乳腺癌（BC）是全球第二大常见恶性肿瘤。 ADGRL4 作为血管生成的调节剂，经历各种影响其生物学功能的表观遗传修饰。在这项研究中，我们的目的是评估 ADGRL4 启动子甲基化状态及其在原发性乳腺肿瘤中的表达水平，并评估其作为 BC 的合理预后生物标志物的效力。此外，我们在体外评估了褪黑激素对 ADGRL4 表达和 BC 细胞活力的影响。收集了 100 份乳腺肿瘤组织样本和邻近的非肿瘤组织，然后进行 DNA 分离、亚硫酸氢盐转化、qRT-PCR、qMSP 测定和免疫印迹。此外，用褪黑激素处理四种 BC 细胞系，并进行 ADGRL4 表达分析和凋亡测定。我们发现 ADGRL4 表达水平与 HER2 状态和疾病阶段之间存在显着相关性 (P<<0.05)。我们观察到与边缘非肿瘤样本相比，肿瘤样本中 ADGRL4 启动子甲基化显着减弱。在褪黑激素存在的情况下，在两种 BC 细胞系中检测到 ADGRL4 的表达显着降低。 MCF-7 和 BT474 褪黑素处理的细胞系显示出比未处理的细胞显着更高的凋亡细胞数量 (P < 0.0001)。根据受试者工作特征（ROC）曲线分析，ADGRL4表达和ADGRL4启动子甲基化状态显示出中等的预后价值。我们发现褪黑激素对 BC 细胞具有抗癌作用。此外，ADGRL4 表达有可能用作 BC 的预后生物标志物。© 2024。作者获得 Springer-Verlag GmbH 德国（Springer Nature 旗下公司）的独家许可。

Breast cancer (BC) is the second most common malignancy worldwide. ADGRL4, as a modulator of angiogenesis, undergoes various epigenetic modifications affecting its biological functions. In this study, we aimed to assess ADGRL4 promoter methylation status and its expression levels in primary breast tumors and to evaluate its potency as a plausible prognostic biomarker in BC. Furthermore, we evaluated the effect of melatonin on ADGRL4 expression and viability of BC cells in vitro. One hundred breast tumor tissue samples and adjacent non-tumor tissues were collected, followed by DNA isolation, bisulfite conversion, qRT-PCR, qMSP assay, and immunoblotting. In addition, four BC cell lines were treated with melatonin and subjected to ADGRL4 expression analysis and apoptosis assay. We found a significant correlation between ADGRL4 expression levels and HER2 status and stage of disease (P < 0.05). We observed a substantial attenuation in ADGRL4 promoter methylation in tumor samples compared to marginal non-tumor samples. A significantly lower expression of ADGRL4 was detected in two BC cell lines in the presence of melatonin. MCF-7 and BT474 melatonin-treated cell lines showed a significantly higher number of apoptotic cells than non-treated cells (P < 0.0001). Based on the receiver operating characteristic (ROC) curve analysis, ADGRL4 expression and ADGRL4 promoter methylation status showed moderate prognostic value. We found that melatonin has anti-cancer effects on BC cells. In addition, ADGRL4 expression can potentially be used as a prognostic biomarker in BC.© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.