BRD7 被确定为鼻咽癌 (NPC) 的肿瘤抑制因子。环状RNA（CircRNA）作为癌基因或抑癌基因参与鼻咽癌的发生和发展。然而，源自 BRD7 的环状 RNA 形式在 NPC 中的功能和机制尚不清楚。在本研究中，我们首先发现circBRD7是一种源自BRD7的新型circRNA，可抑制鼻咽癌细胞的增殖、迁移、侵袭，以及体内异种移植肿瘤的生长和转移。机制上，circBRD7通过增强其宿主基因BRD7启动子区组蛋白3赖氨酸27乙酰化（H3K27ac）的富集来促进BRD7的转录激活和表达，BRD7促进circBRD7的形成。因此，circBRD7与BRD7形成正反馈环，抑制NPC的发生和进展。此外，BRD7表达的恢复挽救了circBRD7对鼻咽癌恶性进展的抑制作用。此外，circBRD7在鼻咽癌组织中呈低表达，与BRD7表达量呈正相关，与鼻咽癌患者的临床分期呈负相关。综上所述，circBRD7 通过与其宿主基因 BRD7 形成正反馈环来减弱鼻咽癌的肿瘤生长和转移，而靶向 circBRD7/BRD7 轴是鼻咽癌临床诊断和治疗的一种有前途的策略。© 2023 作者。约翰·威利出版的《癌症科学》

BRD7 was identified as a tumor suppressor in nasopharyngeal carcinoma (NPC). Circular RNAs (CircRNAs) are involved in the occurrence and development of NPC as oncogenes or tumor suppressors. However, the function and mechanism of the circular RNA forms derived from BRD7 in NPC are not well understood. In this study, we first identified that circBRD7 was a novel circRNA derived from BRD7 that inhibited cell proliferation, migration, invasion of NPC cells, as well as the xenograft tumor growth and metastasis in vivo. Mechanistically, circBRD7 promoted the transcriptional activation and expression of BRD7 by enhancing the enrichment of histone 3 lysine 27 acetylation (H3K27ac) in the promoter region of its host gene BRD7, and BRD7 promoted the formation of circBRD7. Therefore, circBRD7 formed a positive feedback loop with BRD7 to inhibit NPC development and progression. Moreover, restoration of BRD7 expression rescued the inhibitory effect of circBRD7 on the malignant progression of NPC. In addition, circBRD7 demonstrated low expression in NPC tissues, which was positively correlated with BRD7 expression and negatively correlated with the clinical stage of NPC patients. Taken together, circBRD7 attenuates the tumor growth and metastasis of NPC by forming a positive feedback loop with its host gene BRD7, and targeting the circBRD7/BRD7 axis is a promising strategy for the clinical diagnosis and treatment of NPC.© 2023 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.