p63 and its co-binding factor Znf148 cooperate to control squamous cell carcinoma proliferation

Head and neck squamous cell carcinoma (HNSCC) are common and aggressive malignancies, and little progress has been made in improving outcomes for patients. HNSCC exhibit frequent overexpression of the p53-related transcription factor TP63. Here, we show that ZNF148 is an important partner in p63-driven tumorigenesis. Mechanistically, while ZNF148 alone binds CCND1 gene promoter, the p63-ZNF148 complex co-binds a CCND1 upstream enhancer leading to an enhancer-derived RNAs (eRNA3) acting as cis-regulatory elements for CCND1 transcription. The eRNA3 p63/ZNF148-dependent transcription is required to support high-rate proliferation in HNSCC. Interestingly, p63/ZNF148, eRNA3 and cyclin D1 expression is highly co-correlated in primary HNSCC, including laryngeal squamous cell carcinoma (LSCC). Their co-expression correlated to tumor stage and lymph nodes positivity. These results revealed a strong cooperation of the two transcription factors, p63 and ZNF148, as HNSCC oncogenic drivers. Altogether, these findings provide a framework to facilitate categorization of HNSCC sub-types, prognostic/diagnostic biomarkers, and a foundation for development of new therapies. Overall design: ChIP-seq

头颈部鳞状细胞癌（Head and neck squamous cell carcinoma, HNSCC）是一类常见且具有侵袭性的恶性肿瘤，目前患者预后改善领域仍鲜有突破。HNSCC常出现p53相关转录因子TP63的过度表达。本研究发现，ZNF148是p63驱动肿瘤发生过程中的重要调控伴侣。机制上，尽管ZNF148可单独结合CCND1基因启动子，但p63-ZNF148复合物可共同结合CCND1上游增强子，进而诱导产生增强子源性RNA（enhancer-derived RNAs, eRNA3），该RNA可作为CCND1转录的顺式调控元件。依赖p63/ZNF148的eRNA3转录，是维持HNSCC细胞高增殖速率的必要条件。值得注意的是，在包括喉鳞状细胞癌（laryngeal squamous cell carcinoma, LSCC）在内的原发性HNSCC组织中，p63/ZNF148、eRNA3与细胞周期蛋白D1的表达呈现高度共相关性。三者的共表达水平与肿瘤分期及淋巴结阳性状态显著相关。本研究结果揭示，p63与ZNF148这两种转录因子可通过强力协同作用，作为HNSCC的致癌驱动因子。综上，本研究发现可为HNSCC亚型分类、预后/诊断生物标志物的筛选提供理论框架，同时也为新型治疗手段的开发奠定了坚实基础。整体实验设计：染色质免疫沉淀测序（ChIP-seq）