信号传导和转录激活子3（STAT3）的构成性激活和异常表达在宫颈癌（CaCx）的发生和发展中起着关键作用。STAT3如何影响HPV的转录目前尚不明确。在本研究中，我们探讨了STAT3与HPV16/18 LCR的直接和间接相互作用。对LCR上存在的顺式元件进行体外评估发现存在潜在的STAT3结合位点。然而，通过染色质免疫共沉淀-聚合酶链式反应（ChIP-PCR）的实验证实无法确认STAT3与HPV16 LCR的特异性结合。通过蛋白质-蛋白质相互作用（PPI）网络分析发现STAT3与其他能够结合LCR的宿主转录因子（c-FOS和c-JUN）之间存在物理相互作用。这在体外通过共免疫沉淀进一步得到证实，STAT3在CaCx细胞中与c-FOS和c-JUN共免疫沉淀。免疫细胞化学分析和STAT3与c-FOS和c-JUN的共定位进一步支持了这一结果。近距离连接物探针分析验证了STAT3与AP1的物理相互作用和共定位。IL-6处理后，STAT3与c-FOS和c-JUN的共定位增加，而在Stattic处理后减少。改变STAT3的表达会影响c-FOS和c-JUN的亚细胞定位，以及CaCx细胞中病毒致癌蛋白（E6和E7）的表达。在HPV16和HPV18 CaCx队列中，肿瘤组织中c-JUN的高表达与恶性预后相关，而STAT3的高表达仅与HPV18 CaCx病变的恶性预后相关。总体而言，数据表明STAT3通过c-FOS和c-JUN与HPV LCR之间存在间接相互作用，并促进病毒致癌蛋白的转录。版权所有 © 2023. Elsevier B.V. 发表。

The constitutive activation and aberrant expression of Signal Transducer and Activator of Transcription 3 (STAT3) plays a key role in initiation and progression of cervical cancer (CaCx). How STAT3 influences HPV transcription is poorly defined. In the present study, we probed direct and indirect interactions of STAT3 with HPV16/18 LCR. In silico assessment of cis-elements present on LCR revealed the presence of potential STAT3 binding motifs. However, experimental validation by ChIP-PCR could not confirm any specific STAT3 binding on HPV16 LCR. Protein-protein interaction (PPI) network analysis of STAT3 with other host transcription factors that bind LCR, highlighted the physical association of STAT3 with c-FOS and c-JUN. This was further confirmed in vitro by co-immunoprecipitation, where STAT3 co-immunoprecipitated with c-FOS and c-JUN in CaCx cells. The result was supported by immunocytochemical analysis and colocalization of STAT3 with c-FOS and c-JUN. Positive signals in proximity ligation assay validated physical interaction and colocalization of STAT3 with AP1. Colocalization of STAT3 with c-FOS and c-JUN increased upon IL-6 treatment and decreased post-Stattic treatment. Alteration of STAT3 expression affected the subcellular localization of c-FOS and c-JUN, along with the expression of viral oncoproteins (E6 and E7) in CaCx cells. High expression of c-JUN in tumor tissues correlated with poor prognosis in both HPV16 and HPV18 CaCx cohort whereas high expression of STAT3 correlated with poor prognosis in HPV18 CaCx lesions only. Overall, the data suggest an indirect interaction of STAT3 with HPV LCR via c-FOS and c-JUN and potentiate transcription of viral oncoproteins.Copyright © 2023. Published by Elsevier B.V.