Purpose: Ovarian cancer, manifested by malignant ascites, is the most lethal gynaecological cancer. Suspended ascites-derived spheroids may contribute to ovarian cancer metastasis. MicroRNAs (miRNAs) are also associated with ovarian cancer metastasis. Here, we aimed to investigate the differentially expressed miRNAs (DE-miRNAs) in ascites-derived spheroids compared with primary tumour tissues, which may regulate ovarian cancer metastasis.
Methods: The DE-miRNAs between ovarian cancer primary tumour tissues and ascites-derived spheroids were identified by GEO2R screening in samples from 3 high-grade serous ovarian cancer (HGSOC) patients of dataset GSE65819. We used MiRTarBase, TargetScanHuman7.2 and STRING to predict the target hub genes of DE-miRNAs and DAVID to perform functional analysis of hub genes. ALGGEN PROMO and TransmiR v2.0 were used to predict transcription factors (TFs) that potentially regulate DE-miRNAs expression. The observed differences in DE-miRNAs expression were validated with samples from 12 HGSOC patients and 2 ovarian cancer cell lines using PCR. The functions of DE-miRNAs on ovarian cancer progression were verified by invasion, adherent, and angiogenesis assays.
Results: Through bioinformatics screening and experimental validation, miR-199a-3p, miR-199b-3p, miR-199a-5p, miR-126-3p and miR-145-5p were identified as being significantly downregulated in ascites-derived spheroids compared with primary tumour tissues. In addition, TFAP2A was identified as a potentially common upstream TF regulating the expression of the above mentioned DE-miRNAs. The overexpression of miR-199a-3p, miR-199b-3p, miR-199a-5p lead to invasion inhibition, and the overexpression of miR-126-3p, miR-145-5p, miR-199a-5p and miR-199b-3p lead to adhesion inhibition of suspended ovarian cancer cells. High-expressed miR-126-3p, miR-199a-3p, miR-199a-5p and miR-199b-3p contributed to apoptosis of suspended ovarian cancer cells.
Conclusion: The downregulated expression of miR-199a-3p, miR-199b-3p, miR-199a-5p, miR-126-3p and miR-145-5p in ascites-derived spheroids plays a key role in promoting ovarian cancer progression, which may represent novel molecules for targeted therapy for ovarian cancer.

Keywords: ovarian cancer, metastasis, ascites-derived spheroids, primary tumour tissue, microRNAs


中文翻译：

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与原发性肿瘤组织相比，腹水衍生卵巢癌细胞中差异表达 microRNA 的鉴定和功能验证

目的：卵巢癌以恶性腹水为表现，是最致命的妇科癌症。悬浮的腹水衍生球体可能有助于卵巢癌转移。MicroRNAs (miRNAs) 也与卵巢癌转移有关。在这里，我们旨在研究与原发性肿瘤组织相比，腹水衍生球状体中差异表达的 miRNA (DE-miRNA) 可能调节卵巢癌转移。
方法：在数据集 GSE65819 的 3 名高级别浆液性卵巢癌 (HGSOC) 患者的样本中，通过 GEO2R 筛选鉴定了卵巢癌原发性肿瘤组织和腹水衍生球体之间的 DE-miRNA。我们使用 MiRTarBase、TargetScanHuman7.2 和 STRING 预测 DE-miRNA 和 DAVID 的目标中枢基因，对中枢基因进行功能分析。ALGGEN PROMO 和 TransmiR v2.0 用于预测可能调节 DE-miRNA 表达的转录因子 (TF)。使用 PCR 对来自 12 名 HGSOC 患者和 2 种卵巢癌细胞系的样本验证了观察到的 DE-miRNA 表达差异。DE-miRNAs 对卵巢癌进展的作用通过侵袭、粘附和血管生成试验进行了验证。
结果：通过生物信息学筛选和实验验证，与原发性相比，miR-199a-3p、miR-199b-3p、miR-199a-5p、miR-126-3p 和 miR-145-5p 被确定为在腹水来源的球状体中显着下调肿瘤组织。此外，TFAP2A 被鉴定为调节上述 DE-miRNA 表达的潜在常见上游 TF。miR-199a-3p、miR-199b-3p、miR-199a-5p的过表达导致侵袭抑制，miR-126-3p、miR-145-5p、miR-199a-5p和miR-199b的过表达-3p 导致悬浮卵巢癌细胞的粘附抑制。高表达的 miR-126-3p、miR-199a-3p、miR-199a-5p 和 miR-199b-3p 有助于悬浮卵巢癌细胞的凋亡。
结论：miR-199a-3p、miR-199b-3p、miR-199a-5p、miR-126-3p 和 miR-145-5p 在腹水来源的球体中的下调表达在促进卵巢癌进展中起关键作用，这可能代表用于卵巢癌靶向治疗的新分子。

关键词：卵巢癌，转移，腹水来源的球体，原发性肿瘤组织，microRNAs