差异表达的基因、eRNA、增强子和增强子调节的基因。使用 Metascape 和转录因子亲和力预测方法分别进行基因功能富集和转录因子预测。qRT-PCR 用于检测基因转录水平。ChIP-qPCR 用于评估富含组蛋白 H3 赖氨酸 27 乙酰化（H3K27ac）的区域与抗 H3K27ac 的结合。RIP-qPCR 用于检测 FOXQ1 与 LINC00887 之间的结合。CCK8 和 Transwell 分别用于测量 MTC 细胞的增殖和侵袭。使用 ROS 测定试剂盒定量测定细胞内活性氧（ROS）水平。
筛选出 4 个 eRNA（H1FX-AS1、LINC00887、MCM3AP-AS1 和 A1BG-AS1），其中 LINC00887 是促进 MTC 细胞增殖和侵袭的关键 eRNA。鉴定出 135 个受 LINC00887 调节的增强子控制的基因；其中， 和 在“ROS 代谢过程”术语中显著富集。作为调节“ROS 代谢过程”术语中富集的基因的转录因子，FOXQ1 可以募集 LINC00887。FOXQ1 的过表达恢复了 LINC00887 敲低诱导的 MTC 细胞中 和 转录的下调。此外，FOXQ1 的过表达抵消了 LINC00887 敲低对 MTC 细胞增殖和侵袭的抑制作用，并促进了 LINC00887 敲低诱导的细胞内 ROS 积累。
LINC00887 被鉴定为促进 MTC 细胞恶性表型的关键 eRNA。FOXQ1 的参与对于 LINC00887 在 MTC 中发挥促肿瘤作用至关重要。我们的研究结果表明，FOXQ1/LINC00887 轴可能是 MTC 的潜在治疗靶点。
