视网膜母细胞瘤 (RB) 是一种儿科恶性肿瘤，通常在出生时或幼儿期诊断出来。 RB 的发病机制以碱性螺旋-环-螺旋 (BHLH) 转录因子 MYCN 的扩增为标志，该转录因子作为能够与 Dickkopf 3 (DKK3) 结合的转录调节因子。然而，DKK3 在 MYCN 引起的 RB 细胞恶性进展中的确切作用仍不清楚。在本研究中，MYCN 的表达在 RB 细胞中要么过度表达，要么受到干扰。随后，通过定量实时聚合酶链反应和蛋白质印迹分析评估 DKK3 的表达水平。使用 Cell Counting Kit-8 测定和 5-乙炔基-2'-脱氧尿苷染色评估细胞增殖，同时分别通过流式细胞术和蛋白质印迹分析分析细胞周期进展和凋亡。此外，通过蛋白质印迹分析评估了参与 Wnt/β-catenin/Fra-1/p53 信号通路的蛋白质的表达。为了获得进一步的见解，Wnt 激动剂和 P53 抑制剂 PFT-α 被引入探索中。目前的研究显示RB细胞中MYCN和DKK3的表达水平呈负相关。此外，在高表达 MYCN 的 RB 细胞中，DKK3 过表达抑制细胞增殖，促进细胞凋亡，并阻滞细胞周期。此外，增强的DKK3表达通过调节wnt/βcatenin/Fra-1/p53信号通路抑制RB细胞的增殖、促进细胞周期停滞和凋亡。此外，体内实验表明DKK3的过度表达可抑制RB肿瘤的生长。总的来说，我们的研究结果阐明，MYCN 通过抑制 DKK3 表达来刺激 Wnt/β-catenin/Fra-1 通路，最终抑制 p53 活性并导致 RB 恶性进展。© 2024 Wiley periodicals LLC。

Retinoblastoma (RB) is a pediatric malignancy, typically diagnosed at birth or during early childhood. The pathogenesis of RB is marked by the amplification of the Basic Helix-Loop-Helix (BHLH) Transcription Factor MYCN, which serves as a transcriptional regulator capable of binding to Dickkopf 3 (DKK3). However, the precise role of DKK3 in the malignant progression of RB cells caused by MYCN remains elusive. In the present study, the expression of MYCN was either overexpressed or interfered in RB cells. Subsequently, the expression level of DKK3 was assessed through quantitative real-time polymerase chain reaction and western blot analysis. Cell proliferation was evaluated using the Cell Counting Kit-8 assay and 5-ethynyl-2'-deoxyuridine staining, while cell cycle progression and apoptosis were analyzed by flow cytometry and western blot analysis, respectively. Additionally, the expression of proteins involved in the Wnt/β-catenin/Fra-1/p53 signaling pathway was evaluated via western blot analysis. To gain further insights, Wnt agonists and the P53 inhibitor PFT-α were introduced into exploration. The current investigation revealed a negative correlation between the expression levels of MYCN and DKK3 in RB cells. Additionally, DKK3 overexpression inhibited cell proliferation, promoted cell apoptosis, and arrested cell cycle in RB cells with high expression of MYCN. Moreover, enhanced DKK3 expression inhibited proliferation, promoted cell cycle arrest and apoptosis of RB cells by modulating the wnt/βcatenin/Fra-1/p53 signaling pathway. Furthermore, in vivo experiments revealed that overexpression of DKK3 inhibits the growth of RB tumors. Collectively, our findings elucidate that MYCN stimulates the Wnt/β-catenin/Fra-1 pathway by suppressing DKK3 expression, ultimately suppressing p53 activity and contributing to malignant progression of RB.© 2024 Wiley Periodicals LLC.