Abstract

Background

Pancreatic cancer is a lethal malignancy in both sexes throughout the world. Circular RNAs (circRNAs) have been implicated in the development of pancreatic cancer by operating as competing endogenous RNAs (ceRNAs). Here, we explored circ_0099999-mediated ceRNA activity in regulating pancreatic tumorigenesis.

Methods

Ribonuclease R (RNase R) and subcellular localization assays were utilized to characterize circ_0099999. The levels of circ_0099999, microRNA (miR)-330-5p, and fascin actin-bundling protein 1 (FSCN1) were gauged by quantitative real-time PCR (qRT-PCR) and western blot. Cell proliferation, colony formation, apoptosis, migration, and invasion were evaluated by the Cell Counting Kit-8 (CCK-8), colony formation, flow cytometry, and transwell assays, respectively. The levels of glucose consumption and lactate production were determined using the assay kits. A direct relationship between miR-330-5p and circ_0099999 or FSCN1 was validated by dual-luciferase reporter assay. Tumour xenograft assays were used to analyse the role of circ_0099999 in vivo.

Results

Circ_0099999 was highly up-regulated in pancreatic cancer tissues and cells. Knockdown of circ_0099999 impeded cell proliferation, migration, invasion, glycolysis, and promoted apoptosis in vitro, as well as diminished tumour growth in vivo. Circ_0099999 targeted miR-330-5p, and miR-330-5p was a downstream mediator of circ_0099999 function. FSCN1 was a direct and functional target of miR-330-5p. Furthermore, circ_0099999 operated as a ceRNA for miR-330-5p to modulate FSCN1 expression.

Conclusions

Our findings established a novel causal mechanism, circ_0099999/miR-330-5p/FSCN1 ceRNA crosstalk, in regulating pancreatic carcinogenesis and provided that inhibition of circ_0099999 might have therapeutic benefits in pancreatic cancer.

中文翻译：

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胰腺癌中一种新的 circ_0099999/miR-330-5p/FSCN1 ceRNA 串扰

摘要

背景

胰腺癌是全世界男女皆可致命的恶性肿瘤。环状 RNA (circRNA) 通过作为竞争性内源性 RNA (ceRNA) 参与胰腺癌的发展。在这里，我们探索了 circ_0099999 介导的 ceRNA 在调节胰腺肿瘤发生中的活性。

方法

核糖核酸酶 R (RNase R) 和亚细胞定位分析用于表征 circ_0099999。通过定量实时 PCR (qRT-PCR) 和蛋白质印迹测定 circ_0099999、microRNA (miR)-330-5p 和肌成束蛋白肌动蛋白捆绑蛋白 1 (FSCN1) 的水平。细胞增殖、集落形成、细胞凋亡、迁移和侵袭分别通过 Cell Counting Kit-8 (CCK-8)、集落形成、流式细胞术和 transwell 测定进行评估。使用测定试剂盒确定葡萄糖消耗和乳酸产生的水平。通过双荧光素酶报告基因分析验证了 miR-330-5p 与 circ_0099999 或 FSCN1 之间的直接关系。肿瘤异种移植试验用于分析 circ_0099999在体内的作用。

结果

Circ_0099999 在胰腺癌组织和细胞中高度上调。circ_0099999 的敲低在体外阻碍了细胞增殖、迁移、侵袭、糖酵解，并促进了细胞凋亡，并在体内减少了肿瘤的生长。circ_0099999靶向miR-330-5p，miR-330-5p是circ_0099999功能的下游介质。FSCN1 是 miR-330-5p 的直接和功能性靶标。此外，circ_0099999 作为 miR-330-5p 的 ceRNA 来调节 FSCN1 的表达。

结论

我们的研究结果建立了一种新的因果机制，即 circ_0099999/miR-330-5p/FSCN1 ceRNA 串扰，可调节胰腺癌的发生，并表明抑制 circ_0099999 可能对胰腺癌具有治疗益处。